褐云玛瑙螺（Achatina　fulica　Ferussac）嗅神经传入纤维的投射

THE AFFERENT PROJECTION OF THE OLFACTORY NERVE OF THE Achatina fulica Ferussac

用Ｆｉｎｋ－Ｈｅｉｍｅｒ法对褐云玛瑙螺嗅神经传入纤维的投射进行了研究。褐云玛瑙螺嗅神经传入纤维双侧性地投射在中枢神经系统内的所有神经节内，其中脑节为投射纤维最多的部位。传入纤维的末梢除少数延伸至某些神经元胞体附近的轴索基部外，其他所有末梢分布在各节的中心纤维毡内。

The posterior tentacle is the major olfactory organ of Achatina fulica Ferussac, exerting important role in feeding, mating and locomotion. Besides, its retraction response can lead to habituation and sensation. We have studied the afferent projections of the olfactory nerve, using Fink-Heimer method. We find that the projections are very wide. Most of them are projected to both sides of cerebral ganglia symmetrically, while some projected to both sides of buccal ganglia through the cerebro-buccal connection and some projected to pedal, pleural, parietal and visceral ganglia through the cerebro-pleural connection. The terminals of these fibres are mostly distributed at neuropile of each ganglion, only a few terminals terminate at the base of trunks of several giant neurons of the visceral ganglion. These results provide an anatomical evidence that olfaction has wide influence on various behavior of the snail.