Having considered the distinction between inorganic and organic substances, we will proceed to a division which may be more familiar to you; that by which the matter upon our globe is ranged under three kingdoms-the ANIMAL, VEGETABLE, and MINERAL.

We find it somewhat difficult to explain the difference between the different kinds of organized beings, viz. animals and vegetables; the lines of distinction often seem to fade so gradually, that we cannot well decide where the animal ends, and the vegetable begins.

This difficulty may seem at first somewhat strange, as you may perhaps never have been at a loss to tell an animal from a vegetable: you would certainly know how to distinguish between a nightingale and a rose, or between an ox and an oak; but these are animals and vegetables in a comparatively perfect state.

The perfect animal you see has the power to move about, to seek the nourishment most agreeable; you perceive it uttering audible sounds, possessing sensation and apparent consciousness. The plant, on the contrary, is confined to a particular spot, having no other nourishment than substances which themselves come in contact with it; exhibiting no consciousness, nor, to common observation, any sensation. It is only when we examine with close attention the various phenomena in the vegetable and animal kingdoms, that we learn to doubt as to the exact boundaries by which they are separated.

The division of nature into three kingdoms, animal, vegetable, and mineral, is very ancient, and appears at first to be clear and precise. Minerals destitute of life increase by the accumulation of new particles.

Vegetables grow, produce seeds which contain the elements of future plants like themselves, and then die.

Animals unite to the properties of vegetables, the feeling of their own existence; or as Linnæus has said, "Stones grow, vegetables grow and live, animals grow, live, and feel." Although this simple view of the works of creation is pleasing, it is not satisfactory; because we are not able to decide where, in the vast series of organized beings, sensation ceases.

That you may the better understand what is meant by the gradations of animal life, we will present you with a sketch of the classification of animals. The study of this department of nature you have already been told is termed Zoology.

A very general and simple classification of animals is as follows:-
"VERTEBRAL ANIMALS, having backbones.

AVERTEBRAL ANIMALS, destitute of backbones.
VERTEBRAL animals are divided into,

1. Quadrupeds. The science of which has no popular name. It includes four-footed animals; as ox, dog, mouse.

2. Birds. The science of which is called ornithology. It includes the feathered tribe; as pigeon, goose, wren.

3. Amphibious Animals. The science of which is called amphibiology. It includes those cold-blooded animals which are capable of living on dry land, or in the water; as tortoise, lizard, serpent, frog. 4. Fishes. The science of which is called ichthyology. It includes all aquatic animals which have gills and fins; as shad, trout, sturgeon, eel.

Three kingdoms of nature-Distinction between the different kinds of organized beings-The perfect animal-The plant-Minerals-Vegetables-Animals-Zoology-Division of animals into two classes-How many classes of Vertebral animals?

AVERTEBRAL animals are divided into,

5. Insects. The science of which is called entomology. It includes all animals with jointed bodies, which have jointed limbs: as flies, spiders, lobsters.

6. Vermes. The science of which is called herminthology. It includes all soft animals of the avertebral division, which have no jointed limbs, with or without hard coverings; as angle-worms, snails, oysters, polypi, and infusory animals."

The system of Zoology most approved, is the one taught by Linnæus, with some improvements made by the great French naturalist, Cuvier; according to this mode of classification, the animal kingdom is divided into four grand divisions, viz.:—

VERTEBRAL, MOLLUSCOUS, ARTICULATED, and RADIATED. These are subdivided into classes and orders.

Vertebral Animals.

CLASS I. Mammalia, or such as are at first nourished by milk. This class have lungs, and peculiar organs for imbibing their food during their first stage of existence.

The First Order is called Bi-mani, (from bis, two, mani, hands ;) this order includes man only; we find here no generic or specific differences, but the following varieties.

1st. Caucasian race, anciently inhabiting the country about the Caspian and Black seas, from whom we are descended.

2d. The Mongolian, the ancient inhabitants about the Pacific Ocean, from whom the Chinese are descended.

3d. The Ethiopian, or negro race.

The Second Order contains the Quadru-mani, (from quatuor, four, and mani, hands.) These have thumbs or toes, separate on each of the four feet. We here find the ourang-outang, (sometimes called the wild-man,) and the monkey.

The Third Order contains Carnivorous animals, or flesh-feeders having no separate thumbs, or great toe's without nails; as the dog and cat.

