150 BERTRAM G. SMITH. 



The eggs of Cryptobranchm allcgheniensis bear a rather close 

 resemblance to those of C.japonicus as described by Sasaki ('87), 

 Kerbert ('04), Ishikawa ('04) and de Bussy ('05). Other amphib- 

 ians whose eggs are fastened together like a string of beads are 

 Amphiuma (Hay, '88 and '90), Desmognathus, Ichthyofhis, Hypo- 

 geophis (Brauer, '97), and Alytcs. The eggs of Bufo are arranged 

 in strings but without the marked constriction of the envelope 

 between the eggs characteristic of the other forms mentioned. 



B. The Sperm. - -The spermatozoon (Fig. 3) is of considerable 

 size, about 225 // long, but with an unusually small middle-piece. 

 The head of the spermatozoon, excepting the tip or acrosome, 

 stains deeply with Conklin's modification of Delafield's heemo- 

 toxylin. The head is very long and slender, tapering gradually 

 to the extremely fine-pointed acrosome, enabling the sperma- 

 tozoon to pierce easily through the vitelline membrane. The 

 tail-piece is provided with an undulating membrane, bordered 

 with a convoluted filament. 



The spermatozoon of Cryptobranchus allcgheniensis resembles 

 that of C.japonicus as figured by Ishikawa ('04). It is also quite 

 similar to the spermatozoon of Amphiuma (McGregor, '99), but 

 the latter has a larger middle-piece and a slightly barbed 

 acrosome. 



II. BREEDING HABITS. 



A. Method of Fertilization. - - A newly-captured female was 

 isolated in an aquarium not previously occupied by any other 

 specimen. A large number of eggs were laid, which contained 

 spermatozoa within the egg capsule ; moreover the subsequent 

 development of these eggs proved them to have been fertilized. 

 Hence there can be no doubt that in Cryptobranchus alleglien- 

 icnsis, as in all other Urodeles so far as known, fertilization, 

 unlike that of the Anura, is internal. The mode of transference 

 of the male element to the cloaca of the female has not been 

 ascertained. 



Nothing conclusive has been established concerning the method 

 of fertilization of the nearest relative of Cryptobranchus alleglien- 

 iensis, the giant salamander of Japan. In the case Q{ Amphiuma, 

 Davison ('94 and '95) believed a transference of spermatozoa 



