INTRODUCTION xv 



SUGGESTIONS 



Students are strongly urged to be on the "lookout" for cases 

 of parasitism, not only because this lends emphasis to the work 

 in hand, but also because of the scientific importance and value 

 of such observations and collections. 



Internal parasites (taken wet) such as tapeworms, round- 

 worms, bots, warbles, etc., may be preserved in 75% alcohol or 

 4% formaldehyde, preferably the latter. If alcohol is used as a 

 preservative the specimens should be run into the higher grades 

 of alcohol gradually, beginning with 25% and allowing 2 or 3 

 hours between each change (25%, 35%, 50%, 75%). 



Insect specimens may be mounted on pins or points or may 

 also be preserved as above. 



