Lipoid Pin embryo, (Cahn) O 



(nob including membranes) 2day old chick'^ 



I2I0 METABOLISM OF LIPOIDS, STEROLS, [pt. iii 



10 days, the lipoid phosphorus would continue to rise in per cent, of 

 the dry weight, but this is not the case, and the loth day peak repre- 

 sents the point at which the 

 cephalic end of the embryo 

 ceases to dominate the chemi- 

 cal composition of the em- 

 bryo. Cahn himself was more 

 interested in the relation be- 

 tween water and lipoid phos- 

 phorus. In Fig. 38 1, the water- 

 content of the embryo per 

 100 gm. is placed on the same 

 graph as the water-content 



Days ^5 



Fig. 380. 



expressed in terms of grams per 100 mgm. of phosphatide phosphorus. 

 It is evident that the two curves descend without evincing any close 



? , ■ . I 



Days->5 



O Daily increment in mgms. 

 lipoid Pin embryo (Cahn) 



_^,5 O Daily increment in mgms/^ 

 cholesterol in embryo(Cahn)) 



♦ Daily increment in 



mgms. cholesterol in 



em bryo (Roffo &^ Azaretti) 



Fig. 382. 



relationship, for the concavity of one lies towards the abscissa and that 

 of the other towards the ordinate. Cahn next calculated the curve for 

 daily increment of lipoid phosphorus, and found it to show (Fig. 382) 

 an augmentation up to the 15th day, followed by a fall. This cor- 



