224 PROCEEDINGS: BOSTON SOCIETY NATURAL HISTORY. 
comparable to this origin and fusion of cytoplasmic patches was 
seen by Stevens (’99) in Albugo bliti. In this species the oosphere 
is formed by the fusion of several dense masses of cytoplasm which 
are at first indefinite, granular patches that may or may not become 
finely vacuolate before fusion (l . c., fig. 60-61). It should be clearly 
pointed out, however, that Stevens in no way associates the fusion 
of these masses with the formation of the coenocentrum. The 
latter is formed later from the finely vacuolate ooplasm and is not 
associated with the previous fusion of masses. In one case the 
fusion results in the formation of an oosphere ; in the other, a dif¬ 
ferentiated portion of the oosphere is formed, which as we shall 
point out later, has a special function. It is not easy to determine 
at just what stage in the development of the oogonium the central 
ooplasm is most highly differentiated. It seems well formed in 
figure 14 (plate 12) and it is still well developed in figures 16 
(plate 12) and 18 (plate 13). In figure 14 (plate 12) the peripheral 
cells have not been formed; in the figures 18 and 19 (plate 13) the 
sperm has lately entered the oosphere. 
In the light of what is known of the function and fate of this dif¬ 
ferentiated center, as well as what can be determined of its structure, 
it is safe to conclude that, in all probability, it maintains its maxi¬ 
mum development from the time the female enters until the sperm 
nucleus is introduced. 
From the foregoing facts it is clear that we have in Araiospora a 
highly specialized central region of the oosphere which in both 
origin and structure is distinctly unlike the bodies so far described 
in other T^hycomycetes. Instead of appearing in the center of the 
oogonium as is true, so far as known, of similar bodies in other 
Phycomycetes, it arises as stated, in little cytoplasmic patches, 
which migrate to the interior and finally fuse there. There is no 
central globule and no granular mass, such as have been observed 
and figured in some related forms. There can be no room for 
doubt as to the cytoplasmic character of this body; throughout its 
history from the very first evidence of its origin, as individual 
patches, to the time of the entrance of the two nuclei, one female 
and the other male, it preserves its homogeneous, characteristic, 
definite, fine meshed, cytoplasmic structure. Little that is new can 
be added in regard to the probable function of this body. There 
are evidences, however, that it is kinoplasmic in nature. 
