CLOACA AND SPERM AT 1 1 KCA OF GYR1NOPHILUS. 265 



3. Ova, presumably large enough for ovulation (2.25-2.75 

 mm.), appeared in April, June, August and November. Since 

 the August animal was small and possibly ovulating for the 

 first time, the other three might point to spring and fall ovulations 

 in this species; but there is no sequence in size of ova leading 

 up to April, June, or November. Possibly each animal ovulates 

 but once a year, and food, temperature and individual habit 

 may determine the time. 



4. Of the four animals showing large ova, sperms \vere abun- 

 dant in the three taken in June, August and November. The 

 fourth animal, killed in April, had been kept in captivity for 

 several weeks, and would thus have been prevented from mating 

 during that period. 



5. Sperms were not found in abundance except in animals 

 nearly ready to ovulate. Whether or not normal sperms might 

 be retained long enough to fertilize ova at the following ovulation, 

 would be impossible to say from this series. An animal taken 

 in September with ova two thirds of the maximum size (ready 

 to ovulate in October or November?) had a few sperms remaining. 



6. Mature sperms are absent from the vasa deferentia of the 

 male from approximately June I to September I5. 1 Males are, 

 therefore, incapable of functional mating during this period. 

 The sperms found in females between June and September must 

 have been acquired before June probably in early spring or the 

 preceding autumn. Of especial interest is the abundance of 

 apparently normal sperms in the female taken in August. We 

 may conclude that sperms can be stored in the spermatheca for 

 at least two and a half months, and most probably for a far 

 longer period. 



The interesting questions of mating and ovulation cannot be 

 answered without further study; we may conclude that both 

 phenomena are probably quite variable as to time, that sperms 

 are stored in the spermatheca from mating until the succeeding 

 ovulation, and that apparently normal sperms are found for a 

 considerable time after ovulation. 



1 This information is supplied by Dr. R. R. Humphrey. He has examined 

 males killed in every month except April. 



