THE PRESERVATION OF SPECIMENS. 301 



from the body of the insect before mounting it; this 

 is done by placing the specimen in alcohol. If the 

 insect is hard so that there is no danger of shriveling, 

 it may be placed in strong alcohol at once, and then 

 mounted after a few hours. Insects with soft bodies 

 should be hardened gradually by being placed suc- 

 cessively in fifty per cent, seventy-five per cent, and 

 ninety-five per cent alcohol, as described in the pre- 

 ceding section. 



When the specimen is hardened by the alcohol, 

 place it in a watch glass containing a small quantity 

 of oil of cloves, and leave it for a few minutes ; this 

 is to remove the alcohol and render the object more 

 clear. Then put the object on the slide, cover it 

 with balsam, and place a cover-glass over the im- 

 bedded object. In the course of a few days the 

 balsam will become hard, so that there will be lit- 

 tle danger of injury to the specimen by handling the 

 slide. 



Inflating Larv^. — The fact that the appearance 

 of many larvae is greatly altered by preserving them 

 in alcohol leads many entomologists to remove the 

 viscera from such larvae, especially caterpillars, and 

 inflate and dry the skins. The process is somewhat 

 difficult and disagreeable to perform, but if it is well 

 done very beautiful specimens are obtained, which 

 preserve the form and color of the larvae much better 

 than those prepared in any other wa}'. 



The method of preparation is as follows: — Kill 

 the larva by leaving it for a time in a cyanide bottle. 

 Insert the point of a pin into the posterior end of the 

 alimentary canal, and, by moving it about, break off 

 the hind end of the intestine from its attachment 



