'Phototactic' definitions:
Definition of 'Phototactic'
From: GCIDE
- Phototaxis \Pho`to*tax"is\, Phototaxy \Pho"to*tax`y\, n. [NL. phototaxis; photo- + Gr. ? an arranging.] (Biol.) The influence of light on the movements of low organisms, as various infusorians, the zoospores of certain alg[ae], etc.; also, the tendency to follow definite directions of motion or assume definite positions under such influence. If the migration is toward the source of light, it is termed
- positive phototaxis; if away from the light,
- negative phototaxis. -- {Pho`to*tac"tic}, a. -- {Pho`to*tac"tic*al*ly}, adv. [Webster 1913 Suppl.]