9 6 



INSECT LIFE. 



holding the small insects upon which the dragon-flies 

 feed. It is also probable that the freedom of move- 

 ment of the head resulting from the slenderness of the 

 neck is of great use to these insects in seizing their 

 prey. 



9. Study the peculiar features of the thorax, not- 

 ing the following points : Its large size this is neces- 

 sary to give room for the large and powerful mus- 

 cles that move the wings. The position of the legs 

 these are situated much farther forward than is 

 usual with insects, all of the legs being nearer the 

 head than the wings. The legs are used but little for 

 walking, their chief use being for clinging to some 

 support and, perhaps, for seizing prey. With most 

 insects the middle and hind pairs of legs are attached 

 to the thorax farther back than are the correspond- 

 ing wings, and consequently the side pieces of the 

 thorax between the wings, and these legs slope back- 

 ward and downward 

 from the wings. This 

 is shown in Fig. 85, 

 which represents a 



FIG. 85. side view of a locust 



with its wings re- 

 moved. In a dragon-fly these side pieces of the tho- 

 rax slope fonvard and downward. Make a drawing 

 of a side view of a dragon-fly, illustrating this point; 

 the wings need not be represented, and only the 

 bases of the legs need be shown, as is done in the 

 figure of a locust. 



10. Examine the legs of the dragon-fly, noting 

 the spines borne by the femur and tibia. Consider 

 the possible use of these spines in catching and hold- 



