,,*APT] ,,IX3 ,,HYBRIDISM
  ,! VIEW -MONLY 5T]TA9$ 0NATURALI/S IS
T SPECIES1 :5 9T]CROSS$1 H BE5 SPECI,Y
5D[$ ) /]IL;Y1 9 ORD] 6PREV5T _! 3FU.N4
,? VIEW C]TA9LY SEEMS AT F/ HI<LY
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BE5 KEPT 4T9CT _H !Y BE5 CAPA# ( FREELY
CROSS+4 ,! SUBJECT IS 9 _M WAYS
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SPECIES :5 F/ CROSS$1 & T ( _! HYBRID
(FSPR+1 _C H BE5 ACQUIR$1 Z ,I % %[1 0!
PRES]V,N ( SU3ESSIVE PR(ITA# DEGREES (
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  ,9 TR1T+ ? SUBJECT1 TWO CLASSES (
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9 BO? PLANTS & ANIMALS2 ?\< ! =MATIVE
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! MICROSCOPE REV1LS4 ,9 ! F/ CASE ! TWO
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,? 4T9C;N IS IMPORTANT1 :5 ! CAUSE (!
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,X IS IMPOSSI# 6/UDY ! S"EAL MEMOIRS &
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AU?ORS Z 4T9CT SPECIES1 Q F]TILE TGR1 HE
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SE$S PRODUC$ 0TWO SPECIES :5 F/ CROSS$1
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AV]AGE NUMB] PRODUC$ 0BO? PURE P>5T-
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S]I\S ]ROR "H 9T]V5E3 A PLANT1 6BE
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,LEGUM9OSAE1 9 : "! IS AN AC"KL$G$
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= ALL PRACTICAL PURPOSES X IS MO/
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! SAME DEGREE Z IS ! EVID;E DERIV$ F O!R
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  ,9 REG>D 6! /]IL;Y ( HYBRIDS 9
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NE>LY ALL ^! CASES 0AN 9DEP5D5T CAUSE1
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) HYBRID POLL5 (! SAME K9D1 _! F]TIL;Y1
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( ANO!R FL[]1 Z F ! AN!RS (! FL[] XF :
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  ,N[ LET U TURN 6! RESULTS >RIV$ AT 0A
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,HON4 & ,REV4 ,W4 ,H]B]T4 ,HE IS Z
EMPHATIC 9 8 3CLU.N T "S HYBRIDS >E
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SPECIES- Z >E ,KOLREUT] & ,G>TN] T "S
DEGREE ( /]IL;Y 2T 4T9CT SPECIES IS A
UNIV]SAL LAW ( NATURE4 ,HE EXP]I;T$ ON
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,( 8 _M IMPORTANT /ATE;TS ,I W "H GIVE
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N"E SAW 6O3UR 9 A CASE ( XS NATURAL
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?AN -MONLY P]FECT F]TIL;Y1 9 A F/ CROSS
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,CORYDALIS Z %[N 0,PROFESSOR ,HILDEBR&1
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! 9DIVIDUALS1 C ACTU,Y 2 HYBRIDIS$ M* M
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F]TIL;Y (A SPECIES "S"TS DEP5DS4
  ,! PRACTICAL EXP]I;TS (
HORTICULTURI/S1 ?\< N MADE ) SCI5TIFIC
PRECI.N1 DES]VE "S NOTICE4 ,X IS
NOTORI\S 9 H[ -PLICAT$ A MANN] ! SPECIES
( ,PEL>GONIUM1 ,FU*SIA1 ,CALCEOL>IA1
,PETUNIA1 ,RHODOD5DRON1 &C41 H BE5
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,CALCEOL>IA 9TEGRIFOLIA & PLANTAG9EA1
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_H BE5 A NATURAL SPECIES F ! M.TA9S (
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F A HYBRID 2T ,RHOD4 PONTICUM &
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Z X IS POSSI# 6IMAG9E40 ,_H HYBRIDS :5
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NOTORI\S 6NURS]YM54 ,HORTICULTURI/S
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  ,9 REG>D 6ANIMALS1 M* FEW] EXP]I;TS H
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! G5]A ( ANIMALS >E Z 4T9CT F EA* O!R Z
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( PLANTS2 B ! HYBRIDS !MVS >E1 ,I ?9K1 M
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S Z 6AVOID ! ILL E6ECTS ( CLOSE
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9 OPPOSI;N 6! 3/ANTLY REP1T$ ADMONI;N (
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H G"O ON 9CR1S+4
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>E P]FECTLY F]TILE4 ,M4 ,QUATREFAGES
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F ! -MON & ,*9ESE GEESE 7,A4 CYGNOIDES71
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RANK$ 9 4T9CT G5]A1 H (T5 BR$ 9 ? C.TRY
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BR$ 9T] SE4 ,? 0 E6ECT$ 0,MR4 ,EYTON1 :O
RAIS$ TWO HYBRIDS F ! SAME P>5TS1 B F
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NO LESS ?AN EI<T HYBRIDS 7GR&*N (! PURE
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"PS (! C.TRY2 & Z !Y >E KEPT = PR(IT1 ":
NEI PURE P>5T-SPECIES EXI/S1 !Y M/
C]TA9LY 2 HI<LY OR P]FECTLY F]TILE4
  ,) \R DOME/ICAT$ ANIMALS1 ! V>I\S
RACES :5 CROSS$ TGR >E Q F]TILE2 YET 9
_M CASES !Y >E DESC5D$ F TWO OR M WILD
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PROP.D$ 0,PALLAS1 SEEMS 0F> ! MO/
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,AM]ICA1 ALL >E Q F]TILE TGR2 B ANALOGY
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0DOME/IC,N4
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/ATE ( K1 2 3SID]$ Z ABSOLUTELY
UNIV]SAL4
  ,LAWS GOV]N+ ! ,/]IL;Y ( F/ ,CROSSES &
( ,HYBRIDS
  ,WE W N[ 3SID] A LL M 9 DETAIL ! LAWS
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,\R *IEF OBJECT W 2 6SEE :E!R OR N ^!
LAWS 9DICATE T SPECIES H BE5 SPECI,Y
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\R K IS 9 REG>D 6HYBRID ANIMALS1 ,I H
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9ORGANIC DU/4 ,F ? ABSOLUTE Z]O (
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6! /IGMA ( "S "O SPECIES (! SAME G5US1
YIELDS A P]FECT GRAD,N 9 ! NUMB] ( SE$S
PRODUC$1 UP 6NE>LY -PLETE OR EV5 Q
-PLETE F]TIL;Y2 &1 Z WE H SE51 9 C]TA9
ABNORMAL CASES1 EV5 6AN EXCESS (
F]TIL;Y1 2Y T : ! PLANT'S [N POLL5
PRODUCES4 ,S 9 HYBRIDS !MVS1 "! >E "S :
N"E H PRODUC$1 & PROBABLY N"E WD
PRODUCE1 EV5 )! POLL5 (! PURE P>5TS1 A
S+LE F]TILE SE$3 B 9 "S ( ^! CASES A F/
TRACE ( F]TIL;Y MAY 2 DETECT$1 0! POLL5
( "O (! PURE P>5T-SPECIES CAUS+ ! FL[] (
! HYBRID 6)] E>LI] ?AN X O!RWISE WD H
D"O2 &! E>LY )]+ (! FL[] IS WELL "KN 6BE
A SIGN ( 9CIPI5T F]TILIS,N4 ,F ? EXTREME
DEGREE ( /]IL;Y WE H SELF-/]ILIS$
HYBRIDS PRODUC+ A GRT] & GRT] NUMB] (
SE$S UP 6P]FECT F]TIL;Y4
  ,! HYBRIDS RAIS$ F TWO SPECIES : >E V
DI6ICULT 6CROSS1 & : R>ELY PRODUCE ANY
(FSPR+1 >E G5],Y V /]ILE2 B ! P>ALLELISM
2T ! DI6ICULTY ( MAK+ A F/ CROSS1 &!
/]IL;Y (! HYBRIDS ?US PRODUC$- TWO
CLASSES ( FACTS : >E G5],Y 3F.D$ TGR- IS
0NO M1NS /RICT4 ,"! >E _M CASES1 9 : TWO
PURE SPECIES1 Z 9 ! G5US ,V]BASCUM1 C 2
UNIT$ ) UNUSUAL FACIL;Y1 & PRODUCE
NUM]\S HYBRID (FSPR+1 YET ^! HYBRIDS >E
REM>KABLY /]ILE4 ,ON ! O!R H&1 "! >E
SPECIES : C 2 CROSS$ V R>ELY1 OR )
EXTREME DI6ICULTY1 B ! HYBRIDS1 :5 AT
LA/ PRODUC$1 >E V F]TILE4 ,EV5 )9 !
LIMITS (! SAME G5US1 = 9/.E 9 ,DIAN?US1
^! TWO OPPOSITE CASES O3UR4
  ,! F]TIL;Y1 BO? ( F/ CROSSES &(
HYBRIDS1 IS M EASILY A6ECT$ 0UNFAV\RA#
3DI;NS1 ?AN IS T ( PURE SPECIES4 ,B !
F]TIL;Y ( F/ CROSSES IS LIKEWISE 9NATELY
V>IA#2 = X IS N ALW ! SAME 9 DEGREE :5 !
SAME TWO SPECIES >E CROSS$ "U ! SAME
CIRCUM/.ES2 X DEP5DS 9 "P ^U ! 3/ITU;N (
! 9DIVIDUALS : HAPP5 6H BE5 *OS5 =!
EXP]I;T4 ,S X IS ) HYBRIDS1 = _! DEGREE
( F]TIL;Y IS (T5 F.D 6DI6] GRTLY 9 !
S"EAL 9DIVIDUALS RAIS$ F SE$ \ (! SAME
CAPSULE & EXPOS$ 6! SAME 3DI;NS4
  ,0! T]M SY/EMATIC A69;Y IS M1NT1 !
G5]AL RESEMBL.E 2T SPECIES 9 /RUCTURE &
3/ITU;N4 ,N[ ! F]TIL;Y ( F/ CROSSES1 &(!
HYBRIDS PRODUC$ F !M1 IS L>GELY GOV]N$
0_! SY/EMATIC A69;Y4 ,? IS CLE>LY %[N
0HYBRIDS N"E HAV+ BE5 RAIS$ 2T SPECIES
RANK$ 0SY/EMATI/S 9 4T9CT FAMILIES2 & ON
! O!R H&1 0V CLOSELY ALLI$ SPECIES G5],Y
UNIT+ ) FACIL;Y4 ,B ! CORRESPOND;E 2T
SY/EMATIC A69;Y &! FACIL;Y ( CROSS+ IS
0NO M1NS /RICT4 ,A MULTITUDE ( CASES CD
2 GIV5 ( V CLOSELY ALLI$ SPECIES : W N
UNITE1 OR ONLY ) EXTREME DI6ICULTY2 & ON
! O!R H& ( V 4T9CT SPECIES : UNITE )!
UTMO/ FACIL;Y4 ,9 ! SAME FAMILY "! MAY 2
A G5US1 Z ,DIAN?US1 9 : V _M SPECIES C
MO/ R1DILY 2 CROSS$2 & ANO!R G5US1 Z
,SIL5E1 9 : ! MO/ P]SEV]+ EF=TS H FAIL$
6PRODUCE 2T EXTREMELY CLOSE SPECIES A
S+LE HYBRID4 ,EV5 )9 ! LIMITS (! SAME
G5US1 WE MEET ) ? SAME DI6];E2 = 9/.E1 !
