PROCEEDINGS OF SOCIETIES. 271 
p- 27). In the examples now shown we have a plant whose 
endochrome forms an axile band, whose zygospore is formed by 
the total fusion of the entire cell-contents of two conjugating 
joints into the-zygospore within the transverse tube, and without 
any septum between it and the cavities of the parent joints, 
This plant is not a Mesocarpus, being quite shut out from that 
genus for the last reason mentioned. It is in truth a Mougeotia, 
in the de-Baryian, but not the Agardhian sense. It is to be dis- 
tinguished from Mougeotia glyptosperma, de Bary, by its much 
shorter and wider cells, much wider transverse tubes, by its cells 
not becoming kneed or curved during conjugation, but presenting 
(as before mentioned) the appearance of a perforated ribbon-like 
structure, not a wide-looped network, and above all, by its 
zygospore being simply elliptic and destitute of the grooves and 
ribs, and the somewhat acute keel which form so distinguishing 
features of that of I. glyptosperma. 
But another reason for bringing Zygogonium, de Bary, into the 
question in connection with this plant, besides its no doubt con- 
siderable general resemblance thereto, was that at certain stages 
of the process of conjugation the present plant presented appear- 
ances so like de Bary’s figure (op. cit.), but perhaps still more like 
Rabenhorst’s, as to lead to the view, as before mentioned, that it 
and his plant are congeneric, notwithstanding that de Bary made 
a separate genus of his plant. 
This circumstance alluded to is a standstill, as it were, sometimes 
noticeable, of the globular mass of the contents of each parent 
joint, just within the connecting tube, where they became defi- 
nitely bounded, to appearance as if distinct individualised cells, 
ultimately, however, coalescing into the zygospore. 
Now, the question arises—May de Bary’s figures (it will be 
noted, made from dried specimens) have been possibly taken from 
examples arrested at this stage of advancement of the process of 
conjugation, and, from the same cause (that is, dried and dete- 
riorated specimens), may he not have supposed these bodies, thus 
partially advanced towards conjugation, to be portions only, not 
the total cell-contents, wholly retracted from the cell-wall? 
May some external granules have lent to the specimens an appear- 
ance of certain granular contents left behind within the parent 
conjugating cells; and, as regards the two bodies, not; yet 
coalesced, represented by him as specially coated by a cell-wall and 
separated by a septum from the parent-cells, may they not have 
been, just as in the specimens now exhibited, simply the con- 
tracted total cell-contents, without any special coat, arrested or 
caught at the point just before mutual fusion ? 
But great as is the resemblance of the plant figured by de 
Bary, when we reflect on the beauty and accuracy of his observa- 
tions in general, it is indeed with difficulty that we can bring 
ourselves to believe in his having misconceived the character of 
the plant he describes and calls Zygogoniwm didymum; and if 
there be really after all no such misconception, then the present 
