SPERMATOGENESIS IN BLASIA 



Lester- W. Sharp 



WITH PLATE XV 



Introduction 



The following brief account of spermatogenesis in Blasia pusilla 

 is based upon preparations made from a limited amount of material 

 collected near Chicago several years ago. The preparations, 

 which were originally made for use in classes , proved upon care- 

 ful examination to show with admirable clearness all stages included 

 in the last spermatogenous mitosis and the transformation of the 

 androcyte (spermatid) into the spermatozoid. Since the results 

 of the examination differ in two important points from those re- 

 ported by Woodburn (12) in the only previous paper dealing with 

 these features in Blasia, they are here recorded. 



Description 



The description will begin with the spermatogenous cells of 

 the penultimate generation, the androcyte mother cells, to use the 

 terminology of Allen (i). The cells of the earlier generations 

 (androgones) have been examined, and nothing which it is safe to 

 call centrosomes has been observed. Unfortunately, however, 

 the material did not show many androgone nuclei in division; 

 anaphases were present, but metaphases, where centrosomes are 

 usually most conspicuous if present at all, were not found. No 

 conclusive statement can be made, therefore, regarding the pres- 

 ence or absence of centrosomes in the androgones. 



In the androcyte mother- cell, before the stage represented m 

 fig. 1, the cytoplasm has an almost homogeneous appearance, and 

 included in it are several granules or vaguely defined areas. In 

 some cells these granules, from 1 to 6 or more in a thin section, may 

 appear to be all alike ; while in other cells one or two of them may 

 be more sharply denned and more deeply stained than the others. 

 It is possible that of these several granules two survive as the 



Botanical Gazette, vol. 69] 



t2 5 3 



