1208 Wisconsin Academy of Sciences, Arts, and Letters. 
is no possible way of distinguishing between the nuclei of the 
two branches. In fact the nuclei from the two gametes are 
apparently similar in size and content. It seems highly prob¬ 
able, however, that nuclei from each gamete are aggregated 
because nuclei in each group fuse in pairs. This is evidenced 
by the fact that the nuclei show an increase in size and a de¬ 
crease in number prior to any process of nuclear disorganization. 
Prior to fusion, the nucleus is dense and granular and possesses 
a conspicuous nucleolus. After the fusions take place, the 
nuclear plasm appears vacuolate and the nucleolus is much 
larger. As indicated in the figures, within one zygospore (fig. 
11c) there may be found groups of nuclei in which there occur 
from twelve to sixteen small nuclei and other groups in which 
there are five large nuclei and two to four smaller ones. There 
seems little doubt as to the significance of this condition, since 
no marked differences in the size of the nuclei are evident at 
any earlier stage. 
There are certain large, round, red-staining bodies found 
within the zygospore at all stages which must not be confused 
with the nuclei. They are far more conspicuous than the 
nuclei and are larger. They tak^ffie^saf^^iti:" in the same 
way that the nucleolus does and have undoubtedly been in¬ 
terpreted by some workers as nuclei. They a;re usually con¬ 
tained within a clear zone and very often eabh possesses a 
small secondary body (fig. IleZ). Their appearance suggests 
very strongly the crystalloids and globoids of the higher plants. 
These bodies are characteristic of many of the Mucorineae and 
have been described by various workers. The author has been 
able to demonstrate their occurrence at all stages in tHe life 
history of both Sporodinia grandis and Phycomyces nitens. 
They undoubtedly constitute a form of reserve substance, prob¬ 
ably protein in nature. In addition to these, there also occur 
red-staining angular crystals (fig. lie). 
The new wall surrounding the zygospore is established' just 
previous to the nuclear fusions. It is laid down inside of the 
old gametophore wall (fig. 11). It is more or less roughened 
and is probably formed in the same way as in Sporodinia, which 
has been described by Yuillemin (1904). 
Following the nuclear fusions, there occur nuclear disorgan¬ 
izations. The cytoplasm of the zygospore becomes finely vacuo- 
