1. The Effect of Injections of Typhoid Bacilli on Tuberculous Guinea-Pigs E. S. L'Esperance: See this issue, p. 283.
2. Experimental Studies on Lymphocytes—Cytotoxic Sera for Small Thymus Cells A. M. Pappenheimer: The behavior of tonsil and thymus lymphocytes has been studied under a variety of experimental conditions. As a quantitative index of cell injury use was made of the diffuse staining of the nucleus and cytoplasm of the injured cells with dilute solutions of trypan blue. The percentage of stained cells, determined in a blood counting chamber when compared with that of control suspensions maintained under comparable conditions, was found to afford a delicate measure of cell injury.
This technique was applied to a study of the effect of cytotoxic sera for human tonsil and rat thymus lymphocytes.