404 Mr. Hocc’s Observations on the Spongilla fluviatilis, 
des plantes marines donnant par lincinération, des odeurs et des produits 
analogues à ceux des animaux *." Neither is the presence of ammonia in 
these substances at all conclusive of their animal nature; for I have before 
mentioned that some plants contain nitrogen or azote, and from the combi- 
nation of this ingredient with hydrogen the ammonia itself is formed ; where- 
fore in those vegetables, especially in the lower water-plants, which contain 
nitrogen, more or less of ammonia is known to be generally produced. 
Thus it seems that there really exists no more peculiarity in the chemical 
composition of Spongest, than what is also present in that of certain vegeta- 
ble substances. And for the sake of corroborating this, I will cite the follow- 
ing authority from a naturalist, equally illustrious in botany and in zoology, 
who, describing Sponges as animals, nevertheless allows, * chymicis etiam 
principiis paulò similiores plantis deprehenduntur +.” 
To me then it is evident, that the Sea Sponges being so perfectly analogous 
in every part of their structure with the Freshwater Sponges, it is impossible 
that they can be separated from one and the same natural order, or accounted 
as the one pertaining to the animal kingdom, and the other to the vegetable. 
And as I have become convinced that the River Sponge is a true member of 
the latter, and as I have endeavoured so to demonstrate this in the preceding 
pages of my present letter, I must now necessarily be compelled to acknow- 
ledge myself a convert to the vegetability of the Sea Sponges. In the full 
confirmation of this, and in the absence of more direct proofs, which may yet 
be derived from future researches on these marine productions, whilst growing 
in their native localities, I will concisely sum up in a general manner the fol- 
lowing evidence of their want of animal life, or what I may term their non- 
animality. They have no tentacles, no cilia, no mouth, no cesophagus, no 
Stomach or gastric sac, no gizzard, no alimentary canal, no intestine, no 
anus, no ovaria, no ova, no muscles or muscular fibres, no nerves or ganglia, 
“Iode” at p. 594. tom. xxiii. of the Diction- 
Which was written by M. Chevreul, Professor of Chemistry. 
à; on December 7th, 1839. J. H. 
t Dr. Pallas in Elench. Zooph., p. 376. 
