102 The Spermatogenesis of Desmognathus Fnsca 



eggs are laid some time in the summer. Wilder has found eggs laid 

 in captivity, June 1st; Sherwood, 95, on the other hand, has found eggs 

 from July to October, so that there is probably considerable individual 

 variation in the time of ovulation. Desmognathus eggs have been found 

 at Ithaca during July and August. Eecorded observations are insuffi- 

 cient for a more exact determination of the time of ovulation. The 

 development of the form is known only in its grossest outline, but the 

 very interesting statement has been made that cleavage in Desmognathus 

 is meroblastic. Wilder, 99, and this statement has also been guardedly 

 made of a member of an allied family, Autodax luguhris, Eitter, 99. 

 The eggs are laid under stones near the stream in a hollow in the mud 

 and are connected together by albuminous cords, uniting them in a 

 group. The female remains with the eggs, which lie in a mass at her 

 side, according to my observations, not wrapped about her body as 

 Wilder has stated to be the case. 



Mating habits. — Nothing definite is known of the mating habits of 

 Desmognathus. The investigations, especially of Zeller and Jordan, 

 have made us well acquainted with these phenomena in the genus 

 Salamandra and in the genera of the allied family of the Pleurodelidce, 

 where they consist in the deposition of a spermatophore by the male, 

 over which the female passes while her cloacal lips, coming in contact 

 with the mass of spermatozoa, either actively grasp it, or to them the 

 spermatozoa adhere and enter later by their own activity. Within the 

 cloacal chamber the spermatozoa become ensconced in tubules consti- 

 tuting spermathecae, in which they remain until the time of ovulation. 

 Fertilization in Salamandra (Triton and Diemyctylus) takes place in the 

 spring, and is preceded by a mating. In Triton and Diemyctylus, at 

 least, there is occasionally an autumnal mating, the entire winter inter- 

 vening before ovulation. 



As compared with what is known of the mating habits of these forms, 

 our knowledge of the same phenomena in Desmognathus is scanty, indeed. 

 I know of no published observation on this form which, from its retir- 

 ing mode of life and (presumably) nocturnal habits, is difficult to observe. 

 The probability is strong, however, that the same mode of mating occurs 

 in this form, since in the male Desmognathus are present in a well 

 developed condition the same three cloacal glands found in forms whose 

 mating is known and which undoubtedly produce the secretion that 

 constitutes the body of the spermatophore. Likewise, the spermatheca 

 is present in the cloaca of the female, and is a much more highly special- 

 ized organ than in the Salamandridce and Pleurodelidce. In specimens 

 of Desmognathus taken in the fall, winter, spring and summer, it was 



