20 GENERAL SYSTEMATIC BACTERIOLOGY 



Griffith (1853, p. 438) recognized the fact that the Gallionella 

 ferruginea of Ehrenberg was not a diatom, and created for it a new genus 

 Didymohelix. 



Ferdinand Cohn (1854, p. 123) described as a genus the sUmy bacte- 

 rial growth which develops in certain solutions, giving it the name 

 Zoogloea. Later (1872) he abandoned this term recognizing this to be 

 simply a growth stage in the developmental cycle. Cohn's most im- 

 portant conclusion at this time was to the effect that the bacteria 

 (Vibrionien) belong in the plant kingdom rather than with the true 

 Infusoria. 



Henfrej'' (1856, p. 53) described as an alga a form which he termed 

 Clathrocystis roseo-persinica. This was later placed among the sulphur 

 bacteria by Winogradsky (1888). 



Naegeli (1857, p. 760) first created a definite group in the plant 

 kingdom for the bacteria. He united the genera Bacterium, Vibrio, 

 Spirillum, Sarcina, Umbina and Nosema under the group Schizomycetes, 

 the name by which the bacteria have in general since been known. 



Berkeley (1857, p. 313) in his Introduction to Cryptogamic Botany 

 included two new genera among the molds, Chondromyces and Stigma- 

 tella. The work of Thaxter has shown these forms to be the fruiting 

 bodies of myxobacteria. 



In 1865 (p. 156) Trecul studied carefully certain vegetable cells which 

 found developing in putrefying plant tissues. To the various shapes 

 he gave the names Urocephalum, Amylobacter and Clostridium. These 

 terms have been sometimes used by subsequent writers as generic names 

 and ascribed to Trecul, but this ascription is not, strictly speaking, 

 correct, for this author named no species, his names can be regarded only 

 as pseudogeneric. 



Rabenhorst (1865) in Sectio II, Algas Phycochromaceas Complectens 

 of his Flora Europaea Algarum included a number of bacterial genera 

 with the blue green algae. All are included in his order Nematogenae 

 Family Oscillariaceae. The following key to the three subfamilies and 

 to the genera of the subfamily Spirillineae will serve to show this author's 

 conception of relationships. 



Rabenhorst's Classification of Bacteria (1865) 



A. Filaments more or less destitute of color, flexuous or spirally bent, not 

 sheathed, often embedded in mucus. 



Subfamily 1. Spirillineae 



