704 



Mil. J. G. II. FKEW OX THE LAIIYAL 



the pliaiyngeal mass and its associated muscles, forming in tlii» 

 region n complicated plexus. The remaining eiglit latent 1 trunks 

 pass down the lateral body-wall and bifurcate into anterior and 

 posterior branches, by the joining up of which branches (text- 

 fig. 9) a continuous but undulating ventro-lateral trunk is formed, 

 from which branches are given ofl' to the ventral body-wall 

 and a few small ones to the lateral body-wall. The ventral body- 

 wall branches of one side do not appear to anastomose with those- 

 of the other side. 



Text-figure 8. 



0-03 mm. 

 Apicnl view of posterior spiracle. 



Each of the eight posterior lateral trunks except the second 

 and the l:>st gives oil" two large l.iranclios, an anteriorly distributed 

 and a posteriorly distributed ; the latter may arise from the 

 anterior side of the trunk ; the second and last lateral trunks 

 have no anterior branch, and the last has three posterior branches. 

 Tiie anterior branches of the lateral trunks are deep lying; they 



Text-ficure 1). 



])orso-l.iteral view of larva to sliow tracheal system. 



supply the viscera and then run forwards, appi'oaching the median 

 ventral line, and supply a large ventral tracheal plexus in the 

 region of the ganglionic complex. The posterior branches divide 

 into two parts, one supplying the lateral body- wall, the other 

 passing dorsaliy superficial to the dorso-lateral trunk to supply 

 the dorsal body-wall. Tlte traclieation of the dorsal bodi/-wall is 

 supjylied exclasivpjy by branches from the latercd trunks, the dorsal 

 commissures supph/iny no brandies (text-iig. 10 A). 



The first thi-ee (small) antei'ior tracheal trunks are joined to 

 the corresponding trunks of the opposite side by three very 



