94 J. B. JOHNSTON, 
at a short distance from the cells. I have not seen anything that 
I could interpret as T-branching of these fibres. _ 
The PuRKINJE cells offer variations in form and relations similar 
to those which have been noted in the acusticum. In the central 
portion of the valvula are cells corresponding in every way to the 
PURKINJE cells of the body. In the cephalic and dorsal portions 
of the valvula are numerous cells of a peculiar type which are con- 
nected by many transitional forms with the typical PURKINJE cells 
Some of these cells have dendrites which present the characteristic 
appearance of PuRKINJE dendrites, and ‘have also dendrites which 
are devoid of the minute spines and present varicosities like those 
of ordinary dendrites or have larger moniliform thickenings. In the 
dorsal part of the valvula, near the velum medullare anterius, there 
are a number of these cells whose dendrites are all of the varicose 
or moniliform type. The cells shown in Phots. 42—44 are all of 
this extreme form. The cells which have these varicose dendrites 
lie in a part of the valvula which is filled with coarse fibres be- 
longing to tracts from the tectum and other parts of the brain, and 
containing few of the fine fibres characteristic of the molecular 
layer. 
In a single case I have found in the lateral part of the valvula 
a large cell with wide-spreading dendrites, which is shown in Phot. 35. 
It is to be classed with the large cells in the granular layer of the 
body. The neurite was not impregnated. 
There are two varieties of cells of the II type in the valvula, 
distinguished by the character of their neurites. The cells of the 
first variety measure 10—16 by 16—20 y, are numerous in both 
layers of the valvula and present no peculiar characteristics as com- 
pared with II type cells elsewhere (Fig. E). The smaller of these 
cells seem constantly to lie in the molecular layer and to send their 
neurites into the granular layer while the larger ones have no such 
regular arrangement. The cell body is ovoid or stellate, there are 
two or more dendrites, and the neurite is slender and divides into 
several long simple branches which have a wide expansion in the 
valvula. In a few cases I have found these cells sending their neu- 
rites into the lateral lobes. It may be that these neurites break 
up in the lateral lobes, but I have been unable to determine this 
point. The wide expansion of these neurites and the fact that some 
of them enter the lateral lobes suggest that they may be neurites 
of granule cells with T-branching which I have not found other- 
