10 MAMMALIAN ANATOMY 



too heavy ; a stiff spring will tire the fingers needlessly. Both pairs 

 should have teeth on the inside of the tips. 



The scissors should be of two sizes, and their blades should be 

 straight. A convenient tool is a small hand-saw, known in trade as a 

 jeweller's saw. It consists of a handle attached to a bow of iron on 

 which is strung a fine saw such as is used for fret-sawing. The best 

 saws for cutting bone are those employed for sawing metal. 



A small pair of bone-nippers and several of the dental tools called 

 excavators will be useful for following canals in bone. 



A pocket lens is requisite for the examination of small structures. 



Killing an Animal. The most satisfactory method of killing a 

 small animal for study is by the use of chloroform. It is rapid, 

 absolutely painless, and cleanly. 



The animal is placed in a tight box or a large jar which can be 

 covered closely by a lid ; a piece of sponge or a rag wet with three or 

 four teaspoonfuls of chloroform is placed therein, and the lid held 

 firmly for a few minutes while the animal is passing through the stage 

 of intoxication. At the end of twenty minutes, or, at most, half an 

 hour, the animal will be dead. If the box be large or not very tight, 

 more chloroform and a longer time will be required. Before removing 

 it from the box a cloth wet with a few teaspoonfuls of benzine should 

 be slipped in and left for ten minutes, to kill any fleas that may be 

 on the animal. Ether may be used in place of chloroform. It is 

 just as efficient, but produces some discomfort to the animal and acts 

 more slowly. 



In the absence of chloroform or ether, the animal may be enclosed 

 in a coarse bag and drowned. A disadvantage of this method, which 

 is probably almost painless, is the inconvenience of the wet fur. 



After the animal is dead it should be skinned at once, before the 

 still fluid blood coagulates. 



The skinning can be rapidly done as follows : 



The animal is placed on its back on a piece of board or an old 

 table, and the four legs are stretched out at right angles to the body, 

 and held in that position by cords tied round the paws and fastened 

 to nails in the board or passed under the table and tied together. The 

 fur is then parted, with a comb, down the entire middle line of the 

 body. An incision through the skin is made on this line just behind 

 the point of the chin. A grooved director is now introduced into 



