72 MORRILL. [VoL. XIV. 
in the case with similar Golgi preparations. Geberg found that 
in his best preparations the hair cells were not stained. As was 
independently found by both Feist and Niemack, the blood 
corpuscles in the capillaries may stain in a way which is quite 
confusing, as they contain intensely colored granules which 
look like the larger varicosities of the nerves. 
If the fixing fluid is allowed to act too long, the epithelium is 
either macerated off or is so loosened that it is removed in the 
subsequent treatment. The osmic acid tends to prevent this 
maceration, but if too much is added it blackens the epithelial 
cells sufficiently to impair the clearness of the pictures shown. 
The sugar solution tends to prevent the disintegration of the 
epithelium or the rupture of the cells during freezing by pre- 
venting the formation of ice crystals in the cells. If the sugar 
is not removed from the surface of the ampullae, they are not 
held as firmly by the frozen gum arabic. 
Bethe’s method gave very good results, but for this particular 
tissue was not as satisfactory either in the time required or in 
the results obtained as the method outlined above. 
The papers of Dogiel (90) and Apathy ('92) were freely used 
in working out the method which was adopted. 
III. Jnnervation of Auditory Epithelium in Mustelus. 
This investigation was confined to the study of the ampullae. 
Large numbers of medullated nerves blackened by osmic acid 
were seen ascending to the cristae, but just before reaching its 
proximal surface the medulla disappeared. The nerve fibers 
could in some cases be seen through the lightly stained medul- 
lary sheath, and could be traced through the closely crowded 
capillaries found just inside the auditory epithelium. It was 
very difficult at first to do this, as the blood corpuscles were 
stained (as already observed by Feist, '90, and Niemack, '92) in 
such a way that there appeared to be an irregular mass of vari- 
cose nerve fibers crowded together at this point. The nerve 
fibers could be seen on both sides of it, proximally and distally. 
At last, as has been already stated, with more satisfactory 
preparations there was no difficulty in tracing the deep blue 
