332 PA THOGENIC BA CTERIA. film, and when examined microscopically is seen to con- tain long beautiful spirals. The organism sometimes prodnces indol, but is irreg- nlar in its action in this respect. The spirillum of Denecke is mentioned only because of its morphological relation to the cholera spirillum, not because of any pathogenesis which it possesses. It probably is not associated with any human disease. Ex- periments, however, have shown that when the spirilla are introduced into the intestines of guinea-pigs whose gastric contents are alkalinized and whose peristalsis is f j&x i i v~ *»«/•••••• W'K'-^ST *%£§*$? t <* *(Mfct "V ^ X' — X&^^''/*^' ^%^-<- "*- w« "V FlG. 89.—Spirillum Metchnikoff, from an agar-agar culture; x 1000 (Itzerott and Niemann). paralyzed with opium, about 20 per cent, of the animals die from intestinal disease. The Spirillum of Gamal§ia (Spirillum Metchnikoff). —Very closely related to the cholera spirillum in its morphology and vegetation and possibly, as has been suggested, a descendant of the same original stock, is the spirillum which Gamaleia cultivated from the intestines of chickens affected with a disease similar to chicken- cholera. This spirillum is a curved organism, a trifle shorter and thicker than the cholera spirillum, a little more curved, and with similar rounded ends (Fig, 89).