344 



Appendices to Fifth Annual Report 



but speedily a greyish white sediment falls to the bottom, leaving the 

 supernatant liquid quite clear. 



Bread Paste. — Grows rapidly as a creamy-looking film on the surface. 

 The colour, after a time, becomes darker and of a faint brownish yellow. 

 A distinct bluish zone surrounds the margin of the growth as it spreads 

 itself over the bread paste. At first the growth has a moist creamy 

 appearance, but after about a fortnight it begins to become dry and 

 somewhat shrivelled-looking, and gradually it takes on a dark slate- 

 grey colour. A peculiar odour is evolved after a time, somewhat resem- 

 bling that of stale beer. 



Microscopically. — Bacilli show active movement. They vary in size 

 from 1'5/x in length, and *5 fi in breadth, up to long threads of 50, 60, 

 70 /x or longer, and from '5 /x to '7 fx in breadth. Examined in distilled 

 water, the bacilli show active spore-formation, and both the spores and 

 smaller bacilli appear in very active motion. 



In stained preparations the most striking features are the presence of 

 very long straight or slightly curved threads, of very uniform diameter 

 and consistence, averaging *7 fx in width, and 800 to 1000 fx or more in 

 length, with blunt ends. Most of these threads appear solid, and a very 

 few appear hollow and show traces of spore-formation. 



In some respects this organism closely resembles the common ' Hay 

 bacillus,' B. subtilis, both in its growth upon gelatine and upon bread 

 paste. But when grown side by side with B. subtilis, the growth of the 

 latter is of a much purer white colour. Both have the same peculiar 

 granular or worm-like appearance. The microscopic characters also have 

 a close resemblance to some cultivations of hay bacillus, and we are 

 inclined to consider it a variety or closely allied species. 



10. Bacillus. — Tweed, Melrose, right bank above the ' Cauld.' 



Plate Cultivation. — On third day growths are seen. They consist of a 

 central grey point, radiating from which are numerous fine grey fibrils 

 which interlace with each other, forming a delicate network around the 

 central grey spot. As these fibrils extend outwards they get thicker, 

 and form a circle of short rod-like bodies. From the peripheral 

 extremities of these, small fibrils are given off which run outwards, and 

 appear to interlace with those from other points of growth. The whole 

 surface of gelatine has thus an appearance as if covered by fine threads, 

 and, in the case of plates with very numerous growths, this thready appear- 

 ance is so very dense as to lead one to suppose the gelatine to be in a state 

 of liquefaction, which, however, is not the case. 



Test Tube Cultivation. — From the point of inoculation on the surface 

 of gelatine, delicate grey thread-like processes spread outwards towards 

 the side of test-tubes, and gradually come to cover the whole surface, 

 forming a dense greyish film. After a time the growth extends down- 

 wards into the substance of the jelly, and by its downward growth causes 

 a more or less deep cup-shaped depression, the sides and bottom of which 

 are composed of a layer of growth of a dense greyish appearance. No 

 liquefaction of gelatine takes place. The growth along the needle-track 

 is very slow, and takes place chiefly at the upper part. When it occurs, 

 it takes the same form, viz., fine threads like spiders'-web running 

 out towards the periphery of the tube. The resemblance to an insect 

 on the surface of the gelatine is sometimes very striking, and first suggested 

 the nature of the growth. 



Bread Paste Cultivation. — The growth on bread paste is very ill-defined. 

 At first almost no trace of it can be observed, because it differs but little 



