1924] 



Collins: Inheritance in Crepis capillaris (L.) Wallr. 



253 



race with any except that from the Azores, we have evidence of their 

 identity, since they have each been crossed with the Swedish race, 

 which in turn was proved to be identical with the others. The bald 

 plants from France have not been tested. Bald is inherited as a 

 simple monohybrid recessive, as is shown by the results obtained from 

 crossing with glandular plants. Table 2 presents F^ data from crosses 

 of bald X glandular. The one bald plant in culture 20.59 probably 

 resulted from the failure to remove a single pollen grain during 

 emasculation and represents an error in technique. The two bald 



TABLE 4 

 F, Eesults from the Cross BB X bb 



plants in culture 21.21 may be ascribed to this same cause or to errors 

 at time of transplanting, since culture 21.23, containing only bald 

 plants, grew adjacent to 21.21 in the flat before transplanting to the 

 field. 



Table 3 shows that 39 glandular to 38 bald plants were obtained 

 when the F^ (bald X glandular) were backcrossed to the recessive 

 parent strain. The expected 1 to 1 ratio was therefore realized. 



The results from Fo cultures confirm the conclusion regarding a 

 single recessive factor conditioning the appearance of bald. While 

 in almost all cases involving bald the glandular hairs are completely 

 absent, in culture 20.141 some plants appeared to be somewhat inter- 

 mediate, inasmuch as they developed a few small scattered gland hairs 

 on the involucre. They were easily distinguishable from glandular 

 plants. In table 4 these intermediates have been classified as bald. 



