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BACILLI IN CHRONIC INFECTIOUS DISEASES. 491 
made with milk forms an extremely favorable medium, upon which 
a thick, pale-white layer develops in two or three days, which on the 
third or fourth day acquires an amber-yellow color, and the deeper 
layers acquire a brownish-red tint. 
The growth upon solidified blood serwm, in the course of three or 
four days at 37° C., consists of yellowish, transparent drops, which 
later coalesce into a viscid layer, which has a milky appearance from 
the presence of numerous small crystals (Baumgarten). The growth 
upon cooked potato is especially characteristic. In the incubating 
oven, at the end of two or three days, a rather thin, yellowish, trans- 
parent layer develops, which resembles a thin layer of honey. Later 
this ceases to be transparent, and the amber color changes, at the 
end of six to eight days, to a reddish-brown color ; and outside of 
the reddish-brown layer, with more or less irregular outlines, the 
potato for a short distance acquires a greenish-yellow tint. 
Pathogenesis.—Glanders occurs principally among horses and 
asses, but may- be contracted by man from contact with infected 
animals ; it has also been communicated, in one instance with a fatal 
result, by subcutaneous inoculation, resulting accidentally from the 
use of an imperfectly sterilized hypodermic syringe which had pre- 
viously been used for injecting cultures of the bacillus into guinea- 
pigs. The field mouse and the guinea-pig are especially susceptible 
to infection by experimental inoculations ; the cat and the goat may 
be infected in the same way. Lions and tigers in menageries are 
said to have contracted glanders from being fed upon the flesh of in- 
fected animals (Baumgarten). » Rabbits have but slight susceptibility, 
and the same is true of sheep and dogs; swine, cattle, white mice, 
and common house mice are immune. 
The etiological relation of the bacillus is fully established by the 
experiments of Léffler and Schiitz, confirmed by other bacteriologists, 
which show that pure cultures injected into horses, asses, and other 
susceptible animals, produce genuine glanders. The disease is char- 
acterized in the equine genus by the formation of ulcers upon the 
nasal mucous membrane, which have irregular, thickened margins 
and secrete a thin, virulent mucus; the submaxillary lymphatic 
glands become enlarged and form a tumor which is often lobulated ; 
other lymphatic glands become inflamed, and some of them suppurate 
and open externally, leaving deep, open ulcers; the lungs are also 
involved and the breathing becomes hurried and irregular. In farcy, 
which is a more chronic form of the same disease, circumscribed 
swellings, varying in size from a pea to a hazelnut, appear on differ- 
ent parts of the body, especially where the skin is thinnest ; these 
suppurate and leave angry-looking ulcers with ragged edges, from 
which there is an abundant purulent discharge. The specific bacillus 
