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, 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 algoe and have probably descended from them, 

 there is a group of lower algee 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. The protoplasm differs from that of the bacteria 

 in containing chlorophyll and also another blue-green pigment called 

 phycocyan. From the morphological resemblances between the algce 

 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 algre 

 are denominated the schizophyceoe (German, Spaltalgen), while the 

 bacteria or splitting fungi are called the schizomycetes (German, Spalt- 

 pilzen). 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 schizophyceoe. 



& 



ENERAL 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 in, say, 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 which are usually chosen as good stains for 

 the nuclei of animal cells. Certain points have thus been 



