116 Dr Grant’s Observations on the Structure 
rous during the recess of stream-tides, I am forced to differ from 
Mr Ellis, who states, in apology for his deficient account of this 
animal, that it is very rare to find sponges on our coasts, which 
have not been long removed from the places where they grew, and 
whose structure has not been very much injured. In so far as size, 
and number of individuals, and variety of species, are necessary 
to an inquiry into the structure and functions of this animal, the 
anatomist, who confines his investigations merely to the species 
of the Frith of Forth, will find no reason to envy the opportu- 
nities of Marsigli, Donati, and Olivi, who examined them on the 
shores of the Adriatic; of Jussieu, who examined them with the 
microscope on the coast of Normandy ; Spallanzani, on the 
shores of the two Sicilies ; Cavolini in the Bay of Naples ; La- 
mouroux on the coast of Spain ; Schweigger in the Gulf of Ge- 
noa ; Bose, Peron, and Lesueur, who examined them in Equa- 
torial seas ; nor of Peyssonel, who investigated the nature of the 
sponge on the shores of Europe, Africa and America. 
Most sponges, like Thalassiophytes and the lower classes of 
marine animals, suffer, without inconvenience, the occasional pri- 
vation of their natural element ; and the species seem to possess 
this accommodating power in different degrees. The Spongia 
dichotoma inhabits very deep water near Inchkeith, and I have 
never seen it deserted by the tide ; the Spongia coalita covers 
our oyster beds under twenty or thirty feet of water, and por- 
tions of it growing in their natural situation, are seldom deserted 
by the lowest tides ; the Spongia panacea, and the Spongia se- 
riata , (a species which, I believe, undescribed, and which I 
have so named, from the regular close ranges of fecal orifices 
which traverse its flat, smooth surface, and which are never raised 
to the extremities of projecting ridges, as in the S. cristata , but lie 
on a level with the general surface of the animal, as in the S. pa- 
nacea, along with which it is found on the under surface of rocks ; 
see collection in College Museum, Spongia seriate, Gr.), are found 
abundantly on rocks which are only left uncovered during the 
ebb of stream-tides, and are not accessible at ordinary tides ; the 
same is the case with the S . oculata, palmata, prolifera , ecer- 
ampelina, and cristata ; the S. urens and S. papillaris on Leith 
rocks, remain for more than three hours uncovered during mo* 
clerate tides ; the Spongia compressa , which at Leith is com- 
