PN ROD UCL TON, 9 
full compensation in its perpetual bloom; for each coral branch is 
every where covered with its star-shaped animals, the “ coral-blos- 
soms.”’ 
Although the external resemblance to objects of the vegetable king- 
dom is so striking, there is little similarity in actual structure. Each 
of these flower-animals has a mouth, and a cavity to receive and 
digest food ; and the appendages that look like petals are organs fitted 
either for securing their prey or for some other animal function. Some 
species have actually been fed, and the process of digestion watched 
by the naturalist. They are not always invisible animalcules, as has 
been the common impression; on the contrary, many of the most 
common varieties are half an inch in diameter, while others are one, 
two, or three inches, and still others are a foot to eighteen inches. 
Neither have they “the consistence of jelly,” for the texture is usually 
more like flesh, and the exterior is sometimes quite firm and even 
leathery. 
2. The growth of coral has been considered one of the mysteries 
in science, and so few years have elapsed since the facts were first 
made known, that it remains to the many a mystery still. How the 
tree of stone grows and spreads its branches—what its connexion with 
the coral polyps which blossom over its surface, and whence the lime 
that constitutes it, are points which have been but lately explained ; 
and there is still room for additional and corrected information. In 
earlier publications of Dr. Job Baster, of Zurichsee, in Zealand, exhibiting singular igno- 
rance of the subject discussed, and inaccuracy in facts, the complete animality of corals 
has been since admitted without opposition.” 
The sponges have often been improperly classed with corals. There is still doubt as 
to their animality. The latest investigations seem to establish their vegetable nature.® 
4 A more extended history of this science in our own language may be found in Johnston’s British Zoo- 
phytes, 8vo., Edinburgh, 1838; a work distinguished for its literary as well as scientific excellence : 
also, in French in Blainville’s Man. d’Actinologie, 1834. 
> Of recent authors, Grant, Audouin, Milne Edwards, Bowerbank, Dujardin, and Laurent, consider 
sponges as animal; while Link, Blumenbach, Owen, Hogg, and G, Johnston, have inclined to place them 
in the vegetable kingdom, See Grant, Edinb. Phil. Jour. xiii. xiv.; Dujardin, Ann. des Sci. Nat. x. 5, 
2d ser. 1838, in which he endeavours to show, by minute microscopic research, that they are compound 
infusoria ; Laurent, on the Spongille, L’Institut, 1840, pp. 223, 231, 240, and the Microscop. Jour. i. 78, 
who describes the reproductive organs of the supposed animals; Hogg, on the Spongilla, Linn. Trans. 
xviii, 390, who sums up the results of his laboured investigations in the following language,— They have 
no tentacles, no cilia, no mouth, no @sophagus, 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, no 
irritability or powers of contraction and dilatation, no palpitation, and no sensation whatever. Surely, 
then, we cannot any longer esteem these natural substances to be individual animals, or even groups of 
animals, in which not one organ, or a single function or property peculiar to an animal can be detected.” 
3 
