PLATE 8 



EXPLANATION OF TIGURES 



71 Showing an apyrene spermatosome, which has abnormally developed 

 (see text) entering wall of seminal vesicle. X 681. Length of specimen, 

 14 mm. 



72 Showing eupyrene sperm heads (esp) and apyrene sperm (asp) in wall 

 of vesicle. Cytoplasm has extended out along apyrene sperm. One eupyrene 

 sperm head has begun to break up, assuming beaded appearance. Length of 

 specimen, 11 mm. Gonad reduced to small strands. X 681. 



73 to 76 From a s'ngle specimen a large animal (17 mm.) which had been a 

 male when first collected, but which during 48 days under experiment had lost 

 the male condition. All sperm in seminal vesicle had been absorbed. 



73 Section through distal part of goniduct; somewhat oblique section. 

 X 85. 



74 Enlargement of small part of same. X 681. 



75 Section through degenerate seminal vesicle. X 85. 



76 Enlargement of small part of same. X 681. 



77 to 80 Sections through goniduct of large sexually inactive specimen, 

 formerly male. No oocytes yet present in gonad. 



77 Section through distal part of goniduct. X 85. 



78 Enlargement of small part of same. X 681. 



79 Section through proximal part of goniduct (former semial vesicle). 

 X 85. 



80 Enlargement of small part of same. X 681. 



81 to 84 Drawn from the goniduct of an immature female 20 mm. long, 

 with yolked oocytes in ovary (fig. 83). 



81 Distal part of goniduct (now oviduct) showing great growth and infold- 

 ing of walls. X 85. 



82 Enlargement of small part of epithelium of same. X 681. 



83 Proximal part of oviduct in same animal. Somewhat oblique section. 

 X 85. 



84 Enlargement of small part of epithelium of same. X 681. 



85 Section through epithelium of oviduct of adult female, to show unicellular 

 gland. 



68 



