290 Transactions.— Botany. 
and to guide themselves, the former to their relative gymnospores, the latter _ 
to appropriate places whereon to rest and recommence the process of ger- 
mination and growth. 
In thesmethods of fructification, moreover, the resemblances between 
flowering plants and Alge are probably as close as in any other particular. 
Setting aside the Volvocinee, Palmellacee, and some others in which the 
process of multiplication is merely a process of cell division, either intrin- 
sic or extrinsic, we find in the Conferve, Siphonacea, Oscillatoriea, etc., 
that the single cell has the power of producing reproductive spores, thus 
(keeping in mind that an algal cell is the equivalent of a phenogamic 
flower) affording an analogy with the class of so-called hermaphrodite 
flowers. A strictly monecious form of fertilization is met with in the 
(Edogoniacee, where the contents of certain inflated cells are vivified by the 
contents of contiguous antheridial cells which, by rupture of the cell divi- 
sion, gain access to the inflated cells. A distinct advance upon this method 
is found in many (Edogonia and Chetophore. Here the distinction between 
antheridial and sporidial cells is evident—they often occur upon different 
filaments, though sometimes upon distant portions of the same, and are 
easily recognized by their shape and appearance. The contents of the 
antheridial cell (androspore) when mature escape through rupture of the 
cell wall, and, being furnished with cilia, lead an active locomotor life until, 
coming in contact with the gonidial cell (oospore), the locomotion comes to 
anend and the contents of the two combined form a zoospore which 
eventually becomes a young plant, 
The Zygnemacea are veritable diccious plants, and propagate by 
process of conjugation—the cells of two contiguous filaments throw out 4 
connecting tube through which the contents of one (the antheridial) cell 
pass into the other (the gonidial), and thus fertilize them, the result being 
& zoospore. In this process the fertilization of the ovule by the pollen tube 
in Phanerogams is closely imitated. But further, that abnormal self- fertili- 
zation that takes place in certain flowers under unusual conditions, and 
which is termed cleistogamy, would appear to occur at times in certain 
Spirogyra, the filaments of which have the power of producing zoospores— 
the so-called pseudogonia—in certain cells without conjugation ; in fact 
these cells are, like the cleistogamous flowers, not only hermaphrodite, but 
contain within themselves the power of self-fecundation. 
In the following list of fresh-water Alge which have come under BY 
observation during ine nner mecaereesiehe OT 
feel pretty certain Thave verified. ) o merated, because | 
I am at APS: Par Pe a Le ut 2 ae ee = Bo Sey a ok 
earch and 
‘ observation I have no d ea list may be > ig eae ge 
