OBJECTIONS ANSWERED. 



39 



have sacrificed one of the former to your just vengeance catch 

 one of the latter and compare them. I question if, after the 

 narrowest comparison, you will not still venture a wager that 

 they are the very same species. Yet you would most certainly 

 lose your bet. They are not even of the same genus — one 

 belonging to the genus Musca {M. domestica), and the other 

 to the genus Stomoxys (^S. calcitrans)\ and on a second ex- 

 amination you will find that, hoAvever alike in most respects, 

 they differ widely in the shape of their proboscis ; that of 

 the Stomoxys being a horny sharp-pointed weapon, capable of 

 piercing the flesh, while the soft blunt organ of the Musca is 

 perfectly incompetent to any such operation. In future, 

 while you no longer load the whole race of the house-fly with 

 the execrations which properly belong to a quite diflerent 

 tribe, you will cease being surprised that an ordinary descrip- 

 tion should be insufl&cient to discriminate an insect. It is to 

 this insufficiency that we must attribute our ignorance of 

 so many of the insects mentioned by the older naturalists, 

 previously to the systematic improvements of the immortal 

 Linne : and to the same cause we must refer the impossibility 

 of determining what species are alluded to in the accounts of 

 many modern travellers and agriculturists who have been 

 ignorant of Entomology as a science. Instances without 

 number of this impossibility might be adduced, but I shall 

 confine myself to two. 



One of the greatest pests of Surinam, and other low regions 

 in South America, is the insect called in the West Indies, 

 where it is also troublesome, the chigoe {Pulex penetrans), a 

 minute species, to the attacks of which I shall again have 

 occasion to advert. This insect is mentioned by almost all 

 the writers on the countries where it is found. Not less than 

 eight or ten of them have endeavoured to give a full descrip- 

 tion of it, and some of them have even figured it ; and yet, 

 strange to say, it was not certainly known whether it was a 

 flea {Pulex, L.), a louse {Pediculus, L.), or a mite {Acarus, L.), 

 till a competent naturalist undertook to investigate its history, 

 and in a short paper in the Swedish Transactions ^ proved that 

 Linne was not mistaken in referring it to the former tribe, 



1 Swartz in Kongl. Vet. Ac. Nya. hand. ix. 40. 

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