MUSCULAR SYSTEM. 263 



connected ; it consequently bends the whole foot, whereas the extensor, 

 by drawing the first joint, again extends it. 



In the last tarsal joint we again find peculiar muscles, viz., one 

 which originates from the base of the claw, and affixes itself to the 

 tendon of the tarsal flexor. It helps to bend the claws, and is thence 

 called flexor uitguium. The other originates with a broad base from 

 the inner wall of the superior surface of the claw-joint, and runs, 

 becoming pyramidal, to an arch connecting the two claws. It raises 

 the claw, and is therefore styled extensor unguium. 



180. 

 C. MUSCLES OF THE ABDOMEN. 



The collective muscles of the abdomen serve partly to connect it 

 with the thorax and partly to unite the internal organs with it, and 

 they are thence divided into three groups. 



The muscles which unite the abdomen with the thorax are, when 

 the abdomen is sessile, like all the abdominal muscles, flat, and like 

 bands, and originate from the posterior and lateral margins of the 

 thorax, affixing themselves to the first segment of the abdomen. 



Those situated at the dorsal surface, which we call the superior 

 connecting muscles of the abdomen (muse, cbnjungentes superiores, s. 

 dorsales}, are divided into several contiguous bellies, which run flatly 

 from the metanoturn and metaphragma to the first dorsal plate. The 

 lower connecting muscles, which lie upon the ventral surface (muse, 

 conjung. inferiores, s. ventrales), come from below, from the posterior 

 margin of the metasternum, and pass between the femoral cavities to 

 the first ventral plate. 



Between both lie the lateral connecting muscles (m. conjung. late- 

 rales), which come from the lateral margin of the metasternum and 

 the lateral plates, and, passing into the cavity of the abdomen, uniting 

 themselves to the lateral wings of the first or second ventral plate. 



In insects with a petiolated abdomen all these muscles, it is evident, 

 cannot be present, but instead of the dorsal muscles we find a single 

 large band (funiculus of Kirby and Spence), which originates from 

 the inside of the metaphragma as a pyramidal muscle, passing with 

 its point through the hole at the end of the metaphragma, and affixing 

 itself to a short tooth which lies at the anterior margin of the first 

 dorsal plate (PI. XII. No. 2. f. 9. .). The dorsal and ventral plates 

 of the first abdominal segment are prolonged into a broad upwardly 



