636 APPLICATION OF METHODS OF BACTERIOLOGY 



blood contains the organism to be cultivated. The value 

 of this medium is destroyed by the addition of either bouillon 

 or sugar; and the bit of kidney should be taken from a 

 freshly killed animal. The ascitic fluid should be free 

 from bile and when placed in the test-tube should permit 

 of the formation of a loose fibrin meshwork. The culti- 

 vation should be conducted at 37 to 38 C. The growth 

 of the organisms in these media causes no appreciable 

 change in appearance. Multiplication of the organisms is 

 noted after two or three days at body temperature. Sub- 

 cultures should be made between the fourth and ninth 

 days. After about ten days the multiplication of the 

 organisms ceases. After several generations of artificial 

 cultivation the spirochetes gradually lose the power to 

 infect susceptible animals. 



In the various manifestations of relapsing fever the 

 organisms are found in the circulating blood; in syphilis 

 they are found in the diseased tissues and in the juices 

 squeezed from the primary sore and from other superficial 

 lesions; in yellow fever the leptospira icteroides is found 

 in the blood. 



