124 SPECIAL BACTERIOLOGY 



colony become irregular and radiating, finally giving off variously 

 shaped processes. 



In Gelatine Stab Cultures round whitish growths occur along the 

 course of the needle, from which processes sometimes extend into the 

 surrounding medium, the gelatine is liquefied, and gas is quickly 

 formed. 



Grape Sugar Bouillon is densely clouded. 



In Milk there is a slight growth, without any alteration of the 

 medium. 



On Potatoes there is no growth. The cultures give off a smell of 

 butyric acid ; on media containing sugar, the bacilli also form butyric 

 alcohol, hydrogen, carbon dioxide, and methan. 



Pathogenesis. Affects guinea-pigs, mice, and monkeys. One or 

 two drops of a liquefied gelatine culture, given on a piece of bread or in 

 milk, is sufficient to kill the animals. Cats can be fed with large doses 

 without being affected, but when inoculated with large doses (5 to 10 

 c.c.) they die in one to two days, and with small doses (1 to 2 c.c.) 

 in eight to twelve days. 



The incubation period is about thirty-six hours, when the animals 

 become depressed, do not care to move, refuse their food, and on the 

 third day appear stupid, the eyes almost motionless, and the pupils 

 greatly dilated. The enlargement of the pupil increases to an enormous 

 extent in the next few days. The tongue hangs out of the mouth, and 

 finally the animal cannot retract it ; the faeces and urine are withheld, 

 death usually occurring from paralysis of the respiratory and circulatory 

 organs. Very small doses of the bacilli cause marasmus, the cats dying 

 in several weeks with symptoms of paralysis and degeneration of the 

 internal organs. Pigeons receiving 1 to 2 c.c. of a culture exhibit 

 first, paralysis of the wings, and finally general paralysis. 



The pathological anatomical changes usually present are, a more 

 or less well-marked hyperaemia of most of the organs ; in some instances 

 acute, sometimes interstitial, and sometimes parenchymatous hepatitis, 

 with fatty degeneration, and desquamative parenchymatous nephritis, 

 fatty degeneration of the heart muscle, and also of the muscle of the 

 eye. The degenerative changes found in the central nervous system 

 are of especial interest. In the spinal cord the changes are confined 

 almost entirely to the grey substance of the cord along the anterior 

 cornu. In the medulla oblongata the ganglion of the hypoglossal nerve, 

 the dorsal ganglion of the vagus, the middle small-celled ganglion of 

 the motores oculorum, and of other cranial nerves, are affected. 

 Cultures obtained from fresh organs of animals inoculated intravenously 

 do not exhibit a very pronounced growth, but if the organs are 

 previously placed in the incubator at 30 C. for twelve to twenty-four 

 hours, numerous bacilli can be isolated. The Bacillus botulinus does 



