SEXUAL REPRODUCTION OF THALLOPHYTES. 317 
does the same; in Qdogonium the oospore produces four 
zoospores. 
In other groups this is also the case in a less marked 
degree. In Mucor the zygospore develops a filament, which, 
without branching, terminates in a sporangium filled 
with spores; here the vegetative development (represented 
by the filament) is not entirely suppressed. Amongst Pan- 
dorinee we get an interesting condition in Pandorina, where 
the zygozoospore sets free a single zoospore, or rarely two or 
three, after the resting phase. According to Cohn,’ Cien- 
kowski, in 1856, found that the oospore of Volvoz finally 
produces eight zoospores. 
The anomalous sexual processes of Myxomycetes give rise 
to a many-spored fruit, which Sachs® suggests may be con- 
sidered comparable with the sporocarp of mosses. In the 
organisms which belong to the next class the part played by 
the sporocarp, which amongst the Oosporee is only indicated 
in such instances as those above mentioned, rises into great 
prominence. 
Class 1V.—CARPOSPORES. 
The most interesting part of the taxonomic scheme which 
Sachs has propounded for the Thallophytes is that which 
relates to his fourth and highest class—the Carposporea. 'The 
following summary is in the main taken from the fourth 
edition of his ‘ Lehrbuch,’ pp. 240—243. 
The Carposporee agree with the Oosporee, in so far that the 
two sexual organs contribute in very different proportions 
to the formation of the sexual product. While the male only 
stimulates its development, the female supplies the material 
for the whole subsequent growth. 
The female organ, or carpogonium, may consist of one or 
more cells. The male organ varies very considerably in the 
different subordinate groups. Fertilization may—as in the 
Oosporee —be effected by antherozoids (which may be actively 
motile or passively locomotive), or by a kind of conjugation, 
or even by a mere apposition and subsequent diffusion of the 
fertilizing medium. 
The product of the act of fertilization is sometimes a single 
cell developing directly into a new individual (Chara). In 
other cases the fertilized female organ produces zoospores 
(Coleochete), and still more usually a multicellular mass is 
produced in which spores are finally developed. This involves 
1 «Pestschrift,’ p. 22. 
2 * Lehrbuch,’ 4th ed., p. 267. 
