THE MEIOTIC PHENOMENA IN BLAPS 101 
It is quite possible that the complex under discussion is present 
only in some individuals and that the primitive condition would 
not show such association, the X-chromosome being free as in 
the vast majority of the beetles hitherto studied. With regard 
to this point, it seems necessary to emphasize the fact that all my 
specimens have been collected almost in the same spot and that 
their number is not considerable, as such conditions ought always 
to be taken into account in critical cytological research. I do 
not know, therefore, whether the inspection of individuals from 
other localities would lead to the same conclusions. It is inter- 
esting to note that in Blaps waltli, a closely related but sharply 
distinct species, a similar complex occurs and that the behavior 
of this complex during the growth period and first. maturation 
mitosis is the same, although the number and size relations of 
the chromosomes involved is slightly different. Since I have 
slides from only three individuals of this species and the tech- 
nique is not specially favorable for a detailed study, its descrip- 
tion has not been included here. 
The differences between the X-complex of Blaps and those 
hitherto known, suggest that we are probably dealing with a 
condition of the utmost importance in the history of the germ 
cells, closely related with the evolution of the sex chromatin. 
The behavior of the chromosomes of the complex gives the i1m- 
pression either that a group of euchromosomes is in the course 
of secondary association with the sex chromosome or that a large 
composite X-chromosome is breaking up into several bodies 
which have not yet attained to complete independence. Which 
of the two processes is taking place we cannot say at present. 
This case is comparable to the interesting X Y complex of Noto- 
necta indica, described by Miss Browne (716), in which the X- 
chromosome is composite, appearing at the prophase of the first 
maturation division as a central dense mass and two lateral 
threads in which an unequal number of knobs occur. Such a con- 
dition is regarded by the author as a step in the liberation of 
chromatin from the sex chromosome. <A further step would be 
represented by Blaps in which the chromosomes have already 
freed themselves, but still lack the characteristics of the euchro- 
