52 The Form of Insects 



muscles for moving the legs are attached on either 

 side of each tergite towards its front edge (fig. 37) ; 

 the other ends of two of these (adductor and abductor 

 coxals) are attached within the haunch ; the third 

 {extensor femoral) passes through haunch and trochanter, 

 its far end being attached to the inner edge of the 

 thigh, which the muscle by its contraction stretches 

 out. The other important muscle for moving the 

 thigh {flexor femoral) is attached within the outer 

 face of the trochanter, its fibres converging to a 

 tendinous insertion at the outer edge of the thigh. 

 Within the thigh are the muscles for moving the 

 shin, the fibres of the extensor being fixed along the 

 outer, those of the flexor along the inner, edge ; the 

 far ends of these muscles converge to tendons which 

 are attached to the near end of the shin. Muscles 

 for moving the foot are fixed along the inner face of 

 the shin, the fibres of the flexor converging into a 

 tendon which passes through all the segments of the 

 foot to the insertion of the claw, while the two 

 muscles which swing the foot backwards and for- 

 wards parallel to the axis of the body are attached 

 respectively to the hind and fore edge of the near 

 end of the first tarsal segment (fig. 38). 



In describing the skeleton of the thorax, mention 

 was made of the apodemes and forks of the lower 

 wall. The two apodemes are connected by a central 

 longitudinal muscle. To the front one are attached 

 also three pairs of muscles, two pairs connecting with 

 the bases of the front and middle legs, and the third 

 with the arms of the fork behind the mesosternum. 

 The hinder apodeme has four pairs of muscles at- 

 tached to it, two pairs connecting with the bases of 

 the front and middle legs, one with the arms of the 

 fork of the metasternum, and one with the second 

 sternite of the hind-body. These muscles, with 



