EMBRYOLOGY OF CRYPTOBRANCHUS ALLEGHENIENSIS. 151 



from male to female to take place by means of an apposition of 

 the lips of the two cloacae, basing this belief on what appears to 

 me insufficient evidence ; such a process is moreover not in 

 harmony with known methods of fertilization among the Urodeles, 

 in which fertilization is effected by means of spermatophores and 

 without direct cloacal contact (Jordan, '91 and '93). Internal 

 fertilization is said to occur in the Gymnophiona, Iclitliyopliis and 

 Hypogeophis, as well as in the Urodeles. 



B. Breeding Season. - - Fertilized eggs were laid by a specimen 

 in captivity on September 6, and another spawning by the same 

 female took place during the night of September 7-8. Eggs in 

 the first cleavage stage were found in the natural habitat of the 

 animal on September 7, and another spawning of eggs in an 

 advanced stage of segmentation was found in the same habitat on 

 September 8. 



Townsend ('82) records the laying of some eggs by a spec- 

 imen in captivity during the month of August. McGregor ('99) 

 states that the eggs are deposited in August and September. 



No direct observations as to the time when the females are fer- 

 tilized were obtained ; but male specimens killed during the early 

 part of September were found to have the vasa deferentia dis- 

 tended by a large quantity of seminal fluid containing an abun- 

 dance of ripe spermatozoa. According to McGregor ('99) " the 

 sexual union must occur very near or at the time of egg-laying, 

 for the female is devoid of spermathecae, and the spermatozoa do 

 not ripen until late in August." 



Eggs of C. japonicus were found by Sasaki ('87) in August. 

 Kerbert ('04) records the spawning of a specimen in captivity 

 during the night of September 18, 1902, and again on September 

 19, 1903. DeBussy ('05) reports that eggs were laid by Ker- 

 bert's specimen during September 14, 1904, and several days fol- 

 lowing. According to Ishikawa ('04) the eggs are laid princi- 

 pally during the latter half of August, but also in September. 

 Hence the breeding season coincides with that of C. allegheniensis. 



Eggs of Ampliinina in an advanced stage of development were 

 found by Hay ('88 and '90) on September i. Davison ('94 and 

 '95) states that the eggs are deposited in August or September, 

 but without giving the data upon which this statement is based. 



