SYSTEMATIC SYNTHESIS OF TISSUES INTO ORGANS. 231 



* \ 



General View of the Skeleton. 



408. ALL PARTS OF THE SKELETON are connected 

 with the commercial capital by the Blood-tubes, and 

 with the political capital by the nerves. 



409. ARTERIES AND VEINS extend into and out of all 

 the bones by means of the numerous nutritious holes or 

 foramina, that will be found in the surface of any bone, 

 communicating with canals leading to capillaries in every 

 part of it; they have the largest meshes of any in the body. 



410. BY MEANS OF THE BLOOD-TUBES nutritious sub- 

 stances are poured through every part of the bones, and 

 all substances that have become useless are by the same 

 means brought away. 



411. From infancy to maturity THE SKELETON EN- 

 LARGES by the gradual removal of all parts, particle by 

 particle, and the replacing of these on an increased scale 

 over and over again. It is impossible to conjecture how 

 many different skeletons a person has between birth and 

 maturity. The teeth are changed but once. 



412. DIFFERENT PARTS CHANGE OR ENLARGE with 

 varying degrees of rapidity at different periods of growth, 

 the appropriate proportions being most wonderfully pre- 

 served, yet differing at different periods. 



413. CHANGES TAKE PLACE IN THE BONES AFTER MA- 

 TURITY. They become more brittle from the predomi- 

 nance of earthy matter, and more spongiform or cancel- 

 lated, the spaces being filled with marrow. 



414. IT IS NECESSARY TO HAVE THE EARTHY MATTER 



INCREASED to give the necessary resistance when the ex- 

 cavations are made, which are needed to contain marrow, 

 useful in preventing jars from reaching the Brain, and 

 especially in supplying a store of heat-producing mate- 

 rial, when in age the organs cannot at times prepare it 

 from the food directly. 



408. What said ? 409. What said ? 410. What effected ? 411. How does 

 - ? 412. How do ? 413. What ? 414. Why ? 



