CHAPTER IV. 



TO PRESERVE INSECT PARASITES. 



In collecting specimens place them in a bottle 

 containing a piece of gum camphor. After the in- 

 sect is dead it can be mounted on a block of wood 

 by means of a pin thrust through the thorax. Dark 

 or black parasites should be mounted on a light 

 back-ground. These can be placed in suitable 

 bottles with moth ball or gum camphor, and will keep 

 indefinitely. Another way is to fill the bottle with 

 alcohol. This forms a good preservative and does 

 not rust the pins. 



TO MOUNT ECTOZOA. 



1. Wash in alcohol till all dirt is removed from 

 the parasite. 



2. Place specimen in xylol for five minutes. 



3. Mount in Canada balsam. 



By this method lice, gnats, parts of flies, ticks, and 

 scab parasites can be satisfactorily studied. Thus 

 preserved the specimen will keep indefinitely. In 

 mounting thick specimens the glass or rubber cells 

 may be used. Keep slide face up, as in the summer 

 the Canada balsam will become soft and the speci- 

 men gravitate to one side if the slide be kept edge- 

 wise. 



TO PRESERVE ENTOZOA. 



1. The Keiserling method may be used. 



2. A four percent solution of formalin, 



3. Alcohol. 



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