250 Annals Entomological Society of America [Vol. VII, 
branches. During the growth of this form the two longitudinal 
main trunks join anteriorly and posteriorly, forming an oval. 
Spiracles are not developed during this stage. 
In the second larval stage the tracheal system is at first 
similar to that of the mature first stage larva, except that it 
lies deep within the body of the larva. As this larval form 
grows the first, second and fourth to ninth inclusive short 
branches of each longitudinal main trunk grow rapidly and 
terminally at the surface of the body develop spiracles during 
the last stages of this instar. The third and tenth branches 
remain short and do not develop spiracles. 
The above shows the manner in which the eight pairs of 
spiracles originate, thus proving that the statement made by 
Iv Chewyreuv does not hold true. 