The Fourth Order contains the Gnawers, having no canine teeth, (those which are called eye-teeth,) feeding almost wholly on vegetable substances; as the rat and squirrel.

The Fifth Order is Edentata, or animals wanting teeth; as the sloth and armadillo.

The Sixth Order, Pachyderma, contains thick-skinned animals with hoofs; as the elephant, horse, and hog.

The Seventh Order contains the Ruminating animals, such as chew the cud, having front teeth (incisors) below only, and feet with hoofs cloven, or divided; as the ox, sheep, and camel.

The Eighth Order, Cete, contains Aquatic animals, (such as live in water,) having no kind of feet, or whose feet are fin-like limbs ; as the whale and dolphin.

We have enumerated all the orders of the class Mammalia, as it is the one in which man is placed; we shall now notice the remaining classes of animals, without going into so minute a detail of their orders.

CLASS II, contains Birds, (Aves,) which are distinguished by having the body covered with feathers and down, long naked jaws, two wings formed for flight, and bi-ped, (from bis, two, and pedes, feet.)

How are Avertebral animals divided?-Cuvier's four grand divisions-1st class of Vertebral animals-Order bi-mani-Varieties in this order-Order quadru-maniThird order-Fourth order-Fifth order-Sixth order-Seventh order-Eighth orderClass 2d.

The orders in this class are chiefly distinguished from each other by the peculiar make of the bill and feet.

CLASS III, Amphibia, contains Amphibious animals, including what are commonly called reptiles. It is divided into four orders:

1st. With shells over their back, and four feet; as the tortoise and turtle.

2d. Covered with scales, and having four feet; as the crocodile and lizard.

3d. Body naked, destitute of feet; as serpents.

4th. The body naked, and having two or four feet; as the frog, and toad.

CLASS IV, contains Fishes, (Pisces,) natives of the water, unable to exist for any length of time out of it; swift in their motions, and voracious in their appetites; breathing by-means of gills, which are generally united in a long arch; swimming by means of radiate fins, and mostly covered with scales.

Molluscous Animals.

CLASS V. Molluscous animals have soft bodies without bones; their muscles are attached to a calcareous covering called a shell, which is supposed to be formed by the secretions of the animal. This class are destitute of most of the organs of sense; the nautilus and cuttle-fish are of the highest order of molluscous animals. The oyster and clam are destitute of heads; they have a shell of two pieces, which are therefore termed bi-valved.

Articulated Animals.

We proceed next to those animals called Articulated; these have jointed trunks, and mostly jointed limbs. They possess the faculty of locomotion, or changing place; some have feet, and others are destitute of them; the latter move by trailing along their bodies.

CLASS VI, Annelida, contains such animals as have red blood, without a bony skeleton; bodies soft and long, the covering divided into transverse rings; they live mostly in water; some of them secrete calcareous matter, which forms a hard covering, or shell; as the earth or angle-worm, and leech.

CLASS VII, Crustacea, contains animals without blood, with jointed limbs fastened to a calcareous crust; they breathe by a kind of gills. CLASS VIII, Arachnida, contains spider-like animals, without blood, or horns with jointed limbs. They breathe by little openings, which lead to organs resembling lungs, or by small pipes distributed over the whole body; these do not pass through any important change of state, as insects do; they have mostly six or eight eyes, and eight feet, and feed chiefly on living animals; examples of this class are the spider and scorpion.

CLASS IX, Insecta, or insects, without blood, having jointed limbs and horns; they breathe by two pipes, running parallel to each other through the whole body; they have two horns; they are mostly winged, having one or two pairs; a few are without wings; mostly with six feet. They possess all the senses which belong to any class of animals, except that of hearing.

The winged insects pass through several changes or metamorphoses. The batterfly is first an egg; this, when hatched, is long and cylindrical, and divided into numerous rings, having many short legs, jaws, and several small eyes; this is the larva, or caterpillar.

Class 3d-Class 4th-Molluscous animals-Articulated animals-Class 6th-Class 7th-Class 8th-Class 9th-Metamorphoses of insects.

