go TUCKERMAN. [Vol. VII. 



GUSTATORY STRUCTURES. 



The Circiunvallate Papillce. — The papillae are i.io mm. in 

 diameter, and measure the same in height. Their summits are 

 flattened, but overtop the adjacent lingual surface. Serous 

 glands are not very plentiful. Their ducts open at or near 

 the bottom of the trenches. The bulbs are numerous, but 

 the number of tiers varies considerably in different papillae. 

 The mean range is from twelve to fifteen, the number of bulbs 

 in a tier being about ninety. There is a very uniform decrease 

 in the size of the bulbs from above downwards ; that is, from the 

 uppermost to the lowermost tier. The mean length is 0.050 

 mm., and the mean breadth .030 mm. 



TJie Lateral Gustatory Organs. — The organs are 9 mm. in 

 length. Of the twelve to fourteen folds, eight or nine are bulb- 

 bearing. The furrows are fairly uniform in breadth, but vary in 

 depth, the average depth being about 0.70 mm. Serous glands 

 are more abundant here than in the circumvallate gustatory 

 region. The sides of the folds are well filled with bulbs, there 

 being sometimes as many as twenty tiers. They also occur, 

 though sparingly, on the free upper surface. They are smaller 

 in this gustatory area, only measuring 0.045 i^i"^- i^^ length and 

 0.024 mm. in breadth. The fungiform papillae are normal in 

 structure and are well supplied with bulbs, especially those of 

 the tip. Bulbs also occur to some extent in the epiglottis. 



The Tongue of Cebiis hypolencus. 



General Description. — The organ measures 40 mm. in 

 length, 20 mm. in breadth, and is free from the fraenum for 

 15 mm. There is a short mesial raphe on the anterior dorsal 

 surface, and a deep median groove on the under surface of the 

 free part, which becomes superficial at the tip. Fungiform 

 papillae of good size are sparingly but quite evenly distributed 

 over the dorsum, sides, and tip, including its inferior portion. 

 The circumvallate papillae are three in number. They are 

 arranged in the form of an equilateral triangle, with the apex 

 turned towards the epiglottis. The lateral gustatory organs are 

 clearly defined. The basal portion of the dorsum presents a 

 rugous appearance. The limiting fringe of papillae is wanting. 



