Mosquitoes 



83 



male palpi are usually somewhat enlarged toward 

 the tip and bear more or less conspicuous patches 

 of rather long hairs or scales. 



THE MOUTH-PARTS 



The mouth-parts of the mosquito are of course 

 of particular interest to us. At first they appear to 

 consist of a long slender beak or proboscis, but by 

 dissecting and examining with a microscope we 

 find this beak to be made up of several parts 

 (Fig. 66). The labium, which is the largest and 

 most conspicuous, is apparently cylindrical but is 

 grooved above throughout its length. At the tip 

 of the labium are the labellae, two little lobes which 

 serve to guide the piercing organs. Lying in this 

 groove along the upper side of the labium are six 

 very fine, sharp-pointed needles. The uppermost 

 of these, the labrum-epipharynx, or labrum as we 

 will call it, is the largest and is really a hollow tube 

 very slightly open on its under side. Just below 

 this is the hypopharynx, the lateral margins of 

 which are very thin. Down through the median 

 line of the hypopharynx runs a minute duct 

 (Fig. 67, sal) which, though exceedingly small, is of 

 very great importance, for through it is poured the 

 saliva which may carry the malaria germs into the 

 wound made when the mosquito bites. The other 



