18 ] The Classification of Lower Organisms 



2. Cells with firm walls, non-motile or 



motile by means of flagella Class 1. Schizophyta. 



2. Cells with thin walls or none, motile by 

 means of changes of shape, also some- 

 times by flagella Class 2. Myxoschizomycetes. 



1. Cells mostly with internal pigment, living by 

 photosynthesis or chemosynthesis, exception- 

 ally heterotrophic; often producing filaments 

 with prominent sheaths Class 3. Archiplastidea. 



Class 1. SCHIZOPHYTA (Cohn) McNab 



Schizomycetes Nageli ex Caspary in Bot. Zeit. 15: 760 (1857). 



Class Schizophyta or Protophyta McNab in Jour, of Bot. 15: 340 (1877). 



Class Schizomycetes Winter in Rabenhorst Kryptog.-Fl. Deutschland 1, Abt, 1: 



33 (1879). 

 Class Schizomycetae SchafTncr in Ohio Naturalist 9: 447 (1909). 

 Classes Holocyclomor pha and Hemicyclomorpha Enderlein Bakt.-Cyclog. 236 



(1925). 

 Dependent or chemosynthetic Mychota, with walled cells, without photosynthetic 

 pigments and not producing sheathed filaments. 



This class includes as orders the typical bacteria and two minor groups. 

 1. Cells solitary or loosely gathered into clusters 



or filaments, spherical, rod-shaped, or spiral, 



not differentiated along the axis Order 1. Schizosporea. 



1. Consisting of branched filaments not divided 



into cells Order 2. Actinomycetalea. 



1. Cells attached by stalks, the attached and 



free ends differentiated Order 3. Caulobacterialea. 



Order 1. Schizosporea [Schizosporeae] Cohn in Hedwigia 11: 17 (1872). 

 Order Schizomycetes (Nageli) McNab in Jour, of Bot. 15: 340 (1877). 

 Order Eubacteria Schroter 1886. 



Order Haplobacteriacei Fischer in Jahrb. wiss. Bot. 27: 139 (1895). 

 Orders Cephalotrichinae and Peritrichinae Orla-Jensen in Centralbl. Bkt. Abt. 



2,22: 334,344 (1909). 

 Order Eubacteriales Buchanan in Jour. Bact. 2: 162 (1917). 

 Mychota whose cells in the typical condition are without internal pigment, walled, 

 of the form of rods, spheres, or spirals, not differentiated along the axis. As this is a 

 numerous group, likely with advancing knowledge to require division, it will be well 

 to provide it with a nomenclatural standard, and to suggest as such Cohn's principal 

 discovery among bacteria, namely Bacillus sublilis. 



These are the typical bacteria. As originally described by Leeuwcnhoeck (1677), 

 they were taken to be a few kinds of "animacules" distinguished only by extremely 

 small size. Only after many years were they shown to be numerous and varied, and 

 highly important as causes of diseases and of other natural phenomena. 



The natural classification of the typical bacteria has been hard to discern. The 

 characters by which groups can be distinguished include forms of cells and of clusters 

 of cells; absence or presence and arrangement of flagella; non-formation or formation 



