Page:Popular Science Monthly Volume 75.djvu/300

296 "living." Properly speaking, protoplasm is neither dead nor alive: it is between the two.

If we could get together an ounce or a ton of it, we should say it was a substance or mass exhibiting some of the properties of living matter. We could not say it was a living individual. It is simply matter occupying a very high plane in those ascending gradational transformations between the dead and the living: between the simple inorganic constituents of the earth, and those more complex segregations of chemical atoms which finally become surrounded by a limiting insulatory envelope and thus constitute "physiological units," or living beings. But until this formation of units—this individualism—of the mass, protoplasm can not be said to live.

Of course, the direct transformation of inorganic matter into living animal matter is impossible. There must always occur the intermediate phenomenon of vegetable life. Vegetables can transform the inorganic chemical materials of the air and earth into their own structure, but the animal must either feed upon the products produced by the vegetable or upon other animals that have been so fed. No single definition of life, therefore, can include both animal and vegetable life, since the vegetable is an intermediate product between minerals and animals. The evolution of life is a gradational process. Things are not "either dead or alive." Some things, like protoplasm, are between the two.