CONDITIONS INFLUENCING DIGESTION 137 



used to extract the fats and consequently the undigested 

 fat appears to be much larger than it really is. 



Reference has been made to the return to the intes- 

 tinal tract of material that was absorbed into the circula- 

 tion and is in part returned to the intestines for excre- 

 tion, as, for instance, the phosphorus of phytin and other 

 compounds. Such material is not a part of the undigested 

 food residue. 



