294 JOURNAL OF COMPARATIVE NEUROLOGY. 
nucleus as wellas the nucleolus, since methylen-blue, especially 
after Niss_’s technique, colors all the structures a deep blue. 
Not only the technique employed, but the age of the ani- 
mal modifies these staining reactions. The present writer ob- 
tained the following {results from the resting nucleus of the 
nerve cells of the adult white rat which had been preserved 
with Carnoy’s fluid followed by toluidin blue and erythrosin: 
namely, the chromatic granules, as well as nucleolus, were 
stained bluish-color of equal intensity. Using the germinal cells 
of the white rat in an embryonic stage, the tissue having been 
preserved and stained in the same manner as that of the adult 
animal, it was found that the chromosomes only stain a deep 
blue, while the nucleolus appeared a deep red. 
The present writer agrees with the view of Levi in so far 
as he describes the nucleolus as a group of the acidophile par- 
ticles which are surrounded by the linin. But in addition to the 
linin, Levi considers that the basophile substance also surrounds 
the acidophile particles. To the last statements the present 
writer cannot agree, because in this case the basophile substance 
is merely an accumulation, surrounding the nucleolus, and fur- 
ther this hollow sphere formed by the basophile substance is 
clearly separated from the linin which directly surrounds the aci- 
dophile particles. From this, we cannot regard the basophile 
substance as one of the structural parts of the nucleolus, but 
simply as lying outside of it. 
Toucue and Dipe' obtained a result similar to that of 
Levi, stating that the nucleolus is composed of basophile and 
acidophile particles. The present writer, however, concludes 
from their figures that the nucleolus can hardly be regarded as 
composed of the two substances just mentioned, because, as 
their figures show, the basophile particles are separate from the 
acidophile substance. Figs. 1 and 3 of the same paper show 
separation of the basophile particles from that of the acido- 
phile. The rest of the drawings also show evidently a simple 
attachment of the basophile particles to the acidophile. 
1 ToucHE et DIDE: Note sur la structure du noyau et de division amito- 
tique des cellules nerveuse du Cobaye adulte. ev, Neurol., N. 2, 1901. 
