BACILLUS DIPHTHERIA. 237 



causal part in the disease. Of greater weight is another 

 objection which also arises from an observation made by 

 Loeffler. On examining the secretion of the mouth in 

 20 children and 10 adults by the aid of cultivation, 

 Loeffler obtained in one case colonies, which consisted, 

 as shown by the microscope, by cultivation experiments, 

 and by experiments on animals, of these diphtheria 

 bacilli. Nevertheless, it is not impossible that the 

 pathogenic bacilli may at times be present in the secre- 

 tions of the mouth without setting up symptoms of 

 disease, either because there are no points at which it can 

 enter the body, or because, for some other reason, the 

 patient is immune, and this assumption hardly seems to 

 be too unlikely when we remember the characteristic dis- 

 tribution of these bacilli, and the striking result of the 

 experiments on animals, which seem distinctly to imply 

 that at least for a certain group of diphtheritic diseases 

 these bacilli are the causal agents. 



As regards the bacteria of diphtheria in pigeons and 

 calves see below. 



Emmerich has asserted in a preliminary communication Emmerich's 

 published in the proceedings of the Hygienic Congress, at 

 Hague, that the exciting agents of diphtheria are short, thick 

 rods, which are twice as long as broad, and which grow 

 luxuriantly on nutrient jelly in the form of round, whitish 

 colonies, about the size of the head of a pin, and on potatoes 

 in the form of a thick, whitish-yellow layer. The cultivations 

 were successfully inoculated on pigeons, rabbits, and white 

 mice ; if a cultivation was applied to the mucous membrane 

 of the trachea of a rabbit, it was found after death, which 

 occurred about 60 hours later, that the mucous membrane 

 was covered with a croupous, dirty greyish-yellow membrane ; 

 further, there was fibrinous inflammation of the pericardium 

 and fibrinous deposits on the lungs. The bacilli were not 

 only found in the false membrane and the mucous membrane, 

 but were more or less numerous in the blood and internal 

 organs, in the liver and spleen, and more especially in the 

 kidney. Emmerich obtained the same result from 8 cases 

 of human diphtheria, and 6 cases of pigeon diphtheria, and 

 ho looks on human and pigeon diphtheria as diseases caused 

 by the same infective agent. 



Emmerich's conclusions are, however, by no means suffi- 

 ciently satisfactory. According to the best observations, we 



