640 



FREDERICK S. HAMMETT 



The physiology of the mamma is not only of importance with respect 

 to the proper development of the individual, but also from the object of 

 the attainment of a proper functioning to the production of an adequate 

 milk secretion for the nourishment of the young ; which obviously depends 

 upon the completeness of the preliminary growth. 



Growth and Development of the Mammary Glands. Stages of De- 

 velopment. The growth and development of the mammary glands does 



Unldfiood Puberty Menstrual 



to 



f Menstrual to 

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I! 1 











I 



I 



I 



Fig. 1. Diagram of the course of development of the mammary glands and the 

 uterus, after Halban. 



not follow a continuous, smooth curve, but has in its course several sharp 

 deviations from linear uniformity as is shown in the accompanying dia- 

 gram from Halban (c) (1905). 



The intra-uterine growth is regular and continuous until between the 

 eighth and ninth months, when there occurs a relatively marked enlarge- 

 ment as the result of the first growth impulse. After birth, a slight 

 regression is followed by growth, in conformity with the general increase 

 in mass of the body, until at puberty the second or pubertal growth impulse 

 causes the very visible development to the mature gland, ready to receive 



