MORPHOLOGY OF THE FIRST MAXILLAE 



67 



(Fig. 62), the galea being undifferentiated, but in those of saw-flies 

 the galea is present (Fig G3, gal}. 



It now seems most probable that in the first maxillae we have the 

 primary form of buccal appendage of insects, the appendage being 

 composed of three basal pieces with three variously modified distal 

 lobes or divisions ; and that the mandibles and second .maxillae are 

 modifications of this 

 type. 



How wonderfully 

 the maxillae of the 

 Lepidoptera are 

 modified, and the 

 peculiar shapes as- 

 sumed in the Dip- 

 tera, Hymenoptera, 

 and other groups, 

 will be stated in the 

 accounts of those 

 orders, but it is well 

 to recall the fact 

 that in the most 

 primitive and gen- 

 eralized moth, Erio- 

 cephala, the lacinia 

 is well developed 

 (Fig. 64). 



As Newport re- 

 marks, the office of 

 the maxillae in the 

 mandibulate insects 

 is of a twofold 

 kind ; since they are 

 adapted not only for 

 seizing and retaining the food in the mouth, but also as accessory 

 jaws, since they aid the mandibles in comminuting it before it is 

 passed on to the pharynx and swallowed. Hence, as the food varies 

 so much in nature and situation, it will be readily seen that the 

 maxillae, especially their distal parts, vary correspondingly. Thus 

 far no close observations on the exact use of the first and second 

 maxillae have been published. 



The palpi also are not only organs of touch, but in some cases 

 act as hands and also bear minute sense-organs, the function 



FIG. 62. Larva of Khagium linedtufii : lot, lateral view of 

 head and thoracic segments ; mx, first maxilla ; ml, undifferentiated 

 lacinia and galea ; , under side of head and pro- and ineso- thoracic 

 segments ; ?>.?/(,., one of the middle ventral segments, magnified six 

 times: mx' 2d maxilla. 



