﻿216 Proceedings of the Royal Physical Society. 



expenditure of energy, or of starvation, or of malnutrition 

 dependent upon some pathological condition, the environment 

 of the body cells may become markedly less favourable, and 

 therefore, and this is really the same statement, their in- 

 dividuation will be less satisfactory. As before, genesis will 

 be stimulated, and euryplasia will be determined. 



In extreme old age the sites of myo-osseous articulation 

 cease, in some measure, with the ceasing activity of the 

 muscles to be sites of increased periosteal irritation and 

 vascular supply. In all the tissues of the body the anabolic 

 power of the cells is declining, their genetic power is almost 

 exhausted, and absorption, which in the bones leads to osteo- 

 porosis, becomes an important modifying factor, and the more 

 outstanding crests and tubercles become smoothed down or 

 rounded off. 



And so we reach the interesting, and, I think, not un- 

 important conclusion, that the surface details of the bones of 

 the skeleton are only indirectly dependent upon age and sex 

 and muscular activity ; and are not, as Topinard thought, and 

 as is still taught, an index of the absolute muscularity of the 

 individual, but are directly dependent upon, and primarily 

 are an index of the type of nutrition which the somatic cells 

 enjoyed. 



