A conic retractor for retraction of tissue of a mammal may comprise an at least partially hollow first truncated cone (20) a second truncated cone (30), having a similar apex angle and whose opening is wider than the first truncated cone, may be configured to at least partially enter the first truncated cone and to dilate at least a distal end of the first truncated cone as it is pushed to the distal end of the cone. A third truncated cone (40) can be inserted into the second truncated cone, etc. Cones can be dilated by having a longitudinal slit (29) or overlapping longitudinal wall surface edges, or by the nature of the material the cones are made of.