New York Agricultural Experiment Station, 100 



there seems to be an approximate regularity in the excretion of 

 insoluble phosphorus independent of the amount of this form of 

 phosphorus ingested. 



Soluble organic phosphorus. — In the organic phosphorus compounds 

 soluble in 0.2 per ct. hydrochloric acid, we have the phytin of the 

 grains and feces and such small amounts of glycero-phosphates as 

 may occur in the feces. The amount of soluble organic phosphorus 

 in the dung is relatively very small, less than 5 per ct. of the total 

 phosphorus passed from the animal body, except in the fifth period 

 when the phytin content of the feces increased. Only a very small 

 amount of phytin is excreted into the milk and urine.* It forms 

 less than 3 per ct. of the urinary phosphorus and its presence in 

 the milk has not yet been sufficiently demonstrated. In this experi- 

 ment, the soluble organic phosphorus in the milk and urine was 

 not deemed significant at the time the analyses were made and its 

 determination therein were omitted. Our study of phytin phos- 

 phorus is therefore confined to the figures obtained from the analyses 

 of the rations and feces. In Table III, where these data are recorded, 

 we see a relatively small amount of phytin phosphorus in the feces, 

 even in the first and fourth periods when the phytin intake was 51.1 

 grams and 36.6 grams per day respectively, from which we must 

 conclude that the phytin disappears from the alimentary tract to 

 a very large extent. It is readily absorbed and in the tissues is 

 hydrolyzed by enzymes and converted into inorganic phosphate 

 and inosite.^ Any which fails of absorption, or is returned to the 

 intestine after absorption, may also be split by intestinal bacteria, 

 specifically B. coli? Rogosinski, whose work was referred to on 

 p. 15 found that human fecal matter completely destroyed phytin. 

 The dog on the other hand eliminated 70 per ct. of the administered 

 phytin without any change in it. The other 30 per ct. was assimi- 

 lated and a corresponding amount of inorganic phosphorus eliminated 

 in the urine. Hence considering the enormous bacterial flora of the 

 cow's interior it is not surprising to find that only 6.5 per ct. of the 

 soluble organic phosphorus fed in the first period was recovered 

 in the feces. The apparent utilization of the phytin in the calcium 

 phytate period was appreciably less, ranging from 89 to 91 per ct., 

 with one-third more soluble phosphorus in the feces than in the 

 first period, although less phytin was fed. In Table IV, a compari- 

 son between the total phosphorus ingested and the phosphorus 

 balance in periods 3, 2 and 4, shows that the output fluctuates 

 with the intake, hence there is a more direct relation between 

 the two than is observed in nitrogen metabolism, in which the balance 

 is not so immediately influenced by the amount ingested. The 



1 Starkenstein. Biochem. Ztschr. 30: 56. 1910. 



2 McCallum and Hart, Jour. Biol. Chem. 4: 497. 1908. 

 ' Unpublished data by the author. 



