410 



STATE BOARD OF AGRICULTURE. 



Since these cultures respond similarly when tested with thei same 

 sample of serum, it is of interest to trace their origin. 



The original "Ames virus" which is the basis of all our routine work, 

 was kept in sealed bulbs for over six months. The successive transfers 

 were then as follows: 



"Am,es virus" to Expt. pig 124, to Expt. pig 199, to Expt. pig 216, 

 to virus 122. 



''Ames virus" to Expt. pig 123, to Expt. pig 197, to virus 124, to 

 virus 128, to virus 136. 



"In studying the reaction, — we take into consideration two factors, 

 viz. — (a) The clumping or agglutination of the bacteria and consequent 

 clearing of the test fluid and (b) The formation of a characteristic 

 membrane on the bottom of the tube." In the tables under each dilution 



are the signs (-| o) ari'anged in two columns to indicate the degree 



of reaction having reference to the two factors considered above. 



TABLE L — Agglutination Tests With Normal Serum and Culture "Virus 122." 