_M SPECIES ( ,NICOTIANA H BE5 M L>GELY
CROSS$ ?AN ! SPECIES ( ALM ANY O!R G5US2
B ,G>TN] F.D T ,N4 ACUM9ATA1 : IS N A
"PICUL>LY 4T9CT SPECIES1 OB/9ATELY FAIL$
6F]TILISE1 OR 6BE F]TILIS$ 0NO LESS ?AN
EI<T O!R SPECIES ( ,NICOTIANA4 ,_M
ANALOG\S FACTS CD 2 GIV54
  ,NO "O HAS BE5 A# 6PO9T \ :AT K9D OR
:AT AM.T ( DI6];E1 9 ANY RECOGNISA# "*1
IS SU6ICI5T 6PREV5T TWO SPECIES CROSS+4
,X C 2 %[N T PLANTS MO/ WIDELY DI6]5T 9
HABIT & G5]AL APPE>.E1 & HAV+ /R;GLY
M>K$ DI6];ES 9 E "P (! FL[]1 EV5 9 !
POLL51 9 ! FRUIT1 & 9 ! COTYL$ONS1 C 2
CROSS$4 ,ANNUAL & P]5NIAL PLANTS1
DECIDU\S & "EGRE5 TREES1 PLANTS 9HABIT+
DI6]5T /,NS & FITT$ = EXTREMELY DI6]5T
CLIMATES1 C (T5 2 CROSS$ ) EASE4
  ,0A RECIPROCAL CROSS 2T TWO SPECIES1
,I M1N ! CASE1 = 9/.E1 (A FEMALE-ASS 2+
F/ CROSS$ 0A /ALLION1 & !N A M>E 0A
MALE-ASS2 ^! TWO SPECIES MAY !N 2 SD 6H
BE5 RECIPROC,Y CROSS$4 ,"! IS (T5 !
WIDE/ POSSI# DI6];E 9 ! FACIL;Y ( MAK+
RECIPROCAL CROSSES4 ,S* CASES >E HI<LY
IMPORTANT1 = !Y PROVE T ! CAPAC;Y 9 ANY
TWO SPECIES 6CROSS IS (T5 -PLETELY
9DEP5D5T ( _! SY/EMATIC A69;Y1 T IS (
ANY DI6];E 9 _! /RUCTURE OR 3/ITU;N1
EXCEPT+ 9 _! REPRODUCTIVE SY/EMS4 ,!
DIV]S;Y (! RESULT 9 RECIPROCAL CROSSES
2T ! SAME TWO SPECIES 0 L;G AGO OBS]V$
0,KOLREUT]4 ,6GIVE AN 9/.E3 ,MIRABILIS
JALAPA C EASILY 2 F]TILIS$ 0! POLL5 (
,M4 L;GIFLORA1 &! HYBRIDS ?US PRODUC$ >E
SU6ICI5TLY F]TILE2 B ,KOLREUT] TRI$ M
?AN TWO HUNDR$ "TS1 DUR+ EI<T FOLL[+
YE>S1 6F]TILISE RECIPROC,Y ,M4 L;GIFLORA
)! POLL5 ( ,M4 JALAPA1 & UTT]LY FAIL$4
,S"EAL O!R EQU,Y /RIK+ CASES CD 2 GIV54
,?URET HAS OBS]V$ ! SAME FACT ) C]TA9
SEA-WE$S OR ,FUCI4 ,G>TN]1 MOREOV]1 F.D
T ? DI6];E ( FACIL;Y 9 MAK+ RECIPROCAL
CROSSES IS EXTREMELY -MON 9 A LESS]
DEGREE4 ,HE HAS OBS]V$ X EV5 2T CLOSELY
RELAT$ =MS 7Z ,MAT?IOLA ANNUA & GILABRA7
: _M BOTANI/S RANK ONLY Z V>IETIES4 ,X
IS AL A REM>KA# FACT1 T HYBRIDS RAIS$ F
RECIPROCAL CROSSES1 ?\< ( C\RSE -P.D$ (!
V SAME TWO SPECIES1 ! "O SPECIES HAV+ F/
BE5 US$ Z ! "F & !N Z ! "M1 ?\< !Y R>ELY
DI6] 9 EXT]NAL "*S1 YET G5],Y DI6] 9
F]TIL;Y 9 A SMALL1 & O3A.N,Y 9 A HI<
DEGREE4
  ,S"EAL O!R S+UL> RULES CD 2 GIV5 F
,G>TN]3 = 9/.E1 "S SPECIES H A REM>KA#
P[] ( CROSS+ ) O!R SPECIES2 O!R SPECIES
(! SAME G5US H A REM>KA# P[] ( IMPRESS+
_! LIKE;S ON _! HYBRID (FSPR+2 B ^! TWO
P[]S D N AT ALL NECESS>ILY G TGR4 ,"! >E
C]TA9 HYBRIDS :1 9/1D ( HAV+1 Z IS
USUAL1 AN 9T]M$IATE "* 2T _! TWO P>5TS1
ALW CLOSELY RESEM# "O ( !M2 & S*
HYBRIDS1 ?\< EXT]N,Y S L "O ( _! PURE
P>5T-SPECIES1 >E ) R>E EXCEP;NS
EXTREMELY /]ILE4 ,S AG AM;G/ HYBRIDS :
>E USU,Y 9T]M$IATE 9 /RUCTURE 2T _!
P>5TS1 EXCEP;NAL & ABNORMAL 9DIVIDUALS
"S"TS >E BORN1 : CLOSELY RESEM# "O ( _!
PURE P>5TS2 & ^! HYBRIDS >E ALM ALW
UTT]LY /]ILE1 EV5 :5 ! O!R HYBRIDS RAIS$
F SE$ F ! SAME CAPSULE H A 3SID]A#
DEGREE ( F]TIL;Y4 ,^! FACTS %[ H[
-PLETELY ! F]TIL;Y (A HYBRID MAY 2
9DEP5D5T ( XS EXT]NAL RESEMBL.E 6EI PURE
P>5T4
  ,3SID]+ ! S"EAL RULES N[ GIV51 : GOV]N
! F]TIL;Y ( F/ CAUSES &( HYBRIDS1 WE SEE
T :5 =MS1 : M/ 2 3SID]$ Z GD & 4T9CT
SPECIES1 >E UNIT$1 _! F]TIL;Y GRADUATES
F Z]O 6P]FECT F]TIL;Y1 OR EV5 6F]TIL;Y
"U C]TA9 3DI;NS 9 EXCESS2 T _! F]TIL;Y1
2SS 2+ EM95TLY SUSCEPTI# 6FAV\RA# &
UNFAV\RA# 3DI;NS1 IS 9NATELY V>IA#2 T X
IS 0NO M1NS ALW ! SAME 9 DEGREE 9 ! F/
CROSS & 9 ! HYBRIDS PRODUC$ F ? CROSS2 T
! F]TIL;Y ( HYBRIDS IS N RELAT$ 6!
DEGREE 9 : !Y RESEM# 9 EXT]NAL APPE>.E
EI P>5T2 & LA/LY1 T ! FACIL;Y ( MAK+ A
F/ CROSS 2T ANY TWO SPECIES IS N ALW
GOV]N$ 0_! SY/EMATIC A69;Y OR DEGREE (
RESEMBL.E 6EA* O!R4 ,? LATT] /ATE;T IS
CLE>LY PROV$ 0! DI6];E 9 ! RESULT (
RECIPROCAL CROSSES 2T ! SAME TWO
SPECIES1 =1 AC Z ! "O SPECIES OR ! O!R
IS US$ Z ! "F OR ! "M1 "! IS G5],Y "S
DI6];E1 & O3A.N,Y ! WIDE/ POSSI# DI6];E1
9 ! FACIL;Y ( E6ECT+ AN UNION4 ,!
HYBRIDS1 MOREOV]1 PRODUC$ F RECIPROCAL
CROSSES (T5 DI6] 9 F]TIL;Y4
  ,N[ D ^! -PLEX & S+UL> RULES 9DICATE T
SPECIES H BE5 5D[$ ) /]IL;Y SIMPLY
6PREV5T _! 2COM+ 3F.D$ 9 NATURE8 ,I ?9K
N4 ,= :Y %D ! /]IL;Y 2 S EXTREMELY
DI6]5T 9 DEGREE1 :5 V>I\S SPECIES >E
CROSS$1 ALL ( : WE M/ SUPPOSE X WD 2
EQU,Y IMPORTANT 6KEEP F BL5D+ TGR8 ,:Y
%D ! DEGREE ( /]IL;Y 2 9NATELY V>IA# 9 !
9DIVIDUALS (! SAME SPECIES8 ,:Y %D "S
SPECIES CROSS ) FACIL;Y1 & YET PRODUCE V
/]ILE HYBRIDS2 & O!R SPECIES CROSS )
EXTREME DI6ICULTY1 & YET PRODUCE FAIRLY
F]TILE HYBRIDS8 ,:Y %D "! (T5 2 S GRT A
DI6];E 9 ! RESULT (A RECIPROCAL CROSS 2T
! SAME TWO SPECIES8 ,:Y1 X MAY EV5 2
ASK$1 HAS ! PRODUC;N ( HYBRIDS BE5
P]MITT$8 ,6GRANT 6SPECIES ! SPECIAL P[]
( PRODUC+ HYBRIDS1 & !N 6/OP _! FUR!R
PROPAG,N 0DI6]5T DEGREES ( /]IL;Y1 N
/RICTLY RELAT$ 6! FACIL;Y (! F/ UNION 2T
_! P>5TS1 SEEMS A /RANGE >RANGE;T4
  ,! =EGO+ RULES & FACTS1 ON ! O!R H&1
APPE> 6ME CLE>LY 69DICATE T ! /]IL;Y BO?
( F/ CROSSES &( HYBRIDS IS SIMPLY
9CID5TAL OR DEP5D5T ON UN"KN DI6];ES 9
_! REPRODUCTIVE SY/EMS2 ! DI6];ES 2+ ( S
PECULI> & LIMIT$ A NATURE1 T1 9
RECIPROCAL CROSSES 2T ! SAME TWO
SPECIES1 ! MALE SEXUAL ELE;T (! "O W (T5
FREELY ACT ON ! FEMALE SEXUAL ELE;T (!
O!R1 B N 9 A REV]S$ DIREC;N4 ,X W 2
ADVISA# 6EXPLA9 A LL M FULLY 0AN EXAMPLE
:AT ,I M1N 0/]IL;Y 2+ 9CID5TAL ON O!R
DI6];ES1 & N A SPECI,Y 5D[$ QUAL;Y4 ,Z !
CAPAC;Y ( "O PLANT 6BE GRAFT$ OR BU4$ ON
ANO!R IS UNIMPORTANT = _! WELF>E 9 A
/ATE ( NATURE1 ,I PRESUME T NO "O W
SUPPOSE T ? CAPAC;Y IS A SPECI,Y 5D[$
QUAL;Y1 B W ADMIT T X IS 9CID5TAL ON
DI6];ES 9 ! LAWS ( GR[? (! TWO PLANTS4
,WE C "S"TS SEE ! R1SON :Y "O TREE W N
TAKE ON ANO!R1 F DI6];ES 9 _! RATE (
GR[?1 9 ! H>D;S ( _! WOOD1 9 ! P]IOD (!
FL[ OR NATURE ( _! SAP1 &C42 B 9 A
MULTITUDE ( CASES WE C ASSIGN NO R1SON
:AT"E4 ,GRT DIV]S;Y 9 ! SIZE ( TWO
PLANTS1 "O 2+ WOODY &! O!R H]BACE\S1 "O
2+ "EGRE5 &! O!R DECIDU\S1 & ADAPT,N
6WIDELY DI6]5T CLIMATES1 D N ALW PREV5T
! TWO GRAFT+ TGR4 ,Z 9 HYBRIDIS,N1 S )
GRAFT+1 ! CAPAC;Y IS LIMIT$ 0SY/EMATIC
A69;Y1 = NO "O HAS BE5 A# 6GRAFT TGR
TREES 2L;G+ 6Q 4T9CT FAMILIES2 &1 ON !
