MENDELIAN RATIO AND CHROMOSOMES 491 
should not be taken as established. In early bouquet stages 
the vesicles are colorless and always occur on the distal part of 
their respective loops—that is, at the point farthest from the 
center of radiation of the chromatin threads. Figure 12, k, shows 
the double vesicle and its associated loop occupying a position in 
relation to the accessory, x, which is characteristic for them at 
this stage. ‘The single vesicles behave in a similar manner; that 
is, they are colorless, except for a dense peripheral granule through 
which passes the spireme thread. Very soon all of the vesicles 
become densely stained (with Flemming’s tricolor, iron hematox- 
ylin or Auerbach’s stains) but are still certainly recognizable on ac- 
count of the granule which can yet often be made out. The halves 
of the double vesicle come to lie opposite each other, separated only 
bya dense granule common to both, through which the chromatin 
thread passes (fig. 14, 4). This thread is thinner than any of the 
others and even a fragment of it separated from the vesicles can be 
identified. What the later history of this chromosome is has not 
yet been worked out. One of the single vesicles is associated with 
the unequal tetrad, as later evidence shows. Near the end of the 
growth period they begin very gradually to lose their staining 
power (fig. 15) until finally their outline becomes so faint that 
they can no longer be distinguished. 
Figure 16 represents the latest stage of the growth period in 
which they are easily apparent in Arphia, though in some forms 
they persist till a much later period. Figure 23, k, shows one in 
Brachystola, associated with the unequal tetrad and persisting 
until a late prophase. Figure 29, k, shows the same vesicle still 
recognizable at the first spermatocyte metaphase. Since the 
plates were finished, favorable preparations have shown them 
in the second spermatocyte anaphases and in the spermatids. 
The term ‘plasmasome’ is self-evidently not applicable to these 
bodies, since their content is chromatin and they are distinctly 
concerned in the formation of the chromosomes. Wuiniwarter 
indicates (12, fig. 25) a similar condition in human spermatogen- 
esis. His drawing shows the peripheral granule and its connec- 
tion with the spireme beautifully, although he does not mention 
either fact and calls the body a nucleolus. © 
JOURNAL OF MORPHOLOGY, VOL. 24, No. 4 
