SECT. 8] CARBOHYDRATE METABOLISM 1003 



namely, those of Idzumi (Momose-Pavy method) , Sakuragi (Momose- 

 Pavy method), Pavy (Pavy method), Bywaters (Pavy method), Sato 

 (Schenck-Bertrand method), Tomita (Schenck-Bertrand method), 

 Gadaskina (Galwialo method), Vladimirov & Schmidtt (Hagedorn- 

 Tensen method), Pennington (method unknown), Hepburn & St John 

 (FoHn-Wu method), Kojo (FehHng method) and Morner (FehHng 

 method) ^ In addition, the figures of Claude Bernard & Dastre, the 

 first of all, dating from 1879, ^re included. It will be admitted that 

 Bernard's values are remarkably accurate in spite of the crude 

 methods at his disposal. It is striking that with diverse methods 

 the results are in such good agreement, and a glance at Fig. 267 

 convincingly shows that the free glucose in the yolk and white 

 diminishes considerably during the first half of incubation. 



In some cases investigators only give their results in terms of per- 

 centages. In order to reduce them to a common basis, therefore, it 

 has to be assumed that they all worked with normal eggs under 

 approximately the same conditions. From the data given in Table i, 

 it may be assumed that of the weight of the entire egg at zero hour 

 of development, 10-47 P^^" cent, is accounted for by the shell, 56-07 per 

 cent, by the albumen, and 33-46 per cent, by the yolk. Using 

 Murray's figure for the weight of an egg (average of over 500), 

 namely, 57-8 gm., the white will weigh 32-04 gm. and the yolk 

 1 9' 33 gn^- The change in weight during early development due to 

 loss of water by evaporation, assuming a constant humidity, can be 

 read off on the graph given by Murray, The varying water-content 

 of yolk and white due to the current of water yolkwards can be 

 obtained from Fig. 225. 



The free glucose beginning at a maximum of 200 mgm. per egg 

 sinks more or less steadily till the loth day. An interesting point is 

 the difference between the yolk and the white. Pavy and Bywaters 

 only estimated the sugar in the albumen, and their points give a 

 curve on a lower level than the whole egg curve, but roughly parallel 

 with it. This might be taken to mean that there is not only a current 

 of water but also a current of free glucose yolkwards, for by the 9th 

 day the albumen has apparently lost all its free sugar, but the yolk 

 has then lost only half its original amount. But Fig. 267 is mis- 

 leading in that the values for the albumen are expressed as milligrams 

 per egg, although the albumen does not alone account for anything 



1 See also the confirmatory data of Sagara (Schenck-Bertrand method) . 



