54 GENERAL SYSTEMATIC BACTERIOLOGY 



A. Cell content without sulfur granules. 



Order Chlamydobacteriaceae 



1. Filaments unbranched: 



a. Cell division only in one direction of space. 



Streptothrix Cohn 



b. Cell division in gonidia formation in three directions of space, 



X. Cells surrounded by a very delicate, hardly discernible 



sheath (marine) Phragmidiothrix Engler 



XX. Sheath easily discernible (fresh water). 



Crenothrix Cohn 



2. Filaments branched Cladothrix Cohn 



B. Cell contents with sulfur granules Thiothrix Winogradsky 



II. Thread-like, without a capsule, but with undulating membrane and as in 

 Oscillaria, motile cell contents show sulfur granules . Formation of conidia 

 not certainly known. 



Order Beggiatoaceae 

 A. Threads apparently not septate, septa only faintly visible with 

 iodine staining. Colorless or faintly rose colored. 



Beggiatoa Trev. 



During this year (1897) Miyoshi reported three new genera of sul- 

 phur bacteria from hot sulphur springs, Thioderma, Thiosphaera and 

 Thiosphaerion. Ellis named a new iron bacterium Spirophyllum and 

 Meyer one of the bacteria of the B. subtilis group Astasia asterospora. 



In this year also Migula published the first volume of his "System 

 der Bakterien" containing a general discussion of bacterial morphology 

 and physiology and an outline of the classification of genera essentially 

 that of 1895. 



Hewlett (1898) in his Manual of Bacteriology recognized a small 

 group only of genera. Of these the following were used in the sense of 

 Zopf (1885) Micrococcus, Streptococcus, Sarcina, Clostridium, Clado- 

 thrix, Leptothrix. The genus Bacillus was defined to include all rod 

 forms, Spirillum all spiral forms and Streptothrix all thread forms. 



Chester in 1899 revised his classification of the family Mycohac- 

 teriaceae to read as follows : 



Mycobacteriaceae Chester (1899) 



A. Cells in their ordinary form as short cylindrical rods, often bent and 



irregularly swollen, clavate or cuneate. At times Y shaped forms or 

 longer filaments with true branchings. May produce short coccoid 



elements, perhaps gonidia Mycobacterium Lehm-Neum 



(including, Corynebacterium L. and N. 



B. Cells in their ordinary form as long branched filaments. Produce 



gonidia-like bodies. Cultures generally have a mouldy appearance 



due to the development of aerial hyphae. 



Streptothrix Cohn 



Oospora Lehmann-Neumann 



