204 



THE BODY-WALL AND MUSCLES 



[CH. 



wing-muscles, each separate muscle is formed of a number of 

 bundles, bound together by a continuous inter-nbrillar substance, 

 but without a sarcolemma. Most of the muscles are of a white, 

 creamy, or pale greyish colour. The wing-muscles are exceptional 

 in being dark yellow, inclining to orange. The cross-striation of 



B. 



Fig. 89. Synthoracic musculature of Sympetrum ( x 10). A. Inner or proximal 

 view. B. Outer or distal view, with pe removed and ad cut short. Explanation 

 of references for muscles in text. References to parts of thorax (in italics) 

 in legend of fig. 1. ac acetabulum. Adapted from Berlese. 



the wing-muscles differs from that of the other muscles. In the 

 former the striae are thick, and light and dark alternately. In the 

 latter the striae are all alike, not darkened, but carrying rows of 

 small dots. In both forms of muscle the striae are broader and 



