^echanism of immunity against micro-organisms 205 



firmed by other observers. Von Behring\ in a review of the pheno- 

 mena of immunity in general, sums up this question as follows : " we 

 find no antitoxin in the blood of individuals that are naturally 

 refractory." There are, however, certain exceptions, perhaps only [216] 

 apparent, to this rule. Thus Wassermann^ has shown that blood 

 serum from healthy human beings is sometimes antitoxic to the 

 diphtheria poison. The individuals who furnished this antitoxin 

 maintained that they had never suffered from diphtheria. We know, 

 however, that this disease is sometimes present in so benign a form 

 that it may pass unnoticed. More conclusive appears the example 

 of normal horses whose blood serum, as demonstrated by Meade 

 Bolton^ and Cobbett*, is very often antitoxic for the diphtheria 

 toxin. This property, however, is not found in every horse ; in 

 certain individuals it is entirely absent. This last fact affords an 

 indication that the antitoxic property in the blood of horses has 

 been acquired as the result of some affection produced by a bacillus 

 allied to the diphtheria bacillus. This view has not yet been sufficiently 

 examined and consequently cannot claim to be accepted as settled. 

 Recently, Max Neisser and Wechsberg^ have discovered an antitoxin 

 in human blood which is capable of preventing the solution of the 

 red corpuscles by the toxin of staphylococci. This antitoxic power 

 varies considerably in different individuals and is probably to be 

 accounted for by the fact that the staphylococcus is one of the most 

 widely diffused organisms among the bacterial flora of the human 

 body. The small lesions produced by these micro-organisms (acne, 

 boils, etc.) are so frequent in man that they may readily bring about 

 the production of an antitoxin. In this case, however, we have agam 

 an example of acquired antitoxic power. 



The examples just summarised can in no way affect the general 

 thesis that the phagocytes, in order to fulfil their microbicidal 

 function in an animal endowed with natural immunity, have no need 

 of any previous action of the body fiuids to neutralise the correspond- 

 ing toxins. 



1 Article "Immunitat" in the 3rd edition of Eulenburg's Heal-Encyclopddie, 

 Wien, 1896. 



2 Deutsche med. Wchnschr., Leipzig, 1894, S. 120 (of Vereins-Beilage). 



3 [Journ. Exper. Med., New York, 1896, Vol. i, p. 543.] 



■* \journ. Path, and Bacteriol, Edin. and London, 1896, Vol. iii, p. 328 ; Lancet, 

 London, 1899, Vol. n, p. 332; CentralU. f. Bakteriol. u. Parasitenh, Jena, 1899, 

 V^ Abt., Bd. XXVI, S. 548.] 



5 Ztschr.f. Hyg., Leipzig, 1901, Bd. xxxvi, S. 299. 



