LIFE HISTORY OF DESMOGXATHUS FUSCA. 257 



female, however, the whole responsibility for the entrance of 

 one of these into her cloaca (Wright and Allen, '09;; and the 

 still more certain method of the various Tritons, in which the 

 male uses special devices, such as clasping, to ensure the entrance 

 into the cloaca of one of the small number of spermatophores, 

 thus making certain the fertilization of a far larger proportion 

 of the reduced number of eggs. Smith ('07) points out that in 

 the increasing economy in the amount of seminal fluid shown by 

 such mating habits as those of the Amblystoma and Triton we 

 see, as an incidental result, a preparation for possible terrestrial 

 life. 



In Desmognathus fusca we see a form which has availed itself 

 of this, as well as of other possibilities of adaptation to terrestrial 

 existence; for, although the larvae retain the typical aquatic 

 nature of amphibians, the habit of a periodical return to the 

 water for the mating and egg laying which an aquatic larval 

 life usually involves has been abandoned, and both of these 

 functions are performed by the adults without the inconvenience 

 of leaving their terrestrial abode. My information concerning 

 the actual act of mating is drawn from a single observation. 

 Since, however, both Kingsbury ('02) and Hilton ('09) state that 

 nothing definite seems to have been published upon this point, 

 I feel warranted in giving a full report of this single observation. 



On the evening of May 13, 1908, I isolated in a small terrarium 

 a large male, and a female through the abdominal wall of which 

 large eggs could be seen. It was discovered the next morning, 

 however, that another smaller male was also present in the ter- 

 rarium, probably having been carried over unobserved in trans- 

 ferring some wet leaves. On the following morning, May 14, 

 the female and this smaller male were found lying upon the 

 earth under some, wet leaves, the ventral surfaces of the bodies in 

 contact. They reacted so quickly, however, to the disturbance 

 of the leaves that beyond this very hasty observation as to their 

 general position I can state nothing definite as to methods of 

 clasping or exact regions of contact. Protruding from the cloaca 

 of the female was a yellowish, semi-fluid mass which was found 

 upon examination to be a spermatophore of very soft consistency. 

 When placed in a drop of water upon a slide, the spermatophore 



