CIRCULATION IN INSECTS. 



•219 



have been called, of the dorsal part of the tube ; f, 

 one of the small tendinous folds, to which the liga- 

 mentary bands are attached ; and l is one of these 



I 



bands, having a triangular, or, if considered as con- 

 tinuous with that on the other side of the vessel, a 

 rhomboidal shape, and attached at r, to the supe- 

 rior segments of the abdomen. At i is seen a layer 

 of the same fibres, which are partly ligamentous 

 and partly muscular, passing underneath the dorsal 

 vessel, and forming, in conjunction with the layer 

 that passes above it, a sheath, which embraces and 

 fixes that vessel in its place: these inferior layers 

 have been removed from the other parts of the 

 vessel, to allow the upper layers to be seen, as is 

 the case at l. Fig. 335 gives a side view of the 

 anterior extremity of the same vessel, showing the 



