44 



THE TRACHEATION OF WINGS 



Tillyard's description and figure differ from those of Scott in that the 

 former author has the anterior wing tracheae connecting with the leg 

 tracheae and the posterior wing tracheae connecting with the longitudinal 



trachea, while the latter author 

 has the anterior trachea of the 

 fore wing connecting with the dor- 

 sal longitudinal trachea and that 

 of the hind wing connecting with 

 the spiracular trunk near the dor- 

 sal longitudinal trachea. 



The posterior trachea to the 

 wings is said by him to connect 

 with a transverse connective, in 

 the case of the fore wing, and with 



Fig. 34-— The basal connections of the tracheae the dorsal longitudinal trachea in 

 of the wings of Anax. Dorsal view. ,1 r ^.i 1 • j • 



the case 01 the hind wmg. 



The figures accompanying this paper are the result of numerous dissec- 

 tions and show the conditions in a representative of each of the two sub- 

 orders (Figs. 34 and 35). There are two tracheae entering the front of 

 each wing pad, the usual costo-radial trunk (c-r) connecting with the 

 anterior stem of the leg trachea (as) and accessory costo-radial trunk (a. c-r) 

 connecting with the dorsal longitudinal trachea (d. It), in the case of the 

 front wing, and with the trunk to the vestigial metathoracic spiracle, in the 

 case of the hind wing. It is 

 probable that Tillyard has 

 seen the costo-radial trachea 

 in studying the lateral view 

 of the thorax while Scott 

 has seen the accessory costo- 

 radial trachea in his study of 

 the dorsal view of the thorax, 

 which he figures. 



There are likewise two 

 posterior tracheae to each 

 wing pad. The cubito-anal 

 tracheae (cn-a) of both wings 

 are vestigial and are made 

 out with some difficulty but 

 they have retained their 

 original connections with the 

 posterior stems of the leg 



Fig- 35- — The basal connections of the tracheae 

 of the wings of Lestes. Side view. 



tracheae. The accessory cubito-anal tracheae (a. cu-a) are much the larger; 

 the one to the fore wing arises from the transverse connective which lies 



