THE CHROMOSOMES 173 
with a pair of ordinary chromosomes. These pieces 
have been supposed to be the sex chromosomes. 
Their inconstancy and some apparent irregularity in 
their distribution when the polar bodies are formed 
has thrown some doubt on that interpretation. 
Perhaps more significant are the observations of 
Kautsch and Geinitz on the number of chromomeres 
into which the somatic chromosomes of Ascaris are 
resolved. It appears in some individuals (females?) 
there are about 8 more of these than in other in- 
dividuals (males?). This relation might be expressed 
as follows: 
52 chromosomes in male 
(sperm) 
60 chromosomes in female = 22 + 8 (egg) + 22 + 
8 (sperm) 
Kautsch has suggested that the 8 chromosomes are 
attached at the ends of one of the pairs of chromo- 
somes and are set free normally only when the 
chromosomes break apart into their constituent 
chromosomes. In the female two such chromosomes 
would be present, in the male only one member of 
the pair would have the attached part. The results 
would then conform to the ordinary XX—XY 
mechanism. The only objection to such a view is 
that at an early stage the ends of the chromosomes 
that go to the somatic cells appear to slough off. 
If this involved the sex region, the sex determining 
mechanism would be lost in the soma. But there 
is some evidence that the sloughing off does not 
include essential elements of the chromosomes; for, 
22 + 8 (egg) + 22 
