202 MILK AND ITS HYGIENIC RELATIONS 



the curves to approximate about the 200th day of life. It is 

 possible, therefore, that slight overlapping is shown in the curves 

 of the two main series, but against this possibility it must be 

 remembered that the number of infants considered in these two 

 subsidiary series is only approximately half the number contained 

 in the main series, and hence the sources of error are considerably 

 increased. 



In view of the fact that the artificially-fed children undoubtedly 

 suffer more in the early days of life than later, as a result of their 

 method of feeding, it may reasonably be believed that these results 

 are among the most favourable which could be anticipated in 

 connection with artificial feeding. The cases were taken hap- 

 hazard from among the poorer population, and in many instances 

 the housing accommodation was known to be unsatisfactory. 



Taking into consideration the clinical evidence and the evidence 

 contained in these Berlin investigations, where the infants were 

 not in institutions but were in their own homes throughout the 

 period of the investigation, it seems difficult to believe that there 

 can be any disadvantage in using boiled cows' milk instead of raw 

 cows' milk, when artificial feeding is necessary. The initial loss would 

 hardly be less on the raw cows' milk and might conceivably be more 

 in view of the composition of the colostrum and the absorption 

 of foreign proteins which has been considered fully in previous 

 chapters. The fact that the infants thus artificially fed catch up 

 the breast-fed babies at the age of about six months, shows 

 that at one period the rate of growth is more rapid on the part 

 of those artificially-fed children, than on the part of the breast- 

 fed ones. 



Third Period. This period extends approximately from the 

 sixth month of life up to the end of the first year. During the 

 first part of the period the weight -curves are approximately equal, 

 the curve of the breast-fed babies showing, however, rather more 

 fluctuation than that of the artificially-fed ones. 



Several causes arise at about the sixth month to account for 

 the approximation of the curves of the two series at this period 

 and for the fact that they remain parallel up to the end of the first 

 year. In the first place many of the children were weaned at about 

 the sixth month, and were placed upon the same food, that is, boiled 

 cows' milk, as. the infants in the artificially-fed series. Hence the 

 food of the two series tends to become more similar, and by about 

 the ninth month it is probable that all the differences in the feeding 

 were eliminated. Further, in the breast-fed series between the 

 sixth and the ninth month it is probable that the milk supply of 

 the mother was no longer as plentiful as in the earlier months, and 

 it is not unlikely that the infant was receiving rather less food than 

 the corresponding artificially-fed infant, whose food supply was 

 regulated by the physician. The regulation of the food supply in 

 the artificially-fed series probably accounts for the lesser fluctua- 



