nal respiratory organs or gills (nearly as in the Clio[1] and the Cleodora); or lastly, we may see that the germ γ grows opposite to the mouth, at the hinder extremity of the body, as the generator of a new internodium, that is (in the plant) as the producer of a new whole, or the organ of the plant's propagation; and we are thereby enabled to account for the usual place assigned by nature to the organs of generation. In this way we shall always recognise that which has hitherto escaped the attention of the observer, namely, the analogy that exists between the body of the animal and that of the plant as above metamorphosed, as well as the manifest derivation of the former from the latter.
A third consequence of the above is, that the animal being the realization of the abstract idea of unity, in which all parts must relate to a common centre, the sphere must be of necessity the original type of animal organization, the globe being that which tends to its centre with perfectly equal relations (radii). But, so far as the animal is not merely the upper part of the plant become detached, but likewise contains in itself the organs of the root, the globe must be hollow, and contain within itself the intestines, which can be most clearly pointed out in the lower animals. Because, without taking into account that the Infusoria appear merely as so many living hollow globules or cells (see the history of the green matter of Priestley, page 232, &c.), this kind of structure is evident in the bladder-worm (Cysticercus), in which (see fig. C.) the absorbing proboscis b (therefore called the head) is in reality curved inwards into the cavity of the body a, exactly in the manner described in the hypothetical metamorphosis of the plant into an animal. Similar forms are also exhibited by the Echinus tribe, to which we must add, that microscopical observations show most clearly that the whole of the organic mass of higher animals is composed of minute globuli.
The fourth consequence is, that as unity is the characteristic peculiarity of an organism, there must exist, because of the greater multiplicity of its form, a bond which, while it again unites that multitude, exhibits that relationship to a common centre which accords with its organization. However, since the animal presents two sides, a higher one, turned toward the outer world, and peculiarly animal, and a lower one, turned into itself, destined for reproduction, and so far purely vegetative, the above bond must likewise of necessity be twofold, and bear a particular relation to each side.
Fifth consequence.—No reciprocal action can take place between two bodies, except in two directions, (just as the organism itself appears essentially as body and life under two forms only), namely, in its tendency to produce a change and combination of particles, or to a reciprocal transmission of power. Inasmuch as in the animal the change
- ↑ Carus, Lehrbuch der Zootomie, p. 482.
