PREPARATION 23 



should be heated slowly over an alcohol lamp until the glycerin 

 jelly is melted and surrounds the specimens. The heating should 

 be continued until the mounting media has thoroughly penetrated 

 the specimens, gently boiled if necessary. Care must be used 

 not to get the slide too hot and burned or heated until the glycerin 

 jelly is all evaporated. The cover-glass should be added when 

 the heating is completed. The pygidial fringe is easily followed in 

 such specimens and often other structures of the pygidium can be 

 identified. 



The following formula shows the procedure for the potash 

 method : — 



Remove Insect from Host-plant 



Treat with Caustic Potash. 



Wash in Distilled Water. 



Harden in 95 per cent Alcohol. 



Stain in Alcoholic or Aqueous Stain. 



Dehydrate in 95 per cent Alcohol. 



Clear in Carbol-xylol. 



Mount in Xylol Balsam. 



Label Slide. 



