Notes. 
579 
apparently not very favourable. The formation of these bodies, which 
are like the zoospores formed elsewhere, from the tissue of the oospore, 
is perhaps a quite fortuitous circumstance, which differs in no way 
from the usual propagation. But the chief reason for comparison with 
the Mosses, and for the assumption of an alternation of generations, 
lies in the production of specially formed propagative cells from the 
oospore. It might be quite possible that the cells of the oospore in 
Coleochaeie scutata should pass over directly into the thallus, but 
in C. pulvinata perhaps only after a change in the mode of growth. 
The essentially regular germination by help of a pro-embryo, as 
in Chara, , will not be accepted as a formation of a special non-sexual 
generation. It is true that Vines has advanced such a conception, and 
compares the pro-embryo of Chara with the whole sporogonium of 
the Mosses. His view has not been taken up, since as a matter 
of fact in Chara a comparison seems permissible only with the 
protonema of the Mosses, or with the pro-embryo of Batracho- 
spermum. 
Next to Coleochaete it is the Ascomycetes and Florideae, the life- 
history of which has since the time of Sachs been compared with the 
alternation of generations in the Mosses, for in both the fertilized 
ovum has often a complicated development of its own ; the last object 
of this is the formation of spores, which are clearly different from the 
usual propagative cells. As described by Schmitz, and according to 
the latest observations of Oltmanns (1898), the nature and method 
whereby the formation of the fruit depends on an intimate union 
of the fertilized egg-cell with definite auxiliary cells of the mother- 
plant is extremely peculiar. In the higher differentiated forms, 
e. g. Callithamnion , according to Oltmanns, a cell-derivative from the 
fertilized egg-cell — a cell-nucleus with some protoplasm — is united 
with a large auxiliary cell, and coalesces with it into a new cell-unit, 
whereupon the nucleus of the auxiliary cell is pushed aside as 
apparently functionless. This new cell, of which the wall and of 
which the plasma belong for the most part to the mother-plant, is 
stimulated by the ‘ egg-energid ’ to form the spores. In still more 
highly developed forms the mother-plant provides also for the 
enveloping of the spore-producing cells. Oltmanns compares the 
relation of egg-cell and mother-plant with that of a parasite and its 
host-plant, and sees therein a confirmation of the view that the fruit of 
the Florideae corresponds to the sporogonium of the Mosses. But 
