CONTENTS OF BACTERIAL PROTOPLASM. 9 



bacteria especially, it is very difficult to say whether they 

 spore or not. There may appear in such organisms small 

 unstained spots the significance of which it is very difficult 

 to determine. 



The Question of Arthrosporous Bacteria. It is stated by Hueppe 

 that among certain organisms, e.g., some streptococci, certain^individuals 

 may without endogenous sporulation take on a resting stage. These 

 become swollen, stain well with ordinary stains, and they are stated to 

 have higher power of resistance than the other forms, and, further, 

 when vegetative life again occurs it is from them that multiplication 

 takes place. From the fact that there is no new formation within the 

 protoplasm, but that it is the whole of the latter which participates in 

 the change, these individuals have been called arthrospores. The 

 existence of such special individuals amongst the lower bacteria is ex- 

 tremely problematical. They have no distinct capsule, and they 

 present no special staining reactions, nor any microscopic features by 

 which they can be certainly recognised, while their alleged increased 

 powers of resistance are very doubtful. All the phenomena noted can 

 be explained by the undoubted fact that in an ordinaiy growth there is 

 very great variation among the individual organisms in their powers of 

 resistance to external conditions. 



Substances occurring in the Protoplasm of Bacteria. 



In the bodies of bacteria many substances occur. Some 

 have been described as containing chlorophyll, but these 

 organisms are properly to be classed with the schizophyceae. 

 Sulphur is found in some of the higher forms, and starch 

 granules are also described as occurring. Many species of 

 bacteria, when growing in masses, are brilliantly coloured. 

 Comparatively few bacteria, however, associated with the 

 production of disease give rise to pigments. In some of 

 the organisms classed as bacteria a pigment named bacterio- 

 purpurin has been observed in the protoplasm, and similar 

 intracellular pigments probably occur in some of the larger 

 forms of the lower bacteria and may occur in the smaller ; 

 but here exact observation is a work of great difficulty, and 

 in the majority of the latter it is impossible to determine 

 whether the pigment occurs inside or outside the proto- 

 plasm. In many cases, for the free production of pigment 

 abundant oxygen supply is necessary. On the other hand, 

 sometimes, as in the case of spirillum rubrum, the pigment 



