A normal sheep was bled, and no neutralizing antibodies for poliomyelitis virus were found in the blood serum in 1:1 dilutions. The animal was then injected as follows: September 8, 12, 17, and 24, 1934, 10 cc. of a suspension of equal parts of 2% poliomyelitis virus and P.C.B. filtrate intradermally;1 October 1st and 8th, 30 cc. of a suspension of equal parts of a 2% virus combined with P.C.B. filtrate subcutaneously; October 13th, 40 cc. of a suspension made up of equal parts of a 5% virus combined with P.C.B. filtrate subcutaneously; October 23rd, November 8th and 20th, and December 8th, 50 cc. of a suspension made up of equal parts of 5% virus combined with P.C.B. filtrate subcutaneously and intramuscularly. On September 13th, there was some local induration about the injection, and on September 15th, there was a small localized abscess.Although there was still evidence of local induration about the last injection, the animal was bled on November 20th and the serum tested. It was found that this serum...