O!R H&1 CLOSELY ALLI$ SPECIES1 &
V>IETIES (! SAME SPECIES1 C USU,Y1 B N
9V>IABLY1 2 GRAFT$ ) EASE4 ,B ? CAPAC;Y1
Z 9 HYBRIDIS,N1 IS 0NO M1NS ABSOLUTELY
GOV]N$ 0SY/EMATIC A69;Y4 ,AL? _M 4T9CT
G5]A )9 ! SAME FAMILY H BE5 GRAFT$ TGR1
9 O!R CASES SPECIES (! SAME G5US W N
TAKE ON EA* O!R4 ,! PE> C 2 GRAFT$ F> M
R1DILY ON ! QU9CE1 : IS RANK$ Z A 4T9CT
G5US1 ?AN ON ! APPLE1 : IS A MEMB] (!
SAME G5US4 ,EV5 DI6]5T V>IETIES (! PE>
TAKE ) DI6]5T DEGREES ( FACIL;Y ON !
QU9CE2 S D DI6]5T V>IETIES (! APRICOT &
P1* ON C]TA9 V>IETIES (! PLUM4
  ,Z ,G>TN] F.D T "! 0 "S"TS AN 9NATE
DI6];E 9 DI6]5T 9DIVIDUALS (! SAME TWO
SPECIES 9 CROSS+2 S ,SAG]ET 2LIEVES ?
6BE ! CASE ) DI6]5T 9DIVIDUALS (! SAME
TWO SPECIES 9 2+ GRAFT$ TGR4 ,Z 9
RECIPROCAL CROSSES1 ! FACIL;Y ( E6ECT+
AN UNION IS (T5 V F> F EQUAL1 S X "S"TS
IS 9 GRAFT+2 ! -MON GOOSEB]RY1 = 9/.E1
_C 2 GRAFT$ ON ! CURRANT1 ":AS ! CURR5T
W TAKE1 ?\< ) DI6ICULTY1 ON ! GOOSEB]RY4
  ,WE H SE5 T ! /]IL;Y ( HYBRIDS1 : H _!
REPRODUCTIVE ORGANS 9 AN IMP]FECT 3DI;N1
IS A DI6]5T CASE F ! DI6ICULTY ( UNIT+
TWO PURE SPECIES1 : H _! REPRODUCTIVE
ORGANS P]FECT2 YET ^! TWO 4T9CT CLASSES
( CASES RUN 6A L>GE EXT5T P>ALLEL4 ,"S?+
ANALOG\S O3URS 9 GRAFT+2 = ,?\9 F.D T
?REE SPECIES ( ,ROB9IA1 : SE$$ FREELY ON
_! [N ROOTS1 & : CD 2 GRAFT$ ) NO GRT
DI6ICULTY ON A F\R? SPECIES1 :5 ?US
GRAFT$ 7 R5D]$ B>R54 ,ON ! O!R H&1 C]TA9
SPECIES ( ,SORBUS1 :5 GRAFT$ ON O!R
SPECIES YIELD$ TWICE Z M* FRUIT Z :5 ON
_! [N ROOTS4 ,WE >E REM9D$ 0? LATT] FACT
(! EXTRAORD9>Y CASES ( ,HIPP1/RUM1
,PASSIFLORA1 &C41 : SE$ M* M FREELY :5
F]TILIS$ )! POLL5 (A 4T9CT SPECIES1 ?AN
:5 F]TILIS$ ) POLL5 F ! SAME PLANT4
  ,WE ?US SEE1 T1 AL? "! IS A CLE> & GRT
DI6];E 2T ! M]E ADHE.N ( GRAFT$ /OCKS1 &
! UNION (! MALE & FEMALE ELE;TS 9 ! ACT
( REPRODUC;N1 YET T "! IS A RUDE DEGREE
( P>ALLELISM 9 ! RESULTS ( GRAFT+ &(
CROSS+ 4T9CT SPECIES4 ,& Z WE M/ LOOK AT
! CURI\S & -PLEX LAWS GOV]N+ ! FACIL;Y )
: TREES C 2 GRAFT$ ON EA* O!R Z 9CID5TAL
ON UN"KN DI6];ES 9 _! VEGETATIVE SY/EMS1
S ,I 2LIEVE T ! / M -PLEX LAWS GOV]N+ !
FACIL;Y ( F/ CROSSES >E 9CID5TAL ON
UN"KN DI6];ES 9 _! REPRODUCTIVE SY/EMS4
,^! DI6];ES 9 BO? CASES1 FOLL[ 6A C]TA9
EXT5T1 Z MI<T H BE5 EXPECT$1 SY/EMATIC
A69;Y1 0: T]M E K9D ( RESEMBL.E &
4SIMIL>;Y 2T ORGANIC 2+S IS ATTEMPT$ 6BE
EXPRESS$4 ,! FACTS 0NO M1NS SEEM
69DICATE T ! GRT] OR LESS] DI6ICULTY (
EI GRAFT+ OR CROSS+ V>I\S SPECIES HAS
BE5 A SPECIAL 5D[;T2 AL? 9 ! CASE (
CROSS+1 ! DI6ICULTY IS Z IMPORTANT =!
5DUR.E & /ABIL;Y ( SPECIFIC =MS1 Z 9 !
CASE ( GRAFT+ X IS UNIMPORTANT = _!
WELF>E4
  ,ORIG9 & ,CAUSES (! ,/]IL;Y ( F/
,CROSSES &( ,HYBRIDS
  ,AT "O "T X APPE>$ 6ME PROBA#1 Z X HAS
6O!RS1 T ! /]IL;Y ( F/ CROSSES &(
HYBRIDS MI<T H BE5 SL[LY ACQUIR$ "? !
NATURAL SELEC;N ( SLI<TLY LESS5$ DEGREES
( F]TIL;Y1 :1 L ANY O!R V>I,N1
SPONTANE\SLY APPE>$ 9 C]TA9 9DIVIDUALS (
"O V>IETY :5 CROSS$ ) ^? ( ANO!R V>IETY4
,= X WD CLE>LY 2 ADVANTAGE\S 6TWO
V>IETIES OR 9CIPI5T SPECIES1 IF !Y CD 2
KEPT F BL5D+1 ON ! SAME PR9CIPLE T1 :5
MAN IS SELECT+ AT ! SAME "T TWO
V>IETIES1 X IS NEC T HE %D KEEP !M
SEP>ATE4 ,9 ! F/ PLACE1 X MAY 2 REM>K$ T
SPECIES 9HABIT+ 4T9CT REGIONS >E (T5
/]ILE :5 CROSS$2 N[ X CD CLE>LY H BE5 (
NO ADVANTAGE 6S* SEP>AT$ SPECIES 6H BE5
R5D]$ MUTU,Y /]ILE1 & 3SEQU5TLY ? CD N H
BE5 E6ECT$ "? NATURAL SELEC;N2 B X MAY
P]H 2 >GU$1 T1 IF A SPECIES 0 R5D]$
/]ILE ) "S "O -PATRIOT1 /]IL;Y ) O!R
SPECIES WD FOLL[ Z A NEC 3T+5CY4 ,9 !
SECOND PLACE1 X IS ALM Z M* OPPOS$ 6!
!ORY ( NATURAL SELEC;N Z 6T ( SPECIAL
CRE,N1 T 9 RECIPROCAL CROSSES ! MALE
ELE;T ( "O =M %D H BE5 R5D]$ UTT]LY
IMPOT5T ON A SECOND =M1 :IL/ AT ! SAME
"T ! MALE ELE;T ( ? SECOND =M IS 5A#D
FREELY 6F]TILISE ! F/ =M2 = ? PECULI>
/ATE (! REPRODUCTIVE SY/EM CD H>DLY H
BE5 ADVANTAGE\S 6EI SPECIES4
  ,9 3SID]+ ! PROBABIL;Y ( NATURAL
SELEC;N HAV+ -E 96AC;N1 9 R5D]+ SPECIES
MUTU,Y /]ILE1 ! GRTE/ DI6ICULTY W 2 F.D
6LIE 9 ! EXI/;E ( _M GRADUAT$ /EPS F
SLI<TLY LESS5$ F]TIL;Y 6ABSOLUTE /]IL;Y4
,X MAY 2 ADMITT$ T X WD PR(IT AN 9CIPI5T
SPECIES1 IF X 7 R5D]$ 9 "S SLI<T DEGREE
/]ILE :5 CROSS$ ) XS P>5T =M OR ) "S O!R
V>IETY2 = ?US FEW] BA/>DIS$ & DET]IORAT$
(FSPR+ WD 2 PRODUC$ 6-M+LE _! BLOOD )!
NEW SPECIES 9 PROCESS ( =M,N4 ,B HE :O W
TAKE ! TR\# 6REFLECT ON ! /EPS 0: ? F/
DEGREE ( /]IL;Y CD 2 9CR1S$ "? NATURAL
SELEC;N 6T HI< DEGREE : IS -MON ) S _M
SPECIES1 & : IS UNIV]SAL ) SPECIES : H
BE5 DI6]5TIAT$ 6A G5]IC OR FAMILY RANK1
W F9D ! SUBJECT EXTRAORD9>ILY -PLEX4 ,AF
MATURE REFLEC;N X SEEMS 6ME T ? CD N H
BE5 E6ECT$ "? NATURAL SELEC;N4 ,TAKE !
CASE ( ANY TWO SPECIES :1 :5 CROSS$1
PRODUC$ FEW & /]ILE (FSPR+2 N[1 :AT IS
"! : CD FAV\R ! SURVIVAL ( ^? 9DIVIDUALS
: HAPP5$ 6BE 5D[$ 9 A SLI<TLY HI<]
DEGREE ) MUTUAL 9F]TIL;Y1 & : ?US
APPROA*$ 0"O SMALL /EP T[>DS ABSOLUTE
/]IL;Y8 ,YET AN ADV.E ( ? K9D1 IF ! !ORY
( NATURAL SELEC;N 2 BR"\ 6BE>1 M/ H
9CESSANTLY O3URR$ ) _M SPECIES1 =A
MULTITUDE >E MUTU,Y Q B>R54 ,) /]ILE
NEUT] 9SECTS WE H R1SON 62LIEVE T
MODIFIC,NS 9 _! /RUCTURE & F]TIL;Y H BE5
SL[LY A3UMULAT$ 0NATURAL SELEC;N1 F AN
ADVANTAGE HAV+ BE5 ?US 9DIRECTLY GIV5 6!
-MUN;Y 6: !Y 2L;G$ OV] O!R -MUNITIES (!
SAME SPECIES2 B AN 9DIVIDUAL ANIMAL N
2L;G+ 6A SOCIAL -MUN;Y1 IF R5D]$ SLI<TLY
/]ILE :5 CROSS$ ) "S O!R V>IETY1 WD N
?US XF GA9 ANY ADVANTAGE OR 9DIRECTLY
GIVE ANY ADVANTAGE 6! O!R 9DIVIDUALS (!
SAME V>IETY1 ?US L1D+ 6_! PRES]V,N4
  ,B X WD 2 SUP]FLU\S 64CUSS ? "Q 9
DETAIL2 =) PLANTS WE H 3CLUSIVE EVID;E T
! /]IL;Y ( CROSS$ SPECIES M/ 2 DUE 6"S
PR9CIPLE1 Q 9DEP5D5T ( NATURAL SELEC;N4
,BO? ,G>TN] & ,KOLREUT] H PROV$ T 9 G5]A
9CLUD+ NUM]\S SPECIES1 A S]IES C 2 =M$ F
SPECIES : :5 CROSS$ YIELD FEW] & FEW]
SE$S1 6SPECIES : N"E PRODUCE A S+LE SE$1
B YET >E A6ECT$ 0! POLL5 ( C]TA9 O!R
SPECIES1 =! G]M5 SWELLS4 ,X IS "H
MANIFE/LY IMPOSSI# 6SELECT ! M /]ILE
9DIVIDUALS1 : H ALR C1S$ 6YIELD SE$S2 S
T ? ACME ( /]IL;Y1 :5 ! G]M5 AL"O IS
A6ECT$1 _C H BE5 GA9$ "? SELEC;N2 & F !
