None of these features are found in nonliving matter. Some have argued that the cell is but a type of crystal, or, at any rate, that the crystal is no similar to the cell that there is no fundamental difference between them. A resemblance exists, but it is altogether superficial, and they differ radically in composition, structure, method of growth, activity, and natural duration in existence. Man is a vegetant organism. Like the plant, man feeds himself, grows, and propagates.
Nutrition is the preparation and assimilation of nourishing materials in the gastrointestinal tract.
The reproduction of man by propagation occurs when the gametes or germ cells, after a maturation division has reduced the number of chromosomes by one half, unite to form the fertilized ovum. Man is a sentient organism. The animal, as distinct from the plant, has a nervous system with sensory functions. There are sensory or afferent nerves, and also motor or efferent nerves. Appetition is the striving toward or away from objects.