hippocampus morphology trait hippocampus fornix morphology trait Any measurable or observable characteristic related to the shape, structure, color, or pattern of the compact, white, heavily myelinated fiber bundle arising from the Ammon horn of the hippocampus in each cerebral hemisphere and projecting to the hypothalamus and the mammillary body. EFO:0803381 Trait.ontology VT:0003006 fornix hippocampus morphology trait hippocampal fornix morphology trait