CH. XL] BACILLUS: PATHOGENIC FORMS. 119 



oedema is found at the seat of inoculation ; the spleen is 

 large; in the oedematous tissue and in the blood-vessels, 

 large and small, numbers of minute bacilli are found, chiefly 

 contained in the white blood-corpuscles, but also free. They 

 are very minute, about 0*008 to o'ooi mm. long, to o'oooi 

 to 0*0002 mm. thick, isolated or in couples, or in chains of 

 four or more. The smallest quantity of this blood invariably 

 kills, with the same symptoms, house mice and sparrows, but 



FIG. 54. FROM A SECTION THROUGH THE SMALL INTESTINE OF A MOUSE DEAD 

 OF SEPTICAEMIA. 



The figure represents a section through a small vein in the submucous tissue, filled 

 with blood. At i, there is a homogeneous substance and in it numerous bacilli, 

 but these bacilli are much larger than the bacilli of Koch's septicaemia in the 

 mouse. 

 Magnifying power about 700. (Stained with methylene blue and vesuvin.) 



not field mice. Rabbits inoculated with these bacilli in the 

 skin of the ear or the cornea show only a local inflammation, 

 and the affected tissues contain numerous bacilli of the 

 same kind. Such animals after the local effect has passed 

 off, are protected against any further attack by the same 



invade the surrounding tissues. To mention one series of cases only, in 

 ulcerations and in inflammations of the mucous membrane of the 

 stomach and intestine, large numbers of bacilli are occasionally found 

 on the surface of the inflamed parts, and gradually invading the inflamed 

 tissue. Von Recklinghausen (Virchow's Archiv, vol. xxx,), von Wahl 

 (ibidem, vol. xli.), saw minute pustular nodules in the inflamed gastric 

 mucous membrane which were full of bacilli. Whether the presence 

 and growth of these bacilli was the primary cause or only a concomitant 

 symptom (due, for example, to the loss of active vitality of the tissue) 

 remains to be proved. 



