TENTACULAR FUNCTION IN TRAIL FOLLOWING BY THE PULMONATE SLUG LIMAX PSEUDOFLAVUS EVANS

Comparison of the behaviour of slugs before and during trailfollowing shows that there is no change in their rates of locomotionbut that there are decreases in measures of tentacle activity(distance moved and the frequency of substrate contacts) duringtrail following. Bilateral amputation of tentacles has the generaleffect of slowing the speed of locomotion whether trail followingor not, and preventing the decrease in tentacle activity duringtrail following. Amputation of the anterior tentacles results in a decrease inthe accuracy with which trails are followed. Amputation of theposterior tentacles on the other hand, results in a decreasein the frequency with which slugs turned onto trails. Removalof all the tentacles prevents trail following. It is concludedthat the posterior tentacles are concerned with the detectionand identification of trails which are subsequently followedand that the anterior tentacles normally control the behaviourof the slug on the trail. (Received 22 May 1984;