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SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. I43 



Fig. 13.— Examples of the tracheal system of a caterpillar. 

 A, Cutworm (noctuid), ventral half of thorax and first two abdominal seg- 

 ments. B, Same, thoracic segments with muscles removed. C, bame, ventral 

 tracheation of end of abdomen. D, Corn ear worm, Heltothis sea, gonads and 

 their tracheation in fifth abdominal segment; Dct, duct; Gon, gonad; Lxg, 

 suspensory ligament. 



