OPSONINS 27 



amboceptor and complement may be present. The applica- 

 tion of the complement fixation test for the detection of colos- 

 trum is only of scientific interest and mastitis can be much 

 more readily detected by an examination of the sediment of the 

 milk. 



Opsonins, bodies which prepare bacterins for phagocytosis, 

 the process by which a cell (phagocyte) absorbs bacterins and 

 other particulate matter, have also been demonstrated in milk. 



It is possible that anaphylactins, which induce the phenome- 

 non known as anaphylaxis or hypersensitiveness, may occur in 

 milk as it has been shown by Otto that the progeny of hyper- 

 sensitised guinea pigs were anaphylactic to homologous antigens. 

 The transmission, however, may have been either intrauterine 

 or through the milk. Mention might also be made of the bene- 

 ficial effect upon children suckling from mothers being treated 

 with " 606," although whether the results are due to the pass- 

 age of antibodies or arsenic is still in dispute. Considering the 

 indubitable proof of the passage of various classes of anti- 

 bodies from the blood stream to milk, it is reasonable to assume 

 that aggressins, bodies which inhibit the protective power of the 

 cells, and toxins are also transferable. This hypothesis has 

 been experimentally established, but, like the antitoxins, the 

 amounts found in the milk are considerably smaller than in the 

 blood. If it is assumed that the gastro-intestinal tract of infants 

 is penetrated by proteids, the question of the transference of 

 toxins assumes practical importance. Even in individuals 

 showing severe symptoms, by far the greater part of the antigen 

 is anchored to the cell leaving but little in the free or labile 

 condition in the system, and, as only a fraction of this is trans- 

 ferred to the milk, the total amount assimilated by the off- 

 spring is probably negligible; h posteriori observations confirm 

 this deduction. 



Since milk contains various proteid substances, it is capable 

 of acting as antigen and on injection produces a number of 

 antibodies. The lactoserum obtained by the use of cows' 

 milk contains precipitins, amboceptors, and hsemolysins, which 