LAWS GOV]N+ ! V>I\S GRADES ( /]IL;Y 2+ S
UNI=M "?\T ! ANIMAL & VEGETA# K+DOMS1 WE
MAY 9F] T ! CAUSE1 :AT"E X MAY BE1 IS !
SAME OR NE>LY ! SAME 9 AN CASES4
  ,WE W N[ LOOK A LL CLOS] AT ! PROBA#
NATURE (! DI6];ES 2T SPECIES : 9DUCE
/]IL;Y 9 F/ CROSSES & 9 HYBRIDS4 ,9 !
CASE ( F/ CROSSES1 ! GRT] OR LESS
DI6ICULTY 9 E6ECT+ AN UNION & 9 OBTA9+
(FSPR+ APP>5TLY DEP5DS ON S"EAL 4T9CT
CAUSES4 ,"! M/ "S"TS 2 A PHYSICAL
IMPOSSIBIL;Y 9 ! MALE ELE;T R1*+ !
OVULE1 Z WD 2 ! CASE )A PLANT HAV+ A
PI/IL TOO L;G =! POLL5-TUBES 6R1* !
OV>IUM4 ,X HAS AL BE5 OBS]V$ T :5 !
POLL5 ( "O SPECIES IS PLAC$ ON ! /IGMA (
A 4TANTLY ALLI$ SPECIES1 ?\< ! POLL5-
TUBES PROTRUDE1 !Y D N P5ETRATE !
/IGMATIC SURFACE4 ,AG1 ! MALE ELE;T MAY
R1* ! FEMALE ELE;T B 2 9CAPA# ( CAUS+ AN
EMBRYO 6BE DEVELOP$1 Z SEEMS 6H BE5 !
CASE ) "S ( ,?URET'S EXP]I;TS ON ,FUCI4
,NO EXPLAN,N C 2 GIV5 ( ^! FACTS1 ANY M
?AN :Y C]TA9 TREES _C 2 GRAFT$ ON O!RS4
,LA/LY1 AN EMBRYO MAY 2 DEVELOP$1 & !N
P]I% AT AN E>LY P]IOD4 ,? LATT]
ALT]NATIVE HAS N BE5 SU6ICI5TLY ATT5D$
TO2 B ,I 2LIEVE1 F OBS]V,NS -MUNICAT$
6ME 0,MR4 ,REWITT1 :O HAS _H GRT EXP]I;E
9 HYBRIDIS+ PH1SANTS & F[LS1 T ! E>LY
D1? (! EMBRYO IS A V FREQU5T CAUSE (
/]IL;Y 9 F/ CROSSES4 ,MR4 ,SALT] HAS
REC5TLY GIV5 ! RESULTS ( AN EXAM9,N ( AB
#EJJ E7S PRODUC$ F V>I\S CROSSES 2T ?REE
SPECIES ( ,GALLUS & _! HYBRIDS2 !
MAJOR;Y ( ^! E7S _H BE5 F]TILIS$2 & 9 !
MAJOR;Y (! F]TILIS$ E7S1 ! EMBRYOS _H EI
BE5 "PI,Y DEVELOP$ & _H !N P]I%$1 OR _H
2COME NE>LY MATURE1 B ! "Y *ICK5S _H BE5
UNA# 6BR1K "? ! %ELL4 ,(! *ICK5S : 7
BORN1 M ?AN F\R-FIF?S DI$ )9 ! F/ FEW
"DS1 OR AT LATE/ WEEKS1 8)\T ANY OBVI\S
CAUSE1 APP>5TLY F M]E 9ABIL;Y 6LIVE02 S
T F ! #EJJ E7S ONLY TWELVE *ICK5S 7
RE>$4 ,) PLANTS1 HYBRIDIS$ EMBRYOS
PROBABLY (T5 P]I% 9 A L MANN]2 AT L1/ X
IS "KN T HYBRIDS RAIS$ F V 4T9CT SPECIES
>E "S"TS W1K & DW>F$1 & P]I% AT AN E>LY
AGE2 ( : FACT ,MAX ,WI*URA HAS REC5TLY
GIV5 "S /RIK+ CASES ) HYBRID WILL[S4 ,X
MAY 2 "H WOR? NOTIC+ T 9 "S CASES (
P>!NOG5ESIS1 ! EMBRYOS )9 ! E7S ( SILK
MO?S : _H N BE5 F]TILIS$1 PASS "? _!
E>LY /AGES ( DEVELOP;T & !N P]I% L !
EMBRYOS PRODUC$ 0A CROSS 2T 4T9CT
SPECIES4 ,UNTIL 2COM+ ACQUA9T$ ) ^!
FACTS1 ,I 0 UNWILL+ 62LIEVE 9 ! FREQU5T
E>LY D1? ( HYBRID EMBRYOS2 = HYBRIDS1 :5
ONCE BORN1 >E G5],Y H1L?Y & L;G-LIV$1 Z
WE SEE 9 ! CASE (! -MON MULE4 ,HYBRIDS1
H["E1 >E DI6]5TLY CIRCUM/.ED 2F & AF
BIR?3 :5 BORN & LIV+ 9 A C.TRY ": _! TWO
P>5TS LIVE1 !Y >E G5],Y PLAC$ "U SUITA#
3DI;NS ( LIFE4 ,B A HYBRID P>TAKES (
ONLY HALF (! NATURE & 3/ITU;N ( XS "M2 X
MAY "!=E 2F BIR?1 Z L;G Z X IS N\RI%$ )9
XS "M'S WOMB1 OR )9 ! EGG OR SE$ PRODUC$
0! "M1 2 EXPOS$ 63DI;NS 9 "S DEGREE
UNSUITA#1 & 3SEQU5TLY 2 LIA# 6P]I% AT AN
E>LY P]IOD2 M ESPECI,Y Z ALL V "Y 2+S >E
EM95TLY S5SITIVE 69JURI\S OR UNNATURAL
3DI;NS ( LIFE4 ,B AF ALL1 ! CAUSE M
PROBABLY LIES 9 "S IMP]FEC;N 9 ! ORIG9AL
ACT ( IMPREGN,N1 CAUS+ ! EMBRYO 6BE
IMP]FECTLY DEVELOP$1 R ?AN 9 ! 3DI;NS 6:
X IS SUBSEQU5TLY EXPOS$4
  ,9 REG>D 6! /]IL;Y ( HYBRIDS1 9 : !
SEXUAL ELE;TS >E IMP]FECTLY DEVELOP$1 !
CASE IS "S:AT DI6]5T4 ,I H M ?AN ONCE
ALLUD$ 6A L>GE BODY ( FACTS %[+ T1 :5
ANIMALS & PLANTS >E REMOV$ F _! NATURAL
3DI;NS1 !Y >E EXTREMELY LIA# 6H _!
REPRODUCTIVE SY/EMS S]I\SLY A6ECT$4 ,?1
9 FACT1 IS ! GRT B> 6! DOME/IC,N (
ANIMALS4 ,2T ! /]IL;Y ?US SUP]-9DUC$ & T
( HYBRIDS1 "! >E _M PO9TS ( SIMIL>;Y4 ,9
BO? CASES ! /]IL;Y IS 9DEP5D5T ( G5]AL
H1L?1 & IS (T5 A3OMPANI$ 0EXCESS ( SIZE
OR GRT LUXURI.E4 ,9 BO? CASES ! /]IL;Y
O3URS 9 V>I\S DEGREES2 9 BO?1 ! MALE
ELE;T IS ! MO/ LIA# 6BE A6ECT$2 B "S"TS
! FEMALE M ?AN ! MALE4 ,9 BO?1 ! T5D5CY
GOES 6A C]TA9 EXT5T ) SY/EMATIC A69;Y1 =
:OLE GR\PS ( ANIMALS & PLANTS >E R5D]$
IMPOT5T 0! SAME UNNATURAL 3DI;NS2 & :OLE
GR\PS ( SPECIES T5D 6PRODUCE /]ILE
HYBRIDS4 ,ON ! O!R H&1 "O SPECIES 9 A
GR\P W "S"TS RESI/ GRT *ANGES ( 3DI;NS )
UNIMPAIR$ F]TIL;Y2 & C]TA9 SPECIES 9 A
GR\P W PRODUCE UNUSU,Y F]TILE HYBRIDS4
,NO "O C TELL1 TILL HE TRIES1 :E!R ANY
"PICUL> ANIMAL W BRE$ "U 3F9E;T1 OR ANY
EXOTIC PLANT SE$ FREELY "U CULTURE2 NOR
C HE TELL TILL HE TRIES1 :E!R ANY TWO
SPECIES (A G5US W PRODUCE M OR LESS
/]ILE HYBRIDS4 ,LA/LY1 :5 ORGANIC 2+S >E
PLAC$ DUR+ S"EAL G5],NS "U 3DI;NS N
NATURAL 6!M1 !Y >E EXTREMELY LIA# 6V>Y1
: SEEMS 6BE "PLY DUE 6_! REPRODUCTIVE
SY/EMS HAV+ BE5 SPECI,Y A6ECT$1 ?\< 9 A
LESS] DEGREE ?AN :5 /]IL;Y 5SUES4 ,S X
IS ) HYBRIDS1 = _! (FSPR+ 9 SU3ESSIVE
G5],NS >E EM95TLY LIA# 6V>Y1 Z E
EXP]I;TALI/ HAS OBS]V$4
  ,?US WE SEE T :5 ORGANIC 2+S >E PLAC$
"U NEW & UNNATURAL 3DI;NS1 & :5 HYBRIDS
>E PRODUC$ 0! UNNATURAL CROSS+ ( TWO
SPECIES1 ! REPRODUCTIVE SY/EM1
9DEP5D5TLY (! G5]AL /ATE ( H1L?1 IS
A6ECT$ 9 A V SIMIL> MANN]4 ,9 ! "O CASE1
! 3DI;NS ( LIFE H BE5 4TURB$1 ?\< (T5 9
S SLI<T A DEGREE Z 6BE 9APPRECIA# 0U2 9
! O!R CASE1 OR T ( HYBRIDS1 ! EXT]NAL
3DI;NS H REMA9$ ! SAME1 B ! ORGANIS,N
HAS BE5 4TURB$ 0TWO 4T9CT /RUCTURES &
3/ITU;NS1 9CLUD+ ( C\RSE ! REPRODUCTIVE
SY/EMS1 HAV+ BE5 BL5D$ 96"O4 ,= X IS
SC>CELY POSSI# T TWO ORGANIS,NS %D 2
-P.D$ 96"O1 )\T "S 4TURB.E O3URR+ 9 !
DEVELOP;T1 OR P]IODICAL AC;N1 OR MUTUAL
REL,NS (! DI6]5T "PS & ORGANS "O 6ANO!R
OR 6! 3DI;NS ( LIFE4 ,:5 HYBRIDS >E A#
6BRE$ 9T] SE1 !Y TRANSMIT 6_! (FSPR+ F
G5],N 6G5],N ! SAME -P.D$ ORGANIS,N1 &
H;E WE NE$ N 2 SURPRIS$ T _! /]IL;Y1 ?\<
9 "S DEGREE V>IA#1 DOES N DIM9I%2 X IS
EV5 APT 69CR1SE1 ? 2+ G5],Y ! RESULT1 Z
2F EXPLA9$1 ( TOO CLOSE 9T]BRE$+4 ,! ABV
VIEW (! /]IL;Y ( HYBRIDS 2+ CAUS$ 0TWO
3/ITU;NS 2+ -P.D$ 96"O HAS BE5 /R;GLY
MA9TA9$ 0,MAX ,WI*URA4
  ,X M/1 H["E1 2 [N$ T WE _C "U/&1 ON !
ABV OR ANY O!R VIEW1 S"EAL FACTS )
RESPECT 6! /]IL;Y ( HYBRIDS2 = 9/.E1 !
