INVERTEBRATA, CRYPTOGAMIA, MICROSCOPY, ETC. 1007 



A disease, usually known as hen-cholera, sometimes appears with 

 very disastrous effects among fowls. The animal attacked by it is 

 extremely prostrated, the gait is irregular, the feathers become erect, 

 the wings droop, a heavy somnolence comes over it, ending in a quiet 

 death : perceptible alterations are also caused in the internal organs. 

 The observations of Messrs. Moritz, Peroncito, and Toussaint have 

 shown it to be caused by a microscoj^ic form of life, the last-named 

 observer having proved by direct cultivation of it in neutral urine 

 that it is the origin of the poisoning of the blood. 



M. Pasteur had not the same success in his attempts at rearing it 

 pure in neutral urine, but found a very favourable medium for the 

 purpose in a broth made from fowls' muscle, neutralized by potash and 

 heated to from 110^ to 115° C. so as to sterilize it. The organism 

 multijilies in this liquid with such rapidity that in a few hours the 

 most transparent solution commences to be clouded, and is filled 

 with immense numbers of minute and extremely delicate oval-shaped 

 structures slightly constricted in the middle, and appearing at first 

 sight like isolated points. Their transverse diameter is from t^^^j^ 

 to ^5 Joij- inch. They have no independent movements, and it is 

 certain that they belong to a group quite distinct from the Vibriones. 

 These microbia of the fowl-cholera present the striking peculiarity of 

 rapidly perishing in yeast-liquid (although the Bacteria of splenic 

 fever flourish admirabl}'^ and reproduce in this fluid) ; for in less than 

 twenty-four hours they have all died, while any foreign bodies accom- 

 panying them continue their own growth ; this liquid therefore 

 furnishes a valuable reagent by which to ensure the purity of growths 

 which may be introduced into the solution of fowls' muscle. 



If guinea-pigs are inoculated with this organism, an exclusively 

 local injury is caused, especially at a certain age ; this ends in an abscess 

 of greater or less size. If the abscess opens of itself, it heals up 

 without having caused the animal the least harm ; it may persist for 

 several weeks, and in this case is found full of a cheesy j)us contain- 

 ing quantities of the raicrobion among the pus-cells. Here it lives as 

 in a closed vessel, witliout injuring the animal; it remains very pure, 

 and does not lose its vital powers. On inoculating fowls with the 

 contents of the boils, they are found to die very (juickly ; the guinea- 

 pig may also die from its effects, but only when under special 

 circumstances tlio matter passes into the blood or the intestines. It 

 sometimes hap)»en8 that fowls or rabbits living with the infected 

 guinea-pigs suddenly become ill and die without the health of the 

 latter suffering in the least ; it is only necessary for some of the 

 abscesses to open si)oiitaneonsly and a portion of their contents to 

 reach the food of the raJjbits or fowls. Witliout a knowledge of the 

 relations thus made known, one wouM scarcely su])poso the healtliy 

 guinca-{)igs to be the cause of the decimation of their neighbours, but 

 would ratlier believe a spontaneous disease to be its origin. 



In order to cause infection, it is only necessary to place a few 

 drops of a crop of the organism on the bread or meat given as food to 

 the fowls ; it undergoes so rapid a development in their alimentjiry 

 canal that their very excrement when used to inoculate other imli- 



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