138 F- Tuckernian 



The Circumv aliate Papillae. — These papillae appear to be of 

 nearly equal size. Their upper surfaces are smooth and unmarked by 

 elevations, and do not rise above the level of the adjacent lingual 

 surface. Their sides curve downwards and inwards, and the fossa 

 encircling each is deep, narrow, and quite uniform in width. Mucous 

 and serous glands are quite plentiful, the latter penetrating the sub- 

 mucosa a considerable depth. The ducts of the serous glands open at 

 the sides and bollow of the trench. 



The taste-bulbs of this area are disposed at the sides in a girdle 

 of six or seven tiers, the uppermost tier being well up towards the 

 summit of the papilla. Judging from horizontal and vertical sections 

 there appear to be about 380 bulbs for each papilla. The bulbs are 

 fairly uniform in shape, and measure 0,054 mm. in length, their 

 greatest transverse diameter being 0,024 mm. (The shape of the bulbs 

 is shown in figure 2). 



The Papillae Foliatae. — The lateral gustatory organ of S. hud- 

 sonhis consists of nine bulbbearing folds, separated by furrows of a 

 fairly uniform breadth and depth. Near the summit of each fold the 

 mucosa almost invariably divides into two secondary portions, leaving 

 a central depression between. This depression is more or less filled 

 with stratified pavement epithelium. Serous glands are very abundant 

 beneath the folds, and even occur within them. Their ducts open at 

 the sides and bottom of the furrows. The taste-bulbs of the papilla 

 foliata nearly fill the sides of the folds. The tiers, which are usually 

 quite closely set, range in number (relatively) from seven to ten. The 

 number of bulbs in each lateral papilla is about 2260. 



The Fungiform Papulae. — These papillae usually bear a single 

 taste-bulb near their summit. The bulb is placed vertically in the long- 

 axis of the papilla, the basal end resting in a depression of the mu- 

 cosa and the apex penetrating, but to all appearance not perforating, 

 the outer layers of stratified epithelium. The bulbs of this region 

 average 0,045 mm. in length, and are from 0,021 to 0,030 mm. in 

 breadth. They appear to possess from six to eight taste-cells each. 



On the anterior surface of the epiglottis, in about its lower fourth, 

 are a number of bulb-like structures. The basal end and lower two- 



