WAYS AND MEANS OF LIVING 



lien. 



numerous as the species of plants and animals that have 

 existed since life 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 

 life. 



As we have seen, life 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 

 materials 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- 

 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 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. 



Fig. 65. Legs of a honeybee, showing 



special modifications 

 A, outer surface of a hind leg, with a 

 pollen basket on the tibia {Th) 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 (/ Tar), which is 

 used as a brush for cleaning the body 



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