CHEMICAL COMPOSITION OF BACTERIA. 13 



escapes notice, unless when it is specially abundant at the ends. This 

 terminal plasma has also been found by Wager in another bacterium. 

 Among the bacteria Butschli further finds confirmation of his views on 

 the mesh-like structure of protoplasm generally. A bacillus, for instance, 

 he finds consists of four or five more or less square meshes laid end to 

 end, and he gives microphotographs of bacilli presenting such appear- 

 ances (vide Fig. I, Nos. 150 and b). With regard to these observa- 

 tions of Butschli, Fischer holds that the appearances seen were due to 

 plasmolysis, and considers that there is no evidence of differentiation 

 between protoplasm and nucleus in the bacterial cell. 



The Chemical Composition of Bacteria. Some obser- 

 vations have been made on the chemical structure of 

 bacterial protoplasm. Nencki precipitated the bodies of 

 putrefactive bacteria with 2-3 per cent hydrochloric acid, 

 filtered them off, extracted with alcohol and ether, and 

 dissolved the residue with .5 per cent potassium hydrate 

 solution. This solution contained an albumin which was 

 fairly constant in its percentage composition in samples 

 obtained from different mixtures of these bacteria, and 

 which Nencki named mycoprotein ; it was soluble in water, 

 acids, and alkalies, insoluble in solutions of neutral salts. 

 To show, however, that albuminoid constituents of bacteria 

 vary, it must be noted that from anthrax spores Nencki 

 obtained an albumin which he calls anthraxprotein, and 

 which differs from mycoprotein in its being insoluble in 

 water, acetic acid, and dilute mineral acids. Both differ 

 from nucleo-albumin, a constituent of the nuclei of higher 

 cells, in containing no phosphorus. Other observers have 

 isolated similar bodies having, however, different percentage 

 compositions from those given by Nencki. According to 

 some recent results the amount of nitrogenous material 

 present varies according to the temperature at which growth 

 has taken place, according to the age of the culture, and 

 also according to the medium used. Besides nitrogenous 

 material, salts of sodium, potassium, magnesium, and phos- 

 phorus may be present in the bacterial protoplasm. In 

 certain cases traces of cellulose and also fatty bodies have 

 been isolated. It is probable that the composition of 

 bacteria varies according to the species. 



