6 
as in other cases for assuming that the granules and the 
connecting threads are chemically different. 
The nucleolus calls for special attention. Superfcial 
observation would lead to the assumption that it is an 
almost spherical body, about which nothing special can 
be said. More exact observation, even before the action 
of chromic acid, shows that sometimes two small points 
on the nucleolus can be distinguished (Fig. 1). During 
the action of chromic acid (Fig. 2) they become much 
more visible and are seen to be small bodies which some- 
times resemble rodlets. They are situated on the periphery 
of the nucleolus, usually opposite one another and seem 
often half immersed in the principal mass. According as 
a more concentrated or weaker solution of chromic acid 
is used, the nuclear network or the main mass of the 
nucleolus dissolves first (Fig. 2 and 3). In either case, 
however, the two small bodies show a longer resistance. 
During the process of dissolution it can be seen that the 
two small bodies are united by a thread which generally 
runs across the nucleolus and is straight or slightly bent, 
but which may also be much curved. When the nuclear 
network has dissolved and the chromic acid has also had 
a strong solvent action on the main mass of the nucleolus, 
the thread which unites the two small bodies can be 
distinguished, and when the preparations are further stained 
.with “Brilliantblau extra grünlich”, all is still more clearly 
and more easily visible. The two corpuscles are stained 
dark-blue, the thread, which unites them, is paler and 
the rest of the nucleolus is light blue. After more pro- 
longed action of the chromic acid the thread with the 
two corpuscles alone is still present (Fig. 4); after a still 
longer action only the latter are found and finally these 
also are seen to have dissolved. This can all be seen 
with special clearness after staining with “Brilliantblau 
extra grünlich.” 
