BS, 
gee 
: 
1 . 
. 
1898-99. | ON THE CYTOLOGY OF NON-NUCLEATED ORGANISMS 499 
deepen until only a fine strand connects the two terminal spheres, and 
when the bud further develops there may be a complete separation of 
the two parts, one remaining in the mother cell, the other forming the 
corpuscle of the daughter cell. Sometimes, however, the whole corpuscle 
is forced through the neck into the bud. This is to be found not rarely 
in the sap cultures of S. Ludwig# and rarely in S. cereviste. Bus- 
calioni believes that this happens sometimes in S. guttulatus, and Bouin 
found that it does occur in Mycoderma cerevisie. The latter author 
would thus explain the absence of a nucleus from some cells. _ It is in 
this way, I believe, that the complete absence of a corpuscle in the mother 
cell and the presence of a large one in the daughter cell may be ex- 
plained. I have also found the bud ina few cells of S. Ludwigzt grown 
in sap to contain two small corpuscles, while the mother cell gave not 
the slightest evidence of the presence of a corpuscle. In these cases one 
of the daughter corpuscles, after their formation by constriction of the 
parent structure in the manner described, which should, as is usually the 
case, remain in the mother cell, is carried with the cytoplasm into the 
bud. 
In S. Ludwzigit buds may develop and separate without the con- 
striction and division of the corpuscle of the mother cell. This is 
specially the case when the corpuscle is in a part of the cell remote from 
the commencing bud. Wager states that in this case the nuclear body 
(the corpuscle) makes its way to the opening of the mother cell into the 
bud and then begins to divide. This may happen, but I have found in 
a number of instances the bud full grown, while the corpuscle remained 
undivided in the remote part of the cell. 
There can be but one interpretation of these facts. The elongation 
and constriction of the corpuscle are the results of purely physical forces 
and conditions, such as operate on the cytoplasm in the neighbourhood 
of the bud, and the constriction and resulting division of the corpuscle 
are not absolutcly necessary factors in the development of the bud. The 
formation of two corpuscles out of one in this way can scarcely be 
regarded as a case of direct division or simple karyokinesis, as some 
observers have claimed it to be. 
In S. Ludwigit many of the buds contain cytoplasm richer in “masked” 
or organic iron than that in the parent cell. This would indicate that 
the cytoplasm of the bud is richer in chromatin, and the results of 
staining with hematoxylin seem to support this view. It is not infre- 
quently found that the cytoplasm lining that part of the membrane of 
the bud remote from the neck stains deeply and gives a deep reaction 
