Abstract
Studies were made on the influence of host age and route of inoculation on the response of chicks to the virus of avian erythromyeloblastic leukosis. In 2 experiments there were group increases in natural resistance in 21 days to levels 22.7-and 66.7-fold the level present at the 3-day period of age. The data not only revealed the characters of group response but provided information interpretable with respect to the contribution of the individual host. There were revealed, also, evidence of acquired resistance and the effects of acquired resistance on individual and group response. Measurements were made of the levels of host response to virus inoculated intravenously; into the medullary canal of the tibia; into muscle; into the peritoneal cavity; and subcutaneously. The results showed large differences, and the characters of the responses were similar to those which might be expected following the inoculation of different amounts of virus by one route of administration.
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