SECT. l] 



PHYSICO-CHEMICAL SYSTEM 



291 



soluble in water as well as 10 per cent, salt solution, but it cannot be 

 ovoalbumen or any of the egg-white proteins, for it is not coagulated 

 by ether. Plimmer suggested that possibly livetin was vitellin with 

 the majority of the phosphorus-containing parts split off from it. 

 Tables 19, 20 contain Plimmer's figures for these two proteins. 



Ovovitellin has been the subject of recent investigations by Swigel 

 & Posternak. They found that it broke up into three polypeptides 

 which they call ovotyrine a^, ^^ and y^. The properties of these are 

 listed in Table 19. It was found that ovotyrine ^ contained all the 

 iron in the original compound, and that it could be split up into 

 ovotyrine /Sj and ovotyrine ^2 the second of which again contained 

 all the iron. All these derivatives were laevorotatory, and showed 

 considerable resemblance to the lactotyrines which the same workers 

 had previously isolated from casein. They identified their ovotyrine ^ 

 with the avivitellic acid of Levene & Alsberg, and they stated that 

 an enzyme was present in the fresh yolk which would, on standing 

 at 37° C. for 10 days, double the yield of preformed ovotyrine jS. 



19-2 



