422 BOWEN. 



PLATE II. 

 All the figures are from cells of the large generations in Murgantia histrionica. 



11 to 20 Progressive stages in the differentiation of the sperm head (nucleus). 

 (Flemming-hematoxylin, — except Figure 20 which is Hermann-hema- 

 toxylin.) 



21 Head of mature sperm from efferent duct of testis. (Smear prepa- 

 ration. Osmic fumes-hematoxylin.) 



22 Detail of the bleb-like swelling on the tail of the large sperms. (Smear 

 preparation. Osmic fumes-hematoxylin.) 



