NERVE CUTTING IN AMIURUS 381 
day preparation six out of ten buds taken at random contained 
small leucocytes. One had four, two others three, etc., a total 
of thirteen for the six buds, and the majority of the leucocytes 
showed signs of having begun phagocytosis. In these same 
buds three of the included cells with pigment were counted. 
Two preparations of twelve-day barbels, in which the taste 
buds were still present, showed a special accumulation of small 
leucocytes in the capillaries along the sides of the papillae. 
Many of them, too, had escaped from the capillaries and lay 
in contact with the nerve. In several instances as many as ten 
leucocytes could be counted in the capillaries and no erythrocytes 
at all. This is in strong contrast to the normal condition where 
the number of erythrocytes is vastly greater than that of the 
leucocytes. In a blood smear from a normal fish there were 
in one field one white to two hundred red corpuscles, and in 
another, five white to four hundred red corpuscles. In a cross- 
section of a blood-vessel in a normal barbel two white to seventy 
red corpuscles were counted. A sudden increase in the number 
of leucocytes in man usually signifies that there is some abnormal 
process going on, one in which there is foreign material or broken- 
down cells to be disposed of, such as bacteria and tissue cells 
which have been killed by the toxic products of the bacteria. 
The same is evidently true in Amiurus, for this invasion of leuco- 
cytes is the immediate forerunner of the actual disappearance 
of the taste bud—the climax of the process. 
This most striking stage was found in only a limited number 
of twelve- and thirteen-day preparations (figs. 10, 11). The 
part of a sense cell distal to its nucleus seems to be the first to 
be attacked by the phagocytic leucocytes. Buds were seen in 
which the clear space about a single granule-filled leucocyte was 
fully a third of the total volume of the bud. In others there 
were aS many as six included cells, one specimen showing four 
fully developed pigment cells, and two of the small leucocytes 
like naked nuclei. The greater the number of sense cells eaten 
away, the greater was the number of globules of fatty material 
and granules of brown pigment within the leucocytes. Finally, 
the leucocytes disintegrated and the taste bud consisted merely 
