8 BACTERIOLOGY. 



Each female moth was kept separate from the others, and allowed to 

 deposit her eggs on a small linen cloth. The moth was then pinned 

 to the corner of the cloth, and left for future examination. When 

 the time for this arrived, the moth was crushed up with water in a 

 mortar, and a drop examined under the microscope. When any 

 trace of corpuscular matter was found to be present, the cloth with 

 its collection of eggs was burnt ; and if not, the eggs were set aside 

 for use. 



Complete as this appears to be as a demonstration of a causal 

 connection between the micro-organisms and the disease, it could 

 obviously be objected that there was no distinct proof that the 

 corpuscular bodies constituted the actual contagium. There was no 

 isolation of the organisms, no artificial cultivation of them apart 

 from the diseased moth or worm, and subsequent production of the 

 disease by means of the isolated organisms. The same objection 

 was applicable to Davaine's investigations. Davaine found rods 

 in association with anthrax, and maintained that they were 

 causally related ; but others stated that it was possible to inoculate 

 animals with anthrax blood containing rods, and to produce the 

 disease without being able to detect the rods again in the blood 

 of the animal experimented upon. It was also urged that it was 

 possible to infect with anthrax blood after the rods had disappeared, 

 and to find a reappearance of the bacilli in the blood of the 

 inoculated animal. 



The well-known fact that anthrax was especially prevalent in 

 certain seasons and certain localities appeared to lend great support 

 to these objections. The disease, in fact, was regarded by some 

 as originating from peculiar conditions of climate and soil. The 

 fallacies in these objections were, however, rapidly dispelled. 

 Bollinger, in 1872, pointed out that the blood, from which the rods 

 had disappeared, was still virulent owing to the presence of the 

 spores of the bacillus, and that it was owing to the soil being impreg- 

 nated with these spores that the disease broke out in certain 

 localities. Yet there still remained many who refused to regard 

 these particles as living bodies, some looking upon them simply as 

 crystals ; and the question of their importance remained undecided 

 for several years. 



In 1877 Robert Koch published a memoir in which he fully 

 described the life-history of the anthrax or splenic fever bacillus, 

 ;tiid gave a complete demonstration of the life-history of the micro- 

 organism, and the definite proofs of its pathogenic properties. He 

 pointed out how the rods grew in the blood and tissues by lengthen- 



