BACTERIA IN DIPHTHERIA. 383 



are found in great numbers, in the interior of the vessels. This appearance 

 is so characteristic that Loffler considers inoculations in mice to be the most 

 reliable method of establishing the identity of the bacillus. Not pathogenic 

 for chickens, guinea-pigs, rats, or dogs. 



There seems to be some doubt whether the form of diphtheria which pre- 

 vails among pigeons, and which Loffler has shown to be due to the bacillus 

 above described, is identical with the diphtheria of chickens. Diphtheria in 

 man has been supposed by some authors to be identical with that which 

 prevails among fowls, and possibly this may be the case under certain cir- 

 cumstances. But the evidence seems to be convincing that there is an 

 infectious diphtheria of fowls which is peculiar to them, and which, under 

 ordinary circumstances, is not communicated to man. 



50. BACILLUS DIPHTHERIA VITULORUM. 



Described by Loffler (1884) and obtained by him from the pseudo-mem- 

 branous exudation in the mouths of calves suffering from an infectious form 

 of diphtheria. The disease is characterized by the appearance of yellow 

 patches upon the mucous membrane of the cheeks, the gums, the tongue, 

 and sometimes of the larynx and nares of infected animals. There is a yel- 

 lowish discharge from the nose, an abundant flow of saliva, occasional at- 

 tacks of coughing, and diarrhoea. Death may occur at the end of four or 

 five days, but usually the animal survives for several weeks. Diphtheritic 

 patches similar to those in the mouth are also found in the large intestine, 

 and scattered abscesses in the lungs. 



Loffler, in a series of seven cases examined, obtained from the deeper por- 

 tions of the pseudo-membranous deposit a long bacillus which appears to be 

 the cause of the disease. 



Morphology. Bacilli, five to six times as long as broad, usually united in 

 long filaments. The diameter of the rods is about half that of the bacillus 

 of malignant oedema. 



Biological Characters. Attempts to cultivate this bacillus in nutrient 

 gelatin, blood serum from sheep, and various other media were unsuccessful. 

 But when fragments of tissue containing the bacillus were placed in blood 

 serum from the calf a whitish border, consisting of the long bacilli, was de- 

 veloped. These could not, however, be made to grow when transferred to 

 fresh blood serum. 



Pathogenesis. Mice inoculated subcutaneously with the fresh diph- 

 theritic exudation died in from seven to thirty days. The autopsy disclosed 

 an extensive infiltration of the entire walls of the abdomen, which often pene- 

 trated the peritoneal cavity and enveloped the liver, the kidneys, and the 

 intestine in a yellowish exudate. The bacillus was found in this exudate, 

 and by inoculating a little of it into another animal of the same species a 

 similar result was obtained. Not pathogenic for rabbits or guinea-pigs. 



51. BACILLUS OF INTESTINAL DIPHTHERIA IN RABBITS. 



Described by Ribbert (1887) and obtained by him from the organs of rab- 

 bits which succumbed to an affection characterized by a diphtheritic inflam- 

 mation of the mucous membrane of the intestine. The autopsy revealed also 

 swelling of the mesenteric glands and minute iiecrotic foci in the liver and 

 spleen. 



Morphology. Bacilli with slightly rounded ends, from three to four/* 

 long and 1 to 1.4 // in diameter; often united in pairs or in filaments con- 

 taining several elements. 



Stains with the aniline colors, but not so readily in sections as some 

 other microorganisms. Ribbert recommends staining with aniline-water- 

 fuchsin solution, washing in water, then placing the sections in methylene 

 blue solution, and decolorizing in alcohol. Does not stain by Gram's 

 method. 



