68 



EXPERIMENTAL PHYSIOLOGY 



B. Mount a drop of blood quickly, and examine at once 

 with the high power of the microscope. Note the rouleaux 

 of colored corpuscles. What is their color? Note also the 

 white or colorless corpuscles (colorless corpuscles tend to stick 



Fig. 32. — Blood Corpuscles: yl, red corpuscles in rowZeawa;; a, a, colorless corpuscles 

 (X 400); B, red corpuscles in focus; C, view of edge; D, three-quarters view; E, 

 red corpuscle swollen with water; F, G, H, distorted red corpuscles. 



to glass; hence they will remain if the cover glass is pressed 

 with a needle so that the current will drive the others aside ; 

 and they can then be more readily seen). What is the color 

 of the hquid in which the corpuscles are floating? This 

 liquid is called the plasma. Let this preparation stand for 

 fifteen minutes and then run under the cover glass a drop 

 of strong solution of neutral carminate of ammonia.^ This 

 decolorizes the red corpuscles but brings out the nuclei of 

 the white corpuscles and the fibrin filaments. Draw some 

 of the white corpuscles and note the shape of the fibrin fila- 

 ments. Note how the entanglement of these filaments forms 

 the foundation of the clot. 



C. Mount a drop of blood as in B, but before covering it 

 with the cover glass, add a drop of normal salt solution. 

 This causes the separation of the red corpuscles. Draw a 

 surface view and an edge view of a red corpuscle under the 



^A permanent mount may be made of this preparation if a little glycerine 

 is allowed to diffuse under the cover glass and the cover slip is then cemented 

 to the glass with gold size. 



