NERVE CUTTING IN AMIURUS 379 
more cystoplasm, which now extends out in different directions, 
like pseudopodia, through the clear area. With an increase in 
the clear area and the addition of a few brown granules, we have 
the initial stage of the wandering pigment cell. This in turn is 
succeeded by further stages of development which occur in normal 
epidermis, but not in normal taste buds. More and more pig- 
ment is acquired and the cells come together and coalesce to form 
a huge mass of brown granules (fig. 12, a). The pigment in this 
mass is not uniformly distributed, but sometimes as many as 
ten denser regions may be seen. When these special accumu- 
lations of pigment are examined with very strong illumination 
they prove to be a condensation of granules about nuclei which 
still take the blue stain of the haematoxylin, though the color 
is more often completely masked by the brown granules. In 
many cases, however, the nuclei lie in areas devoid of granules 
and are stained normally (fig. 12, a). Finally these huge masses 
migrate to the surface (fig. 12, a, b), and at this time the nuclei 
often lose the power to take a stain, appearing merely as brown 
discs. These masses are probably cast off as waste matter, for 
they are found protruding beyond the surface and under certain 
conditions the granular material of which they are composed 
has been seen scattered along the surface of a barbel, as though 
caught in the mucus after having been discharged (figs. 10, 11). 
I believe, therefore, that the small leucocyte and the larger 
pigment cell are different stages in the history of the same phago- 
eytic cell, and that its function is to remove worn-out cells, 
especially sense cells, and its ultimate fate is elimination with 
its load of waste material from the surface of the skin. 
These wandering pigment cells were probably first seen in 
taste buds by Vintschgau (’80), for he found in practically every 
bud that he examined granules of fatty material. The reason 
for his not discovering that they were enclosed in a special cell 
was probably due to his method of preparing his tissue, since 
he used osmic acid alone without any stain. He thought that 
these granules might play a part in degeneration and regeneration, 
though he had no proof of this. Ranvier (’88) interpreted these 
cells in the rabbit as lymphocytes which had migrated in from 
the dermis and ingested fat granules. 
