19 ° Wager. — The Life-history and 
newly constructed daughter nuclei in close contact with a lightly stained 
substance (Figs. 31 , 44 ), consisting of a very fine network which almost com- 
pletely fills up the rest of the nuclei. A few delicate strands remain for 
a short time between the daughter nuclei (Figs. 35 , 43 ), but these soon 
disappear and the nuclei are left free in the cytoplasm (Fig. 44 ). 
When the nuclear divisions are completed the segregation of the 
cytoplasm around the separate nuclei to form the zoospores begins. 
Irregular splits appear throughout the whole of the sporangium, which soon 
separate off distinct masses each with its own nucleus (Fig. 45 ). Then the 
oil-drops begin to fuse together to form the large oil-drops shown in 
Fig. 46 . These come into close contact with the nuclei, one being found in 
each spore origin. Then a condensation of fine granular deeply stainable 
substance begins to aggregate around the nucleus, and partly enclosing the 
oil-drop and the cytoplasm immediately around, becomes vacuolar and no 
longer stains deeply (Fig. 46 ). It is just at this stage that the sporangium 
becomes homogeneous again by an apparent fusion of the spore origins. 
Soon after this fusion delicate lines of demarcation again appear, separating 
the spores, and delicate cell-walls make their appearance around each spore, 
which now rounds itself off and then become slightly elongated (Fig. 47 ) 
preparatory to escaping from the sporangium. 
Cytology of other Forms. 
The only other members of the Chytridiaceae in which serious 
attention has been given to the cytology are various species of Synchytrium , 
Olpidiopsis , and Olpidium . In Synchytrium numerous curious and abnormal 
phenomena of nuclear division have been observed. Thus Dangeard (’89, ’90) 
and Rosen (’92) both describe a form of direct nuclear division in the 
primary nucleus of Synchytrium Taraxaci , but they also found true mitosis 
at later stages. On the other hand, F. L. and A. C. Stevens (’03) found 
that in S', decipiens , S.fulgens , and S. papillatum the division of the primary 
nucleus is mitotic, whilst it would appear from the observations of Stevens 
(’07), Griggs (’09, &c.), Kusano (’09), and Bally (’ll) that the later divisions 
are very variable, being sometimes mitotic, sometimes amitotic. Griggs 
mentions (’09) that amitotic spiremes are frequently indistinguishable from 
mitotic spiremes, and that amitosis by constriction and also by gemmation 
may occur in the same cyst. Stevens (’07) describes some remarkable 
nuclear phenomena in the later stages of Synchytrium which appear to be 
without parallel in the cytology of any plant or animal yet known, and the 
significance of which is inexplicable. F. Griggs (’09) describes some peculiar 
changes leading to the separation of portions of the karyosome (nucleolus) 
of the primary nucleus either by migration or dissolution of nuclear 
membrane. Each fragment becomes surrounded by a vacuole and a new 
nucleus is formed which later undergoes mitosis, and its descendants form 
