In the course of studies on the evidences of autonomic imbalance which follow removal of cerebral cortex,1 it has been possible to show that some of these effects are specifically due to frontal injury. One of these, as indicated in a preliminary report,1f and the easiest to follow is reticulocytosis. The present investigation is concerned with the latency and degree of this response of the blood as engendered by a frontal lesion.
Adult dogs which had been examined for freedom from parasites were placed on a standard diet and, after a preliminary observation period of thirty days during which the weight and reticulocyte count were frequently checked to ascertain that stability was being maintained, were subjected to simultaneous bilateral removal of all frontal cerebral cortex, as far back as and including the postsigmoid gyrus. Care was taken to avoid infringing on the caudate nuclei or the ventricular