PLATE 41. 



Fig. 46. Gyrocotyle fimbriata. Same specimen as fig. 42. Ventral. 

 Showing vagina and vaginal opening, vesicula seminalis, penis-papilla 

 and ejaculatory duct. X 100. 



Fig. 47. Egg from fifth coil of uterus. Showing single ovum sur- 

 rounded by numerous yolk-cells. Delafield's haematoxylin. X 1000. 



Fig. 48. Same, tenth coil of uterus. Showing division of ovum and 

 disintegration of yolk cells. Note disappearance of nuclei of }'olk cells. 

 X 1000. 



Fig. 49. Yolk cells in vitellarian follicle. Note reduction of cyto- 

 plasm and formation of j r olk-platelets. X 1850. 



Fig. 50. Spermatozoa from receptaculum seminis, showing head, tail 

 and acrosome. X 1850. 



Fig. 51. Ovum in afferent oviduct; note shadow of yolk nucleolus. 

 X 1500. 



Figs. 52, 53, 54. Follicle of ovary. Showing syncytial ova and various 

 stages in the formation and extrusion of the yolk-nucleolus. X 1500. 



cyl. r. — cytoplasmic rim. 



ejac. duct — ejaculatory duct. 



in. long. — inner longitudinal muscle. 



ov. — ovum. 



/>< n. pap. — penis papilla. 



sptz. — spermatozoa. 



ut. — uterus. 



tag. — vagina. 



vag. op. — vaginal opening. 



i as ilrf. — vas deferens. 



yk. c. — yolk cell. 



yk. gr. — yolk platelets. 



yk. ii urlt o. — yolk nucleolus. 



[454] 



