ARCHER, ON PALMOGL@A MACROCOCCA. 131 
but I have not observed in Zygnema that the opening by 
which they escape is produced by their raising up a portion 
of the cell-membrane as a lid or valve-lhke structure, which 
forms so remarkable a feature in this Mesotenium. Similar 
“vesting cells,” not resulting from conjugation, are described 
by De Bary in a Zygnema,* distinguishable from the 
“spores” by their more cylindrical figure, and which germi- 
nate into young plants. But in this Mesotznium this “lid ’’ 
does not form a specially formed cap (so to speak), like that, 
for instance, in some species of Chytridium (Braun), there 
for the exit of zoospores, but seems to be merely a small 
portion of the cell-membrane pushed up from within at any 
point. This “lid,” however, is of a somewhat sharply de- 
fined outline, and of a rounded figure, as it were cut out, 
and not produced by a rough bursting or tearing; and yet 
there can be no suture, the line of separation taking place in 
the most varied directions and positions, between transverse, 
oblique, and vertical. It is well known that somewhat simi- 
lar spore-like bodies are formed by the individualization of 
the whole or a portion of the cell-contents in some Desmids, 
in Spirogyra (here beset with spine-like extensions), &c., but 
they do not seem to have been noticed as yet as being even- 
tually set free; and ifthey are so, it must be by the breaking 
up of the original cells, for no special opening seems to occur, 
if, indeed, those alluded to be not possibly really internal 
parasitic growths. Therefore, so far as I know, the only 
apparent parallel for the curious phenomenon in this plant is 
the probably similar bodies which occur in Zygnema just 
alluded to. But they are possibly structures of an analogous 
nature. 
I do not at all suppose that the apertures here left by the 
raising off of the lid-like portions of the cell-wall are by any 
means to be regarded as for the purpose of admission of sper- 
matozoids—that is, these spore-like bodies have no resem- 
blance to the germ-cell (oospore or Befruchtungskugel, Pring- 
sheim) of Gidogonium. Nothing of the sort was apparent, 
nor is it to be looked for or expected. The true generative 
act, as I regard it, is found in these species in that of conju- 
gation. 
Measurements.—Length of cell, -1; to =4,; breadth, 4, 
to +>; diameter of spore-like body averages about =>; of 
an inch. 
Fig. 20, cell showing edge view of chlorophyll-plate ; 
figs. 21, 22, 23, cell-contents emerging; figs. 24, 25, cell- 
contents emerged, and balled together into a spore-like 
Op. cit., p. 10, t. viii, 13. 
VOL. IV.— NEW SER. K 
