Licence: Public Domain Mark
Credit: Text-book of bacteriology / by Carl Fraenkel. Source: Wellcome Collection.
Provider: This material has been provided by the Royal College of Physicians of Edinburgh. The original may be consulted at the Royal College of Physicians of Edinburgh.
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![able to cultivate artificiall}’' outside of the body and the pathog'enic properties of which he ascertained by experiments on mice and rabbits. His observations were fully confirmed 1)3' Lsaltin and Schottelius and particularl3' b3' Schutz. Tlie}' also produced t3'pi- cal eiysipelas from cultures b}' a successful transmission to hogs. It is, therefore, no longer doubted that this special kind of bacterium is the cause of the hog eiysipelas. The\' are veiy small, slender rods, looking like delicate bristles or tiiw needle-shaped ciystals. Though usuall3' single or in pairs, the3’ sometimes form long threads, and ma}' interlace into a prett}^ network. The3^ have the power of voluntaiy motion; it is as 3'et unknown whether the3' form spores. The3' grow at either room or breeding temperature, belong to the semi-anaerobic kinds, thrive rather better in the absence of ox3’gen, stain with the usual anilin colors, and can be excellentl3' prepared 1)3’- Gram’s method. On the gelatin plate there appears, on the second or third da3', at the bottom of the medium a peculiar cloudiness of gra3'ish-blue or silver-gra3'’ color, distinctly perceptible only on a dark back- ground. Wherever the colonies have grown to a certain extent, extremel3' delicate, greatl3^ ramified, and mistil3' transparent masses are recognized with the naked e3'e; on the whole, the3' resemble somewhat the appearance of a “bone corpuscle” with its tin3^ proc- esses and shoots. The colonies grow on, coalesce, and impart to the entire plate a dim, gra3’ish glimmer. The3' do not, as a rule, ad- vance to the surface of the medium. The gelatin is not liquefied. Microscopic examination adds nothing, and is of little avail on ac- count of the extraordinar3’ fineness and transparenc3^ of the colonies. Test-tube culture shows, in the neighborhood of the inoculation puncture, dense masses of the appearance noticed in the colony on the plate. Development usually commences but a short distance below the free surface of the gelatin and becomes strongest in the deeper layers. It increases but slowly and graduall3', until, finall3', the entire gelatin appears traversed b3^ dim, gra3' clouds. A veiy slight softening of the gelatin is noticed in the course of several weeks which is followed (in consequence of evaporation and simul- taneous dr3ung) 1)3’- the formation of a funnel. On agar and blood-serum (especially at breeding temperatures) a veiy delicate, hardl3' perceptible coating is formed along the inoculating line. No development takes place on potatoes. Experiments of transmission of such cultures ]iroved that hogs, pigeons, rabbits, domestic and white mice were accessible to infec- tion produced in the body-cavities b3’’ inoculation, subcutaneous ap- plication, and injection, while Guinea-pigs and (strange enough)](https://iiif.wellcomecollection.org/image/b21981401_0355.jp2/full/800%2C/0/default.jpg)
