he·li·o·tax·is 
(hē′lē-ō-tăksĭs)
(hē′lē-ō-tăksĭs)n.
The movement of an organism in response to the light of the sun.
he′li·o·tactic (-tăktĭk) adj.
- endogamy
- endogenous
- endogenously
- endogeny
- endolymph
- endolymphatic
- endometrial
- endometriosis
- endometrium
- endomitosis
- endomitotic
- endomorph
- endomorphic
- endomorphism
- endomorphy
- endonuclease
- endoparasite
- endoparasitic
- endoparasitism
- endopeptidase
- endophyte
- endophytic
- endoplasm
- endoplasmic
- endoplasmic reticulum