48 
Franz Schräder 
focusing will reveal that all five of the bodies are in dose proxiinity 
to the nudear wall and not scattered liaphazard thi’ough the nudear space. 
Tlie longitudinal split is a feature that is maintained through all the 
succeeding stages up to the first didsion. Further developments consist 
mainly in a condensation and shortening of the live bodies. Their final 
outline is oval or slightly kidney shaped. In view of theü' development 
and appearance no further doubt of their chromosomal nature can be 
entertained (fig. 10). 
The history of the less dense or more lightly staining chromatin is 
similar in all respects to the foregoing except that it shows absolutely no 
tendency to mass or crowd together. As already stated, the long, lightly 
st ainin g thi'eads quickly lose any polarization that they inay temporarily 
Show, and, as they shorten and condense, come to lie in haphazard order 
in the nucleus. Ver}^ early it becomes certain that, like the chromosomes 
evolved from the denser chromatin, they are five in number (fig. 4 and 30). 
However at no time during these prophase stagös is there any possibility 
of confusing the members of the two groups, since the five chromosomes 
first described evolve considerably in advance of the other group. This 
difference is most mai'ked in P. maritimus and P. nipae, and is less eddent 
in P. citri. But even in the latter, it is always sharp and distinct. 
The split already spoken bf in connection with the chromosomes 
evolved from the dense chromatin, is observed even more plainly here. 
In some cases it becomes apparent while the threads are still fairly long 
(iig. 4) and at a somewhat later stage it has become well established 
(fig. 6 and 31). Just as in the predous case it persists up to the first 
division and in fact, chromosomes destained to an extreme degree show 
it even when already arranged in the metaphase plate immediately prior 
to didsion (fig. 11). The chromosomes have at that time reached their 
final Position and are so placed that the split is at right angles to the 
long axis of the spindle and lies in the plane of the plate. 
The ten chromosomes that now form this plate appear identical in 
size, outline, and staining capacity. The only point of difference between 
the two groups of chromosomes is then to be found in their development, 
during which one group goes through the various stages somewhat in 
advance of the other. An unmistakable reminder of this difference is 
however to be found in their arrangement in the plate. The tendency of 
the first formed group to clump or at least stay fairly closely together 
can be traced through to the time when the plate is formed; here they 
are situated in massed formation (fig. 9) ; or in other cases, touching end 
to end in chainlike arrangement (fig. 10, 33 b and 44). In P. citri this 
