The Ontogeny of Complement Activity. Complement Titers in the Developing Chick Embryo During Graft-Versus-Host Reactions.

Abstract
Summary 1. A method for titration of total C activity in the chicken is briefly described. 2. Chick embryos on the 18th, but not 13 th, day of incubation have demonstrable C activity by this assay. 3. The 18-day-old chicken embryo responds to the stimulus of the gxait-versus-Host reaction with a rise of C' titer.