INTERDEPENDENCE OF ORGANISMS' 



whether there exists any correlations between bilaterality, 

 position of the flower in the cluster, arrangement of the 

 stamens, etc. 



2. The adaptation of insects to flower visitation. 



In the body of an in- 



head thorax , Mntnen sect,there are three prm- 



cipal divisions: head, 

 thorax and abdomen. 

 The head bears eyes, 

 antennae and mouth- 

 parts, the latter con- 

 sisting of upper and 

 lower lips, with two 

 pairs of jaws working 

 horizontally between 

 them. 



FIG. 10. 



insect 



Diagram of the external parts of an 

 a, antennas; e, eye; oc, ocelli; /. 



iiiad.b. i*,- c*iiL^jJiic^ , &,t.yc, l/t,, utjcjll , 1 , pl<j- 



thorax; //, mesothorax; ///, metathorax; 

 W-L and u> 2 , fore and hind wings; l lt 1 2 , / 3 , 

 fore, middle and hind legs; i, 2, 3, 4, etc., 

 segments of the abdomen. 



The thorax is di- 

 vided into three 

 horny rings or seg- 

 ments, each of 

 which bears a pair 

 of legs, and the 

 hindmost two 

 bear each a pair of 

 wings. The abdo- 

 men consists of a 

 variable number of 

 segments. 



The accompany- 

 ing diagram (fig. 10) 

 will serve to repre- p IG n 

 sent the arrange- 

 ment of parts for 

 insects in general. 



Mouthparts of grasshopper and beetle, a, 

 face view of grasshopper (Melanoplus femur-rubrum) 

 showing at /, labrum; b, labiumof same; c, mandi- 

 ble of same; d, maxilla of same; e, mandible of 

 soldier beetle (Chauliognathus scutellaris) ; /, maxilla 

 of same, showing pollen brushes. 



