28 GASTRIC DIGESTION OF PROTEINS 



factors. 81 The many contradictions are not to be wondered 

 at when we remember that the lab-coagulation is really a 

 complex process. Ivar Bang concludes his exhaustive in- 

 vestigations upon the subject with the opinion that the 

 calcium salts of the milk are distributed among the organic 

 and inorganic acids, the lactalbumin, lactoglobulin and 

 casein ; that the casein by virtue of its acid nature combines 

 with the whole group of milk bases ; that there is not one 

 paracasein alone but that there are formed, long before 

 coagulation is apparent, a number of different paracaseins 

 with variable but increasing affinity for calcium phosphate, 

 and that at a certain stage these compounds separate from 

 solution and coagulation takes place. 82 



Ultramicroscopic Studies of Lab-process. Kreidl and 

 Neumann 83 have been able to explain very satisfactorily 

 by direct ultramicroscopic observation a number of 

 features (especially that involved in the differences be- 

 tween cow's milk and human milk) which have more than 

 once been regarded as due to variation in the degree of solu- 

 tion of the casein in the milk. In the milk of different species 

 of animals there are visible minute bodies (lactokonids) , pos- 

 sibly identical with suspended casein or caseinated calcium. 

 "It has been shown by ultramicroscopic study of milk of 

 various animals that in all kinds of milk except human 

 there may be found in addition to the fat globules great num- 

 bers of a second corpuscular element. The plasmatic space 



81 M. Arthus, J. Bang, G. Becker, L. Blum, E. Fuld, M. van Herwerden, 

 S. G. Hedin, H. Kottlitz, S. Lowenhart, E. Laqueur, L. Morgenroth, L. Pinkus- 

 sohn, E. Petry, C. PagSs, H. Reichel, K. Spiro, W. Sawjalow, B. Slowzoff, 

 S. Schmidt-Nielsen, G. Warneken, J. Wohlgemuth and many others. Literature 

 upon the Lab-process and the Proteins of Milk: E. Fuld, Ergebn. d. Physiol., 

 1, 408-504, 1902; R. W. Raudnitz, ibid., 2, 193-251, 1903; E. Laqueur, Biochem. 

 Centralbl., 4, 318, 1905; F. Samuely, Handb. d. Biochem., 1, 567-570, 1909; 

 C. Oppenheimer, Fermente, 3d ed., 286-312, 1909; A. Schlossmann, and S. 

 Engel, Handb. d. Biochem., 3', 405-432, 1910. 



62 1. Bang (Lund), Skandin. Arch. f. Physiol., 25, 105, 1911. 



88 A. Kreidl and A. Neumann (Physiol. Instit., Univ. of Vienna), Sitzungs- 

 bericht d. Wiener Akad. Mathem-Naturwiss., kl., 117'", March, 1908; cf. also 

 Centralbl. f. Physiol., 22, 133, 1908, Pfliiger's Arch., 123, 523, 1908. 



