368 Mr. H. J. Carter on Spongilla. 
to say, without further research, if the ‘ green colour’ is owing 
to an additional tint to the colouring-matter of the cells or 
granules themselves, or to the presence of some foreign or- 
ganism”’ (‘ Annals,’ vol. iv. p. 97, “ Descriptive Account 
of the Freshwater Sponges in Bombay ”’) ; and here is Mr. 
Sorby’s statement in 1875 (‘On the Chromatological Rela- 
tions of Spongilla fluviatilis”), viz.:—“ Though . . . the solu- 
tion contained a small quantity of chlorophyll, yet I could not 
be certain that it had not been derived from a small portion of 
some alga accidentally enclosed in the sponge. The exact 
nature of the green substance is therefore still open to slight 
doubt”? (Quart. Journ. Micros. Sci., n. s., no. 57, January, 
- 47). | 
: No the “green colour” in Spongilla (which in Bombay 
chiefly shows itself in S. Carterz, and here in those parts 
which are most exposed to the light) is situated in the little 
_ spherical granules (? cellulee) of the sponge-cell, the former of 
which vary under the 12,000th, and the latter under the 1000th 
of an inch in diameter: it is what they call “ transparent ;” 
that is, the tint, which presents a bluish emerald-green colour, 
is unaccompanied by any visible material; but as this part 
of the sponge comes into contact with the minute alge of the 
water, which, in its growing state, it often encloses, it becomes, 
as before stated, almost impossible to say how much of one 
or how much of the other contributes to the green colour—not 
of course under the microscope, which can easily deal with 
organisms 1000th inch in diameter, but for separation to 
ascertain the position of the ‘spectral band,” in order to see 
if it be the same as that of chlorophyll (hence Mr. Sorby’s ob- 
servation). 
This, however, is not the case in Hydra, where the 
“‘ oreen colour”’ is accompanied by visible material; that is, 
the green bodies themselves are granuliferous and much larger 
than the “green granules” in the sponge-cell, being about 
1-4300th inch im diameter, and scattered plentifully throughout 
the ordinary tissue or sarcode of the animal, justas in Diflu- 
gia pyriformis, Perty (¢ Annals,’ 1863, vol. xii. p. 253, “ On 
the Presence of Chlorophyll-cells and Starch-granules as 
Normal Parts of the Organism, &c.,” continued, with illus- 
trations, in 1864, vol. xii. p. 21, pl. i. figs. I-4), and 
also in Acanthocystis turfacea (ibid. p. 36, pl. 11. fig. 25, g), 
in both of which instances they are accompanied by separate 
starch-granules. 
Here I might observe that there is a point in the descrip- 
tion of these two Rhizopoda which may be of interest to 
those who accept the views lately put forth by Dr, K. Brandt 
