4 TUCKERMAN. [Vot. II. 
the trench. The bulbs vary somewhat in shape, and in point 
of size they are the smallest I have yet observed, the nearest 
approach to them in this respect being those of the circumval- 
late papilla of the mouse. They vary in length from 0.025 to 
0.030 mm., and their breadth is about 0.015 mm. Usually in a 
bulb of this area, the diameter of the peripheral end of the bulb 
exceeds that of the central. The latter is also curved slightly 
downwards. This form of bulb I have not observed before, 
although it is seen in those figured by Loven in the circumval- 
late papilla of the calf. I did not succeed in finding a bulb 
with the peripheral processes of its gustatory cells projecting 
beyond the pore. One bulb (in vertical section) shows a fissure, 
0.015 mm. long and 0.0015 mm. wide, caused by a separation of 
the edges of two adjoining peripheral cells. 
I was unable to isolate the central or gustatory cells of the bulbs 
sufficiently well for study, but the peripheral cells do not differ 
materially from those already described in the taste organs of 
other mammals. They are elongated, slightly flattened, nucle- 
ated cells, with their two extremities tapering gradually to a 
point. 
The number of bulbs in the left lateral circumvallate papilla 
could not be estimated from my sections with any degree of 
accuracy. The most noteworthy thing about them in this 
region is their very unusual arrangement (Fig. 3). They occur 
only on one side of the papilla; but here they form a continu- 
ous chain, seventeen tiers deep, extending from the base of the 
papilla nearly to its summit. Bulbs are likewise present in the 
lower half of the outer wall of the trench. Here I counted 
eight tiers. The bulbs of this region measure 0.024 mm. in 
length and 0.015 mm. in breadth, being thus a little smaller than 
those of the normal circumvallate papilla. 
The Fungiform Papille. — These papille are distributed quite 
regularly over the dorsum and sides of the tongue, from the 
gustatory area nearly to the tip. Interspersed among those of 
the posterior part of the dorsum are a few which appear to 
be undergoing transition to the circumvallate type of papilla 
(Fig. 6). 
In several instances taste-bulbs were present in the epithe- 
lium at the upper part of these papillae. They are usually 
placed vertically, directly in the long axis of the papilla. By 
