SECT. 12] CYCLOSES, PHOSPHORUS, SULPHUR 1201 



modification of the traditional Neumann method on each fraction. 

 The dry protein residue was split up into nucleoprotein and phospho- 

 protein by treatment with i per cent, sodium hydroxide at 37° for 24 

 hours, which converts the phosphoproteins, vitellin (and livetin?) into 

 inorganic phosphorus, but does not hydrolyse the nucleoproteins. 

 Then finally adding up the organic and inorganic phosphorus in 

 the different fractions, Plimmer & Scott obtained their balance sheet 

 of the phosphorus transformations. Thus they found 215-56 mgm. 

 phosphorus pentoxide in an average egg as the total, and they re- 

 covered in the fractions 21 1-75 mgm. or 98-3 per cent., a result which 

 gave them confidence in their technique. For the whole of develop- 

 ment they found very notable changes, thus: 



The broad outline demonstrated, then, that the inorganic phos- 

 phorus had risen at the expense of the ether-soluble phosphorus, 

 that the vitellin had also disappeared, and that the nucleoprotein 

 had increased. The picture is better seen, however, on a graph con- 

 structed from Plimmer & Scott's data, in Fig. 373. It is composed of 

 two principal change-overs, firstly, the "lecithin" or ether-soluble 

 phosphorus, and the inorganic phosphorus, the former descending 

 from 60 to 20 per cent., and the latter ascending from o to 60 per 

 cent.; and secondly, the phosphoprotein and nucleoprotein phos- 

 phorus, the former descending from 30 per cent, to nothing and 

 the latter rising from i to 1 5 per cent. During all this, the water- 

 soluble organic phosphorus remains practically at a constant value, 

 except for a dip on the 20th day, which probably has no significance. 

 From the graph, then, it would seem as if the lecithin is transformed 

 mainly into inorganic phosphorus, and the phosphoprotein into 

 nucleoprotein, but we must not overlook the probability that a certain 

 fraction of each precursor is devoted to each end product. Fourteen 

 years after Phmmer & Scott's paper, Masai & Fukutomi undertook an 

 exactly similar research. Their figures are assembled in Fig. 374, from 



