338 Proceedings of the Royal Society of Edinburgh. [Sess. 
XIX. — A Preliminary Notice of Five New Species of Iron-Bacteria. 
By David Ellis, Ph.D. (Marburg), D.Sc. (London), F.R.S.E., Lecturer 
in Botany and Bacteriology, Glasgow and West of Scotland Technical 
College, Glasgow. (With Three Plates.) 
(Read March 2, 1908. MS. received March 10, 1908.) 
For the past two years I have been engaged in the investigation of the 
iron- water of Scotland, England, and Wales, and altogether have examined 
over a hundred samples. This publication is a preliminary notice of some 
new species of iron-bacteria which I have found in the course of this in- 
vestigation. At present the number of known forms belonging to this 
class is six. In this paper I wish to outline the main characteristics of 
five new species, reserving for later papers the detailed accounts of their 
life-histories. 
1. S pirosoma ferrugineum (Ellis). — The generic name Spirosoma has 
Fig. 1 . — Spirosoma ferrugineum. In 1& the beginnings of conidia-formation are 
diagrarnmatically shown. 
been introduced by Migula to include seven species, the main characteristics 
of which are a spiral form and an absence of motion. I propose to call 
this, the eighth species, Spirosoma ferrugineum. 
Its general appearance is seen in Plate I. Each individual consists of 
a wavy thread. The waves are regular in size, each wave-length being on 
the average twice or three times the amplitude. All stages are seen, from 
small threads (fig. la) which have just germinated, to large thick threads 
(fig. 16). According to the condition of growth, the size varies from a few 
la. to about 100//, and more. Reproduction is effected more commonly by 
the formation of conidia (Plate I. and fig. 16), and more rarely by the 
process of splitting such as is found in other iron-bacteria, e.g., Leptothrix 
ochracea and Spirophyllum ferrugineum. 
With regard to distribution, I find that in point of numbers it bears the 
