416 BACTERIOLOGY. 



ber of bacilli that appear upon culture plates from the 

 blood and internal organs, and in a lessening in the 

 amount of mechanical obstruction offered to the cir- 

 culation through plugging of the capillaries by masses 

 of bacilli, as detected by microscopic examination of 

 sections of the organs ; indeed, this latter condition may 

 often have almost, if not quite, disappeared. We see 

 here an animal dead from the invasion of the same 

 organism that produced death in the first animal, but 

 with little or none of the appearances to which we 

 were inclined to attribute the death of that animal. It 

 is apparent then, that this organism, with which we 

 have been working, can destroy the vitality of an animal 

 in a way other than by mechanically obstructing its blood- 

 vessels ; it possesses some other means of destroying 

 life. Possibly its growth in the tissues is accompanied 

 by the production of soluble poisons, which when pres- 

 ent in the blood are not compatible with life. 



Let us see if the study of another group of infections 

 will furnish any evidence in support of such an hypothe- 

 sis. Introduce into the subcutaneous tissues of a guinea- 

 pig a small amount of pure culture of the bacillus of 

 diphtheria. In three or four days the animal dies. We 

 proceed with our autopsy in exactly the same way that 

 we did with the animals dead of anthrax, and will be 

 astonished to find that the organs, blood, and tissues 

 generally are sterile, 1 in so far as the presence of the 

 organism with which the animal was inoculated is con- 

 cerned, and by both culture and microscopic methods 

 it is possible to detect them only at the site of inocula- 

 tion, where they were deposited. It is very evident 



1 In by far the greater number of cases this is true, but under particular 

 circumstances there are exceptions. 



