PATHOGENIC BACTERIA 255 



of the enzymes in the body which they attack, or by autolysis 

 (self-destruction by enzymes) of the bacteria themselves. The 

 various species of pyogenic (pus-producing) micrococci, M. 

 pneumoniae,B. typhosus,Msp. comma, and many other bacteria, 

 produce endotoxins. The filtrate (porcelain filter) of cultures 

 of these bacteria is only slightly toxic. The bodies of the 

 bacterial cells are extremely toxic when injected into animals, 

 proving that the poisonous substance is contained within the 

 cell wall. Endotoxins can be extracted by pressing out the 

 intra-cellular substances by means of a high power hydraulic 

 press, or by grinding the bacteria after they have been ren- 

 dered brittle by liquid air. Immunization of animals with 

 bacteria-producing endotoxins yields in the body fluids of the 

 animal injected not antitoxins, but increased bactericidal 

 substances, agglutinins, precipitins, opsonins, etc. The failure 

 to secure antibodies which will combat the action of the endo- 

 toxins directly (antiendotoxins) has seriously impeded the 

 progress of serum therapy. 



The following toxic substances are produced by some of the 

 higher plants. They are not unlike bacterial endotoxins 

 except that antibodies may be produced against them by 

 immunization. They are called phytotoxins. 



Ricin from the seeds of Ricinus communis (castor oil bean). 

 Abrin from the seeds of Abrus precatorius (jequerity bean). 

 Crotin from the seeds of Crotin tiglium. 

 Robin from the leaves and bark of Robina pseudoacacia 

 (locust). 



