Mosquitoes 



87 



terior end are given off five long slender processes, 

 the Malpighian tubules which are organs of excre- 

 tion, acting like the kidneys of higher animals. 

 The hindgut is that portion of the intestine from 

 the stomach to the end of the body. 



THE SALIVARY GLANDS 



Lying under the alimentary canal in the forward 

 part of the thorax are the salivary glands. There 

 are two sets of these, each having three lobes with 

 a common duct which joins the duct from the other 

 set a short distance before they enter the base of 

 the hypopharynx. Each of these lobes is made up 

 of a layer of secreting cells (Fig. 71) which pro- 

 duces the saliva that is poured into the wound as 

 soon as the insect pierces the skin of the victim, 

 and we shall see, too, that the malarial germs also 

 collect in these glands to be carried by the saliva 

 to the new host. 



EFFECTS OF THE BITE 



After a mosquito has bitten a person and with- 

 drawn the stylets, a small area about the puncture 

 whitens, then soon becomes pink and begins to 

 swell, then to itch and burn. Some people suffer 

 much more from the bites of mosquitoes than do 

 others. For some such bites mean little or no in- 



