352 S. SAGUCHI 



the cortical substance. Thus the nucleolus as a whole assumes 

 the confect-shaped appearance. It must especially be noted 

 here that the cortex is question is not to be confounded with the 

 chromatin shell mentioned before, which is closely apposed to 

 the nucleolus; they are different from each other both in form 

 and in staining reactions, and this can be observed with ease in 

 such preparations as those which are made from the same fixed 

 material, but stained in various ways (compare figs. 10 and 11 

 with fig. 13). 



Argentophile granules. The third substance occurs in the 

 form of minute granules in the main-mass, which stain a brown 

 to black color with the CajaPs photographic method, using for- 

 malin prefixation (figs. 31 to 35) . I will designate it 'argentophile 

 granules,' in order to denote its affinity for silver salts. They 

 can never be made manifest, so far as I could ascertain, by such 

 fixatives as sublimate, formalin, trichloracetic acid, alcohol, 

 potassium bichromate and osmic acid, with various stains, but 

 appear only as small clear vacuoles (figs. 1 to 4, 6, 8, 13 to 16, 29, 

 30). These granules are of spherical form and of variable size, 

 although even the largest ones do not exceed one-fifth of the 

 diameter of the nucleolus. They are single or several in number 

 and are situated, in most cases, in the middle of the nucleolus. 

 In case a large number of them are gathered together, it often 

 occurs that the centre of the nucleolus presents an alveolar ap- 

 pearance (fig. 29). The granules are not infrequently seen near, 

 or closely applied, to the periphery of the nucleolus (fig. 8). 

 The granules are not entirely homogeneous, but seem to con- 

 sist of a deeply staining cortical layer and a more slightly stain- 

 ing internal part, as seen in a Cajal's preparation (figs. 31 to 35). 



I have also noticed that the same granules are present outside 

 the nucleolus or are scattered in the nucleus; they vary in num- 

 ber, and are either situated near the nucleolus or are apart from 

 it to a greater or less extent, or even are applied to the inner 

 surface of the nuclear membrane. It is conceivable that the ar- 

 gentophile granules are passing out of the nucleolus and proceed- 

 ing towards the nuclear membrane; from the existence of a few 

 granules in the cytoplasm near the nucleus, as seen in some cases, 

 it would seem that they pass through the nuclear membrane. 



