TOXINS OF THE HIGHER PLANTS AND ANIMALS 119 



exerts a destructive action on erythrocytes (hemotoxin), and the other 

 on leukocytes (leukocidin). 



An anti-hemotoxin that counteracts the effects of the toxin may be 

 produced experimentally, and in human staphylococcus infections the 

 demonstration of such antihemotoxic substances in the blood-serum 

 may be of aid in making the diagnosis of staphylococcus infections. 

 This antistaphylolysin may be found normally in small amounts in the 

 serum of man and horse, and when anti-hemotoxic tests with human 

 serum are made, a normal control should always be included. Anti- 

 leukocidins have also been produced, but are not of practical im- 

 portance. 



The hemotoxin is readily formed in cultures of staphylococci; 

 roughly, the amount produced depends upon the virulence of the culture. 

 In human cases of staphylococcus infections this toxin produces hemoly- 

 sis in vivo, and is partly responsible for the grave anemia that is fre- 

 quently present. 



6. Streptolysin. The grave systemic symptoms that so frequently 

 accompany slight streptococcus lesions are strong indications that these 

 microorganisms produce a powerful diffusible poison, although extensive 

 researches into the nature of these poisons have not given us any clear 

 understanding of the subject. 



Streptococci may yield soluble toxins that, when administered to 

 guinea-pigs, produce rapid collapse and death. While these toxins are 

 not comparable in potency to the soluble toxins of diphtheria and 

 tetanus, they have, nevertheless, been differentiated from the endo- 

 toxins contained within the cell-bodies, and have been found to possess 

 less toxicity. 



Beside these toxins, some streptococci produce a hemolysin which 

 may be conveniently observed by cultivation of the organisms upon 

 blood-agar plates. This hemotoxin is partly responsible for the san- 

 guineous character of a streptococcus exudate. 



TOXINS OF THE HIGHER PLANTS AND ANIMALS 



PHYTOTOXINS 



As has previously been mentioned, the power of forming toxins is not 

 confined to bacteria alone. There is a class of higher plants and ani- 

 mals that produces characteristic poisons against which immunization 

 can be undertaken and an antitoxic serum obtained. Those of most 

 interest medically are pollen toxin and snake poison. 



