INTRODUCTION xv 



service is given by the cheaper doublet type. The magnifying 

 power should not exceed 10 to 14 diameters. 



Dissecting Instruments. — The ordinary dissecting set as 

 required in the elementary course in zoology is sufficient for 

 this course. Heavy scissors with one blunt probe point, or the 

 regular enterotomy scissors are very useful in the examination 

 of animals for intestinal parasites. Bone-cutting forceps should 

 be available. For examination of large animals special equip- 

 ment of skinning knives and other tools is necessary. 



Preservation and Mounting of Specimens. — It will add much to 

 the value of the work if the student will take advantage of 

 opportunities to examine various animals for parasites. These 

 can be preserved by the methods given in the appendix. In 

 every case care should be taken to preserve accurate data as 

 to the host and the organs from which the specimens were 

 taken and the date and locality. 



