'intracellular' poisons 281 



products, all produce one and the same disease when their 

 protoplasm is injected subcutaneously into guinea-pigs; and 

 since they induced death under the same pathological and 

 clinical symptoms, when injected intraperitoneal^, Klein 

 drew the inference that all these bacteria contain the same 

 kind of poisonous body within their protoplasm. This 

 body he termed the ' intracellular ' poison, which must not 

 be confused with the ' toxins ' produced by the metabolism 

 of the same organisms as the result of their growth in 

 artificial media or the animal body. In the case of anthrax, 

 Klein states that the pathogenic properties of this bacillus 

 may be due to two poisons : the metabolic products, which 

 pervade the system ; on the other hand, the protoplasm of 

 the bacilli, which contains the ' intracellular ' poison. The 

 tubercle bacillus he also cites as without question concerned 

 with two kinds of poisons. Again, Klein states that 

 neither tetanus nor diphtheria is due to the action of 

 ' intracellular ' poisons ; in these diseases the specific 

 organism remains limited to one locality of the body, where 

 they produce their toxins, which when absorbed into the 

 system give rise to the symptoms characteristic of one or 

 the other disease. 



Chromogenic Bacteria and Colouring Matters. — As before 

 stated, many of the saprophytic bacteria, as the result of 

 their vital action, give rise to many beautiful colouring 

 matters, such as red, yellow, green, violet, etc. In some 

 cases these colouring matters are contained in the substance 

 of the bacteria themselves, or within the sheath; in others 

 the organisms in themselves are quite colourless, and pro- 

 duce colouring matter as the result of the decomposition of 

 the nitrogenous albuminoid matter contained in the nutrient 

 media. The bacillus of the disease of milk, known as 

 ' blue milk ' (B. cyanogenus), when grown on gelatine, is 

 of a pale-blue colour ; but the organism soon colours the 



