Earthworm pheromones and T-maze performance.
In 2 experiments with a total of 25 Lumbricus terrestris and 35 Diplocardia riparia, Ss appeared to learn to turn either right or left in a T maze containing coelomic fluid deposited during previous trials. When these chemical cues were not present, no evidence of learning was found. The coelomic fluid of L. terrestris was an attractant of conspecifics; that of D. riparia was a repellent. The mucus of both species did not appear to have pheromonal properties.
Rosenkoetter, John S., and Robert Boice. "Earthworm pheromones and T-maze performance." Journal of Comparative and Physiological Psychology 88, no. 2 (1975): 904.
DOI for the article