220 THE CIVIL ENGINEERS OF THE BODY 



plasma wliicli reaches the cells from the rich v^ascular network 

 on the surface of the underlying bone, carries dissolved in it 

 sufficient oxygen to meet the needs of these lubricant-formers, 

 as it carries sufficient protein, carbohydrate, etc., for their use. 



The formation of cartilage and of synovia and the relation 

 of these two substances to bone and to fibrous tissue is a rich 

 field for investigation. Certain colloidal phenomena will occur 

 to the student as suggestive of an explanation, but absolutely no 

 definite physico-chemical facts can be brought forward as accept- 

 able evidence. 



Further Reading 



Thompson. " Growth and Form." Cambridge University Press. 

 Keith. " Engines of the Human Body." Williams and Norgate. 



