54 Biological, Chemical and Physical Characteristics of Milk. 



health of the animal; this proves the passage of the tetanus toxin 

 into the milk. 



Older animals do not become affected even after the adminis- 

 tration per os of large doses of toxins, at least not from diphtheria 

 or tetanus toxins, and the Bacillus botulinus, the toxins of which 

 are absorbed by the stomach but the bacillus does not thrive in the 

 body; therefore the possibility of secreting these toxins through 

 the milk gland is from the first of small importance, especially 

 since in severely affected animals the secretion ceases. 



From a practical consideration of the question of toxin elimi- 

 nation, the plant toxins come principally into consideration, espe- 

 cially ricin, as food adulterations to a great extent take place with 

 ricinus seed and its flower. An elimination of ricin with the milk, 

 however, has not been observed up to the present time. Ehrlich 

 was unable to observe an elimination of ricin in mice which were 

 under the action of ricin; the offspring of these mice w r ere not 

 actively immunized against ricin but acquired only a passive im- 

 munity of short duration. 



Of more importance however are the bacterial toxins, and 

 products of decomposition acting like toxins, which subsequently 

 develop in the milk after certain fermentation processes. 



The above-mentioned immune substances are probably of great 

 importance for the nourishment of the young and the sucklings. 

 The passage of genuine proteids in very young individuals with 

 injured mucous membranes, is an established fact, and with the 

 globulins anti-bodies also pass into the blood of the young, while 

 in older individuals the relatively labile anti-bodies are changed or 

 destroyed by the splitting up of the proteids. 



The absorption of anti-toxins through the intestines of the 

 young has been proved by the classical experiments on sucklings 

 by Ehrlich. 



Other works by Brieger, Ehrlich, Salge and Eomer prove that 

 certain immune substances of milk of like origin pass through the 

 intestines, while in feeding sera or anti-substances of like origin 

 contained in milk of unlike origin the quantity passed was only 

 very slight. Thus Rb'mer succeeded in demonstrating passive 

 immunity in foals after feeding them with anti-toxin milk of like 

 origin, but was unsuccessful after feeding anti-toxic sera of like 

 origin. 



^ In calves of course the results were positive even when the 

 anti-toxin was mixed with the milk as a serum of unlike origin, but 

 the quantity of immune bodies of unlike origin absorbed was 

 smaller than that of like origin. The absorption diminishes with 

 the increase of the age of the animal. 



Relative to the passage of other immune substances from 

 the milk into the blood of the suckling, the same experiences hold 

 as a rule as in the case of milk containing anti-toxin. 



Milk is not only a carrier of anti-bodies, and possibly of anti- 



