Tuckerman.] 
476 
[Feb. 19, 
at the sides in a zone several tiers deep, the uppermost tier usually 
being about opposite the middle of the trench. In the papillae fo- 
liatae they are as a rule restricted to the sides of the folds, which 
they sometimes very nearly fill. In the fungiform papillae the bulbs 
are smaller and more irregular in their distribution. They are em- 
bedded in the epithelium at the upper part of the papillae and, 
not infrequently, communicate with the free surface by a minute 
canal, which leads from their apex to the taste-pore. The bulbs 
vary greatly in size and shape, even in the same individual ; but 
their length always exceeds their greatest transverse diameter. 
(The dimensions of the bulbs of a number of mammals are given in 
the table appended to this paper.) 
The mammalian taste-bulb consists of two distinct kinds of cells, 
the outer or investing cells, which appear to function as support- 
ing and protecting elements, of which there may be several layers, 
and which are modified epithelial cells ; and the inner, sensory, or 
taste-cells, which lie in the interior of the bulb, and which are 
doubtless directly continuous with the terminal branches of the 
gustatory nerves. The outer or cover cells are elongated, slightly 
flattened fusiform structures, with an oval nucleus containing nu- 
cleoli. The outer end of these cells is generally drawn out into a 
point. The inner or basal end, which rests on the mucosa, is usu- 
ally slightly rounded, though it may be notched or even branched. 
Of the taste or sensory cells, of which there are probably from 
twelve to sixteen in a bulb of average size and maturity, several 
forms have been described, but the majority of observers distinguish 
but two forms. The first form comprises the taste-cells of Loven, 
with which the Stiftchenzellen of Schwalbe are identical. These 
are highly refractive elements consisting of an elliptical-shaped nu- 
cleated enlargement, usually situated near the middle of the cell, 
and two poles or processes. The peripheral process is cylindrical 
in form, and frequently terminates in an obliquely truncated apex 
from which projects a very delicate hair-like or styliform process. 
In successful preparations the styliform process may be seen pro- 
truding through the taste-pore. The central process of the taste- 
cell, more slender than the peripheral, and occasionally slightly 
varicose, sometimes divides below the cell-body into two or more 
branches, but more commonly it terminates in a somewhat pointed 
extremity. The second form of taste-cells Schwalbe called Stab - 
zellen, or staff-cells. They differ from those just described in being 
