54 if So ROSS 
Some workers think that the apparatus is an artefact (cf. 
Cowdry, *12). It seems to be definite that at least some of the 
clear spaces appearing in fixed cells from some sources are not 
artefacts. By the Kopsch osmic-acid method some of the 
clear canals in a given section may be stained, while others 
remain unblackened (Cowdry, ’12). 
In examinations of the living nerve cell of the crayfish I could 
not distinguish any apparent reticulations of clear spaces in 
the cytoplasm; the entire mass was seemingly a mixture of 
granules in a more fluid matrix. Nor did intravitam staining 
with thionin, methylene blue, or with pyronin show their pres- 
ence. The fact that failure attended the search for the appara- 
tus in the living cell does not give much evidence against its 
presence. The cell is of such a thickness and it contains so 
many granules of various sizes that it would be difficult to 
demonstrate spaces devoid of granules unless the spaces were 
relatively large. Clear spaces or canals appear in the prepara- 
tions by the Bensley method, as shown in figures | to 6, 8 to 12, 
15, 16, and in preparations fixed with osmic acid, Heidenhain’s 
corrosive sublimate, etc., but not quite so clearly in the Carnoy 
preparations. These unstained spaces are connected with 
somewhat wider elongated spaces radiating from the path of 
the intracellular axone. Numbers of attempts were made to 
demonstrate the apparatus by the Kopsch osmic method, by 
Veratti’s method, and by Cajal’s modified uranium nitrate 
method, these invariably resulting in failure. 
If Nissl bodies do not exist as concrete masses of cytoplasmic 
material in the living cell, then it is very evident that an aggluti- 
nation is effected by the reagents. As a mechanical result of 
such action granules might be withdrawn from some portions 
of the cytoplasm, giving those portions a clear appearance. 
The shape of the spaces would be determined by mechanical 
forces. Mathematical regularity would not result, but rather 
irregularity due to a lack of perfect homogeneity of the cyto- 
plasm. The general appearance of the clear spaces is that of an 
irregular reticulation. Some of the Nissl bodies tend toward a 
polygonal outline, while others are somewhat elongated. ‘The 
