Agressins. 53 



bodies accumulate in the glands so that as a result the milk serum 

 agglutinates more readily than the blood serum. 



Not only anti-toxins and other protective immune bodies pass 

 into the milk, but substances also which inhibit the protective 

 power of the body, for instance aggressins, at least so long as the 

 body has not formed anti-aggressins. The aggressins for instance 

 act against the dissolving of bacteria. Schenk demonstrated anti- 

 staphylolysins and anti-vibriolysins in the milk of goats, cows and 

 women. 



Otherwise the passage of toxic substances of the character 

 of antigen, which are closely allied to proteids, could be just as 

 plausible as the passage of the constituents of the blood which are 

 indispensable in the composition of the milk. The passage of 

 toxins into the milk has not yet been satisfactorily proven for all 

 toxins. 



A large number of known substances from animal and plant 

 life are known as toxins, that is, bodies which do not act like 

 chemical poisons, but exert their toxic action only after a period 

 of incubation, in which time fixation takes place. 



These toxins do not affect all animals in a similar degree, 

 but only those which are susceptible. Certain species of animals 

 are not susceptible to certain toxins ; they are immune. This im- 

 munity may also be artifically established in susceptible animals. 

 The toxin is an antigen, and under certain conditions it produces 

 an anti-toxin contrary to the toxins which act purely chemically. 



Among toxins acting in this manner may be mentioned the 

 products of metabolism of the Bacillus diphtheria, the Bacillus 

 tetani, the bacillus of certain forms of meat poisoning the 

 Bacillus botulinus and the Bacillus pyocyaneus, the bacillus of 

 blackleg, and the body substances of certain bacteria (endo-toxins). 

 They may be of animal origin : snake toxins, spider toxins, scor- 

 pion toxins, turtle toxins, toxin of the blood of eels, salamander 

 toxins, wasp toxins, or of plant origin, such as the abrin, robin, 

 krotin, ricin, etc. 



If it is considered that the gastro-intestinal tract of very 

 young individuals is readily penetrable for proteids, although pro- 

 teids of unlike origin pass with greater difficulty than those of like 

 origin, the question as to whether the milk of the mother may con- 

 tain toxins when toxins are circulating in her blood, assumes prac- 

 tical importance. This becomes, however, unimportant when it is 

 considered that even in severely affected individuals only very 

 small quantities of toxins are circulating free in the blood. Should 

 a part of these minute amounts be secreted in the milk, this quan- 

 tity itself is of only little practical importance even when the great 

 susceptibility of the intestines of the suckling is considered. 



It is true that Miessner succeeded in proving that mice die 

 from tetanus when they are fed with raw milk from a cow affected 

 with tetanus, whereas the feeding of meat has no influence on the 



