CHAPTER II. 



Fig. 258. 



THE PRESERVATION OF SPECIMENS. 



There are two ways of pre- 

 serving entomological speci- 

 mens : they may be either pinned 

 and dried, or they may be placed 

 in a preservative fluid. The 

 method chosen will depend upon 

 the nature of the specimen and 

 the use to which it is to be put. As a rule, any 

 specimen that will preserve its form when dried is 

 pinned. Thus entomologists usually pin the adults 

 of nearly all insects, specimens of nests, infested 

 twigs, mined or rolled leaves, and other similar ob- 

 jects. On the other hand, the immature forms of all 

 insects, and such adults as have soft bodies that will 

 shrivel upon drj'ing, are usually placed in alcohol. 

 Millipedes, centipedes, mites, spiders, and other 

 forms allied to these are also preserved in alcohol. 

 Some insects, on account of their minute size, are 

 mounted as microscopic objects in Canada balsam 

 upon glass slips, as described later. 



In case specimens are desired for anatomical 

 study, the}- are preserved in alcohol or some other 

 fluid, whether the bod)- be soft or not ; and certain 



294 