UNEQUAL F]TIL;Y ( HYBRIDS PRODUC$ F
RECIPROCAL CROSSES2 OR ! 9CR1S$ /]IL;Y 9
^? HYBRIDS : O3A.N,Y & EXCEP;N,Y RESEM#
CLOSELY EI PURE P>5T4 ,NOR D ,I PRET5D T
! =EGO+ REM>KS G 6! ROOT (! MATT]2 NO
EXPLAN,N IS (F]$ :Y AN ORGANISM1 :5
PLAC$ "U UNNATURAL 3DI;NS1 IS R5D]$
/]ILE4 ,ALL T ,I H ATTEMPT$ 6%[ IS1 T 9
TWO CASES1 9 "S RESPECTS ALLI$1 /]IL;Y
IS ! -MON RESULT1- 9 ! "O CASE F !
3DI;NS ( LIFE HAV+ BE5 4TURB$1 9 ! O!R
CASE F ! ORGANIS,N HAV+ BE5 4TURB$ 0TWO
ORGANIS,NS 2+ -P.D$ 96"O4
  ,A SIMIL> P>ALLELISM HOLDS GD ) AN
ALLI$ YET V DI6]5T CLASS ( FACTS4 ,X IS
AN OLD & ALM UNIV]SAL 2LIEF F.D$ ON A
3SID]A# BODY ( EVID;E1 : ,I H ELSE":
GIV51 T SLI<T *ANGES 9 ! 3DI;NS ( LIFE
>E B5EFICIAL 6ALL LIV+ ?+S4 ,WE SEE ?
ACT$ ON 0F>M]S & G>D5]S 9 _! FREQU5T
EX*ANGES ( SE$1 TUB]S1 &C41 F "O SOIL OR
CLIMATE 6ANO!R1 & BACK AG4 ,DUR+ !
3VALESC;E ( ANIMALS1 GRT B5EFIT IS
DERIV$ F ALM ANY *ANGE 9 _! HABITS (
LIFE4 ,AG1 BO? ) PLANTS & ANIMALS1 "! IS
! CLE>E/ EVID;E T A CROSS 2T 9DIVIDUALS
(! SAME SPECIES1 : DI6] 6A C]TA9 EXT5T1
GIVES VIG\R & F]TIL;Y 6! (FSPR+2 & T
CLOSE 9T]BRE$+ 3T9U$ DUR+ S"EAL G5],NS
2T ! NE>E/ REL,NS1 IF ^! 2 KEPT "U !
SAME 3DI;NS ( LIFE1 ALM ALW L1DS
6DECR1S$ SIZE1 W1K;S1 OR /]IL;Y4
  ,H;E X SEEMS T1 ON ! "O H&1 SLI<T
*ANGES 9 ! 3DI;NS ( LIFE B5EFIT ALL
ORGANIC 2+S1 & ON ! O!R H&1 T SLI<T
CROSSES1 T IS CROSSES 2T ! MALES &
FEMALES (! SAME SPECIES1 : H BE5
SUBJECT$ 6SLI<TLY DI6]5T 3DI;NS1 OR : H
SLI<TLY V>I$1 GIVE VIG\R & F]TIL;Y 6!
(FSPR+4 ,B1 Z WE H SE51 ORGANIC 2+S L;G
HABITUAT$ 6C]TA9 UNI=M 3DI;NS "U A /ATE
( NATURE1 :5 SUBJECT$1 Z "U 3F9E;T1 6A
3SID]A# *ANGE 9 _! 3DI;NS1 V FREQU5TLY
>E R5D]$ M OR LESS /]ILE2 & WE "K T A
CROSS 2T TWO =MS1 T H 2COME WIDELY OR
SPECIFIC,Y DI6]5T1 PRODUCE HYBRIDS : >E
ALM ALW 9 "S DEGREE /]ILE4 ,I AM FULLY
P]SUAD$ T ? D\# P>ALLELISM IS 0NO M1NS
AN A3ID5T OR AN ILLU.N4 ,HE :O IS A#
6EXPLA9 :Y ! ELEPHANT &A MULTITUDE ( O!R
ANIMALS >E 9CAPA# ( BRE$+ :5 KEPT "U
ONLY "PIAL 3F9E;T 9 _! NATIVE C.TRY1 W 2
A# 6EXPLA9 ! PRIM>Y CAUSE ( HYBRIDS 2+ S
G5],Y /]ILE4 ,HE W AT ! SAME "T 2 A#
6EXPLA9 H[ X IS T ! RACES ( "S ( \R
DOME/ICAT$ ANIMALS1 : H (T5 BE5 SUBJECT$
6NEW & N UNI=M 3DI;NS1 >E Q F]TILE TGR1
AL? !Y >E DESC5D$ F 4T9CT SPECIES1 : WD
PROBABLY H BE5 /]ILE IF ABORIG9,Y
CROSS$4 ,! ABV TWO P>ALLEL S]IES ( FACTS
SEEM 6BE 3NECT$ TGR 0"S -MON B UN"KN
BOND1 : IS ESS5TI,Y RELAT$ 6! PR9CIPLE (
LIFE2 ? PR9CIPLE1 AC 6,MR4 ,H]B]T
,SP;ER1 2+ T LIFE DEP5DS ON1 OR 3SI/S
IN1 ! 9CESSANT AC;N & REAC;N ( V>I\S
=CES1 :1 Z "?\T NATURE1 >E ALW T5D+
T[>DS AN EQUILIBRIUM2 & :5 ? T5D5CY IS
SLI<TLY 4TURB$ 0ANY *ANGE1 ! VITAL =CES
GA9 9 P[]4
  ,RECIPROCAL ,DIMORPHISM & ,TRIMORPHISM
  ,? SUBJECT MAY 2 "H BRIEFLY 4CUSS$1 &
W 2 F.D 6?R[ "S LI<T ON HYBRIDISM4
,S"EAL PLANTS 2L;G+ 64T9CT ORD]S PRES5T
TWO =MS1 : EXI/ 9 AB EQUAL NUMB]S & :
DI6] 9 NO RESPECT EXCEPT 9 _!
REPRODUCTIVE ORGANS2 "O =M HAV+ A L;G
PI/IL ) %ORT /AM5S1 ! O!R A %ORT PI/IL )
L;G /AM5S2 ! TWO HAV+ DI6]5TLY SIZ$
POLL5-GRA9S4 ,) TRIMORPHIC PLANTS "! >E
?REE =MS LIKEWISE DI6]+ 9 ! L5G?S (!
PI/ILS & /AM5S1 9 ! SIZE & COL\R (!
POLL5 GRA9S1 & 9 "S O!R RESPECTS2 & Z 9
EA* (! ?REE =MS "! >E TWO SETS ( /AM5S1
! ?REE =MS POSSESS ALT SIX SETS ( /AM5S
& ?REE K9DS ( PI/ILS4 ,^! ORGANS >E S
PROPOR;N$ 9 L5G? 6EA* O!R1 T HALF !
/AM5S 9 TWO (! =MS /& ON A LEVEL )!
/IGMA (! ?IRD =M4 ,N[ ,I H %[N1 &!
RESULT HAS BE5 3FIRM$ 0O!R OBS]V]S1 T1 9
ORD] 6OBTA9 FULL F]TIL;Y ) ^! PLANTS1 X
IS NEC T ! /IGMA (! "O =M %D 2 F]TILIS$
0POLL5 TAK5 F ! /AM5S ( CORRESPOND+
HEI<T 9 ANO!R =M4 ,S T ) DIMORPHIC
SPECIES TWO UNIONS1 : MAY 2 CALL$
LEGITIMATE1 >E FULLY F]TILE2 & TWO1 :
MAY 2 CALL$ ILLEGITIMATE1 >E M OR LESS
9F]TILE4 ,) TRIMORPHIC SPECIES SIX
UNIONS >E LEGITIMATE1 OR FULLY F]TILE1-
& TWELVE >E ILLEGITIMATE1 OR M OR LESS
9F]TILE4
  ,! 9F]TIL;Y : MAY 2 OBS]V$ 9 V>I\S
DIMORPHIC & TRIMORPHIC PLANTS1 :5 !Y >E
ILLEGITIMATELY F]TILIS$1 T IS 0POLL5
TAK5 F /AM5S N CORRESPOND+ 9 HEI<T )!
PI/IL1 DI6]S M* 9 DEGREE1 UP 6ABSOLUTE &
UTT] /]IL;Y2 J 9 ! SAME MANN] Z O3URS 9
CROSS+ 4T9CT SPECIES4 ,Z ! DEGREE (
/]IL;Y 9 ! LATT] CASE DEP5DS 9 AN EM95T
DEGREE ON ! 3DI;NS ( LIFE 2+ M OR LESS
FAV\RA#1 S ,I H F.D X ) ILLEGITIMATE
UNIONS4 ,X IS WELL "KN T IF POLL5 (A
4T9CT SPECIES 2 PLAC$ ON ! /IGMA (A
FL[]1 & XS [N POLL5 2 AFWS1 EV5 AF A
3SID]A# 9T]VAL ( "T1 PLAC$ ON ! SAME
/IGMA1 XS AC;N IS S /R;GLY PREPOT5T T X
G5],Y ANNIHILATES ! E6ECT (! =EIGN
POLL52 S X IS )! POLL5 (! S"EAL =MS (!
SAME SPECIES1 = LEGITIMATE POLL5 IS
/R;GLY PREPOT5T OV] ILLEGITIMATE POLL51
:5 BO? >E PLAC$ ON ! SAME /IGMA4 ,I
ASC]TA9$ ? 0F]TILIS+ S"EAL FL[]S1 F/
ILLEGITIMATELY1 & TW5TY-F\R H\RS AFWS
LEGITIMATELY )! POLL5 TAK5 F A PECULI>LY
COL\R$ V>IETY1 & ALL ! SE$L+S 7 SIMIL>LY
COL\R$2 ? %[S T ! LEGITIMATE POLL51 ?\<
APPLI$ TW5TY-F\R H\RS SUBSEQU5TLY1 _H
:OLLY DE/ROY$ OR PREV5T$ ! AC;N (!
PREVI\SLY APPLI$ ILLEGITIMATE POLL54
,AG1 Z 9 MAK+ RECIPROCAL CROSSES 2T !
SAME TWO SPECIES1 "! IS O3A.N,Y A GRT
DI6];E 9 ! RESULT1 S ! SAME ?+ O3URS )
TRIMORPHIC PLANTS2 = 9/.E1 ! MID-/YL$ =M
( ,LY?RUM GALIC>IA 0 ILLEGITIMATELY
F]TILIS$ )! GRTE/ EASE 0POLL5 F ! L;G]
/AM5S (! %ORT-/YL$ =M1 & YIELD$ _M SE$S2
B ! LATT] =M DID N YIELD A S+LE SE$ :5
F]TILIS$ 0! L;G] /AM5S (! MID-/YL$ =M4
  ,9 ALL ^! RESPECTS1 & 9 O!RS : MI<T 2
A4$1 ! =MS (! SAME UND\BT$ SPECIES :5
ILLEGITIMATELY UNIT$ 2HAVE 9 EXACTLY !
