SOME ASPECTS OF THE IMMUNITY QUESTION. 241 



certainty protected 100 per cent, of the experimental 

 animals, and the degree of toxine resistance could, when 

 contrasted with the uninoculated animal, be expressed as 

 1000. No other means of protective inoculation appears 

 so efficacious as this, since the most sensitive animals are 

 rendered immune. 



The question of inherited immunity has been the subject 

 of much recent research. Doubtless at the present time the 

 comparative immunity enjoyed by white races to certain in- 

 fective diseases is probably to some extent due to inheritance, 

 and this may be transferred either by the germ-cell or by the 

 mother to the foetus. The natural immunity which Algerian 

 sheep possess against anthrax was shown by Chauveau (34) 

 to be truly inherited and held by him to be due to the 

 exceeding solubility of protective substances which were 

 transferred to the foetus. However, the rat when adult is 

 exceedingly refractary to anthrax and other bacterial 

 diseases, while young rats are susceptible. Fowls and 

 pigeons are immune to tetanus and to anthrax, and Lazarus 

 and Weyl (35) hold that this condition is inherited and not 

 acquired, since after twenty-four hours of extra-ovular life 

 chickens are found to be immune to the latter disease. 

 The case is quite different with pigeons ; the immunity 

 is relative and not absolute as regards anthrax. The 

 bacilli of this disease live in the tissues of these animals 

 for as long as eight days (36), and while there increase in 

 virulence, but adult birds do not succumb, while young 

 pigeons can be easily inoculated (37). Even though living 

 bacilli exist in the system they do not multiply, neither do 

 the spores develop, and therefore in immune pigeons a 

 bactericidal liquid cannot be the cause of the immunity. 



The subject of inherited immunity has been dealt with by 

 Ehrlich in several papers, in the earliest (38) of which a de- 

 tailed account of his observations on ricin, abrin and robin is 

 given. These bodies he regards as the toxalbumins of the 

 seeds of Ricinus communis and Abrus precatorius, though 

 S. Martin (39) has shown that the abrin isolated from 

 jequirity seeds by Warden and Waddell (40) is a mixture 

 of at least two proteids, a paraglobulin and a phyto- 



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