148 MILK AND ITS HYGIENIC RELATIONS 



the human species for the fulfilment of the function of lactation. 

 Bunge, as a result of investigations carried out by questionnaires 

 to a number of doctors in Switzerland, believed that the period 

 of lactation was becoming shortened. It appears probable that 

 the period over which lactation extended in earlier times was 

 considerably longer than that which is now customary. Even 

 if this is correct, it does not necessarily follow that the duration 

 of capacity for lactation has undergone a change. No reliable 

 records as to the state of infant mortality in previous centuries 

 are available, and it is not unlikely that the period of lactation 

 was more prolonged than was really advisable. In some districts 

 in this country at the present time, many women continue to suckle 

 their babies until well on into the second year of life, often with 

 unsatisfactory results both to mother and child. The present 

 unnatural conditions of life may tend to produce detrimental 

 effects upon a large number of individual women, but it is hardly 

 likely that the capacity of the race for lactation has as yet been 

 appreciably affected. 



In this chapter the advisability of breast-feeding will be assumed. 

 It remains to consider the present state of knowledge as to the 

 best methods to secure the possibility of breast-feeding. Bunge 's 

 work referred to above was subject to some degree of misinter- 

 pretation, many readers believing that he considered the function 

 of lactation to be on the decline. This, as has been mentioned 

 above, is not precisely the point of view to which Bunge was led 

 as the result of his investigations. 



The movement for the preservation of infant life and health 

 which spread over a large part of Europe and in America with aston- 

 ishing rapidity during the last quarter of a century, has thrown 

 a flood of light upon the whole question of breast-feeding. The 

 institutions which have been established for the welfare of mothers 

 and infants differ in their methods according to the characteristics 

 of the country in which they are found. All, however, have assisted 

 in providing data upon this subject, and the results obtained, 

 although differing in certain points of detail, have been funda- 

 mentally confirmatory of one another. 



Two main points will be considered in this chapter: (i) 

 The existing capacity for the function of lactation in the human 

 species, and (2) the period of lactation. 



i. The Capacity for Lactation. There can be little doubt that 

 with few exceptions lactation can be established in every woman. 

 Increased experience has shown that the difficulties which exist 

 in a certain proportion of cases can be satisfactorily surmounted 

 in nearly every instance. In foreign institutions where wet- 

 nurses are frequently used it is recognised that there are fairly 

 wide variations between the extent of the capacity for lactation 

 in different women, yet it is exceptional to find cases where 

 this cannot be established. Budin (i) says : ' Every woman 



