on Saprolegnieae. 343 
changes indicating its ‘ pseudomorphism ’ into a parasite-spore. 
Besides these, other parasitic swarmers are found which 
become somewhat amoeboid (‘ schwach ameboid werden ’) and 
bore into the vegetative hyphae ; these are larger than the 
former and possess a pale nucleus . They may enter the 
antheridium and pass down the fertilizing tubes into the 
oogonium, and according to Zopf form zoocysts therein, but 
do not prey on the spores. The smaller amoebae, and to 
some extent the larger, he regards as identical with Pring- 
sheim’s spermamoebae. Now while it is obvious that in many 
respects Zopf’s larger amoebae correspond with my species, he 
refers them in his monograph to the genus Vampyrellidium \ 
and species V. vorax Z., which differs in that the zoospores 
do not pass through a mastigopod stage, and, from his figures 
(Fig. 37), in the characters of the zoocyst which has granular 
peripheral plasma, with a central nucleus surrounded by 
hyaloplasma ; and finally in preying on green Algae as well 
as on Saprolegnieae. This species I have not found ; but I 
cannot help thinking that he must have overlooked the differ- 
ences between it and mine, which is unmistakably that figured 
by Pringsheim and recognised by Lindstedt, and which I have 
never found absent from old cultures. While in his paper he 
says they do not attack the oospores, in his monograph he 
says they wander c in die vegetativen Schlauche sowohl als in 
die Oogonien und Antheridien hinein, nahren sich vom Inhalt 
dieser Organe, und bilden in ihnen schliesslich auch Dauer- 
sporen.’ I have repeatedly seen my organisms destroy the 
young oospores before encysting in the oogonium, so that the 
same oogonium may contain zoocysts of the parasite and 
oospores of the Fungus ; and they sometimes even attack the 
ripe oospores despite the protection of the thick cell-wall. 
I think it very possible that Zopf may have confused two 
species here. His phrase ‘ Schwarmer, welche schwach amo- 
boid werden 5 would seem to imply that they were previously 
flagellate, and hence could not belong to Vampyrellidium. 
1 Die Pilzthiere oder Schleimpilze, ioi. 
