STRUCTURE OF THE BACTERIAL CELL. 3 



Morphological Relations. The relations of the bacteria to the 

 animal kingdom on the one hand and to the vegetable on the other 

 constitute a somewhat difficult question. The occurrence of spore 

 formation among the lower forms is analogous to what takes place in 

 certain unicellular organisms the flagellata which, though some of 

 the members contain chlorophyll, are usually ranked in the animal 

 kingdom with the protozoa. On the other hand, sporulation as it 

 occurs in the yeasts resembles more closely what takes place among the 

 bacteria, and further, the fact that many bacteria can derive the carbon 

 they require for their nourishment from tartrates and their nitrogen 

 from ammonia or its salts, makes it natural that they should be ranked 

 in the vegetable kingdom with other non-chlorophyllous plants as 

 fungi. Such an association is further borne out by the fact that while 

 the higher fungi present many analogies with the higher algae, both 

 probably having a common descent, there is a group of lower algae 

 the members of which morphologically are analogous to the bacteria. 

 These algse are unicellular masses of protoplasm, having generally the 

 same shapes as the bacteria, and largely multiply by fission. Endo- 

 genous sporulation, however, does not occur, nor is motility associated 

 with the possession of flagella. Also their protoplasm differs from 

 that of the bacteria in containing chlorophyll and another blue-green 

 pigment called phycocyan. From the morphological resemblances, 

 however, between these algae and the bacteria, and from the fact that 

 fission plays a predominant part in the multiplication of both, they 

 have been grouped together in one class as the Schizophyta or splitting 

 plants (German, Spaltpflanzen). And of the two divisions forming 

 these Schizophyta the splitting algse are denominated the schizophycese 

 (German, Spaltalgen), while the bacteria or splitting fungi are called 

 the schizomycetes (German, Spaltpilzen). The bacteria are, therefore, 

 in proper scientific nomenclature, to be spoken of as the schizomycetes. 

 Certain bacteria which have been described as containing chlorophyll 

 ought probably to be grouped among the schizophyceae. 



GENERAL MORPHOLOGY OF THE BACTERIA. 



The Structure of the Bacterial Cell. On account of 

 the minuteness of bacteria the investigation of their structure 

 is attended with great difficulty. When examined under the 

 microscope, in their natural condition, e.g., in water, they 

 appear merely as colourless refractile bodies of the different 

 shapes named. Spore formation and motility, when these 

 exist, can also be observed, but little else can be made out. 

 For their proper investigation advantage is always taken of 

 the fact of their affinities for various dyes, especially those 



