12 



INEZ L. WHIPPLE. 



orbital glands, into the opinion that in Batrachoseps at least, the 

 glandular mass had orifices upon the surface of the conjunctiva 

 also. I have not myself sectioned Batrachoseps but from the 

 relationships which I have worked out from sections of both 

 DcsmognatJuis and Plethodon I am convinced that the orbital 

 glands are absolutely distinct and separate from the naso-labial 

 in these forms. 



Bruner's ('96, //) observations as to the orifices of the glands 

 were correct so far as they went in that these were located in 

 common with those of the external nasal glands of other sala- 

 manders, on the border of the naris. His observations, however, 

 did not extend to those of the glands which open along the naso- 

 labial groove. 



DEVELOPMENT OF THE NASO-LABIAL GROOVE AND GLANDS. 



The naso-labial apparatus is essentially an adult characteristic. 

 In large Desmognathus larvae (25 mm.) collected in early sum- 

 mer and only a few millimeters shorter than the smallest adults 

 which I have found (33 mm.) the groove has hardly begun to 

 develop and the anlagen of only the largest of the glands are to 

 be found. During the two months which follow, these structures 

 undergo rapid development, so that the little adults which abound 



b 



Fi<;. 8. Horizontal section through the head of a Desmognathus fusca larva, cut 

 slightly obliquely. The left side of the section passes just below, the right slightly 

 above, the external naris, < 42. nep, nasal epithelium; //-, trabecula. Other 

 designations as in previous figures. 



