PART III 



LIFE-HISTORY STUDIES ON LIVING 

 PARASITES 



INTRODUCTION 



The work in the laboratory is made very much more interest- 

 ing and profitable if the student has the opportunity of making 

 observations on living animals. Courses opening in the first 

 semester come early enough in the year to make it possible for 

 the student to collect his own material out-of-doors. For courses 

 beginning in the second semester the instructor is cautioned to 

 collect material in the autumn and continue breeding through 

 the winter. This is possible for at least some of the required 

 material. Furthermore, spring usually opens up early enough 

 so that living material can be secured after the course begins, 

 and in time to make observations on the same. It is advisable 

 to have either a special breeding room or a part of the main 

 laboratory set aside for this purpose. 



By doing these exercises the student secures a knowledge of 

 habitat and behavior that will be of great assistance to him in 

 practical field work, and the impressions thus secured will be 

 lasting. 



How to Proceed. The student must secure his own material, 

 either by securing the fully mature specimens (male and female) 

 and providing the conditions under which eggs are deposited, a 

 matter not so easily accomplished in all cases, or by securing 

 the eggs in the field under natural conditions, which plan is 

 recommended. Breeding jars can easily be constructed of pint 

 fruit jars or smaller sized glasses, covered over with fine-mesh 

 bobbinet, gauze or filter paper. 



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