164 FUNGI. 
views of M. A. S. Cirsted,* which have not since been con- 
firmed, but which have been cited with some approval by Pro- 
fessor de Bary, as to a trace of sexual organs in Hymenomycetes. 
He is supposed to have seen in Agaricus variabilis, P., oocysts 
or elongated reniform cells, which spring up like rudimentary 
branches of the filaments of the mycelium, and enclose an abun- 
dant protoplasm, if not even a nucleus. At the base of these 
oocysts appear the presumed antheridia, that is to say, one or two 
slender filaments, which generally turn their extremities towards 
the oocysts, and which more rarely are applied to them. Then, 
without ulteriorily undergoing any appreciable modifications, the 
fertile cell or oocyst becomes enveloped in a network of fila- 
ments of mycelium which proceed from the one which bears it, 
and this tissue forms the rudiments of the cap. The reality of 
some kind of fecundation in this circumstance, and the mode of 
the phenomena, if there is one, are for the present equally un- 
certain. Jf M. Cirsted’s opinion is confirmed, naturally the 
whole of the cap will be the product of fecundation. Probably 
Karsten (Bonplandia, 1862, p. 62) saw something similar in 
Agaricus campestris, but his account is obscure. 
In Phycomyces the organs of reproduction have been subjected 
to close examination by Van Tieghem,t and although he failed 
to discover chlamydospores in this, he describes them in other 
Mucors. In this species, besides the regular sexual develop- 
ment, by means of sporangia, there is a so-called sexual repro- 
duction by means of zygospores, which takes place in this wise. 
The threads which conjugate to form the zygospores are slender 
and erect on the surface of the substratum. Two of these 
threads come into close contact through a considerable length, 
and clasp each other by alternate protuberances and depressions. 
Some of the protuberances are prolonged into slender tubes. At 
the same time the free extremities of the threads dilate, and arch 
* Gersted, in ‘‘ Verhandl der Kénig. Din. Gesell. Der Wissensch,” 1st January, 
1865; De Bary, ‘‘ Handbuch der Physiol. Botanik”’ (1866), p. 172; ‘‘ Annales 
des Sci, Nat.” (5™° sér.), vol. v. (1866), p. 366. 
4 Van Ticghem and Le Monnier, in ‘‘ Annales des Sci, Nat.” (1873), vol. xvii. 
p. 261. 
