WAYS AND MEANS OF LIVING
numerous as the species of plants and animals that have existed since life began. A treatise on entomology, therefore, is an account of the ways and means of living that insects have adopted and perfected in their somatic organization. Before discussing insects in particular, however, we must understand a little more fully the principal conditions of living that nature places on all forms of life.
Fig. 65. Legs of a honeybee, showing special modifications
A, outer surface of a hind leg, with a pollen basket on the tibia (Tb) loaded with pollen. B, a fore leg, showing the antenna cleaner (a) between the tibia and the tarsus, and the long, hairy basal segment of the tarsus (1 Tar), which is used as a brush for cleaning the body
As we have seen, life is a series of chemical reactions in a particular kind of matter that can carry on these reactions. A "reaction" is an action; and every act of living matter involves a breaking down of some of the substances in the protoplasm, the discharging of the waste materials, and the acquisition of new materials to replace those lost. The reaction is inherent in the physical or chemical properties of protoplasmic compounds and depends upon the substances with which the protoplasm is surrounded. It is the function of the creature's mechanism to see that the conditions surrounding its living cells are right for the continuance of the cell reactions. Each cell must be provided with the means of eliminating waste material and of restoring its lost material, since it can not utilize that which it has discarded.
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