ANATOMICAL ELEMENTS. 109 



tions into the constitution of the blood, it may be stated 

 that it is now known to be, composed of a clear fluid, the 

 Plasma, or liquor sanguinis, holding certain corpuscles in 

 suspension. These corpuscles are 



1. Bed Corpuscles; by far .the most abundant, constituting 

 about one-half of the mass of blood. 



2. Leucocytes, or White Corpuscles ; much less abundant, 

 existing only in the proportion of one to several hundred red 

 corpuscles. 



3. Granules; exceedingly minute, called, by Milne- 

 Edwards, globulins, and by Kolliker, elementary granules. 

 These are few in number, and are undoubtedly fatty particles 

 from the chyle. They are to be regarded as accidental con- 

 stituents of the blood. 



Red Corpuscles. These little bodies give to the blood its 

 red color and its opacity. They are true organized structures, 

 containing organic-nitrogenized and inorganic elements molec- 

 ularly united, and, as an exception to the general rule, a lit- 

 tle fatty matter in union with their organic principle. Like 

 other organized structures, they are constantly undergoing 

 decay, and are capable of self-regeneration. They constitute 

 about one-half the mass of blood, and, according to the obser- 

 vations of all who have investigated this subject, are more 

 abundant in the male than in the female ; this constituting, 

 perhaps, the only constant difference in the composition of 

 the blood in the sexes. 



The form of the blood-corpuscles is peculiar. They are 

 flattened, bi-concave, circular disks, with a thickness of from 

 one-fourth to one-third of their diameter. Their edges are 

 rounded, and the thin central portion occupies about one-half 

 of their diameter. Their consistence is not much greater 

 than that of the plasma. They are very elastic, and if de- 

 formed by pressure, immediately resume their original shape 

 when the pressure is removed. Their specific gravity is some- 

 what greater than that of the plasma. 



