THE ANATOMY OF THE ADULT MOSQUITO 



83 



represented all the parts of the highly evolved, suctorial 

 mouth of the gnats ; the only difference being that on 

 the latter the parts are attenuated and elongated into the 

 far more efficient, though more delicate, suctorial organ 

 represented belov^. 



In the Mosquito the labium is a long, narrow, grooved 

 spine ending in a pen-like point, and the lower lip, though 

 bearing some likeness to that of the sand fly, has become a 



Fig I8.--D1AGRAM TO Illustrate the Mouth Parts op a Female 



Mosquito. 



A, median mouth parts, and gnathites of the left side (their relative position 

 at the base is indicated in a purely arbitrary way) ; B, end of proboscis seen 

 from below; C, end of proboscis seen from above; D, the same with the hypo- 

 pharynx drawn away to the left — with the exception of fig. A, after Ficalbi. 

 In the above, a, labrum; b, mandible; c, labium; k, hypopharynx; iv, maxilla; 

 A', maxillary palp ; y, basal joint of maxillse. 



mere sheath for the other organs and no longer bears any 

 resemblance whatever to a fly's tongue ; the mandibles and 

 maxillae have become simple slender lancets, formed on the 

 plan of the mediaeval rapier, with a comparatively thick 

 rod-like back, and a broader edged and pointed lamina ; a 

 mere golden-coloured wire of chitine supporting a narrow 

 blade of the same material, so thin as to be absolutely 

 colourless. The hypopharynx has undergone a similar 

 change and has taken the form of a delicate plate, pierced 

 throughout its entire length by a minute canal ; the whole 

 of the mouth parts, except the lower lip, being so delicately 



