340 



Appendices to Fifth Annual Report 



until all the jelly becomes liquid, with a dark violet sediment at the 

 bottom of the tube. The liquid jelly, at first opalescent, gradually becomes 

 quite clear. 



Bread Paste Cultivation. — Growth at first almost colourless, but 

 gradually a pale violet makes its appearance in the depressions of the 

 surface. This deepens in colour until it becomes a very dark purple. 

 Ultimately it covers the greater part of the bread paste. 



Microscopically. — Bacilli, for the most part forming very long and 

 extremely delicate twisted threads, composed in many parts of distinct 

 segments. The threads appear hollow, are in many places highly granular. 

 Stain feebly. In some of them rounded spores are seen at irregular 

 intervals. The average diameter is rather less than "4 /x. Some isolated 

 rod-shaped bacilli are also seen 1*5 ^ to 2 fx long, most with central or 

 terminal sj^ore-formation. 



4. Yellow Bacillus. — Tweed — Melrose. 



Plate Cultivation. — Growth is very slow on the plate. Each point of 

 growth is of a distinct yellow colour, and under a low power consists of 

 a circular well-defined margin, and yellowish granular-looking contents. 

 Some growths near the surface have somewhat irregular margins from 

 slight inspissation of the jelly. No liquefaction of the gelatine occurs. 



Test Tube Cultivation. — A yellow film slowly develops on the surface 

 around the point of inoculation, and spreads outwards as a slightly elevated 

 yellow growth, with irregularly serrated margin. Along needle-track 

 little or no progress is seen for a considerable time ; but eventually very 

 delicate feathery processes may, in some cases, be seen passing from the 

 needle-track into the surrounding gelatine. In other cases, almost no 

 growth takes place in the needle-track ; and in these the surface growth 

 gradually eats into the subjacent jelly, forming a depression which deepens 

 with the advance of the growth until a cup-shaped excavation is produced, 

 the sides and bottom of which are lined with a thin film of the yellow 

 growth. As a rule the sides are in close apposition to the test tube wall. 

 The progress of the growth is extremely slow, and no liquefaction of 

 gelatine occurs. After a time the colour becomes darker, and of a some- 

 what orange hue. 



Bread Paste. — On bread paste this organism does not present such 

 well-marked features as those which characterise its growth on nutrient 

 jelly. It requires a somewhat moist soil, and, if the paste is moist, it 

 slowly tinges the furrows on the surface a faint yellow, but it usually 

 leaves the slight elevations unaffected. On a dry soil, a very faint colora- 

 tion of the bread paste is the only evidence of its presence. 



Microscopically. — Bacilli about 1*5 /x in length and about *3 jx in breadth. 

 They occur singly, or in long threads — Leptothrix form. These latter vary 

 in length from 4'5 fx up to 100 and from *3 fx to 5 \x in breadth. 



This bacillus appears to agree pretty nearly with a bacillus which has 

 been called B. luteus (Fliigge, p. 290),* but the descriptions given of that 

 organism are hardly sufficient to permit of absolute identification. 



5. Orange-Broivn Bacillus. — Tweed — Melrose, right bank above 

 the ' Cauld.' 



Plate Cultivation. — Small points of growth appear on the second day, 

 having the usual rounded form, and dark granular-looking contents are 

 seen by a low power. On the third day most of the points have caused 



* C. Fliigge, Die Mikro-organismcu, second edition, 18S6. 



