CARTER, ON THE COLOURING MATTER OF THE RED SEA, 185 
the same organism in other parts of the world, one might 
cite those of Péron, who likens it to “poussiére grisitre,” 
and of Darwin, who compares it to “cut hay,” &c. (op. cit.); 
but it seems better for this argument not to go beyond the 
seas washing the shores of Arabia. 
To what the “intense green,” under which this organism 
sometimes presents itself in the Red Sea, owes its production 
T am ignorant, unless it be indicative of sporidification, which, 
from what I think that I have seen in Oscillatoria princeps, 
seems to take place in this family, not from the conjugation 
of its cells, but from the division of their contents into z0o- 
spores. Much, therefore, remains to complete the history of 
this little plant ; and this, unfortunately, can only be obtained 
by watching it long and narrowly in its proper habitat. 
