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ABSTRACT An investigation of a null hypothesis that suggests that Planarians show no specific taxis towards light or gravity. It was found that 63% of specimens examined moved towards darkness while the remaining 37% moved towards the light. Responses related to gravity showed that 72% of the planarians followed gravity while the other 28% did not. These results rejected the null hypothesis. INTRODUCTION Planarians are members of the Phylum Platyhelminthes and Class Turbellaria. More specifically they are described as any member of the Order Tricladida. (Henderson’s., 1996) For the purpose of this experiment the Genus Dugesia will be observed. Described as dorsoventrally flattened worms that are bilaterally symmetrical animals. Planarians are commonly found in streams and ponds. (http://www.uwinnipeg.ca/~simmons/lb6pg6.htm., 5/04