STUDIES OX THE METABOLISM OF PHOSPHORUS IX AXIMALS 167 



In growing animals it was found that the atoms alroadv present at an 

 early stage of the formation of the skeleton beeome distiibuted in the 

 eourse of time over the different parts of the skeleton and other organs 

 demonstrating thus the dynamical nature of the building up of bono tissue. 

 Some of the phosphorus atoms present in the bones leave the skeleton for 

 good, being eliminated through the kidneys or the bowls or becoming located 

 in other organs of the body. 



The replacement of individual phosphorus ato rs by other ])liosphorus atoms 

 also takes place in the bone tissue of adult animals including that of the 

 teeth. 



It was ascertained that about one-seventh of the phosphorus found in 

 the faeces of a human subject is due to material which has entered the 

 intestines through the digestive juices after being located in the blood stream 

 or in the organs of the body for a shorter or longer tim(\ 



