ARCHERINA, GOLENKINIA AND BOTRYOCOCCUS. 427 
beautiful tints of uranium-glass and to suggest the adjective 
“chryso-chlorous” to describe this green and gold phase of 
vegetation. A more highly magnified view of a portion of 
the edge of the frond as seen when under the pressure of a 
cover-glass (Pl. 25, fig. 3) shows that the two colours are 
due (a) to the green colour of the granules, and to some 
extent of the cell-substance of the cell-units which build up 
the organism and form its superficial layer; and (b) to the 
orange-yellow or often brick-red colour of the jelly which is 
formed by the cell-units and holds them together. 
As shown in fig. 2 and fig. 3 of Pl. 25 droplets of a more 
or less oily nature are pressed out of the jelly when a cover 
glass is laid over it. 
In many specimens I found the cells pale green with green 
granules whilst the jelly was brick-red. In other cases the 
cells were as just stated, but the jelly was yellow. I did not 
find any instances in which the jelly was green in colour, 
though Prof. Chodat has figured the fronds in that condi- 
tion. 
In some examples I found that, whilst the general sub- 
stance of the cell had a sage-green tint, the granules were 
orange-yellow. ‘Tliese are shown in PI. 25, figs. 6 to 10. In 
some specimens, which were of very strong brick-red colour, 
the cells contained a very large quantity of orange-red 
eranules (Pl. 25, figs. 11, 12, and 18). 
-I do not gather from Prof. Chodat’s account of Botryo- 
coccus that it has ever been shown that the green colouring 
matter is chlorophyll. My own impression, based chiefly on 
the sage-green tint, was that it was not. But the nature of 
the green pigment seems not to have been definitely deter- 
mined. I mention this because in an organism which has 
very much smaller cell-units, but forms similar hollow botry- 
oidal colonies, namely, Clathrocystis eruginosa, Henf., 
the green colour, though the alga is of an intense apple-green 
when collected in mass (as a sort of cream) is certainly not 
due to chlorophyll, but to a peculiar body insoluble in alcohol 
and changed by ether into a brown pigment. The same 
