268 
Wager.—On the Fertilization 
are multinucleate and agree in their general structure with 
those of the species already described. The protoplasm 
becomes differentiated into an oosphere and periplasm. All 
the nuclei pass into the periplasm and there undergo mitosis. 
The oogonium contains about 250 nuclei, the antheridium 
about 35, which is a larger number than occurs either in 
C. Portulacae or C. candidus . So far the observations are, 
with differences in details, generally in accord with those 
made by previous observers; but he now goes on to point 
out, after describing in detail the process of nuclear division 
in the oogonium, that ‘ those dividing nuclei that lie tangential 
to or wholly outside of the boundary line between the ooplasm 
and periplasm leave their daughter-nuclei in the periplasm. 
Each of the spindles which cross the line (boundary between 
oosphere and periplasm) gives one daughter-nucleus to the 
oosphere and the other to the periplasm, and the line of 
differentiation is sharply defined and unmistakable.’ ‘ As 
a result of the division a large number of nuclei pass into 
the ooplasm, thus producing a multinucleate cell (oosphere) 
containing by actual count an average of forty-five to fifty-five 
nuclei.’ Thus ‘the mature oosphere contains many female 
nuclei, and fertilization is effected by the discharge of many 
male nuclei from the antheridial tube and their subsequent 
fusion with the female nuclei in pairs. An oospore results 
from this multiple sexual act with about one hundred 
fusion nuclei, which remain in the resting condition until 
germination.’ 
These observations are exceedingly interesting, as they 
indicate that the process of fertilization in the Peronosporeae 
is not necessarily the same for all genera or for all species 
even of the same genus. It becomes very important, therefore, 
that the process of fertilization in this group should be studied 
in as many forms as possible. Up to the present time four 
different methods of fertilization in the Peronosporeae have 
been described. One of these, described by Chmielewsky for 
Cystopus candidus, has been shown to be incorrect. The 
others still stand. These three methods are— 
