CHAPTEE XIV. 



THE COMMON FLEA. 



NOTWITHSTANDING his elevated position in the animal 

 creation^ man is no more exempt humiliating though 

 the confession may be from the attacks of personal 

 parasites than other animals ; but of the various species 

 that link their fortunes with his, and subsist upon his 

 person, fleas seem less dependent than any others upon 

 uncleanly conditions and habits of personal neglect on 

 the part of their host, and hence they are not restricted 

 to the lower strata of society, but become a universal 

 nuisance. The ever-present desire to exterminate them, 

 no doubt, operates powerfully against their being min- 

 utely studied, and hence very little seems to be generally 

 known about their structure, habits, and life history 

 beyond what painful experience teaches. And yet they 

 are really extremely curious creatures ; and were it not 

 for the popular prejudice against them, they would, no 

 doubt, attract the attention they deserve. It is no 

 exaggeration to speak of them as zoological oddities. 

 There are many different kinds besides that particular 

 species that infests man. They have been observed on 

 various mammals, especially small ones with thick fur 

 or hair, such as moles, shrews, squirrels, mice, rats, 

 dormice, hares, and rabbits, as well as on dogs and cats. 

 Many birds also are infested by true fleas, in addition 



to their own proper parasites, the bird-lice. The species 



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