218 TEXT-BOOK OF BACTERIOLOGY. 



It has already been stated that garden earth almost always 

 contains germs of the oedema bacillus, and that it is, therefore, a 

 very good material for infecting susceptible animals, such as 

 Guinea-pigs. 



If we examine a Guinea-pig which has died two days after being 

 inoculated 'with garden earth, the following conditions will be 

 noticed : If the skin be incised and thrust aside the peculiar state 

 of the body becomes visible. The subcutaneous cellular tissue and 

 the superficial muscles for a considerable distance round the point 

 of infection are oedematous and saturated with a dirty-red fluid, 

 and almost everywhere, especially in the axillae, a stinking, frothy 

 ichor has collected. 



But what is seen here is not simply the result of oedema. In 

 garden earth there are always, in addition to the oedema bacilli, 

 numerous germs of other bacteria, some of them anaerobic, and of 

 which the Bacillus spinosus, for example, is already known to us. 

 These develop with the bacilli in the body of the animal, are often 

 recognizable under the microscope by their difference of shape or by 

 their want of spontaneous motion, and complicate the pathological 

 examination very considerably. 



That such is the case may be proven by infecting a susceptible 

 animal (rabbit. Guinea-pig, or mouse) with a pure culture of the 

 oedema bacillus. 



Here too a strong, bloody oedema of the subcutaneous tissue 

 and of the superficial muscles extends to a considerable distance 

 from and around the point of inoculation, and gives its name to the 

 entire affection. But the liquid Which collects is no longer ichor- 

 ous, but consists of a reddish serum without odor and without very 

 marked development of gas. 



The internal organs are but slightly altered. The spleen is 

 generally somewhat enlarged and dark-colored | the lungs are of 

 a peculiar grajnsh-red. 



Cover-glass preparations from the oedema fluid, the heart blood, 

 and tissue juices display a very remarkable fact. While the first 

 show large numbers of rod-cells, the tissue juices of the larger 

 organs show but few, and the blood none at all. This experiment 

 is cori'oborated and complemented by the examination of sections 

 from the various organs. Whether we take the spleen, the liver, 

 the lungs, or the kidneys, in no case shall we find bacilli in the in- 

 terior of the tissue; in particular the blood-vessels, the chief seat of 

 alterations with anthrax, will be found perfectly free from them. 

 Only at the edge of the preparations — i.e., on the surface of the 

 organs — large quantities of bacteria will be found in and immedi- 



