Amitosis in the Ovary of Protenor belfragei and a Study of the Chromatin Nucleolus. 225 
the spermatozoa resulting from these divisions having no functional 
activity. 
Only to those who have endowed the chromosomes with causa! 
attributes can variations in their behavior cause embarrassement. If we 
find them subject to marked variations it is a characteristic they have 
in common with other structures in the cell — the nucleolus, the centro- 
some, the mitochondria, the polar rings and other structures which have 
been found to be so variable that interest in speculations as to their 
possible causal significance has steadily waned, and those who believe the 
chromosomes are equally variable may justly suspect that the hypotheses 
sirrroimding these structures may be destined to the same fate as the 
speculations so long surrounding other cell organs, notably the centrosome. 
New York, February 1911. 
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