116 ANIMAL KINGDOM. 



the plants from ordinary seeds, and no increase of mechanical power 

 ever accompanies vegetable development. In animal development 

 from the germ, on the contrary, there is always an increase of power 

 — an increase, in all, of muscular power, and, in the case of species 

 above the lower grade, of psychical and intellectual power, — until an 

 ant, for example, becomes a one-ant power, a horse a one-horse power. 

 Whence, an animal is a self-propagating piece of enginery, of various 

 power according to the species. 



(6.) In the plant, the root grows downward (or dark-ward) and the 

 stem upward (or tight-waxd), and there is thus the up-and-down polar- 

 ity of growth — the higher developments, those connected with the 

 fruit, taking place above, or in the light. In the animal, there is an 

 antero -posterior polarity of power as well as growth — the head, which 

 is the seat of the chief nervous mass and of the senses, and the locus 

 of the mouth, making the anterior extremity. Consequently, there is 

 in animals a connection between grade and the greater or less domi- 

 nance and perfection of the head extremity. An animal, as its ordinary 

 movements manifest, is preeminently a go-ahead thing. Even the in- 

 ferior stationary species, like the polyp, show it in the superior power 

 that belongs to the mouth extremity. 



(7.) Plants have no consciousness of self, or of other existences ; 

 animals are conscious of an outer world, and even the lowest show it 

 by avoiding obstacles. 



From the above diverse characteristics of plants and animals, it fol- 

 lows that, however alike the germs of the two are chemically (that is, 

 although containing the same elements in the same proportions), they 

 must be in their chemical nature fundamentally different. 



2. ANIMAL KINGDOM. 



In the Animal Kingdom, there are Jive Sub-kingdoms, based on 

 distinct types Of structure, each having its system of subdivisions of 

 several grades or ranks. These sub-kingdoms are as follow, beginning 

 with the lowest : — 



I. Protozoans; II. Radiates; III. Mollusks; IV. Articu- 

 lates ; V. Vertebrates. 



The Animal Kingdom may also be divided into Invertebrates, 

 and Vertebrates — Radiates, Mollusks, Articulates, and Protozoans 

 being the Invertebrates. 



I. Protozoans, the lowest and simplest of animals, show their sim- 

 plicity in their minuteness (mostly between a 100th and a 10,000th of 

 an inch in length) ; in having no external organs except a mouth and 

 minute cilia or thread-like processes, and no digestive apparatus be- 

 yond a stomach ; in the fact that the stomach and mouth are some- 



