of the Fishery Board for Scotland, 



343 



Hauser. . It may, indeed, be the P. vulgaris, but the liquefaction of the 

 jelly is slower, and spores are present. There can be little doubt that it 

 is one or other of these, or very closely allied 'to them. 



8. White Bacillus. — Tweed — Melrose. 



Plate Cultivation. — The points of growth are of a greyish appearance, 

 and become visible to the naked eye on the third day. They present the 

 usual rounded appearance under a low power, and do not cause liquefac- 

 tion of gelatine for a considerable time. 



Tube Cultivation. — On the surface of the gelatine the growth is slow, 

 and in the form of a greyish- white film, which does not usually cover the 

 entire surface. Along the needle-track the mode of growth varies according 

 to the consistence of the gelatine. In moderately firm jelly, extension is 

 by fine serrated points into the surrounding medium; whilst in jelly of 

 softer consistence a beautiful dendritic arrangement is seen. In this case 

 the needle-track appears as a greyish central stalk, from which radiate 

 slender greyish branchlets, which in turn give off very fine secondary 

 branchlets after a time. Liquefaction takes place around needle-track, in 

 the case of the moderately firm gelatine, and a slight greyish sediment 

 falls to the bottom of the liquid portion ; the greyish- white surface growth 

 remains floating on the liquid gelatine for a long time. In the case of the 

 softer gelatine, the dendritic arrangement persists, and no liquefaction 

 occurs — at any rate for a very long time. 



Bread Paste. — A whitish growth, spreading somewhat rapidly over a 

 considerable portion of the surface, and having a well-marked glazed, or 

 varnished appearance. A peculiar resinous, somewhat offensive odour is 

 developed in the bread paste flask after the lapse of some weeks. 



Microscopically. — Bacilli from 1 *5 p to 4 //, in length, and about *4 /jl in 

 breadth. 



For the most part they form dense masses of rod-shaped bacteria with 

 rounded ends, many showing spore-formation. We have not been able 

 to identify this organism with certainty. It appears to be pretty 

 common. 



9. Bacillus — Dee, Aberdeen, left bank, Old Bridge. 



Plate Cultivation. — On the third day numerous points of liquefaction 

 are seen, the largest being about the size of a pin's-head. Several small 

 greyish colonies are scattered over the jelly, but these have not caused 

 liquefaction. Under a low magnifying lens the larger liquefying points 

 appear circular, and have a double contour and dark granular-looking 

 contents. The colonies next in size have only a single circular outline, 

 which, however, is more dense than the greyish granular contents. The 

 still smaller growths show a dark centre surrounded by a paler granular 

 zone, which again is bounded by a well-defined dark circular margin. 

 The smallest points are seen to consist of granular contents and circular 

 well-defined margins, and, when viewed by transmitted light, have a 

 distinct yellow hue. 



On the fifth day all the points of growth have caused liquefaction of 

 the gelatine, and converted it into a single large liquid mass. A slight 

 urinous odour is perceived on removing the bell-jar. 



Test Tube Cultivation. — Along the needle-track a bag of liquefaction 

 may be seen on the second day, which rapidly extends outwards and 

 downwards, until on the ninth day, in many of the tubes, complete lique- 

 faction of gelatine has taken place. At first the liquid jelly is opalescent, 

 2 x 



