Observations on the relative percentage composition of milk from the two mammae of women have a dual importance: they add to our information concerning infant nutrition as well as to our knowledge of the physiology of milk secretion.
In earlier papers1 several theories of the mechanism of milk secretion were reviewed and observations on the process in both animal and man were discussed. Analogous studies on the milk obtained from the different quarters of the udder of the cow demonstrated that the milk was similar but not identical in composition.2 It was suggested that the quarters of the udder of the cow show not only anatomic individuality but differences in the physiology of milk formation. Schnorf3 noted, however, that the two forequarters and the two hindquarters of the mammary gland of the cow appeared to function alike.
It would seem that similarity in percentage composition would indicate