SAME MANN] Z D TWO 4T9CT SPECIES :5
CROSS$4 ,? L$ ME C>E;LLY 6OBS]VE DUR+
F\R YE>S _M SE$L+S1 RAIS$ F S"EAL
ILLEGITIMATE UNIONS4 ,! *IEF RESULT IS T
^! ILLEGITIMATE PLANTS1 Z !Y MAY 2
CALL$1 >E N FULLY F]TILE4 ,X IS POSSI#
6RAISE F DIMORPHIC SPECIES1 BO? L;G-/YL$
& %ORT-/YL$ ILLEGITIMATE PLANTS1 & F
TRIMORPHIC PLANTS ALL ?REE ILLEGITIMATE
=MS4 ,^! C !N 2 PROP]LY UNIT$ 9 A
LEGITIMATE MANN]4 ,:5 ? IS D"O1 "! IS NO
APP>5T R1SON :Y !Y %D N YIELD Z _M SE$S
Z DID _! P>5TS :5 LEGITIMATELY F]TILIS$4
,B S* IS N ! CASE4 ,!Y >E ALL 9F]TILE1 9
V>I\S DEGREES2 "S 2+ S UTT]LY & 9CURABLY
/]ILE T !Y DID N YIELD DUR+ F\R S1SONS A
S+LE SE$ OR EV5 SE$-CAPSULE4 ,! /]IL;Y (
^! ILLEGITIMATE PLANTS1 :5 UNIT$ ) EA*
O!R 9 A LEGITIMATE MANN]1 MAY 2 /RICTLY
-P>$ ) T ( HYBRIDS :5 CROSS$ 9T] SE4
,IF1 ON ! O!R H&1 A HYBRID IS CROSS$ )
EI PURE P>5T-SPECIES1 ! /]IL;Y IS USU,Y
M* LESS5$3 & S X IS :5 AN ILLEGITIMATE
PLANT IS F]TILIS$ 0A LEGITIMATE PLANT4
,9 ! SAME MANN] Z ! /]IL;Y ( HYBRIDS
DOES N ALW RUN P>ALLEL )! DI6ICULTY (
MAK+ ! F/ CROSS 2T ! TWO P>5T-SPECIES1 S
! /]IL;Y ( C]TA9 ILLEGITIMATE PLANTS 0
UNUSU,Y GRT1 :IL/ ! /]IL;Y (! UNION F :
!Y 7 DERIV$ 0 0NO M1NS GRT4 ,) HYBRIDS
RAIS$ F ! SAME SE$-CAPSULE ! DEGREE (
/]IL;Y IS 9NATELY V>IA#1 S X IS 9 A M>K$
MANN] ) ILLEGITIMATE PLANTS4 ,LA/LY1 _M
HYBRIDS >E PROFUSE & P]SI/5T FL[]]S1
:IL/ O!R & M /]ILE HYBRIDS PRODUCE FEW
FL[]S1 & >E W1K1 MIS]A# DW>FS2 EXACTLY
SIMIL> CASES O3UR )! ILLEGITIMATE (FSPR+
( V>I\S DIMORPHIC & TRIMORPHIC PLANTS4
  ,ALT "! IS ! CLOSE/ ID5T;Y 9 "* &
2HAVI\R 2T ILLEGITIMATE PLANTS &
HYBRIDS4 ,X IS H>DLY AN EXA7],N 6MA9TA9
T ILLEGITIMATE PLANTS >E HYBRIDS1
PRODUC$ )9 ! LIMITS (! SAME SPECIES 0!
IMPROP] UNION ( C]TA9 =MS1 :IL/ ORD9>Y
HYBRIDS >E PRODUC$ F AN IMPROP] UNION 2T
S-CALL$ 4T9CT SPECIES4 ,WE H AL ALR SE5
T "! IS ! CLOSE/ SIMIL>;Y 9 ALL RESPECTS
2T F/ ILLEGITIMATE UNIONS & F/ CROSSES
2T 4T9CT SPECIES4 ,? W P]H 2 MADE M
FULLY APP>5T 0AN ILLU/R,N2 WE MAY
SUPPOSE T A BOTANI/ F.D TWO WELL-M>K$
V>IETIES 7& S* O3UR7 (! L;G-/YL$ =M (!
TRIMORPHIC ,LY?RUM SALIC>IA1 & T HE
DET]M9$ 6TRY 0CROSS+ :E!R !Y 7
SPECIFIC,Y 4T9CT4 ,HE WD F9D T !Y YIELD$
ONLY AB "O-FIF? (! PROP] NUMB] ( SE$S1 &
T !Y 2HAV$ 9 ALL ! O!R ABV-SPECIFI$
RESPECTS Z IF !Y _H BE5 TWO 4T9CT
SPECIES4 ,B 6MAKE ! CASE SURE1 HE WD
RAISE PLANTS F 8 SUPPOS$ HYBRIDIS$ SE$1
& HE WD F9D T ! SE$L+S 7 MIS]ABLY DW>F$
& UTT]LY /]ILE1 & T !Y 2HAV$ 9 ALL O!R
RESPECTS L ORD9>Y HYBRIDS4 ,HE MI<T !N
MA9TA9 T HE _H ACTU,Y PROV$1 9 A3ORD.E )
! -MON VIEW1 T 8 TWO V>IETIES 7 Z GD & Z
4T9CT SPECIES Z ANY 9 ! _W2 B HE WD 2
-PLETELY MISTAK54
  ,! FACTS N[ GIV5 ON DIMORPHIC &
TRIMORPHIC PLANTS >E IMPORTANT1 2C !Y %[
U1 F/1 T ! PHYSIOLOGICAL TE/ ( LESS5$
F]TIL;Y1 BO? 9 F/ CROSSES & 9 HYBRIDS1
IS NO SAFE CRIT]ION ( SPECIFIC 4T9C;N2
SECONDLY1 2C WE MAY 3CLUDE T "! IS "S
UN"KN BOND : 3NECTS ! 9F]TIL;Y (
ILLEGITIMATE UNIONS ) T ( _!
ILLEGITIMATE (FSPR+1 & WE >E L$ 6EXT5D !
SAME VIEW 6F/ CROSSES & HYBRIDS2 ?IRDLY1
2C WE F9D1 & ? SEEMS 6ME ( ESPECIAL
IMPORT.E1 T TWO OR ?REE =MS (! SAME
SPECIES MAY EXI/ & MAY DI6] 9 NO RESPECT
:AT"E1 EI 9 /RUCTURE OR 9 3/ITU;N1
RELATIVELY 6EXT]NAL 3DI;NS1 & YET 2
/]ILE :5 UNIT$ 9 C]TA9 WAYS4 ,= WE M/
REMEMB] T X IS ! UNION (! SEXUAL ELE;TS
( 9DIVIDUALS (! SAME =M1 = 9/.E1 ( TWO
L;G-/YL$ =MS1 : RESULTS 9 /]IL;Y2 :IL/ X
IS ! UNION (! SEXUAL ELE;TS PROP] 6TWO
4T9CT =MS : IS F]TILE4 ,H;E ! CASE
APPE>S AT F/ SI<T EXACTLY ! REV]SE ( :AT
O3URS1 9 ! ORD9>Y UNIONS (! 9DIVIDUALS (
! SAME SPECIES &) CROSSES 2T 4T9CT
SPECIES4 ,X IS1 H["E1 D\BT;L :E!R ? IS
RE,Y S2 B ,I W N 5L>GE ON ? OBSCURE
SUBJECT4
  ,WE MAY1 H["E1 9F] Z PROBA# F !
3SID],N ( DIMORPHIC & TRIMORPHIC PLANTS1
T ! /]IL;Y ( 4T9CT SPECIES :5 CROSS$ &(
_! HYBRID PROG5Y1 DEP5DS EXCLUSIVELY ON
! NATURE ( _! SEXUAL ELE;TS1 & N ON ANY
DI6];E 9 _! /RUCTURE OR G5]AL 3/ITU;N4
,WE >E AL L$ 6? SAME 3CLU.N 03SID]+
RECIPROCAL CROSSES1 9 : ! MALE ( "O
SPECIES _C 2 UNIT$1 OR C 2 UNIT$ ) GRT
DI6ICULTY1 )! FEMALE (A SECOND SPECIES1
:IL/ ! 3V]SE CROSS C 2 E6ECT$ ) P]FECT
FACIL;Y4 ,T EXCELL5T OBS]V]1 ,G>TN]1
LIKEWISE 3CLUD$ T SPECIES :5 CROSS$ >E
/]ILE [+ 6DI6];ES 3F9$ 6_! REPRODUCTIVE
SY/EMS4
  ,F]TIL;Y ( ,V>IETIES :5 ,CROSS$1 &( _!
,M;GREL ,(FSPR+1 N UNIV]SAL
  ,X MAY 2 URG$1 Z AN OV]:ELM+ >GU;T1 T
"! M/ 2 "S ESS5TIAL 4T9C;N 2T SPECIES &
V>IETIES1 9ASM* Z ! LATT]1 H["E M* !Y
MAY DI6] F EA* O!R 9 EXT]NAL APPE>.E1
CROSS ) P]FECT FACIL;Y1 & YIELD P]FECTLY
F]TILE (FSPR+4 ,) "S EXCEP;NS1 PRES5TLY
6BE GIV51 ,I FULLY ADMIT T ? IS ! RULE4
,B ! SUBJECT IS SURR.D$ 0DI6ICULTIES1 =1
LOOK+ 6V>IETIES PRODUC$ "U NATURE1 IF
TWO =MS HI!RTO REPUT$ 6BE V>IETIES 2 F.D
9 ANY DEGREE /]ILE TGR1 !Y >E AT ONCE
RANK$ 0MO/ NATURALI/S Z SPECIES4 ,=
9/.E1 ! BLUE & R$ PIMP]NEL1 : >E 3SID]$
0MO/ BOTANI/S Z V>IETIES1 >E SD 0,G>TN]
6BE Q /]ILE :5 CROSS$1 & HE SUBSEQU5TLY
RANKS !M Z UND\BT$ SPECIES4 ,IF WE ?US
>GUE 9 A CIRCLE1 ! F]TIL;Y ( ALL
V>IETIES PRODUC$ "U NATURE W ASSUR$LY H
6BE GRANT$4
  ,IF WE TURN 6V>IETIES1 PRODUC$1 OR
SUPPOS$ 6H BE5 PRODUC$1 "U DOME/IC,N1 WE
>E / 9VOLV$ 9 "S D\BT4 ,= :5 X IS /AT$1
= 9/.E1 T C]TA9 ,S\? ,AM]ICAN 9DIG5\S
DOME/IC DOGS D N R1DILY UNITE ) ,EUROP1N
DOGS1 ! EXPLAN,N : W O3UR 6E "O1 &
PROBABLY ! TRUE "O1 IS T !Y >E DESC5D$ F
ABORIG9,Y 4T9CT SPECIES4 ,N"E!.S !
P]FECT F]TIL;Y ( S _M DOME/IC RACES1
DI6]+ WIDELY F EA* O!R 9 APPE>.E1 = 9/.E
^? (! PIGEON1 OR (! CA2AGE1 IS A REM>KA#
FACT2 M ESPECI,Y :5 WE REFLECT H[ _M
SPECIES "! >E1 :1 ?\< RESEMBL+ EA* O!R
MO/ CLOSELY1 >E UTT]LY /]ILE :5
9T]CROSS$4 ,S"EAL 3SID],NS H["E1 R5D] !
F]TIL;Y ( DOME/IC V>IETIES LESS REM>KA#4
,9 ! F/ PLACE1 X MAY 2 OBS]V$ T ! AM.T (
EXT]NAL DI6];E 2T TWO SPECIES IS NO SURE
GUIDE 6_! DEGREE ( MUTUAL /]IL;Y1 S T
SIMIL> DI6];ES 9 ! CASE ( V>IETIES WD 2
NO SURE GUIDE4 ,X IS C]TA9 T ) SPECIES !
CAUSE LIES EXCLUSIVELY 9 DI6];ES 9 _!
SEXUAL 3/ITU;N4 ,N[ ! V>Y+ 3DI;NS 6:
DOME/ICAT$ ANIMALS & CULTIVAT$ PLANTS H
BE5 SUBJECT$1 H _H S LL T5D5CY T[>DS
MODIFY+ ! REPRODUCTIVE SY/EM 9 A MANN]
L1D+ 6MUTUAL /]IL;Y1 T WE H GD GR.DS =
ADMITT+ ! DIRECTLY OPPOSITE DOCTR9E (
,PALLAS1 "NLY1 T S* 3DI;NS G5],Y
ELIM9ATE ? T5D5CY2 S T ! DOME/ICAT$
DESC5DANTS ( SPECIES1 : 9 _! NATURAL
/ATE PROBABLY WD H BE5 9 "S DEGREE /]ILE
:5 CROSS$1 2COME P]FECTLY F]TILE TGR4 ,)
PLANTS1 S F> IS CULTIV,N F GIV+ A T5D5CY
T[>DS /]IL;Y 2T 4T9CT SPECIES1 T 9 S"EAL
WELL-AU!NTICAT$ CASES ALR ALLUD$ TO1
C]TA9 PLANTS H BE5 A6ECT$ 9 AN OPPOSITE
MANN]1 = !Y H 2COME SELF-IMPOT5T :IL/ /
RETA9+ ! CAPAC;Y ( F]TILIS+1 & 2+
F]TILIS$ BY1 O!R SPECIES4 ,IF !
