180 ■ INSTRUCTIONS FOE COLLECTING INSECTS. 



The carho7iate of ammonia is recommended as a substitute for the 

 spirits, in consequence of no vapor collecting in the bottles, and being 

 cheaper and safer in the hands of the young. The best way to use it 

 is first to reduce it to small pieces, (not powder,) and to enclose it in 

 a small bag made of any porous material, and place it with its con- 

 tents at the bottom of the bottle, covering it with a perforated card. 



HOW TO PIN LEPIDOPTERA. 



In the first place, the pin should be adapted as far as possible to the 

 size of the specimen. The pins in use amongst the German and French 

 entomologists are too long and slender, and are liable to bend in 

 thrusting them into the cork unless carefully used. In these respects 

 the English pin is much to be preferred ; that used for the " micros" 

 being only three quarters of an inch long. The common pin, about 

 I5 inch long, answers very well for the large moths, and the size 

 somewhat short of an inch will do for those of moderate size ; but for 

 the micros it is indispensable to have a supply of Nos. 10, 19, and 20 

 of the English make. They are manufactured by Messrs. Edleston & 

 Williams, Crown Court, Cheapside, London. 



The pin should be thrust vertically through the body in the centre 

 of the thorax, or the part to which the wings are attached. After it 

 has fairly entered the thorax a piece of soft cork is used, by pushing 

 the point of the pin into it, to raise the specimen the requisite distance 

 up the pin. At least one half oi the pin should be exposed below, and 

 uniformity in this respect can be obtained by always using the same 

 thickness of cork for this purpose. When about to pin a specimen 

 it should be placed on a cloth-covered surface to prevent it slipping 

 about, and if, under the effect of chloroform, it has turned on its back, 

 be reversed with a pin ; or those of moderate or large size may be 

 taken by the thorax and feet with the thumb and finger of the left 

 hand and pinned whilst being thus held, and the position of the 

 specimen atterwards regulated by the cork. Specimens can be easily 

 transfixed on the top of the collecting box, if it is covered with cloth, 

 without the necessity of touching them with the fingers. Many of the 

 micro Lepidoptera_, however, turn upon their backs and project their 

 posterior legs ; if they cannot be easily reversed again with a pin, 

 they must be taken between the thumb and forefinger of the left 

 hand, by their projecting legs, and permitted to fall in the space formed 

 by the contact of these members, with the head to the left or front 

 according to the position of the hand. Then, by taking a small pia 

 between the thumb and forefinger of the right hand, and resting the 

 unoccupied fingers on those of the left, in order to insure steadiness, 

 the pin is easily pushed through the thorax of even the smallest 

 species. The success attending this operation depends on taking up 

 the specimen so that it will rest closely in the sulcus of the thumb 

 and forefinger, with the head well forward. Of course, previously to 

 taking it up, the head should be turned to the right. A few failures 

 in the first instance should not discourage the beginner. 



