TEXT-BOOK OF BACTERIOLOGY. 



207 



not time with this kind of inoculation to produce circumscribed 

 local effects. Marked oedema of the abdominal walls will be seen. 

 The subcutaneous cellular tissue is gelatinous, partially infiltrated 

 with blood, and shakes when touched, but nowhere (which should be 

 specially noted) do gas-bubbles form. The surface of the muscular 

 tissue is paler, soft and moist, and looks almost as if boiled. The 

 spleen alone is greatly altered — a fact from which the affection 

 takes its name of splenic fever. The spleen is considerably en- 

 larged, of a dark color, soft, and at the same time brittle. The liver 

 too shows some degree of enlargement, the lungs are pale red, the 

 heart full of blood. Nothing further can be found worth noting. 



Next comes the microscopic examination to which the blood and 

 the tissue fluids must be submitted. 



The bacilli, as we are aware, take all the different anilin stains 

 well. The double- staining acording to Gram's system requires 

 great caution, and to obtain good results we must carefully regu- 

 late the time during which we expose our objects to the solution. 

 The bacilli decolor readily and then take the contrasting stain. 

 Not infrequently this takes place with regard to portions of a 

 bacillus only; one sees one end stained with the first color, the 

 other end with the second color. Sometimes too, under the influ- 

 ence of the iodine, the contents of the cell contract into regular, 

 round grains, .so that the bacilli are scarcely recognizable and look 

 more like a chain of micrococci. 



The blood or tissue juice almost always contains very rich quan- 

 tities of bacteria, which are but seldom seen in large aggregations 

 and generally occur in groups of two to five members. The bacilli 

 always lie between the blood-corpuscles or tissue-cells, never in 

 them. 



If we examine tissue hardened in alcohol, we find the chief 

 masses of bacilli confined to the vessels. 



The principal abode of the bacteria is in the capillary vessels 

 where the passages are widest and the current is slowest, equallj'- 

 distant from the commencement of both arteries and veins, but 

 only a few cells wander into the large vessels, while the capillaries 

 sometimes look as if injected, completely filled out and stuffed full 

 of the foreign intruders. The spleen is equa-lly filled with them in 

 all parts; in the liver thej'' lie particularly in the middle between 

 the capillaries of the veins and those of the vena porta. In the 

 villi of the intestines they take possession of the ends, in the kid- 

 neys they fill the glomeruli. Under the pressure of the rapidly- 

 increasing bacilli the capillar^' vessels sometimes burst, and let 

 blood and bacilli escape at the above-mentioned places — i.e., in the 



