CHAPTER VII 

 THE BLOOD AND ITS CIRCULATION 



110. The blood. After the food has been digested in 



the stomach and intestine and made into blood in the 



liver, it is sent to feed each cell of the body. About one 



I thirteenth of a man's body is blood. This makes between 



five and six quarts. 



The blood is a red liquid, but under a microscope it 

 looks like clear water in which there float a great many 



*mimwm round bodies - Most of these bodies 



wjuiunniiiiiiimiif))! .. . 11 i r r 7 T 7/ 



(5) /v are rec *> anc * are ca U e d re <* blood cells 



tf @ or corpuscles; a few are white, and are 

 c o t> (3> called white blood cells or corpuscles. 



B100 ( d X C 4?o U ) SCleS 1U - The bl d CellS ' ~ EaCh rCd bl d 



aapileTredblood Cel1 is a rOUnd > flat P late Jt d es nOt 



cells. feed the cells of the body, but supplies 



b re fla^ws d e. CellSSeen them with oxygen from the air in the 

 c red blood cells seen lungs. The red cells form nearly one 

 d whte g b7ood cells. half of the blood. 



Each white blood cell is round like a 

 ball. It moves with the blood, but it can move all by 

 itself and live outside the blood. It is almost a living 

 being in the blood, separate from the body. The white 

 blood cells are only one three-hundredth as numerous as 

 the red cells. They are always looking for weak or in- 

 jured parts of the body, and when they find such a spot 

 they leave the blood tubes and gather around it to mend 



60 



