CELL-DIVISION IN THE SEX CELLS OF TAENIA a3 
do in Taenia. In fact, the indication of amitosis in Taenia is 
greater than in Moniezia, for, as has been said before, in Taenia 
nuclei are found lying in contact, even in the first segmentation, 
while in Moniezia this condition is not found until late 
segmentations. 
DISCUSSION 
My observations have not shown that amitosis does not take 
place in Taenia or Moniezia, but they have shown no condition 
which cannot be as readily explained as the result of mitotic, 
as of amitotic division. Since all those who have worked on 
cell-division in the cestodes record the occurrence of mitotic 
division, at least occasionally, those conditions which would 
be difficult to explain, if amitosis were the only method of cell- 
division, need not be discussed again. The absence alone of 
unquestionable cases of amitosis is, of course, no absolute proof 
that it does not take place. Whether a cell divide mitotically 
or amitotically is, in itself, of no significance. From the stand- 
point of the mere increase in the number of cells, it matters not 
what the character of the cell-division is. The question becomes 
of interest beyond the mere fact of its occurrence, when its bear- 
ing upon other biological questions is considered. Among these 
questions are the theories of heredity, the continuity of chromo- 
somes, and the relation of the sex chromosomes to the determina- 
tion of sex. 
The fact that the germ cell is a single cell which gives rise to a new 
individual, however simple or complex that individual may be, 
must be the foundation for a discussion of any theory of heredity.: 
This single cell may be the entire individual as in some protozoa; it 
may be a cell similar to the somatic cells, as in reproduction by 
budding; it may be the unfertilized ovum, as in parthenogenetic 
reproduction; or it may be the fertilized ovum, as in bisexual 
reproduction. This cell, whatever it is, contains in it the sum- 
total of the heritage of the species. The characteristics of the 
species are transmitted to the next generation by the division 
of this one cell. No matter what the character of the cell-divi- 
