48 
I'^tharine Foot and E. C. Strobell 
in the behavior of the clironiosomes in the sanie individual. In fact the 
fundamental importance of mitosis itself lias becn cliallenged by those 
students of amitosis who claim that its function in development is as 
vital as that of mitosis. The orthodox adherents of the hypothesis of 
the continuity of the clironiosomes have attempted to cancel the evi- 
dence furnished by amitosis by denying its existence altogether, or when 
this is impossible, by claiming it is found only m cells destined to 
degenerate, and claiming further that amitotic division is never followed 
by niitotic. These views are held by many in spite of the important 
data furnished by careful observers who have made a study of amitosis 
in forms especially favorable for its denionstration. 
The qiiestion of amitosis like sonie other cytological problems has 
given rise to two distinct groups of cytologists and there is an interest- 
ing and significant point of difference between the two. One group is 
so impressed by their belief in the causal significance of mitosis, that 
even when they find amitosis occurring in the sanie life cycle with mitosis 
they feel justified in ignoring amitosis and claiming that mitosis is the 
Sole method of development. The second group on the contrary, does 
not exalt one method at the expense of the other but when both mitosis 
and amitosis are found in the sanie life cycle, does not overlook nor ignore 
mitosis but Claims equal consideration for both methods, beheving each 
has its share in development. It is quite evident that the difference 
in the conclusions of these two groups is due to the degree of funda- 
mental importance each group attaches to morphological expressions 
in the cell. This point of difference has beeil in evidence in every 
controversy over every organ of the cell, and has driven cytologists to 
resort to strained explanations in Order to account for such structural 
variations as seeni to embarrass theoretical assumptions. 
It has beeil frequently demoiistrated that although a definite number 
of chromosomes may be characteristic of a species, occasionally a variety 
is found in which the number is above or below the typical, and this irre- 
gularity has been explained hypothetically by assuming a fiising or a 
separating of two or niore clironiosomes as the case may demand. By 
such a procedure any Variation in the number of clironiosomes could 
be readily accounted for, and the chromosonie theories remain unhampered, 
to those who are satisfied with such a solution of the difficulty. To those 
of US, however, who do not believe in the causal nature of the chromo- 
somes, any forced explanation of facts that are inconsistent with the 
chromosonie theories is unnecessary. We believe these facts are in har- 
mony with all other organic variations, that owe their origin to forces 
