36 CLAUDE EHLLER. 



tracheee are the cephalic terminals of the dorsal longitudinal 

 trunks. 



The extensions of this part of the respiratory stem are : 



(a) The tracheae of the first pair of It-gs, fig. 16. The 

 basal attachments of these are simple ; they are linked 

 together by a transverse commissure traversing- the floor of 

 the neck, the cervical commissure (c. c, fig. 16). 



(b) The paired tracheee of the anterior lateral extensions 

 of the prothorax {a.a., fig. 17). These are somewhat insignifi- 

 cant and arise near the base of each of the upper main 

 tracheae (x.x.) between the spiracle and the point at which the 

 dorsal longitudinal of the body (h.h.) is attached. 



(c) The tracheae of the vertex {d.d., fig. 17) and of the 

 genae (c.c). They arise in the order mentioned from each 

 of the upper main tracheee shortly after these enter the head. 



(d) The paired complexi of the frons {e.e., fig. 17), each 

 complex being a bunch of three dichotomised tracheas. A 

 complex is attached to each of the upper trachete above the 

 point of attachment of the vertical commissure {z.z.). 



(e) The paired tracheas of the lower mouth-parts and the 

 paired trachege of the labrura, figs. 18 and 19. These emerge 

 in the order mentioned from each stem of the U-f'haped trachea. 

 Each trachea of the lower mouth-parts subdivides into three 

 stems. Of these, the innermost stem travels forwards and 

 subdivides into three branches, one bi-anch entering the 

 glossa, another the paraglossa, and the third the labial 

 palpus. The middle stem behaves likewise, its three terminals 

 resting in the lacinia, the galea, and the maxillary palpus. 

 The outermost stem enters the mandibles, extending to the 

 apical tooth and giving oif two side branches, one to the 

 cutting and one to the molar region. Each trachea of 

 the labrum travels upwards to the region of the clypeus, and 

 there bears a complex or bunch of three tracheas, and then 

 enters the labrum, extending along the margin of this part 

 to the apex. Fig. 18 has been prepared from a cleared 

 preparation, and shows all the visible trachefB as seen from 

 below, the nearer tracheae being shown in solid black and 



