No. 1.] EPITHELIUM OF MUSTELUS CANIS. 67 
tion of the nerve fibers at the base of the hair cells. He found 
the nerves branching at any point and does not think there is 
a “nervum plexiforme.” 
2. Recent work on nerve endings in frog's tongue.—The close 
similarity of the nerve endings found in the terminal discs of 
the frog’s tongue and those in the auditory epithelium make it 
important that a brief statement should be made of the results 
obtained by recent investigation. 
Fajersztajn (89) gives the following account of the distribu- 
tion of the nerves in the epithelium of the terminal disc of the 
frog’s tongue. After forming the subepithelial plexus, the fine 
nerve fibrillae become varicose and pass between the proximal 
cells of the disc, and in some cases extend vertically to the 
surface, where they end in distinct enlargements (boutonné) 
among the distal extremities of the cylindrical cells. 
The terminal enlargements do not generally differ in any 
way from the ordinary varicosities, but in a few cases are 
larger and present certain differences in structure. 
Ehrlich’s method, he says, renders it impossible to determine 
whether the terminal enlargements are found between the cells 
or rest upon the cell membrane; probably they adhere to the 
surface of the cells. 
The fibrillae which pass into the epithelium give rise to rami- 
fications, and the lateral branches terminate in enlargements. 
The terminal enlargement, intensely colored, is surrounded 
by a transparent vesicle. 
The arrangement of the nerves and their mode of branching, 
as found by Niemack (92) in the terminal discs of the frog’s 
tongue, are essentially the same as he found in the crista 
acustica of the same animal. 
In the subepithelial plexus he found many anastomoses; the 
nerve endings were rare in this region. From this network 
fibrillae passed between the cells to end free at the surface in 
knob-like thickenings. A second kind of nerve ending is found 
associated with certain cells. The end of the nerve is enlarged 
and attached to the proximal end of the cell. 
This attachment is destroyed by teasing the preparation, and 
the cell and nerve are separated. 
