DIGESTION. 231 



bears out that assumption. These investigators introduced a 

 peptone solution into a doubly-tied, removed knot of the small 

 intestine which was kept active by passing through defibrinated 

 blood, and observed that the peptone disappeared from the intes- 

 tine, but that the blood passing through did not contain any pep- 

 tone. 



If, then, peptone already disappears in the mucous coat, or at 

 least in the walls of the digestive tract, the question naturally 

 arises, what becomes of the peptone in the mucous membrane ? 

 The experiments of MALY, PLOS'Z and GYERGYAI, ADAMKIEWICZ, 

 ZUKTZ and POLLITZER have established that the . albumoses and 

 peptones may be substituted for albumin in the food, and may also 

 be converted into ordinary albumin. We must then assume that 

 peptone is already converted into albumin in the mucous mem- 

 brane of the digestive canal. 



According to HOFMEISTER, a considerable increase of leucocytes 

 occurs in the adenoid tissues during digestion, an observation 

 which is in close accord with that of POHL, who found that in 

 dogs kept on an albuminous diet the venous blood of the intestine 

 contains more leucocytes than the arterial blood. According to 

 HOFMEISTER, leucocytes play an important part in the absorption 

 and assimilation of the peptones. They may take up the peptones 

 and be the means of transporting them to the blood, and secondly 

 by their growth, regeneration, and increase may stand in close rela- 

 tion to the transformation and assimilation of the peptones. 

 HEIDENHAIN, who considers that the transformation of peptone 

 into albumin in the mucous membrane is positively settled, does 

 not, attribute so great an importance to these last in the absorption 

 of the peptones as HOFMEISTER, chiefly on the ground of equaliza- 

 tion of the quantity of absorbed peptones and leucocytes. He con- 

 siders it most probable that the reconversion of the peptones into 

 albumin takes place in the epithelium layers. 



Little is known concerning the forces taking part in absorption. 

 Osmose and filtration were formerly considered as the most impor- 

 tant factors. But as in regard to the peptones, whose formation 

 in the digestion was considered as taking place especially in the 

 interest of a facilitated osmosis and filtration, but whose conditions 

 have been found quite different and much more complicated, so in 



