74 
Druce_, on Confervoidea. 
mention here, as a point to remember in connection with the 
process m Confervse, that the antheridial capsules^ though 
quickly dissolved, are detached with the contained Anthero- 
zoids. I hope to be able to show that a similar process in all 
essentials exists in Spirogyra, and, as seen by Pringsheim, in 
(Edogonium, and by Cohn, in Sphceoplea annulina. I 
have selected this genus Fucus — widely separated from my 
immediate subject — because the relation of the several organs 
is indubitably well known, and the fertilization by the an- 
therozoids often observed. I shall now proceed to the 
Siphonacese, in which we have again the threefold type — 
gemmation by zoospores, and reproduction by spores and 
antheridia, as observed lately in all its details by Prings- 
heim. I would here remark upon two points, viz., that the 
hooklike antheridia and spores are both formed by pouchlike 
protrusions from the main filament, as if for the formation 
of branches ; the process is therefore vegetative, until the 
shutting oflP of the contents of the new cells by septa. I 
mention this here because the outgrowth of the fructification 
renders the nature of the process evident, and it does not 
seem impossible that the antheridia may occasionally stop 
short of perfection, and be converted into the small zoospores 
of certain Confervse, and that the spores themselves, up to the 
time of fertilization, or in default of it, may, by the amount 
of vegetative power inherent in them, be subdivided into 
zoospores, and thus account for much of the confusion at 
present existing between true spores and sporangia, which 
last I have little doubt true spores never become. In the 
curious Hydrodictyon, the formation of resting spores has 
not been discovered, but there is no doubt, from analogy, that 
they exist. There is, however, one point to which I would 
direct your attention, viz., the smaller zoospores or micro- 
gonidia, and, so far as at present known, their ultimate fate ; 
these, after moving for some time, fall to the bottom, and 
become encysted in little green heaps. This I believe to 
occur in other of the Confervse, and to be no less than an 
encysted form of the antheridial capsules; and that the 
fecundation of the resting spores may take place either 
before the formation of the spore coat at all, or in the spring 
when it is ruptured by their expansion. I pass over the 
Batrachospermse and Chsetophoracese, in which the genera- 
tive act has not yet been witnessed, with one observation, 
viz., that if, as Dr. Carpenter has suggested, the setiform 
terminal cells of the latter be antheridia, a connecting link 
would be formed towards the lower Confervoidese, in the less 
degree of differentiation between them and the hooklike 
