CHAP. VI. THE IMAGO STATE. 



37 



and their chief office seems to be to assist in retaining and 

 masticating the food. Near the base of each lower jaw, on 

 the outer side, is a jointed appendage, called the maxillary 

 palpus (Figs. Ill, 112 and 113)*f- Below the lower jaw is 

 placed the lower lip; this is used in retaining the food in the 

 mouth; near the base are two jointed appendages, called the 

 labial palpi (Fig. 106)*f. When the lower lip is very narrow, 

 the terminal portion is frequently called the tongue (lingula). 

 It is attached to the upper and inner edge of the chin (mentum)\ . 



There is sometimes a second pair of appendages, attached 

 to the lower lip, nearer its tip than the labial palpi; these are 

 termed the paraglossa. 



In those insects which obtain their nourishment by suction, 

 such as Bugs, Butterflies, Moths, and the Two-winged Flies, 

 gome or all of the mouth parts are drawn out or elongated, 

 and several of them are sometimes united to 

 form a single organ, or beak; in many in- 

 sects such as True Bugs ( Fig. 114, b ), 

 Horse-flies, etc. the beak (Fig. 114, ) is 

 hard, and fitted for piercing, while in others 

 such as the House-fly it is quite soft, and 

 fitted for lapping. In the Butterflies and the 

 Moths it is usually quite long, frequently as long or longer 

 than the entire body of the insect, and when not in use is 



Fig. 114. 



Fig. 115. 



Fig. 116 



coiled up like the hair-spring of a watch (Fig. 115, </), and 

 concealed beneath the head. 



* See Fig. 89. 



j- See Fig. 103. 



