MULLENIX: EIGHTH CRANIAL NERVE. 225 
part of a terminal organ at one view than is possible when the sections 
are thinner. ‘This renders unnecessary the mental reconstructions 
from thin, serial sections, to which Kolmer (:05) was driven in his 
study of the conditions in the ear of the frog. It was on the basis of 
such a combination of a great number of sections that he arrived at 
his belief in the existence of an intracellular nervous network. 
A further advantage possessed by sections not less than 10 mikra 
in thickness is that in such sections it 1s possible to trace axis cylinders 
much farther toward the brain than with thinner sections. Sections 
of a thickness much in excess of 10 mikra, on the other hand, present 
conditions so complex as to render it difficult or impossible to interpret 
them, owing to the great amount of nervous material which is brought 
into view. 
By the application of a solution of the concentration already described 
for the period stated it has been possible to eliminate, to a great degree, 
the element of chance, which plays so large a part in older methods 
of neurological technique, and to get fairly consistent and constant 
results. The nervous elements are colored dark brown or black, 
and the surrounding tissues are usually stained a light yellow, with the 
exception of the nuclei and nucleoli, which, when preserved, are usually 
darker in color. ‘The sense hairs are commonly well preserved, as 
shown in Figures 11, 12, 16 (Plate 3), 17, 22, 26, 27 (Plate 4), 31 (Plate 
5). ‘There is considerable variation in the effects upon the sense cells. 
Like the basal cells and the basement membrane, they are usually 
stained light yellow, in sharp contrast to the darker color given to the 
nervous material. In some preparations, however, in which impregna- 
tion is good, the epithelial cells show signs of having received harsh 
treatment. I believe that this is due to the action of the ammonia 
of the Bielschowsky’s fluid. ‘The structure of the sense cells may be 
seriously altered, owing to the obliteration of cell boundaries, the 
vacuolation of the cytoplasm, and the collapse of the nuclei. Such 
material, while useful for tracing the courses of nerve fibres and making 
out the forms of nerve terminals, is not to be relied upon to any great 
extent in seeking to determine the relations between axis cylinder and 
sense cell. Figure 16 (Plate 3) represents such a preparation. In 
Figure 12 (Plate 3) a preparation is represented in which the nuclei 
are not well preserved and there is considerable vacuolation, but the 
cell boundaries are not obliterated. I have also obtained an abun- 
dance of well impregnated material in which the cell boundaries are 
clearly marked and the protoplasmic structures of the cell body are 
not essentially unlike those shown in preparations made by methods 
