64 MICROBES AND TOXINS 



also bacterial moulds and bacterial yeasts ; there are even 

 protozoal bacteria, i.e., animal bacteria, the Spirochsetes. 



The conclusion then is that bacteria are not the original 

 forms from which the others were derived but that on the 

 contrary the bacteria are derived from the more definitely 

 characterised fungi and alga;, the specific characters having 

 become obliterated by the parasitic habit. The branching 

 forms rarely observed in the bacillus tuberculosis, the endo- 

 spores of the anthrax bacillus, the arthrospores of the 

 Streptothrices are all atavistic stigmata. 



The Nucleus of Bacteria. — The usual nucleus, consisting 

 of a distinct mass in the body of the protoplasm, does not exist 

 in the bacterial cell. 



A cell without a nucleus ! Several observers (A. Fischer, 

 Migula, Massart) do not shrink from such a paradoxical 

 statement. They can see no trace of a nucleus ; what others 

 have taken for it, large or small, is only, in their opinion, an 

 empty space or a vacuole, taking part in the cell-division and 

 capable of dispersion into smaller vacuoles. Thb scattered 

 granulations in the protoplasm are not grains of chromatin, 

 for they have none of its reactions. They are either products 

 of nietabolism or reserve materials. They have been called 

 metachromatic bodies, because when stained with blue or violet 

 stains they take on a different, reddish tint. 



Such observations are best made on certain large bacteria 

 found in nature. It is remarkable that the bacillus asterosporus, 

 which was the one selected by Migula to demonstrate the 

 absence of the nucleus, has been employed by others to 

 demonstrate the presence of one or even several well-defined 

 nuclei. Able cytologists complain that the supporters of the 

 nucleus have been deceived by appearances ; that they have 

 taken for chromatic masses the transverse segmentations which 

 appear in certain large bacteria at the moment of division, and 

 that they have even chosen for their demonstration bacteria 

 which are not true bacteria; the Bacterium gammari of 

 Vejdowsky is said to be a fungus approaching the yeasts and 

 multiplying by division, while another bacterium studied by 



