OHAPTEE XII. 



HOUSE FLIES AND BLUEBOTTLES Continued. 



THE description given in our last chapter of the mouth 

 organs of the bluebottle will not apply without consider- 

 able modification to our fifth species, Stomoxys calciirans. 

 This, it will be remembered, is the blood-sucking fly 

 that has the annoying habit of piercing our skin in a 

 manner which reminds us of gnats and mosquitoes. No 

 one can look attentively at this fly without suspecting it 

 of possible powers of annoyance : the needle-like pro- 

 boscis, projecting straight forwards, like a lance ready 

 for action, looks vicious enough, and by the weapon of 

 which it forms the sheath, the insect can certainly make 

 a sharp and painful puncture. Apparently, however, its 

 powers in this direction have been somewhat exagge- 

 rated ; such, at least, is my own experience, and although 

 the puncture is irritating enough at the time, there are 

 no painful after-effects, as in the case of gnats and 

 mosquitoes. 



With the naked eye we see in this proboscis nothing 

 more than a black, slightly curved, rod-like organ, pro- 

 jecting nearly horizontally from the lower margin of the 

 head. A hand lens shows it as a somewhat cylindrical 

 polished rod, enlarged towards the base, and with the 

 free end considerably more rounded and less acute than 

 it appeared before. The compound microscope exhibits 



it as a highly polished, deep brownish- black body 



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