342 OKESSWKI.L SIIKAlJKi;. 



has been broken oft' the posterior end. This subsequently 

 joined up with the egg again. 



No pokxr body is given off by the egg while it remains 

 within the cavity of the ovary. I have had a female under 

 observation for several days, and have been able to follow the 

 growth and maturation of a particular egg from the first 

 without seeing the formation of any polar body taking place. 



I have mentioned that the male is often seen to fertilise the 

 female while she is without eggs and still immature and in the 

 larval state. In these females the sperm can be seen working 

 their way through the tissues and finally collecting in the 

 oviduct. 1 believe this invariably takes place. Whether 

 the spernij once in the oviducts, retain their vitality till the 

 female reaches maturity and bears eggs I have been unable to 

 determine. It would seem that it is immaterial whether this 

 does or does not take place. The female is usually fertilised 

 over and over again before she reaches maturity and bears 

 eggs, so that fertilisation is probably effected by the last supply 

 of sperm she may happen to receive. It is clear that the 

 presence or absence of ova in the female play no part as a 

 factor in fertilisation. 



No matter where the sperm are injected into the body of 

 the female — and the male exercises no choice in this respect — 

 they seem to collect ultimately in the ampulla? of the oviducts. 

 It would seem as if some substance in this situation exerted a 

 chemotactic influence over their movements, causing them to 

 collect here from all parts of the body. 



The sperm are frequently seen in the blastocoelic cavity in 

 small masses beneath the gut. In this situation they are still 

 shut off fi-om the cavity of the ovary and the eggs. 



In the anterior end of the ovary, crowded among the small 

 oogonial cells, are frequently seen small masses of sperm. 

 These appear to have undergone considerable change and to 

 have partially lost their tails. It is probable that these sperm 

 have gained access to the ovary by way of the oviducts. It 

 is i-emarkable, however, that in the posterior region of the 

 ovarian cavity no sperm are seen free among the ova, but they 



