34 JouRNAL OF COMPARATIVE NEUROLOGY. 
more than the ordinary microsomes which stainedaccidentally so 
as to appear similar in color as well as form to the centrosome. 
The present writer has found the centrosome, in most cases, 
just near the nucleus as it was described by BUHLER, HoLm- 
GREN, etc. The eccentric position of the nucleus was noticed 
very often by the author. The centrosome, however, occurs 
not only in such a cell but also the cells with centrally located 
nuclei. From this observation, we can say that the position of 
the nucleus is not of primary importance for the occurrence of 
the centrosome. 
The number of the central corpuscles or centrosomes in 
the strict sense of the word has been given differently by dif- 
ferent investigators. Von LENHossrK has counted numerous 
corpuscles within the centrosphere to which collectively he gave 
the name of centrosome. DeEHLER and Miss Lewis have also 
noticed several corpuscles, although they counted only one or 
two in some cases. BUHLER is the first investigator to give the 
number of the corpuscles forming the true centrosome as two, 
NE Is' observed that the centrosome is composed of only one 
corpuscle in a resting state. When the cells are preparing to 
divide, however, under certain conditions, the centrosome may 
also divide into two. Very often he has found the two cen- 
trosomes in the cells one on each side of the nucleus. The 
present writer noticed that the centrosome consists of two 
minute corpuscles in most cases, but many corpuscles occur oc- 
casionally, and in one instance there was only one. In the 
preceding chapter it was stated that when the centrosome is 
formed of many corpuscles the structure of the centrosphere is 
modified in such a manner that the protoplasmic relations in the 
centrosphere become invisible and it presents a homogeneous 
appearance as shown in the adult nerve cells, the centrosphere 
being filled with microsomes. In this case, the radiation in the 
plasmosphere is either destroyed or it still retains its character- 
istic arrangement as far as these preparations are concerned. 
1 NELIs stated that the centrosome is wholly invisible in the resting state 
of nerve cells, but under centain stimulation it may appear, in which event it 
is composed of one corpuscle. 
