216 ARCHER, ON CYLINDROCYSTIS, 
which the antheridial cell gives birth to a single spermatozoid 
not much smaller than the oospore, the main distinctive cir- 
cumstance being, that in the latter the fertilising cell is 
ciliated, making its exit from one, and its entrance into the 
other, parent-cell by, an opening in each, whilst in the 
former neither is ciliated ; and, besides, the parent-cells being 
apart in the one, and joined together by firm inosculation in 
the other. 
It being admitted, then, that this case is one of a true 
generative process, the reproductive elements being seemingly 
well differentiated as germ-cell and sperm-cell, the transition 
downwards through the various forms of Conjugate is easy 
and natural to our Mesotznium and Cylindrocystis ; and it 
seems to compel the admission that the process im all is a 
manifestation of one and the same phenomenon, with one 
and the same import. 
But it may be further objected, that in many of the Con- 
jugatz spores or spore-like bodies very similar to the true 
zygospores, and from which young plants may be developed, 
are formed without any conjugation at all. However, it 
seems to me that these bodies may bear a relationship to the 
ordinary zygospores, the same as that of the ordinary zoospore 
of (dogonium and Bulbocheete to the four zoospores evolved 
from the fertilised oospore; and both bear to the plants 
which produce them an analogy similar to that of the buds, 
bulbils, &c., of higher plants to their seeds. As to the so- 
called “ Asteridia” (Thwaites), ‘‘ Asterophzria,” “‘ Sperma- 
tospheria ” (Itzigsohn), &c., they are most probably parasitic 
growths, and their true nature is as yet not at all under- 
stood. 
But Dr. Hicks intends his queries, first applied to Palmo- 
gloea, to be extended to certain true Palmellacean forms; _ 
and, if applied to some of the lower forms of which, I am 
free to own that they cannot be so easily answered, nor can 
his objections be so readily met. 
There is a point, however, which seems to be overlooked by 
Dr. Hicks, and a consequent confounding of two apparently 
essentially distinct groups fallen into. Dr. Hicks seems to 
ignore the Family Chroococeacee as distinguished. from 
Palmellacez ; thus, forms appertaining to Chroococcacez are 
sometimes, as it appears to me, indiscriminately spoken of as 
originating from some higher plant, whose endochrome is 
chlorophll, and vice versd as regards Palmellacezee. Now, in 
so far as we know, it seems a matter not at all to be 
expected that such a transformation should take place ; that 
is, I should be disposed to hold it exceedingly unlike that a 
