380 J. M. D. OLMSTED 
The cells designated as included cells are by no means confined 
to the taste buds; they are, in fact, much more numerous in 
certain other parts of the epidermis. The small lymphocytes 
are found in varying numbers between the cells of the germinative 
layer and their immediate neighbors, while the wandering pig- 
ment cells are found most abundantly in the more peripheral 
areas—another hint that the latter cell is the derivative of the 
former. 
RESULTS OF NERVE CUTTING 
The first changes observable in any of the preparations occurred 
on the seventh day, when longitudinal sections of barbels fixed 
in Heidenhain’s osmic-sublimate-acetic mixture showed evi- 
dences of beginning degeneration in the nerve (fig. 5). Up to 
this time it had shown the structure typical of medullated nerve 
(fig. 4). The normal condition is well brought out in teased 
osmic-acid preparations, where the myelin sheaths stain heavily 
and the nodes of Ranvier can be seen at intervals. Now, instead 
of the almost unbroken parallel lines of continuous fibers and 
sheaths, there was somewhat of a granular appearance due to 
breaking of the fibers and sheaths into segments. At the same 
time, but becoming more prominent on the eight day, there 
occurred an increase in the number of small leucocytes in the 
epidermis, particularly in the region next to the basement mem- 
brane (fig. 12). By the ninth day the myelin sheaths had 
further broken up into more or less globular fragments (fig. 6) 
and the number of nuclei had increasd—a typical nerve-degener- 
ation phenomenon. Up through the tenth day the taste buds 
always remained intact, but many eleven-day preparations 
showed complete absence of them. In the latter there was a 
decided increase in the number and size of the wandering pig- 
ment cells in the epidermis. If, however, the taste buds were 
still intact, a greater number of small leucocytes than normal 
was to be found in them. In normal taste buds as many as 
three leucocytes may be seen in a single bud, but this is rare, 
and there may be in the field only one bud with included leuco- 
cytes to four or five entirely free from them. In one thirteen- 
