120 THE HEART AND CIRCULATION. 



the function of amoeboid movement by which they not 

 only wander from place to place in the blood, keeping 

 close to the sides of the vessels, but pass through the 

 walls of the capillaries, probably between the cells 

 which form their lining, into the lymph spaces. This 

 is known as migration of the white corpuscles. In in- 

 flammation they collect in the inflamed area to assist 

 in allaying the inflammation by absorbing and carry- 

 ing off its products. Fof they carry waste products 

 and destroy poisons, acting as scaven^ rs and pro- 

 tectors of the body. When they are unsuccessful and 

 the inflammation gets the better of them, they become 

 pus corpuscles. 



Besides the corpuscles there are seen floating in the 

 blood small disk-like substances with no special char- 

 acteristics, the blood plaques or plates, whose function 

 is unknown. 



In anemia the red corpuscles are diminished and the 

 white corpuscles and blood plaques increased in number. 

 After excessive bleeding normal salt solution is in- 

 jected, subcutaneously or by rectum, as being nearly 

 equivalent to blood serum in composition, and the re- 

 newal of the solid elements is left to time. The length 

 of time needed for their restoration is about a week, 

 except in the case of the hemoglobin, which takes 

 longer. 



