374 PLAIN FACTS FOE OLD AND YOUNG 



itself has disappeared, and there is the little particle 

 inside. 



This seems a marvelous process, but it is a peculiar 

 way these little fellows have of taking their food. 

 When they wish to eat, they make a mouth or a stom- 

 ach on purpose for the occasion. If we wait a few 

 moments, we shall see that the little particle so curi- 

 ously swallowed has disappeared; it is now digested. 



Thus we see, by studying the habits of these won- 

 derful little creatures which live in the blood, that, 

 although having no legs, wings, or other organs of loco- 

 motion, they move from place to place at will; having 

 no hands, they feel; having no mouths, they eat; and 

 though possessed of no stomach, they digest. They 

 are born, develop, grow old and infirm, and die, just as 

 larger creatures. Each has its own separate life, and 

 its special duties to perform, just as have horses, oxen, 

 dogs, and the human beings of whom they form a part. 



Thus we learn that the blood is a stream, coursing 

 through the various channels of the body, known as 

 arteries and veins, carrying in each drop millions of 

 creatures which live and grow in the limpid fluid like 

 the fishes in our rivers, or like the birds in the air. 

 These little creatures are known to science as blood 

 corpuscles. Every part of the body is likewise com- 

 posed of living creatures, which has each his special 

 work to do. Those of the same class, or which have 

 the same kind of labor to perform, are grouped to- 

 gether, just as glass-blowers, printers, and other per- 

 sons of the same trade, are associated together in their 

 work. All these groups of living beings, working to- 

 gether, make up that wonderful machine, the human 

 body, the most important parts of which we will now 

 proceed to study. 



