IXTERDEPEXDEXCE 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- 

 Jirad t/utt-ax abdomen 



FIG. 10. Diagram of the external ps 

 insect, o, antennas; e, eye; oc, oceV 

 thorax; //, mesothorax; ///, metathora 

 u/, and u> 2 , fore and hind wings; /,, /. / 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- 

 sent the arrange- 

 ment of parts for 

 insects in general. 



sectthere are three prin- 

 cipal divisions: head, 

 thorax and abdomen. 

 The head bears eyes, 

 antennae and mouth- 

 parts, the latter con- 

 sisting of upper and 

 /"pro- lower lips, with two 

 pairs of jaws working 

 horizontally between 

 them. 



IG. 11. Mouthparts of grasshopper and beetle, a, 

 face view of grasshopper (Melanoptus femur-rubrum) 

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

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

 soldier beetle (Chauliognathus scuteUaris); /.maxilla 

 of same, showing pollen brushes. 



