FERTILIZATION IN LERN/EOPODA EDWARDSII OLSSON. 119 



some of the females, showing that these females have, in all 

 probability, been fertilized three times. After fertilization, the 

 male drops off from the female's body and dies. The female 

 however, grows enormously in size. During this growth period, 

 the ovaries develop and produce a great many eggs. The cement 

 gland also develops completely, and from each side of the extreme 

 lower margin of the abdomen, an egg-sac grows out. The 

 oviducts communicate with these egg-sacs directly. Figure 10 

 shows the abdomen of an adult female, with the eggs (o.), the 

 oviducts (od.), the cement glands (e.g.}, the spermatheca (s)., 

 the spermatophores (sp.), and the egg-sacs (e.s.). 



The eggs are discharged into the oviducts, and are then passed 

 down posteriorly, w r here they are fertilized by the spermatozoa 

 which are stored in the spermatheca. Then they are coated with 

 a layer of cement from the cement glands, and finally pass into 

 the egg-sacs, where they develop into larvae. The cement coating 

 hardens into one of the egg covers. Fig. 1 1 shows the relation 

 of the spermatheca (s.) to the oviducts (od.}. The spermatheca 

 is filled with great numbers of ripe spermatozoa. 



These observations on the structure of the reproductive ap- 

 paratus of the adult female corroborate those of Miculicich 

 (1905), who worked with Lernaeopodidae of the genus Brachiella. 



I wish to express my thanks to Professors M. F. Guyer and 

 A. S. Pearse for reading this paper and for their helpful sug- 

 gestions. 



SUMMARY. 



1. About two and a half or three weeks after the attachment 

 of Lernceopoda edwardsii to the brook-trout, the parasite is 

 mature for fertilization. 



2. The mature male is about one third as long as the mature 

 female. The reproductive organs of the male are paired, and are 

 located in the posterior region of the body, between the intestine 

 and the body wall. They consist of a testis, a coiled vas deferens, 

 and a spermatophore. 



3. The female reproductive apparatus is also paired in char- 

 acter and is located within the abdomen, between the intestine 

 and the body wall. The ovaries give rise to slender oviducts, 

 which open at the lower extremity of the abdomen. Slightly 



