Text-fio. 15. 



Transverse section of lateral wall of abdomen of larva of first 

 stage through a closed spiracle {«(/"). trl, tracheae, Zeiss, 

 ob. DD, DC 4. 



Text- FIG. 16. 



Longitudinal section of liind end of abdomen w-ith breathing 

 apertures (a), atrium (at), and end of main longitudinal tracheal 

 trunk (^0- Zeiss, ob. DD, oc. 0. 



