LABORATORY EXERCISES IN 

 ZOOLOGY 



PRELIMINARY EXERCISES 



I. USE OF THE MICROSCOPE 



Materials. A compound microscope fitted with f and i inch 

 objectives, glass slides for mounting objects, wing of a house fly, 

 cover glasses ; objects for mounting, such as cotton fibers, hairs, 

 blood cell, pond scums, etc. 



Directions. (The author has found it advantageous to set a 

 microscope in a conspicuous position and to have the class make a 

 diagrammatic drawing of it from a side view, afterward, carefully 

 naming all the parts.) 



A. PARTS OF THE MICROSCOPE. With the aid of Fig- 

 ure 1 locate on the microscope the following parts : draw 

 tube, stage, mirror, pillar, large and small milled wheels, 

 eyepiece, objectives. 



B. COARSE ADJUSTMENT. Place the microscope on the 

 table, with the pillar next to the face and with the stage 

 pointing away. Take hold of the large milled wheel on 

 the right side, and turn it toward the operator. What 

 happens to the tube ? As the tube may be rapidly lowered 

 and raised by this wheel, it is called the coarse adjustment. 



C. FINE ADJUSTMENT. Place a glass slide on the stage 

 and lower the f objective until it is about J of an inch from 

 the slip. Put the head down until the eye is on a level 

 with the stage. Sight across the slide, and with the hand 



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