260 Researches into the Nature of the Potato-Funyus. 
and produced the numerous bodies which are described as the 
oogonia, antheridia, and oospores of the potato-fungus. These 
are the second subject in the author's description. If the repre- 
sentations given are conect, these objects do not belong to the 
potato-fungus, and cannot well be oogonia, antheridia, and 
oospores. I confine myself here to fig. 13, p. 69, of the ' Gard. 
Chron. ;' for the fig. 9, p. 68, of the same, and also the figure on 
p. 397 of the ' Journal of the Royal Agricultural Society,' repre- 
sent things which on the face of them show that the pi'eparation 
could not possibly have had the appearance given to it in the 
illustration. It will, therefore, be better to leave them out of 
consideration, especially as, in regard to the question at issue, 1 
should adduce the same objections against them as against fig. 13. 
The principal objections are the following : — Fig. 13 re- 
presents two kinds of mycelium threads — thick ones and 
much thinner ones — which are in local, but not in anatomical 
relation to each other. The extremities of the branches of both 
kinds support globular cells rich in protoplasm ; larger ones (?«) 
on the thick, and smaller ones on the thinner threads. 
The former are called " oogonia " ; their protoplasm afterwards 
withdraws from the original wall, and collects itself into a globular 
cell enclosed within a special membrane, the " oospore." The 
globular cells on- the thin threads rise mostly free in the sur- 
rounding space, many even lie there separated from their pedicels; 
some are attached to the " oogonia," and on this account they are 
called " antheridia." The interpretation expressed by these names 
is based on their supposed similarity to the oogonia, oospores, 
and antheridia of other fungi, say of Peronospora, which are accu- 
rately and definitely known. But on closer examination one sees 
that there is very little similarity. The form, perhaps the struc- 
ture, also, of the " oogonia," may correspond, but these are unim- 
portant, since they suit also the reproductive cells of different 
morphological value, in a variety of fungi, as already shown. 
The same may be said of the antheridia in reference to their 
form ; though I might object that in no known Peronosjwra or 
Saprolegniea do the antheridia possess so regular a globular form 
as the bodies to which this name is given in the fungi here cited. 
In all known Peronosporeai and SaprolegniecB the antheridia are 
not formed until after the extremity of the branch which supports 
them, and from which they are afterwards separated by a septum, 
has attached itself to the oogonium, and this attachment takes 
place in the early stage of both organs. Antheridia originating 
freely in the surrounding space are, as regards the known forms, 
at least a great rarity, if indeed they ever occur, but this is a 
point which I will not here decide. Fig. 13 represents nine 
" antheridia ;" of these, two are attached to the " oogonia five 
