170 



THE RESPIRATORY SYSTEM 



[CH. 



eighth to the first abdominal segment, on either side of the heart, 

 above the alimentary canal. They are not directly connected 



oes 



Fig. 75. Tracheal system of abdomen of Aesc.hna bievistyla Ramb. $ (x2). Heart 

 displaced to right, alimentary canal to left; left dorsal and ventral trunks 

 and left testis removed, an anus; as air-sacs; cr crop; DT dorsal trunk; 

 kg hind-gut ; ht heart ; mg mid-gut ; mp Malpighian tubules ; oes oesophagus ; 

 sp abdominal spiracles; ts testis; vd vas deferens; VNT ventral trunk; 

 VT visceral trunk; 2-8 ganglia of ventral nerve-cord. Original, from a 

 dorsal dissection. 



