36 ELEMENTARY PHYSIOLOGY. [ll. 



blood has been taken the corpuscles will pro- 

 bably form a continuous layer, in which case a 

 drop of '6 p.c. sodium chloride solution should be 

 made to run under the cover-slip (cp. 4). 

 a. The red corpuscles are flattened ellipsoids; 



note their spindle shape as they roll over. 

 6. They appear homogeneous ; if however the 



specimen be not carefully prepared a certain 



number of the corpuscles will be altered and 



show a central oval nucleus. 



c. A single corpuscle is pale yellow, the colour- 

 ing substance being equally diffused through- 

 out it ; when several corpuscles lie over one 

 another they together appear red. 



d. The great majority are of the same size and 

 tint. 



2. Examine the colourless corpuscles in parts of 

 the specimen where the red are not very nume- 

 rous. 



a. They are much fewer than the red. 

 6. They are smaller than the red, but vary 

 considerably in size. 



c. Most have an irregular form, some are 

 spherical. 



d. They are colourless and granular; the gra- 

 nules vary greatly in distinctness and size. 



magnification is of course greater. The f inch and J inch objectives 

 of English make correspond respectively to the A and D objectives of 

 Zeiss. With Hartnack's microscope the nearly corresponding lenses 

 are oc. 2 or 3, obj. 3 (low power) and oc. 3 or 4, obj. 7 (high powei). 





