264 



LAB OR A TOR Y G VIDE IN PI I YSIOL OGY. 



should be adjusted before the corpuscles have time to 

 settle. 

 Observations, 



(1) Make counts of red blood corpuscles from several 

 apparently normal individuals. 



(2) Is there any appreciable variation in the number 

 per cubic millimeter? 



FIG. 39. 



FIG. 39. a. Successful blood spread with corpuscles evenly distributed, 

 b. Poor spread with corpuscles clustered. 



(3) Can the variation be attributed to faulty methods? 



(4) What is the average count for normal individuals? 



(5) What is the range between maximum and minimum 

 observations on the normal individuals observed ? 



(6) Account, if possible, for the variations observed. 



