452 



R. H. A. PLIMMER AND W. M. BAYLI8S. 



this in a similar manner to that of caseinogen with the following 

 results: 



The ovovitellin employed was obtained from egg-yolks by repeatedly 

 extracting them with ether until the residue was quite colourless. 

 This residue was then taken and digested by the enzyme. 



The digestion of ovovitellin by trypsin was very slow in comparison 

 with that of caseinogen. In 24 hours only one-third of the total phos- 

 phorus and about one-half of the nitrogen were converted into a soluble 

 form. Even in 36 days little more than half the total phosphorus had 

 undergone conversion, though practically the whole of the nitrogen had 

 passed into the soluble form. 



The digestion by pepsin was extremely slow. In 24 days less than 

 one-third of the total phosphorus had been changed into a soluble form 

 and at the same time the amount of soluble nitrogen was rather more 

 than one-half. There is, in fact, a great resemblance to the caseinogen- 

 pepsin digestion. 



As is well known, it is extremely difficult to prepare ovovitellin free 

 from lecithin. When it is obtained in a state of purity, free or nearly 

 free from lecithin, it no longer has the same properties, such as solubility 



