SECT. 12] METABOLISM OF LIPOIDS, ETC. 



1 199 



"inorganic" phosphorus as all the non-lipoid phosphorus, and the 

 figures which he obtained were as follows : 



Days 

 o 

 6 

 7 



Milligrams per egg 

 non-lipoid phosphorus 



75 

 128 

 127 

 137 



Milligrams per egg 

 lipoid phosphorus 

 150 



146 



135 

 108 



About the same time Mesernitzki published in a short paper the 

 results of some experiments in which he had followed the amount of 

 ether-soluble phosphorus in the 

 whole egg during incubation. 

 His data, arranged graphically 

 and expressed as lecithin in 

 grams per 100 gm. dry weight gg 

 of egg-contents, are to be found jj 

 in Fig. 372. I 13 



Before going on to discuss _£ ^^ 

 Plimmer & Scott's data for the 

 phosphorus distribution in the 

 egg, we must touch on the ques- 

 tion whether the contents of ^ 

 the egg receive any accession of 6 

 phosphorus from the shell in ^ 

 the case of birds, as has from 

 time to time been supposed. In 

 the analyses of Voit, Hermann, 

 Forster, Feder & Stumpf, the 

 yolk contained 203-86 mgm. of '^' 



phosphorus at the beginning of development, while the white con- 

 tained 7-04 mgm., a total of 210-9. At the end of development the 

 egg-contents contained 237-5 i^g^i-j i-e. an increase of roughly 

 26 mgm., but Voit and his assistants did not mention this fact in 

 their conclusions, and probably, if they noticed it, put it down to 

 experimental error. In Pott & Preyer's experiments of 1882, the 

 following figures were obtained : 



In shell at beginning 



In egg-contents at beginning 



In shell at end 



In egg-contents at end 



PO, 



mgm. 



44 

 228 



42 

 224 



