276 . 
Dr Grant on the Structure and 
sule, and soluble, gelatinous globules ; they differ entirely in 
colour from the substance in which they are found, the spon- 
gilla being of a deep sea-green or grass-green colour, while they 
are of a lively straw-yellow ; and they do not develope themselves 
into young spongillm, as some would lead us to suppose, in the 
same circumstances which evolve the true ova of that animal. 
Different kinds of these bodies appear to occur in the fresh- 
water sponge Linnaeus describes them as shining, bluish glo- 
bules, about the size of a grain of thyme, in the Spongia lacus- 
tris ( Spongilla ramosa , Lamarck), and as green gelatinous 
grains in the Spongia fluviatilis {Spongilla pulvinata, Lamarck). 
Lamarck states, that small, yellow, gelatinous grains are found 
in all the species. Those found in the Spongilla Jriabilis of 
Lochend gre tough, hard, yellow spheres, filled with transparent, 
soluble, gelatinous globules. Lichtenstein considered them as 
the ova of the Tubularia sultana , Blumenbach, as appears from 
Schweigger’s account of his MS., although he is represented by 
the French writers as having mistaken them for the germs of 
the cristatella. From the doubtful nature of these bodies, and 
their appearing in the same state of development for at least six 
successive months, their existence in the spongilla cannot with 
propriety be adduced in proof of this substance being a plant, 
as is done by Lamouroux and others, nor to prove it an animal, 
as was formerly done by Lamouroux, and is at present by La- 
marck. 
The external surface of the spongilla, like that of the marine 
sponge, is covered with numerous, open pores leading into its in- 
terior. The pores are mentioned by Linnaeus and Gmelin in 
two of the species, Sp. lacustris and Sp. fluviatilis. They are 
so conspicuous on the surface of the Spongilla pulvinata , that 
Lamarck has introduced them into the definition of that species. 
On the surface of the recent Spongilla friabilis they are visible 
at the distance of twenty inches, and are quite distinct from the 
large apertures seen between the lobes and branches, which have 
probably alone been observed. They are distributed irregular- 
ly over the whole surface, and are surrounded by projecting, 
naked fibres, very distinct in this species. They appear open, 
round, and smooth on their margins, though they are easily ob- 
literated by handling this delicate substance, or by the natural 
