Sudan III in Metabolism and Inheritance 183 



(in fowls) may increase actively in amount whilst other regions 

 of fat take up no new molecules of fat whatever. 



5 The stained fat may appear in the mesenteric lymphatics 

 as soon as seventy minutes after feeding. Perceptible amounts 

 may be deposited on the periphery of growing ova one or two 

 hours later. 



6 The stain is taken up very slowly, or hardly at all by birds 

 which are being starved and thus made to decrease their store 

 of fat. 



7 Fat stained with Sudan is apparently less available to the 

 organism than is unstained fat. 



8 The stain which is passed through the follicular epithelium 

 into the egg, i. e., into the newly arising organism — shows there a 

 selective distribution; least stain being found in those parts of the 

 egg which contain least fat, namely, the germinal disc and latebra. 



9 The significance m inheritance of our experience with Sudan 

 lies: (i) in the fact that here we get — through relatively accurate 

 knowledge of the properties and physiological behavior of this 

 aniline dyt — -a clear picture of how particles of the food or soma 

 becom.e a part of the germ or new generation; {2) in the emphasis 

 which it lays upon the fact that the normal constituents of the 

 egg have a comparable history; (3) in the seemingly perfect par- 

 allel which it offers in explanation of the inheritance of immunity, 

 etc.; (4) and the possible light which this extremely simple form 

 of inheritance may throw upon the mass of developmental and 

 inheritance phenomena which seem to be of a much higher order 

 of complexity. 



BIBLIOGRAPHY 



(^Sudan) 



Daddi, L. '96 — Nouvelle methode pour colorer la graisse dans les tissus. Archives 



Ital. de Biol., vol. 26. 

 BiEDERMANN, W. 'qS — Beitrage zur vergleichenden Physiologic der Verdauung, 



I. Pfliiger's Archiv, vol. 72. 

 HoFBAUER, L. '00 — Kann Fett unverseift resorbirt werden.? Pfliiger's Archiv, 



vol. 81. 

 Pkluger, E. '00 — Ueber die Resorption kiinstlich gef arbtes Fett. Pfliiger's Archiv, 



vol. 81. 

 Friedenthal, H.'oo — Ueber die PermeabilitatderDarmwandung f ur Substanzen 



von hohem Molekulargewicht. Centralblatt fiir Physiolgie, vol. 14. 



