The Creation of God by Jacob Hartmann (most difficult books to read .txt) 📕

these two from each other. It is not the same when we descend the scale of organisms. Then we arrive at an inferior region where the distinction disappears gradually, and we soon conceive the existence of a frontier zone between the animal and vegetable, a neutral territory which has been designated the kingdom of Protista.

They reproach naturalists for admitting the kingdom of Protista, accusing them of doubling the difficulty, instead of abolishing it; since it is necessary to establish a distinction between Protista, on the one part animal, on the other vegetable. That objection could be made every time they established a new division in the organic kingdom. It does not signify anything for those who know that all divisions that trench on biology are purely subjective and that nature does not bend to our strict system of classification. Natura non facit saltus.

All living bodies can be decomposed into visible elements under the microscope, and these have been named Plastides or Cells. That word is employed in a more general sense. The most simple Plastide is the Cytode, a simple mass of protoplasm without a nucleus or membranous envelope. A cell in a restricted meaning of the word is a Cytode presenting a nucleus, that is to say, a mass of protoplasm in the midst of which is a distinct part of the substance ambient differentiated by its aspect and its property.

1. Plants and animals are always produced under the influence of a living body similar to themselves.

2. They develop from a germ or rudiment, and run through a course of changes, to a state of maturity.

3. Plants increase by a process through which foreign materials are taken, made to permeate their interior, and deposited interstitially among the particles of the previously existing substance; that is, they are nourished by food.

4. Plants and animals alone possess the power of assimilation, or the faculty of converting the proper foreign materials they receive into their own peculiar substance.

5. Connected with assimilation, as a part of the functions of nutrition, is a state of internal activity and unceasing change in living bodies; these constantly undergoing decomposition and recomposition, particles which have served their turn being continually thrown out of the system as new ones are brought in. This is true of both plants and animals, but more fully of the latter.

6. The duration of living beings is limited. They are developed, they reach maturity, they support themselves for a time, then perish by death sooner or later.

Mineral bodies have no life to lose, and contain no internal principle of destruction. Once formed, they exist until destroyed by some external power. They lie passive under control of physical forces.

Life. The great characteristic of plants and animals is life, which these beings enjoy, but minerals do not. We may safely infer that life is not a product, or result, of the organization; but is a force manifested in matter, which it controls and shapes into peculiar forms—into an apparatus, in which means are manifestly adapted to ends, by which results are reached that are in no other way attainable. As we rise in the scale of organized structure from plants through the various grades of the animal organization, the superadded vital manifestations become more and more striking and peculiar. But the fundamental characteristics of living beings—those which all enjoy in common, and which necessarily give rise to all the peculiarities above enumerated—are reducible to two, viz.: 1. The power of self-support, that of nourishing themselves by taking in surrounding mineral matter and converting it into their own proper substance; by which individuals increase in bulk or grow, and maintain their life; 2. The power of self-division or reproduction, by which they increase in number and perpetuate the species.

A striking illustration may set both points in a strong light. The larva of the flesh-fly possesses such power of assimilation that it will increase its own weight two hundred times in twenty-four hours, and such consequent power of reproduction that Linnæus did not exaggerate when he affirmed that “Three flesh-flies would devour the carcass of a horse as quickly as a lion.”

The distinction between vegetable and mineral is therefore well defined. But the line of demarcation between plants and animals is by no means so readily drawn. Ordinarily, there can be no difficulty in distinguishing a vegetable from an animal. All the questionable cases occur on the lower confines of the kingdom, which exhibit forms of the greatest simplicity of structure, and of a minuteness of size that baffles observation. Even here the uncertainty may be attributed rather to the imperfection of our knowledge, than to any confusion of the essential characteristics of the two kinds of beings (the kingdom of Protista above alluded to).

The essential characteristics of vegetables doubtless depend upon the position which the vegetable kingdom occupies between the mineral and the animal, and upon the general office it fulfills.

Plants are those organized beings that live directly upon the mineral kingdom, upon the surrounding earth, air, water. They alone convert inorganic, or mineral, into organic matter; whilst animals originate none, but draw their whole sustenance from the organized matter which plants have thus elaborated. Plants, having thus the most intimate relations with the mineral world, are generally fixed to the earth, or other substance upon which they grow, and the mineral matter upon which they feed is taken directly into their system by absorption from without, and is assimilated under the influence of light in organs exposed to the air, while animals, endowed with volition and capable of responding promptly to external impressions, have the power of selecting the food ready prepared for their nourishment, which is received into an internal reservoir or stomach. The permanent fabric of plants is composed of only Carbon, Hydrogen, and Oxygen. The tissue of animals contains an additional element, viz., Nitrogen. Plants, as a necessary result of assimilating their inorganic food, decompose carbonic acid and restore its oxygen to the atmosphere. Animals in respiration continually recompose carbonic acid, at the expense of the oxygen of the atmosphere and the carbon of plants.