ZOOLOGY. 341 



Fauna. Climate has undoubtedly a great influence on the character 

 of a Fauna ; we see in the same zone, separated by impassable bar- 

 riers, a tendency to similar animal productions, though there is at the 

 same time sufficient diversity to exclude the idea of a common origin ; 

 different countries have analogous, not identical, species. Geological 

 data, the history of the surface of the earth, and our fast increasing 

 knowledge of the intimate relations of animals to the circumstances in 

 which they live, all lead to the conclusion of their local creation in 

 their present habitats. The relations of parasites afford considerable 

 proofs against the hypothesis that the differences of terrestrial condi- 

 tions have caused the differences in animals. We could not suppose 

 that the lice living on European birds would be different from those 

 of the analogous species of American birds, if they arose from a com- 

 mon stock ; their parasites ought to agree as to species. This is not 

 the fact ; not only do the parasites of our animals, compared with 

 analogous species in Europe, present differences greater than those of 

 the animals on which they live (their species being more distinct than 

 those of the higher animals) , but even our species of birds or mam- 

 mals, having no representative on the other continent, have their own 

 parasites as distinct as themselves. Those animals which, by their 

 own powers of locomotion, or by human means, are common to both 

 continents, have parasites identical in character, as far as observation 

 goes. The lice of our cow, horse, or hog do not differ from those of 

 the same animals in Europe ; the same is true of some birds. The 

 legitimate inference from these facts is, that the analogous species of 

 animals of the different continents were created as such, and there- 

 fore have their proper parasites, and did not emanate from parent 

 stocks. 



Man himself is fortunately annoyed by but few parasites ; his ubiq- 

 uity renders the conditions of his existence different from those of 

 other animals. Many of the higher mammals man has gathered 

 around him in domestic life ; and, as they go wherever he goes, the 

 facts relating to them can have no great w r eight. The lice of the 

 Quadrumana, or monkeys, seem to be different from those of man ; in 

 fact, the species of man are not found on the monkeys, except when 

 their presence may be accounted for by accident ; and those of the 

 monkeys are found only on them. 



Dr. Burnett has also established to his satisfaction the following 

 facts : 1. That although there are single species of parasites pecu- 

 liar to particular animals, there are others which are found in different 

 species of the same genus, as is the case in the parasites living on 

 birds of the genus Latus (gulls), and the diurnal birds of prey. 2. 

 The parasites of the human body confine themselves strictly to par- 

 ticular regions ; when they are found elsewhere it is the result of ac- 

 cident. Thus, the Pediculus capitis lives on the head ; the P. vesti- 

 menti upon the surface of the body ; the P. tabescentium on the bodies 

 of those dying with marasmus ; and the Phthirius inguinalis about the 

 groins, armpits, mouth, and eyes, or the homologous parts of the body. 

 From an examination of the structure of these animals, Dr. Burnett is 

 of the opinion that they should be placed in an order by themselves, 



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