ISG, ' :^rR. c. b. iiardexburg 



of the larva. If the straw is wetted it will greatly facili- 

 tate its slipping in. Having the straw inserted through- 

 out the entire length of the larval skin will prevent the 

 sides from adhering to each other, or the larva from drop- 

 ping down too near the hot plate during the blowing 

 process, in case the pressure gives out. It also gives ad- 

 ditional support to the larva when mounted. The skin 

 is now tied on to the straw, the string running around 

 the projecting rectal tube. In this way no part of the 

 larva is distorted or destroyed; and, if properly done 

 and well tied, there is no leakage and tlie skin will hold 

 pressure. It is now inflated in the usual manner, api^ly- 

 ing the heat slowly at first. The heat should be gentle 

 during the entire process. It is true that a very hot oven 

 will hasten the drying, but in the case of hairy larv?e the 

 hairs may become singed and turned at the ends, and 

 there will be much more discolouration than when gentle 

 heat is applied. 



It is inevitable that the colours, especially in the thin- 

 skinned cateri)illars, change during tliis process, and 

 sometimes even pass bcA^ond recognition. The colours 

 which tend to keep best are the dark blue, red, yellow, 

 brown and gray; the greens Avill turn to yellow, the 

 yellow to orange, and the light blues have a tendency 

 to disapijear altogether. But a great deal can be done 

 towards preserving those colours by not i:>ressing the 

 larvae out too clean (this applies especially to the thin- 

 skiniied kinds), and by a])plying only a very gentle heat 

 during the entire process of inflating. 



A great drawbiick to tins inflating process is that the 

 skin often stretches far too m\ich, thus giving the cater- 

 j)illar an unnatural ai)pearance. We have found that 

 Hi is can 1h' ])reventod to a certain extent by allowing 

 the emj)ty skin to soak in .")% formalin for a couple of 

 days. This will somewhat harden the intersegmental 

 mciiil)r;in(vs nnd, if tlic air i)ressure applied in the blowing 

 be not loo strong, the in Hated larva can be held down 

 to more or less normal proj)ortions. 



