PATHOGE^ T IC SPIRILLA. 499 



its termination ; sometimes they are present in great numbers, and 

 at others can only be found by searching several microscopic fields; 

 they are not present in the various secretions urine, sweat, saliva, 

 etc. In fatal cases the principal pathological changes are found in 

 the spleen, which is greatly enlarged, and in the liver and marrow 

 of the bones, which contain inflammatory and necrotic foci. Koch 

 and Carter have succeeded in transmitting the disease to monkeys 

 by subcutaneous inoculations with small amounts of defibrinated 

 blood containing the spirillum. After an incubation period of seve- 

 ral days typical febrile paroxysms were developed, during which 

 the actively motile spirilla were found in the blood in large numbers. 

 Blood from one animal, taken during the attack, induced a similar 

 febrile paroxysm when inoculated into another of the same species 

 relapses, such as characterize the disease in man, were not observed. 

 Onl attack did not preserve the animals experimented upon from a 

 similar attack when they were again inoculated after an interval of 

 a few days. Recently Soudakewitch (1891) has made successful in- 

 oculation experiments in monkeys, and has shown that in monkeys 

 from which the spleen has previously been removed the spirilla con- 

 tinue to multiply very abundantly in the blood and the disease has a 

 fatal termination, whereas in monkeys from which the spleen has 

 not been removed the spirilla disappear from the blood within a few 

 days after tlie access of the febrile paroxysm and the animal recovers. 



154. SPIRILLUM ANSERUM. 



Synonym. Spirochaeta anserina (Sakharoff). 



Obtained by Sakharoff (1890) from the blood of geese affected by a fatal 

 form of septicaemia due to this spirillum. This disease prevails among geese 

 in Caucasia, especially in swampy regions, appearing annually and destroy- 

 ing a large number of the domestic geese. 



Morphology. Resembles the spirillum of relapsing fever. The long and 

 flexible spiral filaments, when, the disease is at its height, are often seen in 

 interlaced masses, around the margins of which radiate single filaments 

 w.hich by their movements cause the whole mass to change its place, as if it 

 were a single organism. These masses are sometimes so large that a single 

 one occupies the entire field of the microscope. 



Stains with the usual aniline colors. 



Biological Characters. An aerobic, motile spirillum. Not cultivated 

 in artificial media. The movements are very active, resembling those of 

 Spirillum Obermeieri, but cease in an hour or two in preparations made from 

 the blood of geese containing it. 



Pathogenesis. A small quantity of blood from an infected goose inocu- 

 lated into a healthy animal of the same species induces the disease after a 

 period of incubation of four to five days. The infected goose ceases to eat, 

 becomes apathetic, remaining 1 in one place, and usually dies at the end of a 

 week ; the temperature is increased, and in some cases there is diarrhoea. 

 The spirilla are found in the blood at the outset of the malady, but after 

 death they are not seen either in the blood or in the various organs. The 

 heart and the liver are found to have undergone a fatty degeneration, and 

 yellowish, cheesy granules the size of a millet seed are seen upon the surface 

 of these organs. The spleen is soft and easily broken up by the fingers. 



