NERVE CELLS OF THE CRAYFISH ao 
shapes of the bodies and of the spaces are correlated. In the 
earlier part of my work I was of the opinion that these spaces 
are the Golgi internal reticular apparatus, but now I believe 
them to be artefacts. 
Poluszynski’s work (711) on the ganglion cells of Astacus, 
Homarus, and Squilla, chiefly by the Kopsch method, but also 
by the original method of Golgi as a control, shows the struc- 
tures stained by this method very variable in appearance. 
Instead of an ‘apparato reticulare’ present in most cells, he 
finds a series of isolated structures darkened by the procedure. 
He believes this ‘granular’ form of the Golgi-Kopsch apparatus 
to be characteristic of arthropods, certainly of Crustacea. His 
figures of the cells of Astacus show bodies of the same order 
of magnitude as the reticular apparatus of other nerve cells, but 
he is somewhat doubtful whether they are normal structures. 
He considers the most typical form of the apparatus to be 
delicate filaments blackened by the Kopsch method in Homarus 
cells. By this same method I have demonstrated similar fila- 
ments in Cambarus cells, but I am convinced that they are not 
the Golgi apparatus, but are fine ramifications of the tropho- 
spongium which anastomose, thus differing, from the reticular 
apparatus in Astacus as described by Poluszynski. The fila- 
ments are much more delicate than the clear spaces observed in 
the same cells after A. O. B. fixation. It may be said also 
that the Kopsch method is not to be considered specific, since 
under certain conditions the mitochondria also are well stained 
by it. 
The figures given in the papers by Monti represent elongated 
threads of various shapes convoluted and frequently anastomos- 
ing that in no way can be considered homologous with the clear 
spaces appearing between the Nissl bodies in mypreparations. 
The threads are more regular in diameter and do not form such 
a continuous reticulation. Both of the papers tend to corrobo- 
rate my conclusion that the clear spaces between the Nissl 
bodies in my preparations are not the Golgi reticular appara- 
tus, but are mechanical artefacts. There can be no question 
but that the structures observed by Monti in the small nerve 
cells of Astacus and Homarus are the Golgi apparatus. 
