CENTRAL BODY OF BACTERIA 121 



of higher cells, the light in which I consider it. Whether 

 it possesses aU the properties of the latter or not, is a 

 question which requires further investigation, and moreover 

 it does not seem to be absolutely necessary for this to 

 be the case. The central body of the Oscillariw is thus, 

 according to the observations of both Zacharias and myself, 

 which moreover are anticipated by the statements of some 

 earlier authors, to be observed in the cell quite plainly, even 

 during life, as a colourless central portion ; just in the same 

 way I pointed out a similar visibility of the corresponding 

 central body of Chromatium okenii, and that, as a matter 

 of fact, it may even be observed in Bacterium lineola 

 while living. This being so, how any one can presume to 

 defend the assertion, that the central body is only the 

 central mass of the cell contents contracted by plasmolysis, 

 is to me inscrutable, and it certainly offers a proof of the 

 strange manner in which arguments are frequently carried 

 on at the present day. If we consider further, that, as 

 Zacharias and I showed at some length, the central body is 

 marked out both by especial tingibility and by its behaviour 

 towards digestive fluids, the untenability of Fischer's asser- 

 tion becomes more and more beyond doubt. Last but not 

 least, an additional point which is capable of absolute proof 

 comes to our help, which I did not lay stress upon formerly, 

 since it seemed to me impossible to raise the objection 

 under consideration. In Chromatium okenii, as also in 

 Oscillariw, I frequently had opportunity to observe, in my 

 preparations, cells in various stages of plasmolysis, i.e. cells 

 in which the contents had more or less shrunk away 

 from the cell membrane.* In such specimens it could be 

 determined in the most definite manner that, as the result 

 of the plasmolysis, the entire radiate alveolar protoplasm had 

 separated itself from the membrane, with a sharp, smooth, 

 limiting surface. Of Chromatium in particular, I have found 

 specimens in which the entire contents were retracted 

 strongly from the membrane, and which, nevertheless, showed 

 most beautifully both the protoplasmic cortex and the central 

 body. Even in Bacterium lineola it was possible to observe 

 similar conditions with certainty. 



