228 BOTANICAL GAZETTE [march 



later history of the blepharoplast and the development of the sperm, 

 but A these features, particularly the relation of the blepharoplast to 

 the spiral band, are shown so much more clearly in my preparations 

 of Ceratozamia, that I have refrained from any extended description 

 at this time. 



forthcoming 



sperm 



DISCUSSION 



With Thiessen's (14) paper on the seedling of Dioon edale, my 

 own paper on the ovule and female gametophyte, the present paper 

 on spermatogenesis, and a study of fertilization and embryogeny 

 now nearly completed, considerable information concerning this 

 form is available. The temptation to draw conclusions is strong, 

 but studies on Ceratozamia mexicana and Dioon spinulosum are well 

 under way, and Sister Helen Angela (12) has already completed 

 an investigation of the anatomy of Ceratozamia. Since any theories 

 will be more likely to be well founded if based upon a comparative 

 study, I shall reserve speculations for a safer opportunity. At present 

 I shall merely consider a few points suggested by the foregoing de- 

 scription. 



The largest staminate sporophylls in the Cycadales are found in 

 Cycas and the smallest in Zamia. The number of sporangia corre- 

 sponds, roughly, to the size of the sporophyll. The sporangia in 

 Cycas, Encephalartos, Dioon, and all the forms with large micro- 

 sporophylls, so far as I have been able to examine them, have the 

 sporangia in definite sori with 3, 4, or 5 sporangia in a sows, n 

 forms with smaller sporophylls, like Zamia, Ceratozamia, and Micro- 

 cycas, some of the sporangia are single, but most of them are grouped, 

 with 2 or 3, or occasionally 4 sporangia in a sorus. Caldwell (9) 

 states that in Microcycas the sporangia are not arranged m son 

 but his photograph shows that even on the smaller sporophyll m°s 

 of the sporangia are in sori ; the number of sporangia is about 100 

 on the larger sporophyll. The number of sporangia on a spo r °P^ ' 

 according to Miss Grace Smith (8) is as follows: Cycas cimn *^ 



700, Encephalartos Caffer 700, Macrozamia Miquelii 600, #"*' 

 lartos villosus 500, Dioon edule 200, and Zamia floridana U- 



