VI] GENERAL CHARACTERS OF BACTERIA 105 



sorters' and hide-sorters' disease, which is virulent anthrax 

 in the human beings engaged in the sorting of wool or the 

 handhng of hides derived from animals — sheep, goats, and 

 cattle respectively — which had succumbed to fatal anthrax. 

 In these cases it is always spores of the bacillus anthracis 

 which are the cause of infection of the human beings 

 handling these articles. 



Observing baciUi, which do form spores {e.g. bacillus 

 subtihs, various species of " potato bacillus," bacillus 

 mesentericus, bacillus anthracis, and the bacillus fila- 

 mentosus above mentioned), it is noticed that the first sign 

 of the appearances of spores is indicated by the presence 

 of a bright, glistening globule in the protoplasm of the 

 bacillus ; at the same time the bacillus is distinctly broader 

 and paler in its substance as compared with the other 

 bacilli. This globule gradually enlarges in diameter, 

 becoming at the same time slightly oval ; this continues till 

 the thickness of the globule often exceeds the breadth of 

 the bacillus, this latter being now markedly pale and trans- 

 parent. The writer has watched in bacillus anthracis and 

 bacillus filamentosus the spores from their first appearance 

 as bright globules till they had reached their full thickness 

 and length ; this took about three hours, and he has also 

 noticed that after sowing on the surface of solidified agar 

 the blood of the heart or spleen of a guinea-pig dead of 

 anthrax and keeping it under observation at the tempera- 

 ture of 20° C. spores would be noticed in a few of the 

 bacillary filaments after twelve hours ; in the case of the 

 bacillus subtilis, various potato bacilli, and bacillus fila- 

 mentosus growing in broth, copious spore formation was 

 noticed in a superficial pellicle after sixteen hours. Koch 

 first observed that spore formation in bacillus anthracis 

 occurred after six hours. But not all bright granules that 



