NERVE CUTTING IN AMIURUS ono 
pit as do the three types of sense organs belonging to the acustico- 
lateralis system (Herrick, ’01). In this respect also they differ 
from mammalian taste buds, which possess ‘Geschmacksgriibechen 
and a distinct pore (Heidenhain, ’14). In Amiurus they are 
pear-shaped (fig..3), never truly spherical or oval as in the dog 
or rabbit. This peculiarity in shape is due to the different shapes 
of the cells composing the two kinds of buds In Amiurus the 
sense cells are very much attenuated above the region containing 
the nucleus. The majority of mammalian sense cells, on the 
contrary, are much more uniformly spindle-shaped with no 
sudden bulge at the level of the nucleus. The basement mem- 
brane below the germinative layer of the epidermis continues 
beneath the bud at a short distance below the visible proximal 
ends of the sense cells, the intervening space being filled with 
fibers which form a loose network (fig. 2, a). In this region are 
occasionally to be seen one or two nuclei with only a small amount 
of cytoplasm around them. This is the kind of cell which Her- 
mann (’84) called ‘basal cell,’ and which von Ebner (’99) and 
Retzius (712) contended were simply the result of oblique cutting. 
Heidenhain (14), however, claims that he does find in addition 
to obliquely cut cells others, indifferent epithelial cells of exactly 
the same nature as those in the epidermis, and these he considers 
may be called the true basal cells. Such cells in Amiurus always 
appear to be obliquely cut sense cells, for if one follows them 
through several sections one will find that they possess the pro- 
longation characteristic of the true sense cells, and furthermore 
_they have an amount of cytoplasm around the nucleus which 
is more nearly the proportion found in sense cells than in the 
ordinary epithelial cell. I have never observed a case of mitosis 
in a normal taste bud, though it is not a rare occurrence in the 
germinative layer of the epidermis. 
In the first accounts of taste buds in the mammalian tongue, 
given simultaneously by Lovén (’68) and Schwalbe (’68), there 
were described two kinds of cells, those composing the peripheral 
layer of the taste bud, long, markedly cone-shaped cells, often 
vacuolated and with poorly staining spherical nuclei, and those 
occupying the central portion of the bud, smaller cells, with 
