150 ANTHRAX AND ANTHRACOID DISEASES. 



placed in aqueous humour, and kept at a temperature of 35° to 

 37° C (95° F.), the rods, as already stated, lengthen out very 

 considerably. This process of lengthening of the rods into fila- 

 ments is apparently effected by the temperature. In five hours 

 a rod at a temperature of 32° C. (89° "36 F.) may have increased 

 so as to be from eighty to one hundred times its original length, 

 and in twenty-four hours the filament may be full of spores. If 

 the temperature, however, be kept about 28° C. (82°"24 F.), the 

 spores may not appear till the thirty-sixth or fortieth hour. 

 When the spores have once appeared, all the other changes go 

 on at ordinary temperati;res from 12° (53°"36 F.) to 18° C. 

 (64°'24 F.), but not nearly so rapidly, even when the prepara- 

 tion is kept in the sun for a few hours daily, as when artificial 

 heat is applied. On the other hand, a high temperature, 37° to 

 40° C. (98°-36 to 104° F.), at once checks all developmental 

 changes. 



The filaments differ . in cultivated specimens very much in 

 their arrangements. Sometimes they form a network — indeed 

 a mycelium — made up of numerous, nearly parallel, unbranched 

 threads, crossing each other at different levels ; the threads are 

 sometimes straight, but have generally a wavy outline. This 

 condition may obtain throughout the whole preparation, but 

 generally at some parts the filaments are extremely irregular 

 and much convoluted. 



It has been stated by several observers (Koch, Bollinger, 

 Siedamgrotzky, &c.) that the bacilli are always motionless ; 

 Dr Cossar Ewart says they are sometimes motile, but this re- 

 quires confirmation. 



Pasteur stated that the spores of bacilli remained toxic after 

 boiling ; and after being subjected to a pressure of twelve atmo- 

 spheres of oxygen, Dr Burden Sanderson and Dr Cossar Ewart 

 tested the accuracy of this statement, and found that mice 

 inoculated with the boiled and compressed solutions remained 

 quite well. 



The experiments of Bert, however, support to some extent the 

 conclusions of Pasteur. In a series of experiments Bert sub- 

 mitted anthrax blood to the action of considerably compressed 

 oxygen, and found the bacilli had disappeared, killed by the 

 oxygen, and yet the blood retained its virulence, for it killed 

 rabbits, guinea-pigs, and dogs inoculated with it ; and in another 

 series of experiments Bert took anthrax blood containing bacilli, 

 and added drop by drop of absolute alcohol to it, until a j^reci- 

 pitate was formed, and which was dried in vacuum. This dried 

 powder was injected under the skin, and it killed a rabbit, a 

 guinea-pig, and even a dog. 



If this alcoholised precipitate be dissolved in water and 

 filtered, the filtrate is still virulent. If alcohol is again added 



