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rated from each other. The most conspicuous colonies were those 

 which liquefied the gelatine ; among others producing no liquefaction 

 Miwtfoccus candicans and a yeast were especially noted for their 

 frequent occurrence ; but no trace of any of the higher fungi was 

 found. The colonies were next transplanted by means of a sterile 

 platinum wire into test-tubes containing about 10 c.c. of nutrient 

 gelatine ; and after numerous trials 1 was satisfied that pure cultures 

 were obtained. 



The various organisms as isolated were sown by means of a freshly- 

 heated platinum wire upon sterile but living blocks of turnip. To 

 prepare these blocks the turnips were first washed, and then soaked 

 in a 1 per cent, solution of corrosive sublimate to destroy any organisms 

 adhering to the outer surface, the corrosive sublimate being afterwards 

 thoroughly washed away by means of water sterilised by discontinuous 

 boiling. The rind was then removed by a sterile knife, the turnips 

 l)eing cut into suitable blocks on a sterile plate and quickly inserted in 

 the test-tubes. Treated in this way the blocks of turnip, while quite 

 sterile, were composed of healthy living cells, as was shown by three 

 sets of control tubes. In the first set the blocks, prepared as above, 

 were immersed in cooled liquid nutrient gelatine, in the second similar 

 blocks were immersed in sterile water; in neither case were any 

 colonies found to develop either when the blocks were partially or wholly 

 submerged, and after eight days no sign of decay had appeared. In the 

 third set the blocks were simply inserted in the tubes, and kept in a damp 

 atmosphere ; on microscopical examination cell division was observed 

 to have taken place in the outer layers of uninjured cells, and the cell 

 tissues presented a normal and entirely healthy appearance. 



In the tubes containing the inoculated blocks many showed signs of 

 advanced decay in about twelve hours, and all those in which any 

 rottenness appeared were carefully noted. 



After repeated experiment and a long series of cultures, I succeeded 

 in isolating a bacterium which liquefies gelatine, and which, when sown 

 on the sterile blocks of living turnip, produced the characteristic 

 ' White Rot " previously described. 



The isolation of the bacterium in this manner was further confirmed 

 by pricking out the colonies by means of Unna's harpoon. Small 

 colonies of about 15 p growing in a petri capsule were selected and 

 transplanted by the harpoon into petri capsides containing some sterile 

 turnip bouillon. A specially fine harpoon needle was obtained, but the 

 point was still larger than these very small colonies, and it was only 

 after some practice that they could be successfully transplanted. The 

 colonies selected were those growing quite apart, which appeared to 

 have arisen from a single bacterium, to eliminate as far as possible any 

 chance of the needle touching more than one. Lest, however, even 

 these small colonies might have grown from more than one bacterium, 





