190 TUCKERMAN. [Vol. IV. 



Gustatory Structures. 



TJie Circitmvallatc PapillcB. — The summits of the papillce are 

 smooth, but more convex than in Macacus cynomolgus. The 

 trenches are narrow and of uniform breadth. Serous glands 

 are not very abundant. The ducts open into the trenches at 

 their deeper part. The taste bulbs are disposed at the sides of 

 the papillse in ten to twelve tiers. A few bulbs are also scat- 

 tered over their upper surface. They are not very closely 

 packed, there being only about fifty bulbs in a tier. They vary 

 greatly in size and shape, but the mean length is 0.068' mm. and 

 the mean breadth 0.036 mm. 



The Lateral Gustatory Organs. — These organs consist of a few 

 folds of the mucous membrane. The intervening furrows are 

 narrow, and 0.60 mm. in depth. Serous glands are not abun- 

 dant. The bulbs, of which there are ten or more tiers, measure 

 0.066 mm. in length and 0.036 mm. in breadth. 



The fungiform papillae are of normal structure, and are richly 

 supplied with bulbs. One deeply placed bulb, lying directly in 

 the long axis of a papilla, measured 0.062 mm. in length and 

 0.045 J^"^- i^ breadth, the canal leading from it to the exterior 

 having a length of 0.016 mm. and diameter of 0.003 mm. 

 Bulbs were also present on the anterior surface of the epiglottis. 



Concluding Remarks. 



Far-reaching generalizations, based upon the study of the 

 gustatory organs of the widely separated forms (some of them 

 scarcely typical of their kind) which have been considered in 

 this paper, would be of very doubtful value. It is therefore my 

 intention to say but little at this time, reserving further remarks 

 for a future occasion. 



In the Marsupialia the circumvallate papillae are three in 

 number. They are arranged in the form of an equilateral or 

 isosceles triangle, the apex of which is directed backwards.^ In 

 some genera, as Halniaturns, Macropus, Petrogale, and Dasyu- 

 rus, these papillae might very justly be called gustatory ridges, 

 from their general shape, extreme protection, and concealed 

 position. In these respects, as well as in the arrangement of 

 the bulbs, they resemble the ridges of OrtiitJiorJiynchiis ana- 



1 In Dendrolagus, according to Owen ( Comp. Anat. and P/iys. of Veris., vol. iii., 

 1869, p. 191), the apex of the triangle is turned forwards. 



