No. I.] OBSERVATIONS ON THE GUSTATORY ORGANS. 93 



the other hand, lie more obliquely, present a less regular con- 

 tour, and are somewhat depressed at the centre. Within the 

 space bounded by the four gustatory papillae are three transi- 

 tional forms, which are obviously modifications of the fungiform 

 type. The dorsum posterior to the gustatory region is wrinkled, 

 but devoid of papillae. The lateral gustatory organs are placed 

 obliquely at the sides of the base, very much as in Lepus. The 

 fringe of filiform papillae is wanting. 



The tongue of Ateles possesses a fraenal process very similar 

 to that already described in Cebus. It measures 6.5 mm. in 

 length, and its greatest width is 4.5 mm. The tip is forked, 

 and the edge more or less fimbriated. 



GUSTATORY STRUCTURES. 



The Circiinivallatc PapillcB. — The papillae vary greatly in 

 size and are occasionally lobate. The summits of the anterior 

 pair do not project from the openings of the trenches, and 

 hence they are more protected than the posterior pair. They 

 measure from 0.70 mm. to 2.30 mm. transversely, and are 

 0.75 mm. in height. Serous glands are fairly abundant and 

 occur within the papillae. The ducts open at the usual places. 

 The bulbs are disposed on the lateral area of the papillae in ten 

 tiers. A few scattered bulbs are also present on the free upper 

 surface and, more rarely, may be found embedded in the epithe- 

 lium of the outer wall of the trench. The bulbs are closely set, 

 and, in crowded tiers, number one hundred and forty. The 

 mean is probably one hundred. They measure 0.051 mm. in 

 length and 0.027 mm. in breadth. 



The Lateral Gustatory Organs. — ■ The organs are flattened or 

 slightly rounded on top, and measure 8 mm. in length and 

 4.5 mm. in breadth. The folds are fairly uniform in size, and 

 twelve of the fifteen bear bulbs. The furrows are narrow, and 

 measure 0.65 mm. in depth. Serous glands are fairly plentiful 

 and occur within the folds. The ducts open into the furrows at 

 their deeper part. The bulbs, of which there are some ten tiers, 

 measure 0.051 mm. in length and 0.027 mm. in breadth. 



The fungiform papillae are of normal structure. Those about 

 the tip, more especially its under part, are richly supplied with 

 bulbs. Here they are numerous but small, and in some papillae 



