I02 Lectures on Bacteria. [J ix. 



other textile plants, in order to obtain the fibres, and in such as 

 the wet-rot of bad potatoes according to Reinke and Berthold. 

 Van Tieghem is inclined to attribute to Bacillus Amylobacter a 

 prominent part in the nutrition of ruminant animals, since it 

 vegetates in their stomachs and splits up the cellulose of their 

 food into soluble products of decomposition capable of re- 

 sorption. 



Van Tieghem has also shown or made it probable that this 

 Bacillus has been an active destroyer of cellulose at least since 

 the period of the coal-measures. Fossil plants silicified in a 

 more or less advanced state of maceration, show in their sec- 

 tions the same progression in the destruction of the cell-wall 

 which is observed in macerated plants of the present day, and 

 also the silicified remains of a Bacterium, which he identifies 

 with B. Amylobacter. 



The active powers of fermentation and decomposition of this 

 Bacillus are not confined to the non-nitrogenous bodies just 

 enumerated, as is shown by the investigations of Fitz, which 

 have been before briefly mentioned. The details of these in- 

 vestigations will be found in the works already cited. The 

 behaviour of this Bacillus to proteids will be noticed presently. 



Though there can be no doubt that much the larger number 

 of fermentations producing butyric acid are caused by Bacillus 

 Amylobacter, yet it cannot be said to be the exciting cause of 

 all fermentations which have butyric acid for their primary pro- 

 duct. On the contrary, Fitz describes a large round chain- 

 forming Micrococcus and a short non-endosporous rod-shaped 

 Bacterium, as ferments producing butyric acid in calcium 

 lactate and in some sugars. His former statement, that 

 Bacillus subtilis forms butyric acid by fermentation from starch- 

 paste, and that this fermentation is a very advantageous method 

 of procuring butyric acid, must be founded on a confusion of 

 forms. The typical B. subtilis of Brefeld and Prazmowski can- 

 not be the species intended, for Prazmowski distinctly states that 

 it does not excite fermentation of any kind in starch-paste. 



