174 



THE RESPIRATORY SYSTEM 



[CH. 



each divides into two branches. One of these turns inwards to 

 supply the posterior part of the rectum, the anal region, and, in 

 Zygoptera, the median caudal gill. The other turns sharply 

 outwards to receive a short branch from the junction of the 



ai 



VNT 



VN1 



9. 



10. 



Fig. 76. Tracheal system of larva of Dendroaeschna conspersa Tillyard, exclusive 

 of head ( x 6). aZ x , al 2 alar trunks ; ht trachea to heart ; p z , p 3 pedal tracheae ; 

 pa branch to metastigma; R rectal efferents; TA thoracic anastomosis; 

 Vc visceral crossing; Vr visceral remnant; 1-10 abdominal segments. 

 Other references as in fig. 75. Original, from a dorsal dissection. 



