THE BLOOD. 



135 



6. The Corpuscles of the Blood. Fresh-drawn blood is, 

 to the unaided eye, a uniform red liquid. But a micro- 

 scope shows it to consist of a colorless liquid, the blood- 

 plasma, in which float vast numbers of tiny solid parti- 

 cles, named the blood-corpuscles (Fig. 35). 



FIG. 35. Blood-corpuscles, magnified. At A the corpuscles are shown as seen 

 when magnified four hundred diameters. The red corpuscles have adhered to- 

 gether by their flat sides, as they usually do soon after a drop of blood has been 

 drawn. At a are seen colorless corpuscles. 2?, red corpuscles, very greatly mag- 

 nified, seen in full face. C, the same seen edgewise. Z>. the same, adhering by 

 their flat faces, f, G, H, colorless blood-corpuscles, very much magnified. 



A few of the corpuscles are colorless and irregular in 

 form (7% G, H, /), but by far the greater number are 

 faintly colored. Seen by itself, each one looks pale yel- 

 low; but a number crowded together appear red. 



6. What does a microscope show blood to consist of ? Color and 

 form of most of the corpuscles? Name? Number? Why is blood 

 red ? How may it be made yellow ? 



