110 Kepokt of Department of Animal Industry of the 



average intake of total phosphorus in the transition period between 

 periods 1 and 2 is 51.2 grams, and the outgo is 46.3 grams, giving 

 a balance less than any in the calcium phytate period with an average 

 ingestion of 43.8 grams of total phosphorus per day. The apparent 

 digestibility of phytin phosphorus in the low-phosphorus period is 

 even less. These figures suggest that the various phytins are not 

 utilized with equal ease, and those which were less readily washed 

 out of the original bran were the more apt to pass through the 

 alimentary tract unchanged. This is purely speculative; more 

 data are required before an intelligent interpretation can be made. 



Inorganic phosphorus. — In this experiment, as in the previous 

 work, there was in all cases more inorganic phosphorus eliminated 

 than had been given in the rations. The end product of phosphorus 

 metabolism is inorganic phosphate, which in the herbivora is excreted 

 chiefly by way of the intestinal canal as salts of the alkah earths.^ 



Bases. — In all the periods, more potassium was excreted than was 

 taken into the system. The amount of this element in the bran 

 was reduced by the leaching to which it had been subjected, so that 

 there was, therefore, a lessened intake in the periods during which 

 washed bran was fed, accompanied by a decreased elimination in the 

 feces and urine. On the addition of calcium phytate, there was an 

 increase of potassium in the dung and urine amounting to somewhat 

 more than six grams in each; on the withdrawal of calcium phytate, 

 fecal potassium fell ten grams per daily output but the urinary potas- 

 sium slightly increased. 



The whole-bran period gave a magnesium balance of -|- 4.6; all the 

 other periods were deficient in this element. The magnesium differed 

 from the calcium and potassium in that the amount in the urine 

 decreased constantly from the first period to the end of the experi- 

 ment. The decrease was most marked between the third and fourth 

 periods, probably due to the influence of calcium phytate which 

 seemed to draw the magnesium toward the intestinal canal. The 

 fecal magnesium was quite constant, about ten grams per day, 

 except in the fourth period when it seems to have been influenced 

 by the increased calcium intake. At the beginning of the experi- 

 ment, about half as much magnesium was excreted in the urine 

 as in the feces, but at the end, when the labile magnesium of the 

 body had been largely exhausted, only about one-fifth as much 

 was eliminated in the urine. 



The calcium elimination in the urine increased remarkably when 

 the phosphorus intake was diminished, and fell again to its former 

 level when the phosphorus was increased. In the last period, when 

 the low phosphorus ration was given for a long time, the calcium 

 in the urine rose to five times the amount excreted through this 

 channel in the phytin period. The calcium in the dung also in- 



^ According to Berg as tri-basic calcium phosphate, Biochem, Ztschr. 30: 107. 1910. 



