1890 .] 
477 
[Tuckerman. 
slightly larger, less numerous, and less highly refractive ; and, more- 
over, the}' lack the styliform process. They are also placed more 
externally than the cells of Loven, the latter having a tendency to 
group themselves nearer the axis of the bulb. A third form of 
taste-cell, quite similar in structure to the fork-cells of the end- 
discs of batrachians has been described by Ditlevsen and Krause, 
but this form has not been very generally recognized by later ob- 
servers. A third element which enters into the construction of a 
taste-bulb is a fine network, composed of very delicate filaments, 
through the meshes of which the sensory cells pass, and which may 
be derived from the subepitlielial nerve plexus. 
Hermann, a recent writer on the gustatory organs of mammals, 
describes three kinds of supporting cells in the taste-bulb of the 
rabbit. First, the outer or “ pillar cells,” which constitute the true 
supporting element of the bulb ; second, the inner supporting cells, 
which resemble the “ staff- cel Is,” of Schwalbe and heretofore sup- 
posed to be sensory in function ; and, third, “ basal cells” which 
he regards as compensating cells for the bulbs. 
The cells within the bulb which fail to conform structurally to 
either the taste-cell of Loven or the staff-cell of Schwalbe, may pos- 
sibly represent intermediate or degenerate forms of the one or the 
other, as the case may be, and what is observed may be either cells 
in process of growth or the remains of degenerated ones. As far 
as the finer structure of the bulbs is concerned subsequent research 
has really done little more than confirm the results reached by the 
early investigators. Of late years, however, something has been 
accomplished towards a better understanding of the nature and 
distribution of the mammalian taste-organs, and something, too, 
has been learned about their mode of development. 
The gustatory papillae of the back of the tongue are supplied by 
the glosso-pharyngeal nerve. Fine medullated branches of this 
nerve, containing small groups of ganglion cells, are distributed to 
the circumvallate papillae and break up in their interior, ramifying 
in all directions. After dividing and subdividing they form a plexus 
at the upper part and sides of the papilla. Many of these branches 
have lost their medullary sheath, but retain the primitive sheath. 
In the mucosa directly underlying the layer of columnar cells of 
the epithelium, the nerve-fibrils form a fine delicate network. In 
the common hare, in gold preparations, the subepithelial network 
is very beautifully shown, the nerve-fibrils and small ganglia, which 
