70 HOUSEHOLD INSECTS 



constitutes the part of the beak that we see from the 

 outside. The bristle-like organs inside are the real 

 puncturing part of the beak, for the sheath does not enter 

 the flesh when a mosquito bites. The sheath bends and 

 the bristles project beyond the end and bore their way 

 into the flesh. The whole apparatus serves as a carrier 

 to conduct the blood to the mouth. 



While the mosquito is puncturing the skin an irritating 

 substance, the chemical nature of which is not known, is 

 injected into the wound. It is thought by some authors 

 that this poison comes from special glands situated be- 

 tween the salivary glands in the mouth of the insect. 

 Others think it comes from the salivary glands themselves, 

 while others think it is a liquid secreted in certain pouch- 

 like organs connected with the esophagus and known as 

 the oesophageal diverticula. At any rate a sensation of 

 itching is produced by the bite. The immediate area 

 turns red, becomes inflamed, and in some individuals 

 much swelling follows. 



The itching and irritation may be relieved by the appli- 

 cation of dilute solutions of ammonia or a 5 per cent 

 solution of carbolic acid or a 1 per cent alcoholic lotion of 

 menthol. 



RELATION OF MOSQUITOES TO MALARIA 



It has been common knowledge, for nobody knows how 

 long, that in some way malaria is connected with stagnant 

 or standing water. Along with this we have also known 

 that malaria is most prevalent in bottom lands, valleys, 

 swamps, and in regions at the mouths of rivers because 

 it is in such places that water collects and stands. It has 