,PALLASIAN DOCTR9E (! ELIM9,N ( /]IL;Y
"? L;G-3T9U$ DOME/IC,N 2 ADMITT$1 & X C
H>DLY 2 REJECT$1 X 2COMES 9 ! HI<E/
DEGREE IMPROBA# T SIMIL> 3DI;NS L;G-
3T9U$ %D LIKEWISE 9DUCE ? T5D5CY2 ?\< 9
C]TA9 CASES1 ) SPECIES HAV+ A PECULI>
3/ITU;N1 /]IL;Y MI<T O3A.N,Y 2 ?US
CAUS$4 ,?US1 Z ,I 2LIEVE1 WE C "U/& :Y )
DOME/ICAT$ ANIMALS V>IETIES H N BE5
PRODUC$ : >E MUTU,Y /]ILE2 & :Y ) PLANTS
ONLY A FEW S* CASES1 IMMLY 6BE GIV51 H
BE5 OBS]V$4
  ,! R1L DI6ICULTY 9 \R PRES5T SUBJECT
IS N1 Z X APPE>S 6ME1 :Y DOME/IC
V>IETIES H N 2COME MUTU,Y 9F]TILE :5
CROSS$1 B :Y ? HAS S G5],Y O3URR$ )
NATURAL V>IETIES1 Z SOON Z !Y H BE5
P]MAN5TLY MODIFI$ 9 A SU6ICI5T DEGREE
6TAKE RANK Z SPECIES4 ,WE >E F> F
PRECISELY "K+ ! CAUSE2 NOR IS ?
SURPRIS+1 SEE+ H[ PROF.DLY IGNORANT WE
>E 9 REG>D 6! NORMAL & ABNORMAL AC;N (!
REPRODUCTIVE SY/EM4 ,B WE C SEE T
SPECIES1 [+ 6_! /RU7LE = EXI/;E ) NUM]\S
-PETITORS1 W H BE5 EXPOS$ DUR+ L;G
P]IODS ( "T 6M UNI=M 3DI;NS1 ?AN H
DOME/IC V>IETIES2 & ? MAY WELL MAKE A
WIDE DI6];E 9 ! RESULT4 ,= WE "K H[
-MONLY WILD ANIMALS & PLANTS1 :5 TAK5 F
_! NATURAL 3DI;NS & SUBJECT$ 6CAPTIV;Y1
>E R5D]$ /]ILE2 &! REPRODUCTIVE FUNC;NS
( ORGANIC 2+S : H ALW LIV$ "U NATURAL
3DI;NS WD PROBABLY 9 L MANN] 2 EM95TLY
S5SITIVE 6! 9FLU;E ( AN UNNATURAL CROSS4
,DOME/ICAT$ PRODUC;NS1 ON ! O!R H&1 :1 Z
%[N 0! M]E FACT ( _! DOME/IC,N1 7 N
ORIG9,Y HI<LY S5SITIVE 6*ANGES 9 _!
3DI;NS ( LIFE1 & : C N[ G5],Y RESI/ )
UNDIM9I%$ F]TIL;Y REP1T$ *ANGES (
3DI;NS1 MI<T 2 EXPECT$ 6PRODUCE
V>IETIES1 : WD 2 LL LIA# 6H _!
REPRODUCTIVE P[]S 9JURI\SLY A6ECT$ 0!
ACT ( CROSS+ ) O!R V>IETIES : _H
ORIG9AT$ 9 A L MANN]4
  ,I H N Z YET SPOK5 Z IF ! V>IETIES (!
SAME SPECIES 7 9V>IABLY F]TILE :5
9T]CROSS$4 ,B X IS IMPOSSI# 6RESI/ !
EVID;E (! EXI/;E (A C]TA9 AM.T ( /]IL;Y
9 ! FEW FOLL[+ CASES1 : ,I W BRIEFLY
AB/RACT4 ,! EVID;E IS AT L1/ Z GD Z T F
: WE 2LIEVE 9 ! /]IL;Y (A MULTITUDE (
SPECIES4 ,! EVID;E IS1 AL1 DERIV$ F
HO/ILE WIT;SES1 :O 9 ALL O!R CASES 3SID]
F]TIL;Y & /]IL;Y Z SAFE CRIT]IONS (
SPECIFIC 4T9C;N4 ,G>TN] KEPT DUR+ S"EAL
YE>S A DW>F K9D ( MAIZE ) YELL[ SE$S1 &A
TALL V>IETY ) R$ SE$S GR[+ NE> EA* O!R 9
8 G>D52 & AL? ^! PLANTS H SEP>AT$ SEXES1
!Y N"E NATUR,Y CROSS$4 ,HE !N F]TILIS$
?IRTE5 FL[]S (! "O K9D ) POLL5 (! O!R2 B
ONLY A S+LE H1D PRODUC$ ANY SE$1 & ? "O
H1D PRODUC$ ONLY FIVE GRA9S4 ,MANIPUL,N
9 ? CASE CD N H BE5 9JURI\S1 Z ! PLANTS
H SEP>AT$ SEXES4 ,NO "O1 ,I 2LIEVE1 HAS
SUSPECT$ T ^! V>IETIES ( MAIZE >E 4T9CT
SPECIES2 & X IS IMPORTANT 6NOTICE T !
HYBRID PLANTS ?US RAIS$ 7 !MVS P]FECTLY
F]TILE2 S T EV5 ,G>TN] DID N V5TURE
63SID] ! TWO V>IETIES Z SPECIFIC,Y
4T9CT4
  ,GIR\ DE ,BUZ>E+UES CROSS$ ?REE
V>IETIES ( G\RD1 : L ! MAIZE HAS SEP>AT$
SEXES1 & HE ASS]TS T _! MUTUAL F]TILIZ,N
IS 0S M* ! LESS EASY Z _! DI6];ES >E
GRT]4 ,H[ F> ^! EXP]I;TS MAY 2 TRU/$1 ,I
"K N2 B ! =MS EXP]I;T$ ON >E RANK$
0,SAG]ET1 :O MA9LY F.DS 8 CLASSIFIC,N 0!
TE/ ( 9F]TIL;Y1 Z V>IETIES1 & ,NAUD9 HAS
-E 6! SAME 3CLU.N4
  ,! FOLL[+ CASE IS F> M REM>KA#1 &
SEEMS AT F/ 9CR$I#2 B X IS ! RESULT ( AN
A/ONI%+ NUMB] ( EXP]I;TS MADE DUR+ _M
YE>S ON N9E SPECIES ( ,V]BASCUM1 0S GD
AN OBS]V] & S HO/ILE A WIT;S Z ,G>TN]3
"NLY1 T ! YELL[ & :ITE V>IETIES :5
CROSS$ PRODUCE LESS SE$ ?AN ! SIMIL>LY
COL\R$ V>IETIES (! SAME SPECIES4
,MOREOV]1 HE ASS]TS T1 :5 YELL[ & :ITE
V>IETIES ( "O SPECIES >E CROSS$ ) YELL[
& :ITE V>IETIES (A 4T9CT SPECIES1 M SE$
IS PRODUC$ 0! CROSSES 2T ! SIMIL>LY
COL\R$ FL[]S1 ?AN 2T ^? : >E DI6]5TLY
COL\R$4 ,MR4 ,SCOTT AL HAS EXP]I;T$ ON !
SPECIES & V>IETIES ( ,V]BASCUM2 & AL?
UNA# 63FIRM ,G>TN]'S RESULTS ON ! CROSS+
(! 4T9CT SPECIES1 HE F9DS T ! 4SIMIL>LY
COL\R$ V>IETIES (! SAME SPECIES YIELD
FEW] SE$S 9 ! PROPOR;N ( #HF 6#AJJ1 ?AN
! SIMIL>LY COL\R$ V>IETIES4 ,YET ^!
V>IETIES DI6] 9 NO RESPECT EXCEPT 9 !
COL\R ( _! FL[]S2 & "O V>IETY C "S"TS 2
RAIS$ F ! SE$ ( ANO!R4
  ,KOLREUT]1 ^: A3URACY HAS BE5 3FIRM$
0E SUBSEQU5T OBS]V]1 HAS PROV$ ! REM>KA#
FACT1 T "O "PICUL> V>IETY (! -MON TOBA3O
0 M F]TILE ?AN ! O!R V>IETIES1 :5 CROSS$
)A WIDELY 4T9CT SPECIES4 ,HE EXP]I;T$ ON
FIVE =MS : >E -MONLY REPUT$ 6BE
V>IETIES1 & : HE TE/$ 0! SEV]E/ TRIAL1
"NLY1 0RECIPROCAL CROSSES1 & HE F.D _!
M;GREL (FSPR+ P]FECTLY F]TILE4 ,B "O (
^! FIVE V>IETIES1 :5 US$ EI Z ! "F OR
"M1 & CROSS$ )! ,NICOTIANA GLUT9OSA1 ALW
YIELD$ HYBRIDS N S /]ILE Z ^? : 7
PRODUC$ F ! F\R O!R V>IETIES :5 CROSS$ )
,N4 GLUT9OSA4 ,H;E ! REPRODUCTIVE SY/EM
( ? "O V>IETY M/ H BE5 9 "S MANN] & 9 "S
DEGREE MODIFI$4
  ,F ^! FACTS X C NO L;G] 2 MA9TA9$ T
V>IETIES :5 CROSS$ >E 9V>IABLY Q F]TILE4
,F ! GRT DI6ICULTY ( ASC]TA9+ ! 9F]TIL;Y
( V>IETIES 9 A /ATE ( NATURE1 =A SUPPOS$
V>IETY1 IF PROV$ 6BE 9F]TILE 9 ANY
DEGREE1 WD ALM UNIV]S,Y 2 RANK$ Z A
SPECIES2- F MAN ATT5D+ ONLY 6EXT]NAL "*S
9 8 DOME/IC V>IETIES1 & F S* V>IETIES N
HAV+ BE5 EXPOS$ = V L;G P]IODS 6UNI=M
3DI;NS ( LIFE2- F ^! S"EAL 3SID],NS WE
MAY 3CLUDE T F]TIL;Y DOES N 3/ITUTE A
FUNDA;TAL 4T9C;N 2T V>IETIES & SPECIES
:5 CROSS$4 ,! G5]AL /]IL;Y ( CROSS$
SPECIES MAY SAFELY 2 LOOK$ AT1 N Z A
SPECIAL ACQUIRE;T OR 5D[;T1 B Z 9CID5TAL
ON *ANGES ( AN UN"KN NATURE 9 _! SEXUAL
ELE;TS4
  ,HYBRIDS & ,M;GRELS -P>$1 9DEP5D5TLY (
_! F]TIL;Y
  ,9DEP5D5TLY (! "Q ( F]TIL;Y1 ! (FSPR+
( SPECIES &( V>IETIES :5 CROSS$ MAY 2
-P>$ 9 S"EAL O!R RESPECTS4 ,G>TN]1 ^:
/R;G WI% X 0 6DRAW A 4T9CT L9E 2T
SPECIES & V>IETIES1 CD F9D V FEW1 &1 Z X
SEEMS 6ME1 Q UNIMPORTANT DI6];ES 2T ! S-
CALL$ HYBRID (FSPR+ ( SPECIES1 &! S-
CALL$ M;GREL (FSPR+ ( V>IETIES4 ,&1 ON !
