578 DR. J. B. HICKS ON THE GONIDIA AND 
each patch, a large stream of these Chlorococcus-like bodies may be seen, running 
downwards. I have not separately drawn these cells, because they are so like those on 
PL LVIII. fig. 18 c, to which I refer the reader. 
Sometimes on trees I have observed that, instead of producing the globular free cells 
just described, as occurs in 
most situations, the whole cells of the filament, which 
generally tapering towards the extremity, undergo this quaternary form of segmenta- 
tion in situ. It will be first noticed that the cell-walls become thicker, the contents less 
-> 
while the whole filament increases in diameter, and that then the contents 
segmenting (PL LVIII. fig. 18 a). After a time the parent-cell walls dissolve away, 
and the subdivisions become free (PL LVIII. fig. 18 b). Erom this point the description 
applied to those cells which were free before division corresponds so exactly as not 
to need repetition (PL LVIII. fig. 18 c). By this means, as by the other, large por- 
tions of bark of trees are covered with the Chlorococcus-like bodies, which multiply also 
indefinitely. 
But in some filaments there is a still more unsuspected change, namely, in the pro- 
duction of cells of Glceocapsa. The segmentation proceeds within the filament, as in the 
instance just quoted ; but the divisions become invested in a gelatinous envelope, while 
the parent-cell wall breaks up. These Gloeoeapsa-like bodies then become free, and 
continue the segmenting process as in Glceocapsa. This I have shown on PL LVIII. 
fig. 19 a. It is a condition by no means rare in the winter months : considerable masses 
of these bodies are to be found so produced. 
I have frequently seen Glceocapsa poly dermatica (Kutzing), &c, formed, as well as 
other so-called species. After frequent segmentation, the cells are imbedded in an 
indefinite mass of gelatinous substance. 
But there is a variety of this " Glceocapsa-form&tion " frequently met with (PL LVIII. 
fig. 20 dd). 
The cells of a filament in one or in every part at once begin the process of quaternary 
segmentation, as before noticed, at first regularly, but shortly after irregularly ; besides 
this, a certain amount of free-cell formation goes on within the divisions (mother cells) ; 
so that it is difficult to say which kind of cell-formation predominates (PL LVIII. 
fig. 20 a a). In this manner large irregular masses of segmentary cells are produced, 
like some of those resulting from segmentation of the so-called Palmellaeeae (PL LVIII. 
fig. 20 b b) . The cells set free from them are either Chlorococcus-]ike cells of variable 
size (PL LVIII. fig. 20 c c), or they are like Glceocapsa, undergoing segmentation in their 
variable manner (PL LVIII. fig. 20 dd). 
These changes can be readily observed in the colder months. They frequently, by 
distortions in all directions, produce a mass whose origin might be very doubtful to 
determine, were it not generally possible to find some small part retaining the original 
filamentous condition (PL LVIII. fig. 20 a a). 
Up to this point of the observations I have made, with the exception of that just 
noticed, the efforts made by the eonfervoid filaments towards multiplication have been 
carried out upon the plan of the " parietal cell-formation " of Nageli, and that principally 
upon the quaternary mode. 
