376 Mr. Hodd's Observations on the Spongilla fluviatilis, 
rules, and as they are so extremely similar to those of certain species of the 
Marine Sponge, which were discovered in 1825 by Dr. Grant, I could not 
help thinking that in spite of the strong evidences which I had indisputably 
obtained in favour of its vegetable nature, I had also discovered one, which 
would perhaps go far in proof of its animality, and thus compel me to be- 
come somewhat of an unwilling believer in the monstrous theory which has 
of late years been revived amongst some foreign naturalists*, that certain 
bodies belonging to several Cryptogamous plants are at first animals, and 
that after a time they change into true vegetables}. Notwithstanding the 
power of locomotion has generally been accounted as one of the strongest 
tests of animal life, and that which constitutes the most obvious difference 
between an animal and a plant, still this power is not alone confined to the 
beings included in the first great division of nature; for many observers have 
witnessed it in subjects which pertain to, and really are members of the se- 
cond division, or the vegetable kingdom. I here allude to the extraordinary 
phenomena, which have been noticed by some distinguished botanists on the 
Continent, as to the locomotive powers of the seeds or sporules of certain 
Confervæ, as well as of other plants belonging to the Alge; and more espe- 
cially to the singular discoveries of Dr. Unger in 1826, which relate to the 
spontaneous movements of the seeds of the Ectosperma clavata of Vauchert. 
The original memoir descriptive of these appearances is contained in the Act. 
Acad, Nat. Curios. vol. xiii. p. 791. Bonn, 1826, with an accompanying plate. 
* As far as I can find, Miinchausen was the first author of this theory nearly half a century ago, 
but he ns to have obtained few followers until very recently. For further opinions on this theory 
refer to Nématophytes, p. 524, vol. 1x. of the Dictionnaire des Sciences Naturelles, edit. 1830 : likewise 
the articles Némiizoaires and Némazoones, at p. 365, vol. xxxiv. of the same Dictionnaire; and the ar- 
ticle Psychodiaires, p. 516 of vol. xliii. of the same work. 
A This theory may be termed the 
writes, The tribe of Zoocarpia” (certain of the Cryptogamia 1 
i This plant is synonymous with the Vaucheria clavata of De 
Candolle; and ilatata 
B. clavata of Roth, and y. bursata are only different states of the fhe Conferva dilata 
same, 
