346 G. G. SCOTT. 



To the Wings. Just posterior to the hinder origin of the cres- 

 cent arises the anterior limb of a loop (Fig. I, F W") which fur- 

 nishes the fore wing with tracheae. The posterior limb of the 

 loop passes back and joins the dorsal connective. The posterior 

 limbs of both the fore wing loops join the dorsal connective side 

 by side (Fig. i). Five tracheae pass out from the face of the 

 wing loop. By the successive branching of these five tracheae 

 the whole wing is supplied. The first or the most anterior does 

 not bifurcate simply but sends about twenty short branches to the 

 edge of the wing. The second and third branches are the largest 

 and supply the greater portion of the wing while the fourth and 

 fifth send fine branches to the posterior margins of the wing. 

 The distribution to the hind wings is similar to that of the fore 

 wings. There are five main tracheae originating also from a loop 

 whose anterior limb (Fig. I, H W] arises from the mesothoracic 

 a short distance from its origin from the dorsal. The posterior 

 limb of the loop joins the dorsal midway between the origin of 

 the meso- and the metathoracic tracheae. In the larva the legs 

 are used much more than in the adult. The wings on the other 

 hand are functionless in the larva. Therefore it is not surprising 

 that the tracheae to the legs are much larger in the larva. And 

 yet although the wings are not used there is a complex distribu- 

 tion to every part. 



Anterior to the Stigmata. Two pairs of tracheae originate 

 from the dorsal at the stigmata, an inner or cephalic pair (Fig. i, 

 CEPH} and an outer or labial pair (Fig. I, LAB]. 



The labials (Fig. 2, LAB} pass alongside the cephalics for a 

 distance, then down around the esophagus and out to the mask 

 (Fig. 2, M}, sending out many branches. The distribution to 

 the mask should be noted, as this organ is in constant activity in 

 larval life for the capture of prey. The prothoracic trachea 

 (Fig. i, P 777") arises from the labial, a short distance anterior 

 to the stigmata. 



The cephalics (Fig. i, CEPH] pass along the dorsal face of the 

 esophagus and can be traced forward to the brain. There they 

 are connected by a loop (Fig. I, C L) and from this loop five 

 branches pass forward. The middle branch (Fig. I, 77) passes 

 dorsally to the top of the head. The two pairs on each side (Fig. 



