﻿202 [February, 



ligneous acid for a short time ; then gently squeeze the inside out, upon 

 or between pieces of blotting paper, taking care not to tear or enlarge 

 the anal orifice. After having extracted all the moisture and intestines, 

 insert in the aperture a bent glass blow-pipe, having a bulb in the mid- 

 dle, and inflate the larva over a spirit lamp, having a flat piece of 

 zinc fixed over the flame. Holding the tube so that the larva does not 

 touch the zinc plate, blow gently, until it is quite dry and hard. This 

 requires great care, as it is liable to scorch ; and, if the skin be only 

 partially dry, it will, although apparently finished, become indented or 

 depressed in those places where it is not thoroughly hardened. To 

 ascertain if the operation be complete, cease blowing, and draw in the 

 breath gently ; when, if the larva is not dry, it will shrivel up, and must 

 be inflated again immediately ; if, on the other hand, it is dry, it will 

 remain distended to its natural size and appearance. To prevent the 

 head from being extended too much, dry all the body except the first 

 and second segments, take the larva away from the spirit lamp, and 

 press the head into its natural position, afterwards drying it at some 

 distance from the flame, without blowing through the tube. If the 

 larva require colouring (as almost all green larvae do) some very finely 

 powdered dry colour (rather darker than the original colour of the 

 larva) must be introduced into the skin after it is thoroughly dry. To 

 get the colour evenly on the inside of the skin, it must be rolled about 

 in the hand. In order to direct the heat on to any particular place, a 

 small hole (about the size of the head of a pin) should be made in the 

 centre of the piece of zinc. This will be found to be particularly useful, 

 when finishing the head of the larva, as above described. The object of 

 having the glass tube bent is, that the head is then above the level of 

 the flame ; and the bulb is to prevent any moisture from the mouth 

 running down the tube into the inside of the larva. I generally put a 

 piece of blotting paper in the mouth-piece of the tube. 



The inflation while the larva is over the lamp must be kept up 

 without intermission. This is very easy after a little practice, and does 

 not cause any exertion, as the breathing is carried on through the nose. 

 A larva should be kept without food for a day before being killed, as it 

 is almost impossible to extract the food that it has just eaten ; and, after 

 the larva is dried, this shows in an ugly black patch just behind the head. 

 Very frequently it occurs, that, while blowing, the larva will slip off the 

 tube ; this can be prevented by tying a thin piece of cotton round the 

 end of the tube and the last pair of claspers. It is, however, as well, if 

 possible, to dispense with tying the larva on the tube, as it very often 

 distorts the shape of the last segments. The best larva for a first ex- 



