264 
Wager .— On the Fertilization 
In Pythium , for example, it was shown that nearly the whole 
of the protoplasm in the antheridium passed over into the 
oosphere through the fertilizing tube. In Phytophthora a very 
minute quantity only was seen to pass over into the oosphere, 
and in the other genera the passage of protoplasm from the 
male to the female organ could not be seen. 
At that time nothing was known of the part taken by the 
nuclei in this process. The presence of nuclei in the cells 
of the Peronosporeae had been announced by Schmitz in 1879 1 , 
but their behaviour in the process of fertilization was first of 
all studied by Fisch in 1885 2 . He investigated the genera 
Pythium and Cystopus, and came to the conclusion that, in 
Pythium , the nuclei of the oogonium fuse together to form 
a single female pro-nucleus, that the antheridium contains 
a single nucleus probably also due to the fusion of several 
nuclei; and that in the process of fertilization the nucleus 
of the antheridium passes over into the oosphere and becomes 
fused with the female nucleus to form the single nucleus of 
the oospore. 
These observations on Pythium have never been confirmed 
or refuted; and in the light of recent investigations it is very 
desirable that this genus should be thoroughly studied. This 
is the more important, as the imperfect observations made by 
Fisch upon fertilization in Cystopus 3 , which, he stated, pre¬ 
sented, so far as could be seen, phenomena of fertilization 
similar to those observed in Pythium , have since been shown 
by more than one observer to be incorrect. His observations 
on the multinucleate character of the oogonium and anther¬ 
idium in Cystopus have however been confirmed by all 
observers except Chmielewsky 4 , who described the oogonium 
and antheridium of C. candidus as uninucleate structures, and 
states that Fisch must have mistaken the knots in the proto¬ 
plasmic network for nuclei. 
1 Untersuchungen iiber die Zellkerne der Thallophyten. Verhandlungen des 
naturhistorischen Vereins der preussischen Rheinlande und Westfalens, Bd. xxxvi, 
P- 345 - 
2 loc. cit. 
loc: cit. 
1 loc. cit. 
