28 
Henfrey, on Chlorosphara. 
their expulsion from the parent-cell. In some cases the 
parent- cells exhibited large green or brown encysted cor- 
puscles (figs. 7 and 10), such as are often formed from the 
cell-contents of Spirogyra,"^ where, as above noticed, the 
Pythium form is not unfrequent, and in which we have once 
seen bi- ciliated zoospores. All these conditions may be the 
result of disease, exhibiting pseudo-organization into regular 
form, comparable with the formation of definitive kinds of 
galls, &c., in the higher plants; but we are rather led to 
imagine that they are eventually connected with the repro- 
duction of the plant, and are conditions of the antheridial 
structures. 
This notion is rendered more plausible from the circum- 
stance that we have met with bodies mixed with the green 
spheres, which are in all probability resting- spores. Among 
the actively vegetating green specimens it is not unusual to 
find some with yellowish- brown contents (fig. 15) ; but these 
do not appear to persist normally in this state. In the 
middle of summer, parent-cells, either simple or in the state of 
division into two chambers, were found containing four or 
sometimes eight round brownish-yellow spores (figs. 17 — 
19), which we are inclined to regard as resting-spores, formed 
by the segmentation of large spores after an impregnation. 
The further history of these spores has not been made out. 
Lastly, it is not unusual to find halves of parent-cells some- 
times closed, but often widely opened at one side, with 
portions of decayed contents still lying in them ; and some 
of them so far retain their vitality as to produce a great mass of 
gelatinous thickening layers upon the inside of the wall of 
the parent-cell. The contents are here of a dull yellow colour, 
and the wall hyaline ; it is observed, that the thickening 
layers are wanting at one part of the wall, apparently 
when the half-cell separated from its fellow (fig. 16). It 
seems probable that the contents of those cells which are to 
produce resting-spores do not slip out when the parent- 
cell dehisces, but receive impregnation by the slit, and 
then become encysted within the parent-cell, which either 
falls into two parts or remains double. Probably, when the 
impregnation fails, the cells survive, and become the diseased 
forms, with thick gelatinous wall (fig. 16). 
The present plant does not appear to have been described 
hitherto, unless we are to refer to it, which seems very 
likely, the form mentioned by Hofmeister, in his memoir 
on the Desmidiese and Diatomeae.^ He does not give any 
* Translated from the "Bericht. Sacbs. Gesell," in the * Annals of Nat. 
History,' 3d series, vol. i, p. 14, pi, i, figs. 26 — 29. 
