432 THE BACILLUS OF TYPHOID FEVER. 



the bacillus under consideration bears a causal relation to typhoid 

 fever. Eberth was only successful in finding the bacillus in the 

 lymphatic glands or in the spleen in eighteen cases out of forty in 

 which he searched for it. On the other hand, he failed to find it in 

 eleven cases of various nature partly infectious processes and in 

 thirteen cases of tuberculosis in which the lymphatic glands were 

 involved, and in several of which there was ulceration of the mucous 

 membrane of the intestine. 



Koch, independently of Eberth and before the publication of his 

 first paper, had found the same bacillus in about half of the cases 

 examined by him, and had pointed out the fact that they were lo- 

 cated in the deeper parts of the intestinal mucous membrane, beyond 

 the limits of necrotic changes, and also in the spleen, whereas the 

 long, slender bacillus of Klebs was found only in the necrosed por- 

 tions of the intestinal mucous membrane. 



The researches of W. Meyer (1881) gave a larger proportion of 

 successful results. This author confined his attention chiefly to the 

 swollen plaques of Peyer and follicles of the intestine which had not 

 yet undergone ulceration. The short bacillus which had been de- 

 scribed by Eberth and Koch was found in sixteen out of twenty cases 

 examined. The observations of this author are in accord with those 

 of Eberth as to the presence of the bacillus in greater abundance in 

 cases of typhoid which had proved fatal at an early date. 



The fact that in these earlier researches the bacilli were not found 

 in a considerable proportion of the cases examined is by no means 

 fatal to the view that they bear an etiological relation to the disease. 

 As Gaffky says in his paper referred to : 



" This circumstance admits of two explanations. Either in those 

 cases in which the bacillus has been sought with negative results 

 they may have perished collectively, before the disease process which 

 thev had induced had run its course ; or the proof of the presence of 

 bacilli was wanting only on account of the technical difficulties which 

 attend the finding of isolated colonies." 



Gaffky's own researches indicate that the latter explanation is the 

 correct one. 



In twenty-eight cases examined by this author characteristic 

 colonies of the bacillus were found in all but two. In one of these, 

 one hundred and forty-six sections from the spleen, liver, and kid- 

 neys were examined without finding a single colony, and in the other 

 a like result attended the examination of sixty-two sections from the 

 spleen and twenty-one sections from the liver. In the first of these 

 cases, however, numerous colonies were found in recent ulcers of the 

 intestinal mucous membrane, deeply located in that portion of the 

 tissue which was still intact. These recent ulcers were in the neigh- 



