108 MICRO-ORGANISMS AND DISEASE. [CHAP. 



these elongate and divide, and in artificial cultures again grow 

 into the long leptothrix filaments, which again form spores. 

 Koch J saw in preparations of aqueous humour kept at 35 C. in 

 the incubator the spores germinating after three to four hours. 

 The single bacilli as they present themselves in the blood 



Fio.74. PART OF A BLOOD CLOT FROM THE HEART OF A MOUSE DEAD OF ANTHRAX. 

 Magnifying power 500. (Stained with Spiller's purple.) 



measure between 0'005 and 0'02 mm. in length, and O'OOl to 

 O'OOl 2 in thickness ; they are truncated. 2 The spores pro- 

 duced by growing the bacilli with free access of air are about 

 O'OOl mm. thick, and about 0'002 to 0'003 mm. long. They 

 are not stained by dyes and differ herein from the bacilli. 



In the human subject mnlignant anthrax occurs as " woolsortcr's disease " ; 

 for the aetiology and pathology of this malady see Spears (Report of the Medical 

 Officer of the Local Government Board, 1881 and 1SS2) and Greenfield (ibid. 1SS1). 



All rodents and herbivorous animals are susceptible to anthrax ; rats are, 

 however, infected with difficulty, pigs are very insusceptible, and so are dogs 

 and cats. Infection of animals can be produced by inoculation into the skTn 

 and subcutaneous tissue, intravascular injections, and by inhalation of spores 

 (Buchner, Untersuclmngen iiber niedere Pilze, by Prof. v. Na'geli, 1882, p. 178). 

 In woolsorter's disease the usual mode of infection is by inhalation of spores 

 adhering to the wool of the fleeces of animals (sheep, goats) dead of anthrax. As 

 in rodents infected with anthrax, so also in man, the blood-vessels of all organs 

 contain the bacilli, and extravasations of the infected blood are frequent in many 

 parts of the body. The presence of bacilli in the extravasations into the mucous 

 membrane of the trachea and bronchi does not necessarily mean that these parts 

 represent the points of entrance of the bacilli into the system, as Greenfield 

 seems to regard as self-evident (Reports of the Medical Officer of the Local 

 Government Board, 1881). As a matter of fact I find in every lung of mouse, 

 rabbit, and guinea-pig, dead after subcutaneous inoculation with anthrax, 

 bacilli anthracis in the alveolar cavities and in the smaller and larger bronchi. 

 Ingestion of bacillar material is sometimes followed by anthrax, but in 



1 Eeitr. z. Biol. d. Pflanzen, vol. ii. part ii. p. 2S8. 



2 It is generally assumed that the bacilli are the same in all animals affected 

 with splenic fever, but this is most undoubtedly not the case, as has been already 

 pointed out by Huber (Deutsche med. Woch. 1881) ; the bacilli of the guinea-pig 

 are thicker than those of the mouse or sheep, and these again are thicker than 

 those in the rabbit. 



