Bacteria of Davaines Septicaemia. By G. F. Bowdeswell. 311 



two ends are the most highly refracting, they take the staining 

 more deeply than the intermediate portion, which is often with 

 difficulty perceptible ; the ends thus stained present the appearance 

 of forming spores, in some cases so distinctly that I am disposed to 

 think this is really the case, though I have never witnessed their 

 complete development. 



The preparation shown is from the blood of a rabbit of the 

 third generation of artificial infection, it was made very shortly 

 after death, and treated by the methods introduced by Weigert and 

 Koch, which have been described elsewhere, and are now pretty 

 generally known and adopted. I have not found these Bacteria in 

 any of the organs or the tissues, excepting the blood and the lymph 

 of an infected animal, examined immediately after death, not even 

 in the lungs or the spleen, where, judging from other cases, we 

 should expect to meet with them ; their minute size, however, 

 and more especially their not readily staining, would render them 

 very difficult to distinguish in the tissues. In the blood this 

 Bacterium is evidently motile, sometimes very actively so. 



Notwithstanding the interest and attention which this affection 

 has excited during several years, and the importance of the micro- 

 phyte in relation to the question of the true nature of the contagium, 

 it has not, I believe, been figured or at all carefully described by 

 any one, excepting only by Coze and Feltz, in a work published at 

 Strasbourg and Paris several years ago ; their description is im- 

 perfect, and does not in any way coincide with my own observa- 

 tions ; they even give the diameter of the organism just three 

 times as great as I have found it. These measurements I have 

 checked by the use of the admirable standard stage micrometer 

 recently constructed by Professor Kogers, of Cambridge, U.S.A., 

 one of which I have received, and which is most valuable in 

 enabling different observers to compare exactly their measurements. 

 The immense discrepancy, however, between my observations and 

 those of Coze and Feltz, cannot be reconciled by any variations in 

 the standard scale used, and renders it difficult to believe that the 

 same organism has been observed in the two cases. This opens up 

 a very important, indeed a fundamental question with reference to 

 the etiology of this affection, which need not be discussed here ; I 

 will only say that in the course of very numerous experiments, in 

 different series, I have found the organism specifically distinct, 

 invariable and constant in all cases, thereby conforming to the 

 first and most important condition which has been laid down as a 

 test for a specific parasitical contagium. 



In relation to the dimensions of the organism, and the infective 

 virulence of the blood in which they are contained, a very curious 

 question arises as to how many Bacteria or their germs can be 

 contained in a given quantity of blood, and this, as far as I know, 



