BRITISH INSECTS 



number of these Lice devote their chief attention to 

 birds, and it used to be a common supposition in Gilbert 

 White's time that the possession of a supply of these 

 parasites was helpful to such birds as Martins and Swal- 

 lows, so that, when pressed for food during migration, 

 these familiar harbingers of Summer would find an 

 abundant food-supply close at hand. Dogs, sheep, 

 and other mammals are also troubled with representa- 

 tives of these distressing parasites, and a large number 

 which we have examined under a microscope, secure 

 from carrying out their distasteful practises, have caused 

 intense interest by reason of their curious facial ex- 

 pressions, to say nothing of their wonder of form and 

 structure. 



ORDER III. ORTHOPTERA, OR EARWIGS, 

 COCKROACHES, CRICKETS AND GRASS- 

 HOPPERS 



The interesting series of insects included in the Order 

 Ortlwptera are divided into several families, the members 

 of which have distinguishing characteristics, such as 

 three, four, or five-jointed legs ; legs formed for jump- 

 ing, leaping, running, seizing, or walking, and long, or 

 not very long, antennae. 

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