INVERTEBRATA. 419 



The mountain districts, of temperate latitudes, are not so 

 obnoxious to the infliction of mosquitos as flat or low 

 countries abounding in water. There are but few species of 

 the genus Culex on the mountains of Pennsylvania. 



The Midge, or Tipulidse family, is also an interesting 

 group of diminutive insects who have friendly leanings to- 

 ward man.* 



Of the spiritual manifestation or the play of the facul- 

 ties of instinct of insects, many astonishing records are made 

 by entomologists, under the chapters of "Affection of insects 

 for their young ;" " Stratagems employed by insects in pro- 

 curing food ;" "Habitations of insects for their young and 

 for their own use;" "Habitations of insects living in so- 

 ciety;" "Perfect and imperfect societies of insects," etc. 

 These seem heads of chapters, not of insects, but of men. 

 To read the chapters is to doubt and wonder, for the fancy 

 seems alone to have created them ; and yet, these great 

 facts are now the common property of science, and natural- 

 ists assert them as the most familiar things. An example is 

 found in the wonderfully-organized kingdom of the honey- 

 bee, known to all, but however familiar, seeming forever an 

 incredible romance, for human society has thus far failed in 

 any comparative organization. Was it not a vain and short- 

 sighted flash of the poet, that the " only study of mankind 

 is man"? The fact that Tumble Beetles will leave their 

 work and go and help a brother in trouble to roll his ball 

 when his hill is too steep for him to do it alone, was no 

 doubt the origin of the clever custom of log-rolling among 

 Congressmen. Many of the family Formicas, or Ants, live 

 in societies, or commonwealths, in burrows of their own con- 

 struction, or mounds, f or regular nests on trees and rushes. 



* The Hessian fly belongs to this group. 



f The large mounds of the yellow American ant abound on the 

 highest summits of the Alleghany. They seem to be filled by great 

 numbers of ants, and are sometimes three or four feet in diameter, 



