SECT. 12] GYCLOSES, PHOSPHORUS, SULPHUR 1237 



Milligrams % P2O5 in egg-contents 



Days , ^ ^ 



development Inorganic Organic Total 



o 6 342 348 



15 13 280 293 



30 15 266 281 



45 123 106 229 



Hatched 365 52 417 



The figures for total phosphorus are insufficiently regular to permit 

 any conclusion as to whether any of it is deri\'ed from the shell. 

 The inorganic phosphorus is practically confined to the body of the 

 embryonic reptile, and the organic phosphorus to the yolk. Only 

 minimal amounts of either are found in the egg-white or in the 

 amniotic or allantoic liquids. 



The choline has been estimated by Takahashi (see Fig. 400). 



12-9. Lipoids and Sterols in Amphibian Eggs 



If we first enquire as to what is known of the phosphorus distribution 

 in amphibian eggs, we find that Plimmer himself made a step in 

 this direction, collaborating with Kaya in 1909. He used the eggs 

 of the frog [Rana temporaria) in two lots: [a) ovarian and {b) shortly 

 after being laid. It is to be supposed that a certain amount of develop- 

 ment had taken place. The figures were as follows : 



% of the total phosphorus 



Ether-soluble phosphorus ... 

 Total water-soluble phosphorus 

 Inorganic phosphorus 

 Total protein phosphorus ... 

 Phosphoprotein phosphorus 

 Nucleoprotein phosphorus 



Thus there was every evidence of much the same changes as we 

 have seen take place in the egg of the chick. The ether-soluble phos- 

 phorus and the phosphoprotein phosphorus were declining, the nucleo- 

 protein and the water-soluble organic phosphorus were rising. Only 

 the inorganic phosphorus seemed to be maintaining a very low level. 

 This general arrangement fits in with the few later analyses of Parnas 

 & Krasinska, who estimated the lipoid phosphorus only, finding 

 0-00532 mgm. present in one ^gg and 0-0039 mgm. in one hatched 

 larva : a loss of 26 per cent. This is not so great a fall as in the chick. 



