No. 2.] ON THE GUSTATORY ORGANS. 1 6/ 



their ducts open at the bottom of the trench. The bulbs are 

 more numerous than in Fiber, but are similarly arranged. There 

 are eight tiers of them in the papilla and seven on the outer 

 wall. They form an unbroken chain around the bottom of the 

 trench, which is continued on to both walls to about the same 

 level. Isolated bulbs occur on the free surface of the papilla, 

 and occasionally extend along the outer wall of the trench nearly 

 to its upper angle. The mean length of the bulbs is 0.036 mm. 

 and the mean breadth 0.024 ""^rn- 



The Lateral Gustatory Organs. — The lateral taste organs are 

 simple in construction, and resemble those of Fiber sibethiciis. 

 They consist of four or five unequal folds of the mucosa, sepa- 

 rated by furrows of varying depth. The average depth is about 

 0.20 mm. Serous glands are not abundant. There are three 

 or four tiers of bulbs, forming a chain around the bottom of the 

 furrow. Isolated bulbs also occur near the top of the lateral 

 wall. The bulbs of both the circumvallate and foliate taste 

 areas vary greatly in size and shape. Here they measure 

 0.036 mm. in length and 0.021 mm. in breadth. 



The fungiform papillae are of normal structure, and bear a 

 few bulbs at their upper part. Those of the papillae of the mid- 

 dorsal region are only 0.020 mm. in length and o.oio mm. in 

 breadth. In the papillae near the tip they are larger, and meas- 

 ure 0.039 nini. in length and 0.021 mm. in breadth. A careful 

 search of the epiglottis and other parts of the larynx failed to 

 reveal the presence of bulbs. 



The Tongue of Hesperoniys lencopus. 



This tongue, like the last, was a spirit specimen. 



General Description. — The shape of the organ suggests a 

 division into an anterior and a raised posterior part. The pos- 

 terior division is the longer of the two by one millimetre, the 

 total length of the organ being 13 mm. The anterior division 

 is free from the floor of the mouth for 4.5 mm. The tongue is 

 4 mm. in breadth and about the same in thickness. The upper 

 surface is covered with small conical papillae, the apices of which 

 are directed backwards. Anteriorly it is marked by a deep 

 mesial groove which passes through the tip, and is continued 

 for a short distance on to the under surface. The under surface 

 is smooth, and somewhat hollowed out. Fungiform papillae are 



