258 The Unity of the Organism 



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the cover to a base-ball. It is an essential, active, living 

 part of the organism. It seems to correspond more to the 

 skin of a higher animal than to a man's coat, or to the 

 shell of a mollusc or of a walnut. "Unlike the cell-wall of 

 the higher plants, it [the outer layer of the bacterium] gives 

 usually no reactions of cellulose, nor is chitin present as in 

 the fungi, but it consists of a proteid substance and is ap- 

 parently a modification of the general protoplasm." ^^ This 

 appears to express the most common view, especially among 

 bacteriologists proper. Some authorities, as Kolle and 

 Wassermann, speak of the ectoplasm and endoplasm, and 

 declare that a "cell-membrane, such as is present in plant 

 cells, is not to be thought of" ^^ in the bacteria. If the 

 membrane is comparable with that of the cells of any multi- 

 cellular organisms at all, it would seem to be more akin to 

 that of the animal cell than the plant cell, for nearly all 

 authorities consulted agree that only in exceptional cases 

 does cellulose occur in it, and W. Beneke says that the re- 

 peated assertion of the presence of cellulose in many bacteria 

 is unproved. Even the presence of chitin, still more fre- 

 quently affirmed by writers, is doubted by this author, and 

 he tells us "we know nothing concerning the chemical struc- 

 ture of the wall." ^^ Arthur Meyer takes vigorous ground 

 against the views above indicated as to the nature of the 

 bacterial membrane. He believes these organisms are more 

 closely related to the fungi than to any other group and 

 that through these their kinship to higher plants is estab- 

 lished. But even he admits that "It is very easy to recog- 

 nize that the bacteria possess a cell-membrane morpholog- 

 ically similar to the membrane of fungi, even to that of 

 higher plants." ~^ And he thinks that perhaps there is more 

 similarity between the epidermis of aquatic higher plants 

 and the bacterial wall than between the latter and the cell 

 wall of higher plants. 



Aside from the question of the chemical composition of 