At length it casts off its skin, and appears in another form without limbs. It neither takes nourishment, moves, nor gives any signs of life; this is the chrysalis. In process of time, by examining it closely, the imperfect form of the butterfly may be seen through the envelope; this it soon bursts, and a perfect butterfly appears. When about to pass into the chrysalis state, of which they appear to have warning, the insect selects some place where it may repose safely during its temporary death.* The silk-worm spins a silken web for a shroud to wrap itself in, and from this all our silks are made.

CLASS X, Zoophites, or animal plants. Here we find the lowest beings in the animal kingdom. Some of the orders of this class contain animals which have neither heart, brains, nerves, nor any apparent means of breathing. These are sometimes called animal plants; many of them, as the corals, are fixed to rocks, and change place. The term coral includes under it many species; the red coral used for ornaments, is the most beautiful. The substance of coral, when subjected to chemical analysis, is found to consist chiefly of carbonate of lime; the hard crust which envelops the animal substance, is an excretion formed by it in the same way as the shells of the oyster and lobster are produced, or as nails grow upon the fingers and toes of the human body. The quantity of this carbonate of lime, elaborated by the little coral animal, is truly wonderful; islands are formed, and harbours blocked up by it. Fig. 158, a, represents a branching coral; the dots show the apertures by which the animal receives its nourishment. Some of the zoophites are fixed by a kind of root, to the bottom of the sea; some, as the sea-nettle, which appears like the segment of a circle, are carried about by the motion of the waters, without any voluntary motion, as are also the sea-daisy, sea-marygold, and the sea-carnation, so named from an apparent resemblance to those plants. We find here the sea-fan, the sea-pen, and the madrepore, the latter of which are often thrown together in vast quantities.

*May not this be considered as a lesson to man to anticipate and provide for the change in his existence, which, his bodily infirmities and daily observation teach him, is to be his own lot?

Class 10th-Description of zoophites-Corals-Various kinds of zoophites.

The sponge also belongs to this class of strange animal substances; it consists of a fibrous mass, containing a jelly-like substance, which when touched, discovers a slight sensation, the only sign of life manifested by it. There are many species of sponge; those most valued in the arts are found in the Mediterranean sea and Indian ocean. Some grow upon rocks, and are found covering the interior of submarine caves. The Spongia parasitica is seen growing upon the back and legs of a species of crab; sometimes as many as forty individual sponges extend themselves over the crab, impeding the motion of its joints, spreading like a cloak over its back, or forming for its head grotesque and towering ornaments, from which the poor crab vainly attempts to disencumber itself.

Some species of the sponge grow to a very large size; one has been found in the East Indies in the form of a cup, capable of containing ten gallons of water. The fibrous part of the sponge is the skeleton of the animal; the large apertures (see fig. 158, b,) serve to carry out fluids from within; while the water by which the animal is nourished, is imbibed by minute pores: this continual circulation of water is one of the most important functions of the living sponge. These animals resemble plants in their manner of producing others; they form a species of germ, like the bud growing upon the stalk; this falls off from the stem, and becomes a perfect animal. If a part of one of these animals is separated from the rest, it will itself be as perfect a living animal as was the whole before. A polypus can be divided into as many animals as it contains atoms; some of this order are very properly called hydras, (many-headed.) Besides these, there is another order of animal substances, infusoria, which appear like a homogeneous mass, having no appearance of any limbs whatever; these are either angular, oval, or globular.

LECTURE XLVII.

COMPARISON BETWEEN ANIMALS AND PLANTS.

In our last lecture, after a glance upwards to the heavenly bodies, we returned to our globe, and considered its various substances; here we found two classes of bodies, inorganized and organized substances; the former including minerals, the latter embracing the animal and vegetable kingdoms. We then took a brief view of the animal creation.

At the head of the animal kingdom, we found man, sufficiently resembling brute animals in his material frame to constitute part of an extensive class, embracing the ape, elephant, and dog; yet between the lowest degree of intelligence in the human race, and the highest faculties of brutes, there is a line of distinction marked by the hand of the Almighty, in characters too obvious for doubt. God said, "Let us make man in our own image, and he breathed into him the breath of life, and man became a living soul."

Some writers have attempted to show that man differs only from the inferior order of animals in possessing a greater variety of instincts. But however wonderful may appear the instinctive perception of brutes, they are destitute of reason, and incapable of being

Sponge-Manner in which these animals are reproduced-Recapitulation-Man at the head of the animal kingdom-How resembling inferior animals.