SECT. 12] CYCLOSES, PHOSPHORUS, SULPHUR 



1209 



lipoid phosphorus, on the loth day of development, and it is probable 

 that it simply represents the impingement of the law of cephalocaudal 



Molecixles 

 gra-ms. 



40 00 



3000 



2000 



1000 



320 



240 



160 



OEmI^^i 



14 



16 



18 



20 21 



Days 



Fig. 379- 



differential growth on the partition of solid substances in the body. 

 If the central nervous system continued to occupy all through develop- 

 ment the important ponderal position which it occupies in the first 



77-2 



