1 68 TUCKERMAISr. [Vol. IV. 



p.ot numerous, but are of the usual type. There is a single, 

 deeply set, circumvallate papilla situated in the median line, 

 2.5 mm. from the base of the organ. As in Fiber zibethicus, the 

 trench is anteriorly incomplete, but perfectly so posteriorly and 

 laterally. 



Gustatory Structures. 



The Circumvallate Papilla. — The general surface adjacent to 

 this gustatory area is more or less marked by papillary eleva- 

 tion of the mucous membrane. The papilla is quite simple in 

 structure, and measures 0.25 mm. in diameter and about the 

 same in height. It is flattened on top, and nearly encircled by 

 a wide trench. Mucous glands do not seem to be as abundant 

 as usual in this region of the tongue. Their ducts, however, 

 are very large, and pass through the mucous membrane to open 

 on the free lingual surface. Serous glands, on the contrary, are 

 quite plentiful, and even extend into the papilla itself. Their 

 ducts discharge into the trench at its deeper part. The bulbs 

 fill a portion of the lower part of the lateral area of the papilla, 

 but do not always extend to its base. The corresponding region 

 of the outer wall also contains bulbs. They are far from 

 numerous in this gustatory area, there being but three tiers in 

 the papilla and but two on the outer wall of the trench. They 

 traverse the epithelium obliquely, their bases being bent more 

 or less downwards. They have a short neck, and measure 

 0.048 mm. in length and 0.024 mm. in breadth. 



The Lateral Gustatory Organs. — These organs were so incon- 

 spicuous as to be overlooked in the superficial examination of 

 the tongue. They are very simple and primitive in character, 

 and resemble in some degree a circumvallate papilla. They con- 

 sist merely of a single fold of the mucosa, 0.16 mm. in diam- 

 eter, on either side of which is a wide furrow, 0.18 mm. in depth. 

 In the underlying stroma serous glands are relatively plentiful. 

 There are two or three tiers of bulbs on the walls of the folds, 

 and one or two tiers on the opposed walls of the furrows. 

 They measure 0.042 mm. in length and 0.024 mm. in breadth. 



The fungiform papillae are small, measuring only 0.14 mm. in 

 height and 0.05 mm. in diameter. They usually contain bulbs. 

 The latter lie partly in the epithelium and partly in the mucosa, 

 their apices, apparently, not piercing the outer layers of the 



