HOW TO INFLATE A CATERPILLAR 57 



Rapid drying can only be effected by artificial heat. A 

 small tin canister with a hole an irich in diameter cut out 

 of the hd and heated by a Bunsen flame is convenient.* 

 If the canister gets too hot the larva will scorch; if it is 

 not hot enough the operation will be protracted for an un- 

 necessary length of time. Pass the distended larva well 

 into the canister. On withdrawing it, ascertain by a slight 

 touch of the finger whether the skin is rigid or gives way. 

 The heating should not be discontinued until the skin is 

 quite rigid. It is best and safest to do the drying by heat 

 rather slowly and to break off two or three times to find 

 out how things are going on. When you think the skin is 

 quite dry repeat the heating once more. It is not uncommon 

 for a skin which is supposed to be sufficiently dry to collapse 

 a few minutes afterwards. When the skin has become quite 

 cool, release the springs. The dry skin is apt to cling to 

 the glass tube, from which it should be cautiously detached 

 with a pin-point. Make a coil of fine silk-covered wire by 

 winding it round a pin. Straighten the free end of the wire 

 for an inch or more according to circumstances, and make this 

 adhere to the under side of the dry skin with gum or coaguline. 

 The wire should pass between the abdominal feet. When 

 the gum is dry the preparation is complete. The caterpillar 

 can be attached by the wire to a twig, if a more natural 

 appearance is desired. 



A good deal of practice is desirable, and a demonstration 

 by an experienced hand will save many mistakes. The 

 commonest mistakes are: — (i) imperfect emptying of the 

 skin, causing distortion or partial inflation; (2) collapse from 

 insufficient drying; (3) leakage from bad fitting of the ends 

 of the springs ; (4) over-distension, causing the larva to appear 

 much larger than life-size ; (5) scorching ; (6) injury during 

 detachment from the glass pipe. The anal feet are sometimes 

 broken off in this operation. 



The best and almost the only way of learning how to 

 set moths neatly is to see a skilled hand at work. There 

 are many little details which cannot be described in print, 

 but which are essential to complete success. The necessary 

 implements are grooved setting - boards and entomological 



* Some hold the skin over a hot iron plate, and keep it in view ^11 the 

 time. 



