IN THE SPECIES OF PBIMULA.. 



87 



lens with respect to the two stigmas iu F. veris, Sinensis, and 

 auricula. In each species four crosses can be tried ; namely, the 

 stigma of the long-styled by its own-form jJoUen and by that of 

 the short-styled, and the stigma of the short-styled by its own- 

 form pollen and by that of the other form. It is necessary to use 

 and remember two new terms for these crosses : when the long- 

 and the short-styled stigmas are fertilized by their own-form pol- 

 len the union is said to be " homomorphic ;" when the long-styled 

 and short-styled stigmas are fertilized by tlie pollen of the other 

 form, the union is " heteromorphic." I speak of the " own-form 

 pollen," because in the following homomorphic unions, iu order 

 to make the experiment perfectly fair, I never placed the pollen 

 of the same flower on its own stigma, but, to avoid the possible ill 

 effects of close interbreeding, I always used the pollen from an- 

 other plant of the same form. In the following experiments all 

 the plants were treated in exactly the same manner, and were 

 carefully protected from insects as far as that is possible. I per- 

 formed every manipulation myself, and weighed the seed in a che- 

 mical balance. Some of the capsules contained no seed, or only 

 two or three, and these are excluded in the column marked " good 

 pods." First for P. Sinensis, as the simplest case. 



Primula Sinensis. — Table I. 





'S^.ri 



1 "S ri 



t-_- 



^ -. 



By Calculation. 





"a fS^ 



III! 







Good ( ^^'«'8^' of 





S eg 



tng^o 



^•o^ 



;slfe 



PodT- '«<"» 





^ "S 



g a 







( grains. 



Long-styled by own- 













form pollen (homo- 



20 



18 



13 



5-9 



or as 100 to 43 



morphic union) .... 













Long-styled by pollen' 













of short-styled (hete- • 



24 



18 



16 



9-3 



or as 100 to 58 



romorphic union)... 













Short-styled by own- 













form pollen (homo- ■ 



7 



6 



4 



0-9 



or as 100 to 22 



morphic union) 







• 







Short-styled by pollen ' 













of long-styled (hete- [• 



8 



8 



8 



61 



or as 100 to 76 



romorphic union). . . J 













Summary : 













The two homomorphic 1 

 unions J 



27 



23 



17 



6-8 















The two heteromorphic 1 

 unions J 



32 



26 



24 



15-4 















For the sake of comparison, we may reduce these latter figures 

 as follows : — 



