and who, of his infinite power and benevolence, has communicated it to a part of his creation, can fully comprehend its nature and its essence.

Of the abundance of life, take the following illustrations: Of phanerogamic plants, the number can scarcely be calculated at less than 250,000; of cryptogamic, 50,000. The number of existing species of insects cannot be less than 3,000,000, it is more probably 5,000,000; of reptiles, perhaps, 2000 species; of birds, 10,000; of fishes, 12,000; of mammals, 2000; of mollusca, 20,000. Truly it may be affirmed that, in the vast domain of nature, life is the rule, its absence the exception. What then shall we say when we reflect upon the vast mass of microscopic organism everywhere spread abroad, and that world beyond the reach of our senses, however aided—the ultra-microscopic-in which we cannot help inferring, while we cannot definitely perceive, the presence and influence of vitality!

"Everything," says the aged savant, Humboldt, in his Views of Nature, already quoted, "everything proclaims a world of active organic forces. If, in the greatest apparent stillness of nature, we listen closely for the faintest tones, we detect a dull muffled sound, a buzzing and humming of insects close to the earth, in the lower strata of the atmosphere. In every shrub, in the cracked bark of trees, in the perforated ground, inhabited by hymenopterous insects, life is everywhere audibly manifest."

When we observe closely the relations of the vital

principle, we shall find two qualities, or properties, uniformly present, and manifesting themselves by obvious phenomena in masses or structures which we call organic as contra-distinguished from inorganic or dead matter. The coincidence of these may be safely regarded as demonstrative of the presence of this principle, and infallible proofs of its active condition.

They are, first, motion-or rather motivity, the power of motion-self-generated; and, second, the capacity of self-protection, by resistance to, or reaction against, the influence of foreign or extraneous agents. If the latter were ever simply passive, it would be enough of itself to denote the living condition; but it is difficult to conceive of such resistance without some internal movement or action of positive opposition to agents applied externally. We infer, then, the first from our perception of the second of these properties, and conclude that they always and of necessity co-exist.

And here I take occasion to remark upon the incorrectness of Carpenter's statement, in reference to these capacities of spontaneous action, when he declares that "the changes exhibited by any living being have one manifest tendency-the preservation of its existence as a perfect structure." Far more than this, and, indeed, in direct contrast with it, all these-its internal movements and changes which thus incidentally resist external agencies-tend ultimately, and with inevitable certainty, to its own destruction; it must thus wear out and die.

Inanimate masses of matter, unless impelled by some extrinsic force, must remain forever motionless. They possess within themselves no energy which can enable them to change their place or give rise to any alteration in the relative position of the ultimate atoms of which they are composed. Every particle, on the other hand, which is by any means endowed with vitality, or is made a constituent portion of a living body, becomes at once a centre of motion, as it were, an impelling agent; restless, active, and incessantly employed; self-consuming, and spontaneously efficient in impressing upon itself destructive changes.

The monad-the minute animalcule, which, among millions of his fellows, finds abundant space in a drop of water-Ehrenberg's point of life, of which mineral masses are sometimes compounded; these, when brought by the microscope within the reach of our vision, are known to be living by their motion alone, or chiefly. The earliest vivification of the larger germ becomes cognizable in the punctum saliens, the circulatory nisus commencing there, and continuing its throbbings until the last pulsation is lost in the tranquil stillness of death.

The thrusting forth of the corculum, or sprout, is only one test of the living condition of the vegetable seed, from henceforth destined to ceaseless motions; the juices of the plant, shrub, and tree being kept in constant agitation; absorbed by the roots, expanding into leaves, and thus exposed to the influences of air and light, and de

positing in their course the appropriate materials of growth and increase, flowering and fruitage.

The second of the essential living properties mentioned above, the capacity, namely, to resist the influence of external agents, manifests itself in a great variety of modes, many of which are, doubtless, familiar to my readers. All bodies while alive enjoy a definite and regulated temperature of their own, independent of the diffused caloric of the atmosphere. The blood of the mammalia is about 98° of Fahrenheit. Birds are warmer than man reptiles much colder. The nose of a dog is always cold. The sap of a tree, throughout the severest winter, not only does not freeze, but retains tenaciously its proper degree of heat. A man's body does not become a degree hotter in an oven where meats are baked, nor a degree colder in an icehouse. A tænia will live, it is said, in boiling veal-broth. Such facts are very

numerous.

The play of chemical affinities, as shown in the ordinary processes of decay and decomposition, are efficiently resisted by the vital principle, even when most subdued and reduced to the lowest condition of passive, or, as we phrase it, "suspended" animation. This is, indeed, a rule so definitely ascertained that we now refuse to admit of any certain proof of death except the re-establishment of those chemical laws in their previously abolished or controlled sway, as shown by molecular change and putrefaction.

How profoundly interesting in this point of view is the condition of dormant vitality-the potentiality of development—the principle of life present but seemingly passive, yet repelling, with a force incalculably tenacious and energetic, the invasion of all external agencies within its circumscribed seat. Seeds kept in the herbarium of Tournefort more than one hundred years were found fertile. Professor Lindley says that raspberries were raised from seeds taken from the stomach of a man whose skeleton was found thirty feet under ground buried with some coins of the Emperor Hadrian; whence it is probable the seeds were 1600 or 1700 years old. Nay, bulbous roots, found inclosed with mummies in their Egyptian envelops, perhaps in a seclusion of 3000 years, produced fac-similes of their parent plants.

Similar stories are told us of the ova of many animals. The infusory animalculæ seem to be capable of an indefinite protraction of dormant life. The rotifer, for instance, may be dried so completely as to splinter when touched with the point of a needle, and in this state would, doubtless, preserve its integrity for 1000 years, and revive readily when moistened again. Every one has read Dr. Franklin's record of experiments on the drowning and revival of the common house-fly. Lister and Bonnet have seen caterpillars recover that had been so hard frozen that, when dropped into a glass vessel, they chinked like stones; and fish are transported great distances, in Northern Europe, frozen and yet alive. The