Unbranched Forms of the Freshwater Sponges. 271 
him “ Spongilla fragilis ;” as also by the late Mr. J. K. Lord at 
Lake Osogoos, in the Cascade Mountains of British Columbia, 
but hitherto in no other part of the world. That Spongilla 
sibirica is Spongilla fragilis, Leidy, is not only shown by the 
description, but confirmed by the characteristic, polygonal cell- 
structure among the statoblast spicules represented in the illus- 
trations (Taf. i. figs. 12 @ and 12 5). 
Then as regards Uruguaya corallioides, 1 have before 
stated that, under the most careful examination of several 
large specimens not a trace of a statoblast has as yet been 
found, so that (also as before stated) it becomes questionable 
whether it is ever propagated by statoblasts or not, seeing 
that the sexual as well as the statoblast means may take place 
in Spongilla, as pointed out by Lieberkiihn in his Spongilla 
erinaceus, so far back as 1856 (Archiv f. Anat. Physiologie 
&e. Heft iv. p. 405, Taf. xv.). 
Unfortunately, I have nothing but dried specimens of Uru- 
guaya corallioides in my possession, so have been obliged to 
have recourse to an indirect method of examining the sarcodic 
parts under the microscope, which, however, has yielded much 
more than might have been expected ; for by softening minute 
fragments of the interior of a branch from two different speci- 
mens, through placing them for a few hours in liquor potasse, 
and then, after they have been washed, examining them under 
a microscope, the sarcode is found to be abundantly charged 
with spherical cells of a light brown colour, which are granu- 
liferous and nucleated, together with others that are less 
round. ‘These, when the fragments have been stained with 
magenta-dye (red ink), become much more deeply coloured 
than the other parts of the sarcode, and after having been 
washed in water and mounted in glycerine, afford a prepara- 
tion which can be deliberately examined at any time. 
The granulifero-nucleated cells in their sharply delineated 
spherical form are from 3- to 4-6000ths inch in diameter, 
which being much larger than the spongozoa (“Geisselzellen”’), 
and much smaller than the ampullaceous sacs (“Geisselkam- 
mern”), both of which are also present for comparison, shows 
that the former are spermatic cells or young ova, or both 
mixed together ; but here the analysis ends for want of a wet- 
preserved specimen or more matured ova, if there be any 
present. 
It is not improbable that hereafter Uruguaya corallioides 
may be found to propagate itself by ova alone ; but then this 
can only be determined by inference, since Lieberkiihn, as just 
mentioned, has shown that the freshwater sponges may be 
propagated by ova or statoblasts. 
