414 BACTERIOLOGY. 



typhoms for auimals. By some it was held that the 

 effects of its introduction into animals were manifestly 

 of toxic ^ origioj while others regarded them as evidences 

 of genuine infection.^ These diversities of opinion are 

 hardly surprising when we remember that animals 

 never suffer naturally from a disease similar to typhoid 

 fever, and therefore offer many obstacles to its faithful 

 reproduction, and that the vigor of this organism when 

 cultivated from various sources is liable to a wide range 

 of fluctuation. For a time there seemed to be good 

 grounds for the opinion that. under exceptional circum- 

 stances baoiUus typhosus did exhibit truly infective 

 properties, and the reported experiments of Cygnseus^ 

 in particular, as well as a single observation by the 

 writer,^ in no wise weakened this opinion. By a variety 

 of methods Cygnaeus demonstrated that this organism 

 possessed the property of multiplying within the in- 

 ternal organs of animals and of causing constitutional 

 symptoms and pathological lesions that very closely 

 simulated those of typhoid fever as seen in man. In 

 1890 the writer called attention to the lesions found in 

 one of a number of rabbits that had succumbed to 

 intravenous injection of large amounts of fluid cultures 

 of this organism. 



In this case there was an ulcer in the ileum which 

 was macroscopically and microscopically identical with 

 those found at autopsy in the small intestine of human 



' Toxic — poisonous results not necessarily accompanied by tlie growth 

 of organisms throughout the tissues. 



^ Infective or septic — poisoning of the tissues as a result of the growth 

 of bacteria within them. 



'Cygnneus: Ziegler's Beitrage zur Anat. und Path., 1890, Bd. vii. 

 Heft 3, S. 377. 



■* Bulletin of the Johns Hopkins Hospital, 1890, vol. i. p. 63, 



