Urine. Under normal conditions ereatin is absent from the urine of 

 men when living on a ereatin free diet; it is constantly present in th< 

 urine of children and frequently occurs in the urine of women. Powi 

 and Kaper have shown that children eliminate more ereatin during th 

 day than at night. In the young the supply of carbohydrate and fa 

 appears to be unable to meet the demands of growth and maintenance, 

 and as a consequence muscle tissue disintegrates, ereatin is liberated ah" 

 appears in the urine. The frequent occurrence of acetonuria in childre 

 and the rapidity with which the glucose content of their blood is lowered 

 during starvation are further indications of a limited supply of glyco, 

 (Sawyer, Stevens and Bauman). The occurrence of ereatin in the urin 

 of children may also be due to a diminished ability to destroy it (Krau 

 (&), 1913; Gamble and Goldschmidt (a), 1919). In infants the in- 

 creased excretion of ereatin when they are on a pure milk diet may be dui 

 to the ereatin present in the milk and not to the protein therein (GambL 

 and Goldschmidt (6), 1919). . 



Sawyer, Stevens and Bauman observed that the increased excretion o 

 ereatin which occurs in children when deprived of carbohydrates is usually 

 followed by a period of ereatin retention upon resumption of the normal 

 diet. It appears as if the body retained ereatin with great regularity 

 under these circumstances. 



The alleged occurrence of creatinuria after menstruation (Krause (a) 

 1911) has not been confirmed by M. S. Rose, who found no definite rela- 

 tion between the ereatin output and the sexual cycle, nor was creatin 

 excretion affected by protein feeding. In normal pregnancy the excretion 

 of creatin is usually less than 20 per cent of the creatinin excretion (Van 

 Hoogenhuyze). A pregnant woman excretes about 170 mgs. of creatin 

 and the same woman during the lying-in period eliminates about 470 mgs. 

 (Van Hoogenhuyze and ten Doesehate). After cesarean section an in- 

 creased elimination of creatin occurs even when the uterus has been re- 

 moved at the time of operation (Mellanby (6), 1913 ; Morse). F. G. Bene- 

 dict (c), and F. G. Benedict and Diefendorf first noted the occurrence of 

 creatin in the urine of starving men and women. Mendel and Rose (a) 

 (1911) found creatin in the urine of adult animals when they were de- 

 prived of carbohydrates and began to break down their body proteins. 

 Certain animals having small reserves of glycogen and fat, as the rabbit, 

 will excrete creatin after a short, fast, while others with large stores of fat, 

 as the pig, can be fasted for from 14 to 16 days without excreting creatin 

 (McCollum and Steenbock). In this respect the human being and dog 

 occupy intermediate positions. Mendel and Rose (a) (1911) found that 

 rabbits began to excrete creatin on the second day of starvation and that 

 the amount excreted gradually rose until death. Depriving the tissues of 

 carbohydrates by means of phlorhizin poisoning also leads to creatinuria 

 (Mendel and Rose (a), 1911 ; Cathcart and Taylor). 



