OKIGIN OK PHOSPHORUS COMPOTXDS IN IIENS' EGOS 



281 



b) Specific activity of yolk phosphorus 



We administered to a hen 100 ingin. I' iis sodium-phosphate showing an activity 

 of 10^ counts and killed the hen after the lapse of 28 hours. From the ovary 34 

 yolks were removed and from the oviduct one egg. The weights of these are recor- 

 ded in Table 7. 



Table 7 



The specimens of 700 mgm and more weie treated separately while averages 

 of the 30 mgm and the 100 mgm. yolks were taken. The lecithin was extracted 

 by ether and the residue brought into solution as described above. The results 

 obtained are seen in Table 8. 



The specific activity of the total P shows a maximum in the case of the 2500 

 mgm yolk. This result, puzzling at first sight, can be easily understood after consi- 



Table 9. ^ Specific Activity of Yolk Phosphorus 

 (Percentage of the activity administered present in 1 mgm P) 



Weight of yolk 



30—100 mgm 

 700 



2500 



4(500 



7700 

 13(500 



dering Fig. 2 taken from a paper of H. GerhabtzI, in which the daily increase 

 in weight of the yolks of a hen is recorded. The yolk grown from active blood 

 and thus active will be diluted by the non-active yolk already present and this 

 dilution will load to a decrease of the specific activity of its P content. The dilution 

 being least in the case of the 2500 mgm yolk, (comp. Fig. 2) its specific activity 

 is bound to be highest. It takes some time after administration of the labelled 

 sodium phosphate until labelled lecithin is transported into the plasma whereas 



' H. Gerhartz, Arch, dtsch. Ges. Physiol. 156, 215 (1914). 



