1912] GRIGGS—RHODOCHYTRIUM I51 
in Synchytrium, these are most abundant in the vicinity of the 
nucleolus (karyosome), frequently touching it. Closer examination 
will often reveal many in the act of budding out from it (figs. 
43, 47). During the growth of the nucleus there is, of course, an 
enormous increase in the amount of chromatin it contains. This 
increase of the chromatin probably takes place both in the nucleo- 
lus during its growth and in the free chromatin of the nuclear 
cavity. But the withdrawal of the chromatin from the nucleolus 
must be more rapid than its formation therein, since the vacuolation 
of the nucleolus increases with age. The linin reticulum, which, 
as has been seen, loses its affinity for stains in the young cysts, 
never reappears in the primary nuclei. The chromatin, as it is 
withdrawn from the karyosome, does not seek the nuclear mem- 
brane, but is distributed through the nuclear cavity. In the early 
stages of growth the chromatin spherules are often connected by 
indefinite strands of linin, which anastomose to some extent 
through the nuclear cavity (figs. 3, 14, 44). But in many of the 
nuclei (fig. 43) such linin connections never appear, and in any 
case they disappear before the nucleus reaches its full size. In 
mature nuclei (fig. 45) the chromatin appears as amorphous, 
almost flocculent, spheroidal masses scattered through the nuclear 
cavity, singly or in loose chains. The amount of chromatin and 
the size of its masses vary considerably in different nuclei. In 
some cases there are relatively few large globules, while in others 
the chromatin, in a comparatively fine state of division, almost 
fills the cavity of the nucleus. The small intensely staining granules, 
which are so conspicuous against the membranes of the primary 
nuclei of Synchytrium, are seldom observed in Rhodochytrium, but 
in some instances (fig. 57) were as prominent as in Synchytrium. 
The peculiarities of the primary nucleus characterize to a large 
extent the nuclei of the binucleate and tetranucleate stages, but 
gradually disappear as the nuclei become smaller, until, from 
about the 32-nucleate stage on, the nuclei resemble those commonly 
found in other organisms. Except in the very latest stages, how- 
ever, both the chromatin granules and the linin connections are 
coarser than in most nuclei. 
