384 GENERAL SYSTEMATIC BACTERIOLOGY 



Intermediate between the "micromycetes" and true bacilli, hence the name. 

 Young cultures actively motile. Rod-like organism. Spores by "enkystemment 

 partiel." The older filamentous growths lose their motility. Certain portions 

 of the filaments are Gram-positive, others Gram-negative. Isolated from cere- 

 bral ventricle in case of acute arthritis. 



Mycobacteriaceae. A family name proposed by Chester (1897, 

 p. 37) with the genus Mycobacterium Lehmann and Neumann as a 

 type. It has been used by Chester (1897 and 1899) with the follow- 

 ing description: 



Cells short or long cylindrical or clavate-cuneate in form without a sheath 

 surrounding the chains of individuals. Without endospores, with possibly the 

 formation of gonidia-like bodies. With true dichotomous branching (this forms 

 an important group standing between the true Bacteriaceae and the true fungi on 

 the one hand and the Chlamydobacteriaceae on the other). 



The genera Mycobacterium and Corynebacterium are included. 

 The definition was somewhat altered by Chester (1901, p. 349) 

 later to include the Actinomyces forms. The diagnosis reads 



Cells either short or long, cylindrical-clavate-cuneate in form, which at times 

 may show true branching or as long branched mycelial-like filaments. Fila- 

 ments not surrounded by a sheath as in Chlamydobacteriaceae. Without endo- 

 spores, but with the formation of gonidia-like bodies due to a segmentation of the 

 cells. Division at right angles to the axis of a rod or filament. 



The family is recognized by A. J. Smith (1902, p. 270) Schneider 

 (1912, p. 25) Benecke (1912) and by Miehe (1908, p. 131). The last 

 named author evidently is unaware of the previous use of this name 

 by Chester, for he proposes it as new. He places it in his scheme of 

 classification following Coccaceae and Bacteriaceae and before Spiril- 

 laceae. He included 



Einzellige Individuen von sehr unregelmassiger Stabchenform; auch in norma- 

 len Zustand sprossende Verzweigung und zwar regelmassig oder nur gelegentlich; 

 keine Myzelbildung nach Art der Fadenpilze; zuweilen fadige Entwickelung der 

 Individuen, keine Endosporen, keine Bewegung. 



Winslow et al. (Committee Soc. Am. Bact., 1917, p. 553) included this 

 family under the Eubacteriales with the description: 



Cells usually elongated, frequently filamentous and with a decided tendency 

 to the development of branches, in some genera giving rise to the formation of a 

 definite branched mycelium. Cells frequently show swellings, clubbed or irregu- 

 lar shapes. Endospores not produced, but conidia developed in some genera. 

 Usually Gram-positive. Non-motile. Many species are parasitic in animals or 



