AND MEANS OF LIVING
numerous as the species of plants and animais that have existed since lire began. A treatise on entomology, there- fore, is an account of the ways and means of living that insects have adopted and perfected in their somatic organ- ization. Before discussing insects in particular, however, we must understand a little more fully the principal con-
ditions of living that na- ture places on all forms of lire. As we have seen, lire is a series of chemical re- actions 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 break- ing down of some of the substances in the proto- plasm, the discharging of the waste materials, and the acquisition of new materia]s to replace those lost. The reaction is in- herent in the physical or chemical properties of protoplasmic compounds and depends upon the substances with which the protoplasm is sur- rounded. It is the func-
Tb
.'Fb ?:?!?ïllen
Fm. 6 5. 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, halry basal segment of the tarsus (t Tar), which is used as a brush for cleaning the body
tion of the creature's mechanism to see that the con- ditions surrounding its living cells are right for the con- tinuance of the cell reactlons. 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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INSECTS
