LABORATORY MANUAL OF PHYSIOLOGY. 



is much less. A special pipette is employed, with which a dilution 

 of i to i o or i to 20 may be obtained. The diluting fluid employed 

 is usually a 0.2 of one per cent acetic acid. This accentuates the 



f 



FIG. 24. Human Blood-corpuscles, a, Red blood-corpuscles for comparison; , 

 small hyaline cell or small lymphocyte ; c, large hyaline cell or large lymphocyte ; </, 

 fine granular oxyphile ; e, coarse granular oxyphile or eosinophile ; /, basophile. (F. 

 C. Busch.) 



nuclei of the white cells and decolorizes the reds. Aside from this, 

 the technique of counting is the same as that for the reds. 



II. CHANGES PRODUCED IN THE CORPUSCLES THROUGH VARI- 

 ATIONS OF OSMOTIC PRESSURE. 



Dilute equal volumes of defibrinated blood with (a) distilled 

 water; (b) o.8-per-cent sodium- chlorid solution; (c) 5-per-cent 

 sodium-chlorid solution. 



Note the color and opacity of (b) and (c) as compared with (a) . 

 Place samples of the three preparations under the microscope. 

 Note the changes of form and color of the corpuscles : (b) is an iso- 

 tonic solution for the blood, (c) is hyperisotonic, and (a) is hypo- 

 isotonic. 



