176 



HUMAN BODYi 



nourished by liquid which soaks through the walls of 

 blood-vessels in neighboring parts. 



The Histology of Blood. Fresh blood is to the unassisted 

 eye a red opaque liquid showing no sign of being made up 

 of different parts; but when examined by a microscope it is 



FIG. 53 Blood-corpuscles. A, magnified about 400 diameters. The red 

 corpuscles have arranged themselves in rouleaux; a. a, colorless corpuscles; 

 B, red corpuscles more magnified and seen in focus; E, a red corpuscle slightly 

 out of focus. Near the right-hand top corner is a red corpuscle seen in three- 

 quarter face, and at C one seen edgewise. F,G,H,I> white corpuscles highly 

 magnified. 



seen to consist of a liquid, the blood-plasma } which has 

 floating in it countless multitudes of closely crowded and 

 extremely minute solid bodies known as Hood-corpuscles. 

 The liquid is colorless and watery-looking; the corpuscles 

 are of two kinds, red and colorless. The red corpuscles are 



Describe the appearance of fresh drawn blood. What is seen 

 when a drop is examined with a microscope? Describe the blood- 

 plasraa. Name the kinds of blood-corpuscieSc 



