HABITS OF CRYPTOBRANCHUS ALLEGHENIENSIS. I 5 



On August 14 a large female was examined. The ovaries 

 contained several hundred eggs almost fully developed, besides 

 many smaller ones. The oviducts were empty. 



Observations of this kind were continued throughout the 

 month. On August 24 a female was found in which a few eggs 

 had descended into the oviducts and become surrounded by a 

 gelatinous envelope. This specimen was somewhat exceptional, 

 as in others examined up to September 1 the eggs had not left 

 the ovaries. Evidently there is considerable individual variation 

 in the time when females ripen. On September 1 the first nest 

 of eggs was found ; these were in the first and second cleavage 

 stages, hence had probably been deposited about 24 hours before. 

 On September 3 a female was examined in which the eggs, sur- 

 rounded by their gelatinous envelopes, had all collected in the 

 lower part of the oviduct — the "uterus" — which was much 

 distended, spindle-shaped, about 10 cm. long by 4 cm. in diam- 

 eter at its widest part ; its thin walls had a rich blood supply. 



The preparations of the males for the breeding season pro- 

 ceeded at equal pace with those of the females. On August 31, 

 in a specimen 38 cm. long, having the glandular region about 

 the cloacal opening very much swollen, the vas deferens was 

 found to be much distended with milt, and measured about 8 mm. 

 in diameter. From this specimen the seminal fluid could be 

 easily stripped. The spermatozoa were motile ; the motion of 

 the shaft is slow as compared with other forms, but that of the 

 undulating membrane is rapid. The posterior third of the testis 

 was darkened and shrunken, and appeared much degenerated ; 

 as stated by McGregor ('99), a wave of maturation begins at the 

 posterior end of the testis and passes forward. 



Hence the breeding season in this locality may be said to be- 

 gin about the last of August. Possibly it is influenced by tem- 

 perature ; cool nights, accompanied by a marked decrease in the 

 temperature of the water, set in three or four days previously. 

 During the breeding season the temperature of the water ranged 

 from 14 to i8°C. The egg-laying season lasts about two 

 weeks. 



Oviposition. — In a ripe female, the string of eggs in the uterus 

 is aggregated in a much twisted and tangled mass. The egg 



