514 Origin and Destiny of Cholesterol in the Animal Organism. 



may be, however, it may be accompanied either by a total destruction of a 

 portion of the cholesterol, which in view of the great chemical stability of 

 the molecule of this substance is unlikely, or a change of a portion into some 

 non-crystalline oily product. 



We do not think, however, that a comparison of the total weights of the 

 unsaponifiable matter of the faeces given in Table I with the weights of 

 •cholesterol in the food bears out the second explanation, more especially when 

 we remember that the latter weights should be increased by the quantities of 

 cholesterol poured into the gut with the bile during digestion. The weights of 

 unsaponifiable matter are, moreover, generally higher than the truth, as they 

 are often rather difficult to dry, without drastic means, and often contain 

 traces of soap. 



If the first-mentioned explanation were strictly true, we should not have 

 expected to find any cholesterol in the fasces of the cats fed on the artificial 

 cholesterol-free diets — the fasces should have been cholesterol-free, just as are 

 those of herbivorous animals. Small quantities of cholesterol were, how- 

 ever, found. In Experiment V, on bread, egg, and cream diet, the cat 

 excreted 0'05 gramme per day, a minute fraction of which, however, may 

 have been due to cream ; and further, in this weight is included the 

 phytosterol of the bread. In the case of the cats on extracted germ 

 of wheat, in Experiments VII and VIII, the quantities excreted were 

 €■033 and O03 gramme per day respectively. These values may also have 

 contained traces of phytosterol left in the germ after extraction. Whether 

 these quantities are large enough to represent the whole of the cholesterol of 

 the bile daily poured into the intestine, no data are available to determine. 

 If, however, we adopt the data given for dogs, the values are undoubtedly too 

 low. Further, the quantities of faeces produced per day on the vegetable 

 diets were very much larger for a given weight of food than in the case of 

 meat diets, and possibly this may have caused some of the cholesterol to 

 escape absorption. 



In the case of Experiments VI, IX, and X, however, in which known 

 quantities of cholesterol or phytosterol were added to the daily rations of the 

 artificial foods, no excess of cholesterol above that administered was recovered 

 from the fasces. 



From the point of view of deciding whether in the case of carnivorous 

 animals the cholesterol of the bile is normally reabsorbed along with the bile 

 salts in the intestine, these results are inconclusive. Experiments are, how- 

 ever, in progress to compare the effect on the blood of the addition of 

 cholesterol to artifical diets such as those used in the experiments detailed 

 in this paper. The results of these experiments we expect to give more 



