Abstract
In our paper of the above title, published in The Journal of Immunology, XXIII, No. 1, July, 1932, we inadvertently omitted reference to a paper by Falk, McGuire, Valentine and Whitney, published in The Journal of Immunology, XXI, No. 3, September, 1931, 199–219, in which the authors say in reference to the protection test on Antipneumococcic Serum Type I (page 203):
“Even with preparations which give irregular results on the individual experiments, it was found that if these experiments were repeated sufficiently frequently so that perhaps fifty to one hundred mice were tested at each dilution of antibody the total results would be progressively uniform, that is, with less antibody, a greater percentage of deaths.”
We regret that this observation escaped our memory, since our work in this respect confirms that of the above mentioned authors.