42 THE COCKROACH : 



There are three pairs of jaws, disposed behind the labrum, as 



in the diagram : 



LABRUM. 



1st pair of Jaws (MANDIBLES). 



2nd ,, (MAXILLAE). 



3rd ,, (LABIUM, or 2nd pair of Maxillae). 



Lm 



Fig. 19. Diagram of Cockroach Jaws, iii horizontal section. 



The mandible is undivided in all, or nearly all, Insects. Each 

 maxilla may consist of 



A palp on the outer side, 



A gaka (hood), 



A lacmia (blade), on the inner side. 



The galea (hood) of the 3rd pair of jaws is sometimes called 

 the paraglossa. 



A tongue-like process may be developed from the front wall 

 of the mouth (epipharynx) , or from the back wall (hypopharynx 

 or lingua)* Both epipharynx and hypopharynx project into 

 the mouth, and, in some Diptera, far be} r ond it. 



The tip of the labium is sometimes produced into a long 

 tongue, called the ligula (strap). 



The mouths of Insects may be classed as : 



BITING. Orthoptera, Neuroptera, Coleoptera (in some 

 Coleoptera a licking tongue is developed), most 

 Hymenoptera. 



LICKING AND SUCKING. Some Ifymenoptera e.g., Honey 

 Bee. 



SUCKING. (a) With lancets Diptera, Hemiptera. 

 (b) Without lancets Lepidoptera. 



* Professor Huxley has proposed to call the attached base hypopharynx, and the 

 free tip lingua. 



