565 



ELEVENTH CHAPTER. 



THE HABITATS OF INSECTS. 



311. 



WHEN the question is asked where are insects found, we may 

 unconditionally reply everywhere except in the sea, for there is no 

 spot upon the earth accessible to organic beings that is not inhabited 

 by insects. In this universality of their abode it will appear desirable 

 to class them under several heads, that we may be thereby enabled to 

 combine them more closely together ; we may therefore consider this 

 subject under the differences of elements, the differences of season, and 

 lastly, the differences of climate, the last of which has usually been 

 called their geographical distribution, and which, although it has been 

 already elaborated by several entomologists *, is as yet laid down in 

 a very meagre outline. The materials we have collected for the com- 

 pletion of this subject are as yet too imperfect to submit them to the 

 public, and which we therefore defer to another opportunity, and shall 

 here consequently only examine them with reference to their abode, 

 as respects the elements and seasons. 



312. 



As regards the elements, we have already in several places indicated 

 that insects are animals of the air, and are referred especially to live 

 in that element. Yet this means only that the majority of them possess 

 the power of raising themselves in the air, and there moving at will for 

 a time, and not that they exclusively dwell in it. The air is absolutely 

 necessary to every organic being, and in so far every animal is an air 

 animal ; for although many live in the water, they even here make use 

 of the air intermixed with it for the preservation of their lives. But 

 there is yet a certain difference between the different classes of animals 

 with respect to this necessity, and if insects do not belong to those ani- 



* P. A. Latreille, Considerations sur la Geographic des Insectes. Mt'm. du Mus. 

 1815 W. S. M'Lcay, Horse Entomologies. Lond. 181921. 8vo. vol. i. p. 1. 

 Kirby and Spcnce, Introd. to Entom. vol. iv. p. 48b', &c. 



