BACTERIA IN DIPHTHERIA. 367 



nasal catarrh, two from simple enlarged tonsils, fifteen from chronic 

 pharyngitis, one from subacute laryngitis, one from chronic laryngi- 

 tis, one from rhinitis, and two from an affection of the tonsils and 

 pharynx. In forty-nine cases nothing of particular interest was ob- 

 served. A variety of microorganisms were isolated, and of these 

 the pyogenic micrococci were the most common. 



In four cases microorganisms were found which resembled the 

 Bacillus diphtherias of Loffler in their morphology and growth in cul- 

 ture media, but which proved not to be pathogenic. Abbott says : 

 ' ' The single point of distinction that can be made out between the 

 organisms obtained from Cases I. , III. , and IV. and the true bacil- 

 lus of diphtheria is in the absence of pathogenic properties from the 

 former, whereas in addition to this point of distinction the organism 

 from Case II. gives, as has been stated, a decided and distinct 

 growth upon the surface of sterilized potato." 



49. BACILLUS DIPHTHERIJE COLUMBRARUM. 



Described by Loffler (1884), who obtained it from diphtheritic pseudo-mem- 

 branes in the mouths of pigeons dead from an infectious form of diphtheria 

 which prevails in some parts of Germany among these birds and among 

 chickens. 



Reddened patches first appear upon the mucous membrane of the mouth 

 and fauces, and these are covered later with a rather thick, yellowish layer 

 of fibrinous exudale. In pigeons the back part of the tongue, the fauces, 

 and the corners of the mouth are especially affected ; in chickens the tongue, 

 the gums, the nares, the larynx, and the conjunctival mucous membrane. 

 The disease is especially fatal among chickens, the young fowls and those of 

 choice varieties being most susceptible. It is attended at the outset by fever, 

 and usually proves fatal within two or three weeks, but may last for several 

 months. 



Morphology. Short bacilli with rounded ends, usually associated in ir- 

 regular masses, and resembling the bacilli of rabbit septicaemia (fowl 

 cholera), but a little longer and not quite so broad. In sections from the 

 liver they are seen in irregular groups in the interior of the vessels. 



Biological Characters. An aerobic, non-motile, non-liquefying bacillus. 



Grows in nutrient gelatin in the form of spherical, white colonies along- 

 the line of puncture, and upon the surface as a whitish layer. Under the 

 microscope the colonies in gelatin plates have a yellowish-brown color and 

 a slightly granular surface. Upon blood serum the growth consists of a 

 semi-transparent, grayish- white layer. Upon potato a thin layer is formed 

 having a grayish tint. 



Pathogenesi*. Pigeons inoculated with a pure culture in the mucous 

 membrane of the mouth are affected exactly as are those which acquire the 

 disease naturally. Subcutaneous inoculations in pigeons give rise to an in- 

 flammation resulting in local necrotic changes. Pathogenic for rabbits and 

 for mice. Subcutaneous injections in mice give rise toa fatal result in about 

 five days. The bacillus is found in the blood and in the various organs, in 

 the interior of the vessels, and sometimes in the interior of the leucocytes; 

 they are especially numerous in the liver. The lungs are dotted with red 

 spots, the spleen is greatly enlarged, and the liver has a marbled appearance 

 from the presence of numerous irregular white masses scattered through the 

 pale-red parenchyma of the organ. These white masses are seen, in sec- 

 tions, to consist of necrotic liver tissue, in. the centre of which the bacilli 



