2 DR. £. KLEIN. 



order that could be directly brought into connection Avith the 

 bacteria^ provided that these latter be introduced in small 

 quantities only. Large quantities, on the other hand, are pro- 

 ductive of putrid intoxication, not so much on account of the 

 presence of bacteria as on account of the now well known and 

 generally accepted chemical putrid poison of Panum, Bergmann, 

 and others. 



It is equally well known that pathogenic bacteria prove their 

 efficacy when introduced in minimal quantities, for it is essen- 

 tial to their character to find in the animal organism a suitable 

 soil for multiplication and by their increase of numbers to 

 produce directly or indirectly a definite disorder in the animal 

 economy. 



In order, then, to investigate whether saprophytic bacteria 

 have assumed the properties of pathogenic organisms it is 

 necessary to bear in mind that they must be expected to show 

 these properties after their introduction in minimal quantities 

 into the animal organism ; that is to say, they must be capable 

 to resist and overcome the effects of the healthy tissues — effects 

 proving invariably deleterious to ordinary saprophytic bacteria — 

 and, having done so, of starting' a definite disorder in the 

 tissue. 



It will be admitted, I presume, that it is not necessary that 

 the disorder be of a general nature ; in some well-established 

 instances, such as anthrax, febris recurrens, pneumo-enteritis 

 of the pig, the malignant oedema (Koch), a general disorder 

 ensues on the introduction of the pathogenic organism, but in 

 other instances, such as the actinomycosis in cattle and man, 

 known through the researches of Bollinger, Jahn, Israel, Pon- 

 fick, the effect of the invasion by the actinomyces is at first, at 

 any rate, of a purely local nature, being generally limited to 

 the lungs ; similarly the introduction of tubercular virus into 

 the anterior chamber of the eye is followed by an eruption of 

 tubercles in the iris (Cohnheim and Salomonsen), and of the 

 same character is the pulmonary tuberculosis occurring in dogs 

 after inhalation (Tappeiner) of the tubercular virus. The ma- 

 lignant ulceration in mice (Koch) is in the same way at first a 