O!R H&1 !Y AGREE MO/ CLOSELY 9 _M
IMPORTANT RESPECTS4
  ,I % "H 4CUSS ? SUBJECT ) EXTREME
BREV;Y4 ,! MO/ IMPORTANT 4T9C;N IS1 T 9
! F/ G5],N M;GRELS >E M V>IA# ?AN
HYBRIDS2 B ,G>TN] ADMITS T HYBRIDS F
SPECIES : H L;G BE5 CULTIVAT$ >E (T5
V>IA# 9 ! F/ G5],N2 & ,I H MYF SE5 /RIK+
9/.ES ( ? FACT4 ,G>TN] FUR!R ADMITS T
HYBRIDS 2T V CLOSELY ALLI$ SPECIES >E M
V>IA# ?AN ^? F V 4T9CT SPECIES2 & ? %[S
T ! DI6];E 9 ! DEGREE ( V>IABIL;Y
GRADUATES AWAY4 ,:5 M;GRELS &! M F]TILE
HYBRIDS >E PROPAGAT$ = S"EAL G5],NS1 AN
EXTREME AM.T ( V>IABIL;Y 9 ! (FSPR+ 9
BO? CASES IS NOTORI\S2 B "S FEW 9/.ES (
BO? HYBRIDS & M;GRELS L;G RETA9+ A UNI=M
"* CD 2 GIV54 ,! V>IABIL;Y1 H["E1 9 !
SU3ESSIVE G5],NS ( M;GRELS IS1 P]H1 GRT]
?AN 9 HYBRIDS4
  ,? GRT] V>IABIL;Y 9 M;GRELS ?AN 9
HYBRIDS DOES N SEEM AT ALL SURPRIS+4 ,=!
P>5TS ( M;GRELS >E V>IETIES1 & MO/LY
DOME/IC V>IETIES 7V FEW EXP]I;TS HAV+
BE5 TRI$ ON NATURAL V>IETIES71 & ?
IMPLIES T "! HAS BE5 REC5T V>IABIL;Y1 :
WD (T5 3T9UE & WD AUG;T T >IS+ F ! ACT (
CROSS+4 ,! SLI<T V>IABIL;Y ( HYBRIDS 9 !
F/ G5],N1 9 3TRA/ ) T 9 ! SU3E$+ G5],NS1
IS A CURI\S FACT & DES]VES ATT5;N4 ,= X
BE>S ON ! VIEW : ,I H TAK5 ( "O (!
CAUSES ( ORD9>Y V>IABIL;Y2 "NLY1 T !
REPRODUCTIVE SY/EM F 2+ EM95TLY S5SITIVE
6*ANG$ 3DI;NS ( LIFE1 FAILS "U ^!
CIRCUM/.ES 6P]=M XS PROP] FUNC;N (
PRODUC+ (FSPR+ CLOSELY SIMIL> 9 ALL
RESPECTS 6! P>5T-=M4 ,N[ HYBRIDS 9 ! F/
G5],N >E DESC5D$ F SPECIES 7EXCLUD+ ^?
L;G-CULTIVAT$7 : H N _H _! REPRODUCTIVE
SY/EMS 9 ANY WAY A6ECT$1 & !Y >E N
V>IA#2 B HYBRIDS !MVS H _! REPRODUCTIVE
SY/EMS S]I\SLY A6ECT$1 & _! DESC5DANTS
>E HI<LY V>IA#4
  ,B 6RETURN 6\R -P>ISON ( M;GRELS &
HYBRIDS3 ,G>TN] /ATES T M;GRELS >E M
LIA# ?AN HYBRIDS 6REV]T 6EI P>5T-=M2 B
?1 IF X 2 TRUE1 IS C]TA9LY ONLY A DI6];E
9 DEGREE4 ,MOREOV]1 ,G>TN] EXPRESSLY
/ATES T HYBRIDS F L;G CULTIVAT$ PLANTS
>E M SUBJECT 6REV].N ?AN HYBRIDS F
SPECIES 9 _! NATURAL /ATE2 & ? PROBABLY
EXPLA9S ! S+UL> DI6];E 9 ! RESULTS >RIV$
AT 0DI6]5T OBS]V]S3 ?US ,MAX ,WI*URA
D\BTS :E!R HYBRIDS "E REV]T 6_! P>5T-
=MS1 & HE EXP]I;T$ ON UNCULTIVAT$
SPECIES ( WILL[S2 :IL/ ,NAUD91 ON ! O!R
H&1 9SI/S 9 ! /R;GE/ T]MS ON ! ALM
UNIV]SAL T5D5CY 6REV].N 9 HYBRIDS1 & HE
EXP]I;T$ *IEFLY ON CULTIVAT$ PLANTS4
,G>TN] FUR!R /ATES T :5 ANY TWO SPECIES1
AL? MO/ CLOSELY ALLI$ 6EA* O!R1 >E
CROSS$ )A ?IRD SPECIES1 ! HYBRIDS >E
WIDELY DI6]5T F EA* O!R2 ":AS IF TWO V
4T9CT V>IETIES ( "O SPECIES >E CROSS$ )
ANO!R SPECIES1 ! HYBRIDS D N DI6] M*4 ,B
? 3CLU.N1 Z F> Z ,I C MAKE \1 IS F.D$ ON
A S+LE EXP]I;T2 & SEEMS DIRECTLY OPPOS$
6! RESULTS ( S"EAL EXP]I;TS MADE
0,KOLREUT]4
  ,S* AL"O >E ! UNIMPORTANT DI6];ES :
,G>TN] IS A# 6PO9T \ 2T HYBRID & M;GREL
PLANTS4 ,ON ! O!R H&1 ! DEGREES & K9DS (
RESEMBL.E 9 M;GRELS & 9 HYBRIDS 6_!
RESPECTIVE P>5TS1 M ESPECI,Y 9 HYBRIDS
PRODUC$ F NE>LY RELAT$ SPECIES1 FOLL[ AC
6,G>TN] ! SAME LAWS4 ,:5 TWO SPECIES >E
CROSS$1 "O HAS "S"TS A PREPOT5T P[] (
IMPRESS+ XS LIKE;S ON ! HYBRID4 ,S ,I
2LIEVE X 6BE ) V>IETIES ( PLANTS2 &)
ANIMALS "O V>IETY C]TA9LY (T5 HAS ?
PREPOT5T P[] OV] ANO!R V>IETY4 ,HYBRID
PLANTS PRODUC$ F A RECIPROCAL CROSS1
G5],Y RESEM# EA* O!R CLOSELY2 & S X IS )
M;GREL PLANTS F A RECIPROCAL CROSS4 ,BO?
HYBRIDS & M;GRELS C 2 REDUC$ 6EI PURE
P>5T-=M1 0REP1T$ CROSSES 9 SU3ESSIVE
G5],NS ) EI P>5T4
  ,^! S"EAL REM>KS >E APP>5TLY APPLICA#
6ANIMALS2 B ! SUBJECT IS "H M* -PLICAT$1
"PLY [+ 6! EXI/;E ( SECOND>Y SEXUAL "*S2
B M ESPECI,Y [+ 6PREPOT5CY 9 TRANSMITT+
LIKE;S RUNN+ M /R;GLY 9 "O SEX ?AN 9 !
O!R1 BO? :5 "O SPECIES IS CROSS$ )
ANO!R1 & :5 "O V>IETY IS CROSS$ ) ANO!R
V>IETY4 ,= 9/.E1 ,I ?9K ^? AU?ORS >E "R
:O MA9TA9 T ! ASS HAS A PREPOT5T P[] OV]
! HORSE1 S T BO? ! MULE &! H9NY RESEM# M
CLOSELY ! ASS ?AN ! HORSE2 B T !
PREPOT5CY RUNS M /R;GLY 9 ! MALE ?AN 9 !
FEMALE ASS1 S T ! MULE1 : IS ! (FSPR+ (!
MALE ASS & M>E1 IS M L AN ASS1 ?AN IS !
H9NY1 : IS ! (FSPR+ (! FEMALE ASS &
/ALLION4
  ,M* /RESS HAS BE5 LAID 0"S AU?ORS ON !
SUPPOS$ FACT1 T X IS ONLY ) M;GRELS T !
(FSPR+ >E N 9T]M$IATE 9 "*1 B CLOSELY
RESEM# "O ( _! P>5TS2 B ? DOES "S"TS
O3UR ) HYBRIDS1 YET ,I GRANT M* LESS
FREQU5TLY ?AN ) M;GRELS4 ,LOOK+ 6! CASES
: ,I H COLLECT$ ( CROSS-BR$ ANIMALS
CLOSELY RESEMBL+ "O P>5T1 ! RESEMBL.ES
SEEM *IEFLY 3F9$ 6"*S ALM MON/R\S 9 _!
NATURE1 & : H SU45LY APPE>$- S* Z
ALB9ISM1 MELANISM1 DEFICI5CY ( TAIL OR
HORNS1 OR A4I;NAL F+]S & TOES2 & D N
RELATE 6"*S : H BE5 SL[LY ACQUIR$ "?
SELEC;N4 ,A T5D5CY 6SU45 REV].NS 6!
P]FECT "* ( EI P>5T WD1 AL1 2 M* M
LIKELY 6O3UR ) M;GRELS1 : >E DESC5D$ F
V>IETIES (T5 SU45LY PRODUC$ & SEMI-
MON/R\S 9 "*1 ?AN ) HYBRIDS1 : >E
DESC5D$ F SPECIES SL[LY & NATUR,Y
PRODUC$ ,ON ! :OLE1 ,I 5TIRELY AGREE )
,DR4 ,PROSP] ,LUCAS1 :O1 AF >RANG+ AN
ENORM\S BODY ( FACTS ) RESPECT 6ANIMALS1
-ES 6! 3CLU.N T ! LAWS ( RESEMBL.E (! *
6XS P>5TS >E ! SAME1 :E!R ! TWO P>5TS
DI6] LL OR M* F EA* O!R1 "NLY1 9 ! UNION
( 9DIVIDUALS (! SAME V>IETY1 OR ( DI6]5T
V>IETIES1 OR ( 4T9CT SPECIES4
  ,9DEP5D5TLY (! "Q ( F]TIL;Y & /]IL;Y1
9 ALL O!R RESPECTS "! SEEMS 6BE A G5]AL
& CLOSE SIMIL>;Y 9 ! (FSPR+ ( CROSS$
SPECIES1 &( CROSS$ V>IETIES4 ,IF WE LOOK
AT SPECIES Z HAV+ BE5 SPECI,Y CR1T$1 &
AT V>IETIES Z HAV+ BE5 PRODUC$ 0SECOND>Y
LAWS1 ? SIMIL>;Y WD 2 AN A/ONI%+ FACT4
,B X H>MONISES P]FECTLY )! VIEW T "! IS
NO ESS5TIAL 4T9C;N 2T SPECIES &
V>IETIES4
  ,SUMM>Y ( ,*APT]
  ,F/ CROSSES 2T =MS1 SU6ICI5TLY 4T9CT
6BE RANK$ Z SPECIES1 & _! HYBRIDS1 >E V
G5],Y1 B N UNIV]S,Y1 /]ILE4 ,! /]IL;Y IS
( ALL DEGREES1 & IS (T5 S SLI<T T ! MO/
C>E;L EXP]I;TALI/S H >RIV$ AT
DIAMETRIC,Y OPPOSITE 3CLU.NS 9 RANK+ =MS
0? TE/4 ,! /]IL;Y IS 9NATELY V>IA# 9
9DIVIDUALS (! SAME SPECIES1 & IS EM95TLY
SUSCEPTI# 6! AC;N ( FAV\RA# & UNFAV\RA#
3DI;NS4 ,! DEGREE ( /]IL;Y DOES N
/RICTLY FOLL[ SY/EMATIC A69;Y1 B IS
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