524 THE HUMAN BODY 



sweetens much less than cane-sugar, and infants used to the latter 

 often refuse milk in which milk-sugar is substituted. In order to 

 bring the percentage of fat up to normal it is usual to dilute, not 

 "whole milk" but "top milk." The latter, after the milk has 

 stood for a few hours, contains enough of the rising cream to 

 supply the needed fat. As the infant grows older less diluted 

 cow's milk may gradually be given; after the seventh or eighth 

 month no water need be added. 



It should not be necessary to emphasize the vital importance of 

 giving to infants only the purest milk obtainable. It is unfor- 

 tunately true that the milk produced in the average dairy is not 

 only dirty but swarming with micro-organisms. In cities it has 

 become the practice for medical societies to inspect various dairies 

 and set their seal of approval upon those that fulfil the sanitary 

 conditions essential to the production of pure, clean milk. The 

 slightly higher cost of such " certified " milk should not be allowed 

 to bar it from homes where children are to be fed except where 

 extreme poverty makes its procurement impossible. In small 

 towns and in the country personal inspection of the source of 

 the milk supply on the part of parent or physician should give 

 assurance of its cleanliness. Where it is impossible to procure 

 milk free from suspicion, pasteurization (heating to 120 F. for 

 20 minutes) should be resorted to. This destroys most of the 

 dangerous organisms, but of course is not a complete substitute 

 for cleanliness and care in the production of the milk in the be- 

 ginning. 



In the first weeks after birth it is no use to give an infant starchy 

 foods, as arrowroot. The greater part of the starch passes through 

 the bowels unchanged; apparently because the pancreas has not 

 yet fully developed, and has not commenced to make its starch- 

 converting enzym. Later on, starchy substances may be added to 

 the diet with advantage, but it should be borne in mind that they 

 cannot form the chief part of the child's food; it needs proteins for 

 the formation of its tissues, and amyloid foods contain none of 

 these. Many infants are, ignorantly, half starved by being fed 

 almost entirely on such things as corn-flour or arrowroot. 



Puberty. The condition of the reproductive organs of each sex 

 described in preceding pages is that found in adults; although 

 mapped out, and, to a certain extent, developed before birth and 



