Fig. 18.—Plate Culture from Puer Wheel.
Fig. 19.—B. Putrificus.
Pigeon-Dung Bate as used for Hides.—The bacteria contained in the intestines of birds and in bird dung have not been studied to the same extent as those of mammals, so that it is not possible to give anything but a meagre account of them. A microscopical examination of fresh pigeon dung, collected on a sterile Petri dish, showed debris of food, cellulose, etc., among the debris, a large number of dumb-bell bacteria (b) (Fig. 20), and a few motile pairs (c); no bacilli were seen. Cells of a saccharomyces (a) were also observed. From this pigeon dung attenuations were made by a modification of Soyka’s method,[82] and from the fourth attenuation a plate culture was made in ordinary nutrient gelatin. The colonies from this plate were principally of two varieties (both non-liquefying organisms), corresponding to the bacteria observed in the original dung. Large cultures were made in a Carlsberg vessel, as described in Chapter [VI]., and the effect of these cultures tried upon skin. No particular reducing effect was obtained.
Fig. 20.—Organisms in Pigeon Dung. × 1000.
A microscopical examination of a bating pit used for kips, showed an extraordinary mixture of bacteria, bacilli, vibrios, and monads; some comparatively large dumb-bell shaped bacteria, very motile, were present. The difference between the bating liquor and the fresh dung was very marked, especially in the variety of species present. Cultures made from several colonies isolated from the above bate, in a nutrient liquid, consisting of 10 litres water, and 20 grm. gelatin, peptonized by heating under pressure with 10 c.c. sulphuric acid, afterwards neutralizing with ammonia, and adding the soluble matter from 200 grm. bone-meal, had no action on skin.