ii64 FAT METABOLISM [pt. iii 



Among the later workers, Tangl & von Mituch and Iljin simply 

 estimated the amount of fatty acids in the whole egg before and after 

 development. 



Table 167. 



Iljin's figures are not comparable with those of Tangl and of Tangl 

 & von Mituch, for he worked only on the yolk, and, though the 

 exclusion of the egg-white does not matter, as there is practically 

 no fat in it, yet the exclusion of the chick at the end of development 

 would make a considerable difference. Judging from Murray's 

 figures we might putitsfat content at i -2 gm., and this subtracted from 

 Iljin's figure would make it agree with the rest. Tangl & von Mituch 

 divided the fatty acids as follows: of the original 5-68 gm. in the 

 average egg, 1-59 gm. went into the embryo, i.e. 28-0 per cent, of 

 the original amount, 1-79 gm. remained in the yolk at the end of 

 incubation, i.e. 31-5 per cent., leaving 2-11 gm. fat burnt, or 40-5 

 per cent. Sakuragi and Idzumi later studied the fat loss by the hen's 

 egg in detail, both using a modified Kumagawa-Suto technique. 

 Their results are plotted on Fig. 359, from which it can be seen that 

 the utilisation of fatty acids follows a regular curve, descending more 

 rapidly towards the end than towards the beginning of incubation. 

 On the same graph are included the figures of Eaves ; Murray, and 

 some already mentioned, and from the whole group a notable 

 measure of agreement appears. It is difficult to draw exact con- 

 clusions from a curve which has been constructed from the data of 

 so many different investigators, but it is certainly interesting to plot 

 the milligrams of fatty acid disappearing each day from the egg, and 



