1. Though thymus-fed salamander larvae often metamorphose normally, thymus feeding sometimes retards and in rare cases inhibits metamorphosis completely. 2. The addition of normal food to a thymus diet abolishes the inhibitory effect of the thymus. 3. Addition of a small quantity of iodothyrin leads rapidly to precocious metamorphosis of thymus-fed larvae. 4. The inhibitory effect of the thymus...

Effects of capsaicin on the circular muscle motility of the isolated guinea-pig ileum were investigated. Capsaicin produced a contraction followed by a relaxation of the circular muscle. Both responses were easily desensitized. As the late relaxation response was not sufficiently intense to be analyzed, the inhibitory effect of capsaicin on substance P-induced contractions was explored. Capsaic...