88 TUCKERMAN. [Vol. VII. 



of which bear bulbs on their lateral walls. The furrows average 

 in depth about 0.60 mm. Serous glands are scattered about 

 within and beneath the folds. The ducts open for the most part 

 at the bottom of the furrows. The bulbs (of which there may 

 be twelve tiers) are irregularly disposed on the lateral walls, but 

 are in the main confined to their lower two thirds. In size and 

 general appearance they agree closely with those of the circum- 

 vallate papillae. 



Bulbs are plentiful in the fungiform papillae. An unusually 

 large one in this region measured 0.060 mm. in length and 0.030 

 mm, in breadth. 



The Tongue of Canis viesomelas. 



General Dcscripticm. — In general appearance the organ closely 

 resembles that in Cmiis faniiliaris. It measures 100 mm. in 

 length, 32 mm. in breadth, and is free for 35 mm. from the 

 fraenum. The upper surface is marked by a mesial raphe. 

 The raphe, near the tip, is very distinct ; but posteriorly it be- 

 comes gradually superficial, and before reaching the area of the 

 circumvallate papillae disappears altogether. The fungiform 

 papillae are small, but quite uniform in their distribution, and 

 fairly abundant. The extreme posterior region of the tongue 

 bears the usual fleshy papillae. The tip is very slightly bifur- 

 cate, and the under surface somewhat wrinkled transversely. 

 The five circumvallate papillae are in two rows converging 

 posteriorly. The small lateral gustatory structures are well 

 forward, their posterior end being on a line with the anterior 

 circumvallate papillae. The marginal fringe of papillae, usual at 

 this point in many mammals, is wanting. 



GUSTATORY STRUCTURES. . 



The Circumvallate Papillce. — The papillae measure from 1. 10 

 to 1.45 mm. transversely, and are i mm. in height. Their 

 summits are verrucose, and some of the secondary papillae 

 terminate in partly cornified spines. The walls encircling them 

 are narrow and deep, and are more or less fimbriated. It is 

 evident, I think, that in some cases, if not in all, the outer walls 

 have developed directly from the simple papillae of the adjacent 

 area. Serous glands are not abundant. Their ducts open into 



