96 



Mr. E. Mellanby. 



[Oct. 3, 



The following points are indicated by these figures : — 



(1) There is a rapid increase in the nitrogen excreted in the first few days 

 after delivery. This point has been frequently observed before and has 

 been commented upon at the beginning of this paper. It will be noted 

 that the rise usually starts on the second day, but in the case of Mrs. Gy. 

 it is delayed until the fourth day. This variation in different women has 

 also been previously noticed and has not been interpreted satisfactorily, 

 some ascribing it to variations in uterine involution, others to variations in 

 mammary gland activity. 



(2) Except possibly for the first day after delivery the excretion of 

 creatinin exhibits its usual constancy.* 



(3) The creatin rises in the first few days. Consequently, there is a rise in 



creatin . , 



the r-r— ratio m these days. 



creatinin 



(4) An examination of the 



creatin 



ratio of the four cases and a com- 



creatinm 



parison with the rates of progress of the infants indicate that the increase in 

 weight of the children is roughly proportional to the creatin excreted by the 

 respective mothers, thus : 





Creatin 

 Creatinin" 



Increase of baby's 

 w eight per diem. 







oz. 



Mrs. St. C 



340 



-75 (Baby St. C.) 



„ Ghr 



-427 



-93 (Baby Gr ) 



„ Grj 



0-531 



1 -21 (Baby Gy.) 



„ T 



0-631 



1 -70 (Baby T.) 



It may be stated that the children were entirely breast-fed, so that what- 

 ever increase in weight they experienced was due to the milk secreted by the 

 mother's mammary glands. Consequently, the above figures indicate that the 



creatin ra ^.- Q Q ^ ^ e urine is related either to the quantity or quality, or 

 creatinin * J * J 



both, of the milk secreted by the mammary glands of the mother. In keeping 



also with this interpretation is the fact that the crea ^ in r atio increases 



creatinin 



pari passu with mammary gland activity in the first two days after delivery, 

 at a time when the colostrum is being changed to milk. 



It is evident that, in order to establish the hypothesis of a relation between 



* This constancy is such that when there is any great diminution in a day it may 

 usually be assumed that the 24 hours' specimen is not complete. 



