PRINCIPAL FEEDIXfJ PERIOD. 



39 



The amount of nitrogen invested per 1,000 grams of body weight 

 for ;i seven-day period was as follows: No. 1, C-.7 grams; No. :;. (>.S 

 grams: No. 1. ">._ grains. The amount of nitrogen absorbed per 

 1,000 grains of body weight per period f seven days was likewise 

 very uniform, excepting for rabbit No. _\ being ">.(> grams for No. 1 

 and No. .". l.s grains for No. 4, and ">._ grams for No. L\ The amounts 

 of nitrogen excreted in t he urine and feees show considerable variat ion. 

 the ratio of urine nitrogen to feces nitrogen being highest in No. 1, 

 that iBj v7:l, and lo\\e>t in No. _. -.i\:\. No. 1 showed a. ratio of 

 3.9:1, and No. :5 a ratio of 3.4:1, 



In Table IV the ratios of nitrogen to phosphoric aeid. calcium to 

 magnesium, and phosphoric acid to calcium in food, feces, and urine 

 in given. The relation of urine nitrogen to urine phosphoric is 

 highest in the cases of the rabbit*. fVd organic phosphorus. This is 

 due to a larirer excretion of phosphorus in the urine of rabbits Nos. 

 :; and 1. fed on inorganic phosphorus. This ratio in the feces is very 

 regular, being !.">:! in thivr :;d for No. _> inereasing to 2.1:1. 



A higher ratio of calcium to magnesium is noted in the feees of the. 

 r:ihhit> fed inorganic phosphorus. This ratio varies considerably in 

 the urine of the individual rabbit-. 



T \IIIK 1\ /; 'in. nn -/ phosphorus **, and urine 



/ 



RABBITS IKI> OBG INK PHO8PHO3 





liAHIU! - 1 Fl> IS. i|t,; \SI< |'| loSIM I o I: I 8. 



The figures show also that the phosphorus-calcium ratios of the 

 food of rabbit - N ia 1 and J arc 1 \\ er than in the food of rabbits Nos. 

 3 and 4: this is due to a larger iiiLTc-tioii of phosphorus in the latter 

 cases. The ratio of phosphoric acid to calcium in the feces varies 

 \vith the individual case. The phosphoric acid to calcium ratios in 

 the urine again show more phosphorus eliminated by rabbits Nos. 

 3 and \ than by rabbits NOB. 1 and 2. The nitrogen and phosphoric 

 acid eliminated in the urine are generally considered to represent the 



