NATURAL HISTORY 



III. THE INSECT WORLD 



Insects almost Ubiquitous 



THE immense and varied group of Insects constitutes by 

 far the largest class in the Animal Kingdom ; it numbers 

 as many as 200,000 named species, the majority of which 

 are predominantly active types. Such a wealth of forms the 

 species in u single family of insects may outnumber the stars one 

 can count on a clear night shows that, as a class, Insects are 

 extraordinarily successful. Many reasons are given for this 

 dominance, all pointing to the striking fact that insects, by means 

 of manifold adaptations, are able to fill many niches, and so attain 

 a wide distribution. Few haunts are destitute of insect life. 

 Butterflies and mosquitoes are known to penetrate to extreme 

 Arctic regions; a small kind of butterfly is found in Ecuador at 

 an elevation of 16,500 feet; insects inhabit desert tracts far out 

 of reach of water ; and limestone caverns have their cave-dwellers, 

 often pale and blind unless their descent to this unusual haunt has 

 been comparatively recent. Many forms live in fresh water ; even 

 hot-springs have their insects, and some beetles, for instance, are 

 found on the tidal zone of the sea-shore. The actual sea seems 

 very unsuitable for insect life, and yet there is a family of Skim- 

 mers (Halobatidse) which run about on the surface of the open 

 ocean, and even dive when it is stormy. 



The Success of Insects 



Insects are typically winged creatures, and their power 

 of flight extends their range, giving the opportunity to colonise 



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