THE CONDITION OF OLD AGE 



21 



amount of blood which we require is moderate in 

 amount moderate in the sense that the destruction 

 of the blood continually going on in the body is not 

 a very rapid process ; but if, through some accident, 

 a person loses a large quantity of blood, then, by one 

 of these teleological reactions of which I have spoken, 

 the production of new blood is increased, the loss is 

 soon made up, and we discover that the blood, so to 

 speak, has been repaired. Or when a little of the 

 skin is lost, it quickly heals over. That again is due 

 to the power of repair. Ordinarily so long as the 

 skin remains whole that power is not called into ac- 

 tion, but if a wound comes, then the regenerative 

 force resident always in the skin, but inactive, comes 

 into play and produces the mending which is such a 

 comfort. So in old people, some of this luxury of 

 reparative power persists, so that they can recover 

 from wounds in a far better way than we should 

 imagine if we judged them only by the general phys- 

 iological and anatomical decline exhibited through- 

 out all parts of the body. Some of the luxury of 

 repair comes in usefully in old age. 



Now if we consider all these changes in the most 

 general manner, we perceive that they are clearly of 

 one general character; they imply an alteration in 

 the anatomical condition of the parts ; but it is an 

 alteration which does not differ fundamentally in kind 

 from the alterations which have gone on before, but 

 it does differ in the extent and in part in the degree 

 to which these alterations have taken place. When 



