400 Mr. Hoae’s Observations on the Spongilla fluviatilis, 
inclined to believe belonged to them, and which the statement made by so 
high an authority as Baron Cuvier, in his first edition of the Règne Animal*, 
induced me partly to acquiesce in. Since the year 1823, I have not had an 
opportunity of re-examining any of the Sea Sponges in a living state and in 
their native element. But the subsequent investigations of Professor Grant, and 
of other observers, have clearly determined that they are not endowed with the 
least irritability. 
Being so wedded to my former opinion of the animality of all Sponges, and 
being by my researches on the River Sponge at length assured of its vegeta- 
bility, I then began to imagine, agreeably with the suggestions expressed by 
Montagut, De Lamarck}, and Bell &, that it might possibly be quite a dif- 
ferent substance from the Sea Sponges; and if so, these latter might be yet 
esteemed of a true animal nature|. However, still more recent and minute 
comparisons of many of these, as preserved in several collections with the 
Spongilla, have compelled me to abandon that idea ; for I cannot find any 
more solid ground for it, than for holding that one genus of the Fungi, as 
Merulius, belongs to a perfectly distinct division of nature, from another 
genus of the same order, for instance, Agaricus; and as all who should 
behold them would immediately and unhesitatingly acknowledge both the 
one, and the other, to be a true Mushroom or Fungus; so we are equally 
obliged to admit, that the Spongia and Spongilla are in fact both real Sponges ; 
indeed there scarcely is even so much as a generic difference between them ; 
and in this, with the earlier naturalists Dr. Fleming coincides, for he places 
both kinds in one and the same genus, Halichondria. 
Both the Freshwater and the Sea Sponges are furnished with a skeleton of 
fibres interlacing, crossing, and anastomosing with themselves ; generally also 
strengthened with those singularly crystallized particles termed spicula; with 
a parenchymatous soft portion or jelly; with a fine and transparent envelop- 
* See tom. iv. p. 88. 
t For the observations of Montagu, refer to the Wernerian Memoirs, 
1 Anim, sans Vert., tom. ii. pp. 98, 99, edit. 1816. 
$ See Mr. Bell’s Remarks on the Animal Nature of Sponges in the Zool. Journ., vol. i. p. 204. 
| This is alluded to by Dr. Johnston, in his note on the 
nature of Sponges, at p. 325 of Brit. Zooph. 
4 See History of British Animals, p. 524, à sa 
vol. ii. part 1, p. 76. 
