The connection of the vomeronasal nerves with the accessory olfactory bulb in the opossum and other mammals

It is well known that there exists in most mammals an acces-sory olfactory bulb, which is similar in structure and in its peri-pheral and central connections to the chief olfactory bulb, though it is much smaller and is distinctly separated from it. On the other hand, it has been clearly shown that the vomeronasal or Jacobson’s organ is olfactory in character and that it gives origin to nerve filaments, like those of the olfactory mucosa, which form bundles that pass upward through the cribriform plate to the region of the median surface of the olfactory bulb. It has not, however, been recognized, as far as the writer knows, that the fibers arising from the vomeronasal organ and the fibers connected with the accessory bulb are one and the same thing. It is the purpose of the present paper to report some observations which establish this connection, and which show that we have in the vomeronasal nerves the combined filaments from the vomeronasal organ, and that they are the fibers that terminate in the accessory olfactory bulb and are the only fibers i t receives. We thus have in the accessory olfactory bulb a receptive station for the stimuli coming from the mucosa of the vomeronasal organ. The writer’s attention was turned toward this subject in the course of an investigation of the olfactory apparatus of th