122 ELEMENTARY BIOLOGY. [CHAP. 



about J the size of the red ones. Examine 

 under a high power. 



b. The red corpuscles. 



a. Their form oval when seen en face ; almost 

 linear in profile but slightly swollen at the 

 centre. 



/?. Their size ; their length, breadth, and thickness ; 

 measure. 



y. Their colour ; pale yellow, when seen indivi- 

 dually ; redder when seen in the aggregate. 



8. Their structure ; homogeneous for the most part, 

 but possessed of a central oval or rounded nucleus. 



. Treat with water; they swell up and become 

 more spherical ; their colouring matter (hczmo- 

 globiri) is gradually dissolved out, leaving be- 

 hind a colourless protoplasm. The nucleus is 

 rendered very evident, and ultimately all the 

 rest of the corpuscle disappears. 



. Treat with dilute acetic acid; results same as 

 with water, but produced more rapidly. 



77. Treat with alcohol and borax-carmine suc- 

 cessively. The nucleus stains with great in- 

 tensity, the rest of the corpuscle remaining un- 

 affected. 



c. The white corpuscles. 



Obtain a drop of fresh blood and examine as be- 

 fore under your highest power. 



a. Their form ; very irregular, the surface being 

 produced out into a number of blunted pro- 

 cesses or pseudopodia. 



