SO-CALLED -' BIOLOGICAL PROPERTIES ' OF MILK 125 



easily absorbed than ox serum. He found that even where the 

 condition was such as to allow of the passage of a ' foreign ' protein, 

 recovery was still possible. 



Some observers have believed that the ' foreign ' protein of 

 cows' milk, of which a small portion is probably absorbed by the 

 infant, was actually detrimental, but the evidence upon this point 

 cannot be regarded as entirely conclusive. 1 



At birth the young animal appears to have no capacity for 

 providing its own resistance to the invasion of foreign substances 

 or organisms. This capacity develops gradually during the early 

 months of life, apparently about the sixth month in breast-fed 

 children, and about the fifty-third day in young rabbits. 8 Artifici- 

 ally-fed children appear to develop this capacity rather earlier. 

 A greater strain is thrown initially upon the organism, leading, 

 when this initial strain has been overcome, to the rather earlier 

 development of a protective mechanism. The strain on the 

 artificially-fed child is referred to in Chap. X, where the generally 

 lower weight of artificially-fed babies during the early weeks of 

 life as compared with breast-fed ones, is shown. 



Investigations by Moro (i, 3) and Salge show that greater natural 

 properties of immunity are possessed by the breast-fed child than 

 by the artificially-fed one. This subject is beyond the scope of the 

 present work, but further information can be obtained in the papers 

 by Halban, Halban and Landsteiner, Bertarelli, and Gewin. 

 There can be no doubt of the extreme value to the young animal 

 of the colostrum of its species. It is stated that in some species 

 the young do not survive if deprived of this form of nourishment, 

 and there can be no doubt that the artificially-fed human infant, 

 although it does not die, and may even show no outwardly detri- 

 mental effects from early artificial feeding, leads a much more 

 precarious existence than its fellow who has received its natural 

 food after birth. 



REFERENCES "IN CHAPTER VI 

 Immunity 



VAN ALSTYNE AND GRANT, ' Absorption of Albumin without Digestion,' Journ. 



of Med. Research, 1911, xxv. 399. 

 BARTELLI, ' Beitrag zum Studium der Bakteriozidine der Milch,' Milchw. Zen- 



tralb. 1909, v. 462. 



BASENAU. (i) Arch.f. Hyg. 1895, xxiii. 44, 177. 

 BAUER, (i) ' Ueber die Durchgangigkeit des Magendarmkanals fur Eiweiss 



und Immunkorper, etc.', Arch. f. Kinderh. 1905, xlii. 399. (2) ' Ueber 



biologische Milchdifferenzierung,' Munch, med. Wochensch. 1908, Iv. 847. 



(3) ' Zur Biologic der Milch,' Verh. d. Gesellsch.f. Kinderh. 1909, p. 56. 

 BAUER AND SASSENHAGEN, ' Ein neues Verfahren zum Nachweis der Mastitis- 



Milch,' Med. Klinik. 1909, p. 1927. 



1 Cp. Salge (2) and Moll. * Cp. Gewinn and Ossimin. 



