100 Dr Grant’s Observations on the Structure and 
a mouth, or organs, or any thing, in fact, which we observe in 
other animals, and says that this hypothesis is less problematical 
than any other, and is supported by observations made by him 
on the sponges of the coast of Calvados in Spain. This state- 
ment, from the present illustrious Professor of Natural History 
at Caen, and author of the most complete and valuable work on 
zoophytes that has yet appeared, and statements as erroneous 
concerning the marine sponge from Lamarck, Cuvier, and other 
eminent modern naturalists, have induced me to push the in- 
quiry to some length, with regard to a very few species ; and, 
though these observations have been made in the depth of win- 
ter, and only on the small sponges of the Frith of Forth, they 
have enabled me to correct some mistakes, and to suggest some 
new views regarding these animals, which may be useful to those 
who are interested in such inquiries. 
Marsigli, after much research into the nature of marine plants 
and zoophytes, was convinced that the sponge is a vegetable, 
and is nourished like Thalassiophytes, by absorbing water through 
the holes on its surface ; and, notwithstanding that he enter- 
tained such an opinion of its nature, he was the first who de- 
clared, in 1711, that he saw a systole and diastole of certain 
round holes on its surface. This extraordinary and inconsistent 
statement, made, for the first time, after this marine production 
had been studied for upwards of two thousand years, soon 
spread, with the fame and writings of its author, through 
Europe, and was well known to our countryman Ellis, before 
he began to investigate the nature of the sponge. The state- 
ment which Ellis communicated to the Royal Society of Lon- 
don, in 1765, is a memorable example of the influence of imagi- 
nation over our very perceptions. This great zoophytist, having 
his mind already prepossessed by the assertion of the Italian na- 
turalist, placed living portions of the Spongia urens and Spon- 
gia cristata in glasses of sea-water, when on the coast of Sussex, 
and declares that he not only saw the contractions and dilatations 
of the apertures mentioned by Marsigli, but likewise saw the 
water pass to and fro through the same apertures on the sur- 
face. Pallas immediately copied this hasty assertion from the 
Transactions of the Royal Society, into his Elenchus Zoophyto- 
rum, which he published tfie following year. Other naturalists 
followed so great an example, and thus was established and pro- 
