Sudan 111 in Metabolism and Inheritance 177 



trical conductivities. This proved impracticable because of the 

 extremely low conductivity of the oils. The writer is therefore 

 not prepared to state whether the presence of the stain in the mole- 

 cule of fat has any effect upon the power of lipase to hydrolize 

 that molecule. 



(8) It seemed advisable next to learn the effect of the presence 

 of the stain on the rate of the spontaneous oxidation of the fats. 

 By a method described elsewhere^ Prof. A. P. Mathews and the 

 writer, in connection with other work, made a few experiments on 

 the rate of oxidation of linseed oil with and without the stain. It 

 was determmed that the oxidation proceeds more slowly in the 

 oil + Sudan than in pure oil. Light has, however, such a profound 

 effect upon the rate of oxidation that it is perhaps possible to 

 attribute much or all of the retardation measured in our experi- 

 ments to the absorption of light rays by the. Sudan. The ques- 

 tion that has been raised of the lessened availability of Sudan- 

 stained fats must then be left without conclusive answer, but with 

 such evidence as the preceding statements afford. 



DISCUSSION AND CRITIQUE 



The main facts at hand have already been given in a rather 

 long historical statement and in the preceding account of the 

 writer's own results. The specific statements on the several topics 

 of fat metabolism need not be agam referred to. The general 

 question of the basis or source of usefulness of Sudan III in such 

 studies as the present may, however, be touched upon here. We 

 can now consider too another most interesting aspect of our sub- 

 ject, namely, the significance in inheritance of the observed trans- 

 mission of this aniline dye from soma to germ cell, and its redis- 

 tribution among the daughter cells of the serm. We treat the 

 former topic first. 



In the study of the problems of fat metabolism, what is it 

 that gives value and significance to the use of Sudan III.^ The 

 answer must be that it is because Sudan sticks to fat or fatty con- 

 stituents as long as they remam such in the bod v. Where the 



' See article by A. P. Mathews, O. Riddle and S. Walker, The Spontaneous Oxidation of Some Gel! 

 Constituents, Abstract in Joiirn. Biol. Chem. vol.. 4, p. xx, June, iqo8.. 



