324 INEZ WHIFFLE WILDER. 



The changes in structure during adult life are otherwise those 

 of the natural growth of the various organs. Thus, although the 

 epidermis retains the condition reached soon after metamorphosis 

 of some two or three layers of cells beneath the moult layer, the 

 acinous glands increase constantly in size and number, and the 

 loose corium in which they are embedded, as well as the dense 

 corium beneath, becomes correspondingly thicker and the whole 

 skin more deeply pigmented and more vascular. So also the 

 other integumental glands, such as the naso-labial and the 

 orbital, become more numerous and their tubules more con- 

 voluted and longer, while the naso-labial groove itself grows 

 deeper and more clearly marked. 



The muscular development keeps pace with the general 

 increase in size. Thus the power and rapidity of motion which 

 may be observed in all stages of this species becomes very 

 pronounced in the large adults. The long muscular tail plays 

 an important role in locomotion, acting as a strong propelling 

 organ as it strikes against the ground first upon one side, then 

 upon the other, thus sending the body forward. This method of 

 locomotion is of course a part of the adaptation to a burrowing 

 habit. 



The following list of the contents of the stomachs of 18 speci- 

 mens of adult Desmognathus of different sizes and collected at 

 different times and from different localities will serve to illustrate 

 the variety of food materials which are made use of. It will be 

 noted that the food is wholly animal and that the list includes 

 aquatic as well as terrestrial forms. 



Specimen No. i. Moulted skin of Desmognathus (presum- 

 ably his own). 



No. 2. A caddice fly, and three dipterous larvae. 



No. 3. A small adult dipterous insect. 



No. 4. Unidentifiable animal fragments. 



No. 5. Insect larva, unidentified. 



No. 6. Spider, probably an Azalena, with egg 

 mass. 



No. 7. Large black ant. 



No. 8. Fragments of beetles, hymenopterous in- 

 sects, and sowbugs. 



