SECT. 8] CARBOHYDRATE METABOLISM loii 



to 640 units). These researches will be referred to in more detail in 

 Section 14-7. Finally Komori demonstrated that most, if not all, of 

 the glucose in the ovomucoid molecule could be liberated by in- 

 cubation with amylase prepared from meal. 



It remained to demonstrate that the egg itself, or certain parts of 

 it, possessed the power of hydrolysing ovomucoid, and I made the 

 requisite experiments in 1927, The ovomucoid preparation itself con- 

 tained no free glucose, but when incubated alone about 2 mgm. were 

 split off, perhaps because of the presence of minimal amounts of the 

 enzyme. This auto-digestion effect was subtracted from the crude 

 results. It was noted in the first place that the slight excess of glucose 

 in the embryo preparations after standing at 37° was much more than 

 accounted for by the correction mentioned above ; the effect of the 

 egg-white was much reduced, but the yolk and the yolk-sac results 

 still retained considerable magnitude. The enzyme ovomucoidase is 

 thus not contained in the embryonic tissues themselves, and only to 

 a negligible extent in the egg-white, but the yolk is very rich in it, 

 and the blastoderm and yolk-sac also show a fair activity. Thus the 

 embryo tests yield o per cent, of the theoretical, the white i -49, the 

 yolk 31-2 and the yolk-sac 7-13. This conclusion is not affected by 

 the varying amounts of solid material which must have been con- 

 tained in the original samples, for the yolk retains its superiority even 

 when this is allowed for. 



These results fit in well with the rest of our knowledge. Roger, 

 for instance, found more amylolytic activity in the yolk than in the 

 white. Bywaters' conclusion that ovomucoid was not split up into 

 protein and sugar before absorption only holds for the white and for 

 that fraction alone the results do not conflict. The ovomucoid may 

 be pictured passing from the white to the yolk by the vitelline vessels, 

 and there being split up into free glucose and protein before absorp- 

 tion into the embryo. It is interesting that the embryo possesses no 

 ovomucoidase, or very little; the hydrolysis must therefore be con- 

 sidered to take place outside it. Idzumi's observations on the increase 

 of activity of the yolk amylase during development also fit in with 

 the increasingly rapid disappearance of ovomucoid seen in Fig. 269. 

 It would be desirable to extend these observations by investigating 

 the kinetics of the enzyme, and by determining whether its activity 

 remains the same in all fractions during development. 



The question now arises as to the value of the ovomucoid to the 



