Sochaczewer has examined the olfactory organs in the Pulmogasteropoda. In these animals the organ of Semper, the pedal gland, and the tentacula have each been considered to have the function of an olfactory organ. Sochaczewer states that: (a) The organ of Semper is small in Helix, Avion, and Limnceus; but is well developed in Limax. In the last mentioned animal it has the form of four or five glandular lobate processes, which are set at the sides of the mouth. This organ is supplied with four nerve-fibres. The two median are muscular in character, while the lateral branches are the proper labiales, which give off, one on either side, fine nerve-branch to the glandular branches of the organ of Semper. The cells of the constituent lobes resemble the glandular cells of the salivary glands; in other words, this organ has not an olfactory function, (b) The pedal gland is an olfactory organ. It is well supplied with nerves; but experiments are difficult to try in such an organ, (c) The tentacula of Helix pomatia are not the seat of the olfactory organs. After having cut off the tentacula, and allowed the wounds to heal, he then placed the snails on a flat plate, the edge of which was smeared with turpentine. He says that both the mutilated and unmutilated specimens turned away from the edges, and he therefore concludes that this proves that the tentacula are not the seat of the olfactory organ.