154 GYMNOSPERMS 



than a hundred seeds were secured, and now (December, 1934) more 

 than fifty thriving F, plants look as if they were large enough to pro- 

 duce cones. It will be remembered that, normally, Ccratozamia has 

 only one cotyledon, while Zamia has the usual two. In 1925, when 

 the seedlings were being repotted, a careful examination was made 

 and of the fifty-six which had survived up to this stage, forty-seven 

 showed two cotyledons; three had one cotyledon, and in the other 

 six the cotyledon situation could not be determined without sacrific- 

 ing the seedHngs (fig. 170). 



It is evident that, in this generic hybrid, Zamia is dominant as far 

 as the cotyledons are concerned. At this time (1934) not a single one 

 of the Fi plants has coned. The leaves now look like Ceratozamia 

 mexicana leaves, and some of them would be diagnosed as C. longi- 

 folia. 



Miss Sophia Papadopoulos''^^ made a comparison of the leaflets 

 of the two parents and the Fi generation, and found that in some 

 features the F^ resembled one parent and in some resembled the 

 other; but that in the stomata there were features of both parents. 



When cones are produced it will be interesting to find whether the 

 sporophylls have the two strong horns of Ceratozamia or the truncate 

 apex of Zamia. 



