134 ANATOMY AND PHYSIOLOGY FOR NURSES 



and returns to the lungs (changed in character from red to 

 blue blood) through the venous system. 



The red corpuscles have a remarkable power of absorb- 

 ing certain gases; for it has been found by Scherer that a 

 solution of hematin imbibes a considerable amount of 

 oxygen, which is the principal constituent of the composed 

 strength of the corpuscle itself. 



When examined beneath the microscope, the red cor- 

 puscles may be seen floating in the liquor sanguinis of 

 the blood, exhibiting a marked tendency to approximate 

 one another ; usually coming into contact by their flattened 

 surfaces, so that a number of them aggregated present 

 the appearance of a pile of coins set upon their edges 

 (rouleaux] . If the stratum should be too thin to permit 

 them to lie in this manner they will overlap one another, 

 especially so when the current is impeded. They will 

 be seen at times to change their shape, become elongated, 

 yet afterward resuming their natural shape ; the elongation 

 is due to pressure from without, or from the diminution of 

 the interior of the vessel in which they are contained. 



The white corpuscles are called leukocytes; they are 

 few in number in comparison with the red; they are 

 spheroid in form, and measure about ^sVir f an mcn m 

 diameter. The average proportion of the white to the 

 red is i to 500; in certain diseased conditions the white 

 cells are rapidly increased; this abnormal state is called 

 leukocytosis . 



The white corpuscle has no limiting membrane like the 

 red corpuscle ; it consists of a mass of transparent albumin- 

 ous substance called protoplasm, containing one or more 

 nuclei. They are endowed with the power of spontaneous 

 movement, and are thus capable of changing their 'form 

 and place. The nuclei vary in shape: they may be 

 crescentic, horseshoe shaped, or multiple. 



In their movements they pass through the vessels into 



