146 
Fernandus Pavne 
they both inove to the sanie pole in the first division. This possibility 
Mls in line witli Stevex’s Suggestion ('06) that the X-elenient inay have 
arisen by separating froin one of the meinbers of an original YY pair, 
except that in this case the original paii’ was in all probabüity an XY 
pair. The second possibility is that there has never been any Connec- 
tion between the idiochromosonie pair and the odd chromosome and that 
the two have arisen independently of each other. 
Sex Production. 
If we accept the view that this chromosome complex in Gryllotalpa 
is simply a double X-element and a single Y-elenient, the case falls in 
line with what we find in the Reduviidae and Thjanta. On the other 
hand, if we interpret the complex as a pair of idiochromosomes and an 
odd chromosome we have in the sanie form two chromosomes each of 
which has been shown to be correlated with sex production. Does such 
a condition conflict with the theories of sex production based upon the 
sex chromosomes? It seems to me this is not necessarUy so if we assume 
the X-chroniatin to be seggregated in two chromosomes instead of one 
as in those forms with an odd chromosome or in those with a single pair 
of idiochromosomes. 
It certainly offers no objection to the quantitative hypothesis of 
sex production, but Wilsox in a recent paper (11) practically abandons 
this theory, and I think justly so as the evidence in favor of it is fax from 
convincing. It seems to me, as has been suggested by Mexdel, Batesox 
and others, that sex must be inherited in the same manner any other 
character is inherited, and I hardly believe many students of heredity 
would care to take the stand that the heredity of all characters is a question 
of the quantity of chroniatin. So when we solve the riddle of the here- 
dity of sex, we shall have gone a long way in the solution of the whole 
Problem of heredity. 
Arrangement and movement of the chromosomes. 
As [ireviously stated, it has been taken for granted that the arrange- 
ment of the chromosomes on the spindle is a matter of chance. Gryllo- 
talpa gives US the first form, so fax as I know, in which we find two clu’omo- 
somes, appaxently independent of each other, moving to the same pole 
of the spindle. This is certainly no haphazard arrangement and I cannot 
refrain from suggesting, that since we find law and order in the arrange- 
