274 LECTURE XII. 



duction of the alcapton acids. The largest amounts are, however, produced 

 in cell-metabolism, after the cell has disintegrated the proteins into their 

 components, and now completes the decomposition of the amino acids. 

 This is where the anomaly, or restriction, occurs. 



If we combine all our knowledge of the proteins, their composition, and 

 their decomposition, with what we know experimentally about the diges- 

 tion, absorption, and assimilation of the albuminous materials of our food, 

 together with the information gleaned from our study of their changes 

 and their final disintegration in the tissues, we shall find that we are 

 obtaining a very good idea of the whole subject of albumin-metabolism. 

 To be sure, many bridges have been built purely provisionally from analo- 

 gous conclusions and probable relations, to enable us to pass from one 

 well-founded principle to another, and hypotheses still permeate all of 

 our views. We, however, do not doubt that the progress of albumin 

 chemistry will strengthen one position after another, and that eventually 

 facts will supplant our assumptions. 



