PERSONAL APPEARANCES IN HEALTH AND DISEASE. 65 



were mingled a number of small round bodies to which 

 the name corpuscles were given. Then it came to be 

 found that of these corpuscles there were two kinds, some, 

 and these formed the large majority, were of a pale 

 yellowish red colour, hence called " red corpuscles ; " 

 whilst others, larger, less regular in shape, were pale or 

 devoid of colour. Ever since that time attention has 

 been largely directed to the nature and properties of 

 these constituents of the blood, and we must describe 

 them in slightly more ample detail, limiting our remarks 

 only to the red corpuscles. If a drop of blood be 

 placed on a glass slide and examined under the micro- 

 scope, the field will be seen to be in great part occupied 

 by small circular bodies, in which a faint yellowish tint 

 indicates their possession of some colouring matter. 

 They are not only circular, but are flattened from side to 

 side, and careful observation will show that their 

 flattened surface is really depressed 

 (Fig. 13). They are in fact small 

 discs with a slight concavity on 

 each surface, a character which is 

 perceived at once when a corpuscle 

 happens to roll over whilst it is 

 being observed, and the observer 

 sees it edgeways. A single cor- 



* Blood corpuscles, all with one exception being red. 



