No. 2.] ON THE GUSTATORY ORGANS. 189 



Gustatory Structures. J^, 



The Circumvallate PapillcE. — The papillae are of nearly equal 

 size. Their summits are more or less flattened, and their sides 

 symmetrical and nearly vertical. The trenches are narrow and 

 deep. Serous glands are abundant, and their ducts open at or 

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

 and are disposed in a varying number of tiers. In some sec- 

 tions there appear to be not less than twenty tiers, but the mean 

 is probably ten. The number of bulbs in a well-filled tier is about 

 a hundred. They measure 0.058 mm. in length and 0.032 mm. 

 in breadth. 



The Lateral Gustatory Organs. — The lateral taste organs are 

 6 mm. in length, and consist of seven or eight bulb-bearing 

 folds. The furrows are quite uniform in breadth, and average 

 0.70 mm. in depth. Serous glands and ducts are quite plenti- 

 ful. The bulbs are disposed at the sides of the folds in nine or 

 ten tiers, and measure 0.057 mm. in length and 0.031 mm. in 

 breadth. 



The fungiform papillae contain many bulbs, those about the 

 tip being particularly well supplied. In a section of a papilla 

 of this region I have seen as many as twelve. No true bulbs 

 were detected in the epiglottis. 



The Tongue of Macacus rhesus. 



General Description. — The organ is 41 mm. in length, 15 mm. 

 in breadth, and is free from the fraenum for 13 mm. The tip 

 is rounded, and covered with closely set fungiform papillae. 

 Papillae of this type are also thickly distributed over the dor- 

 sum, and upon the sides and under surface to the lateral line of 

 union of the papillate with the non-papillate surface. The cir- 

 cumvallate papillae, three in number, are arranged in an isosceles 

 triangle, the apex of the triangle being directed backwards. 

 The posterior papilla is 1 1 mm. from the base of the organ. 

 The papillae viewed from above present a smooth, slightly oval 

 surface. The lateral gustatory organs are placed more obliquely 

 than in Macacus cynomolgus, their posterior end being nearly on 

 a level with the upper surface of the tongue. 



