In an optical system for an oblique incidence interferometer, first and second prisms are used as luminous flux dividing means and luminous flux combining means, respectively. The chamber of the trap is in two segments, the floors of which form an obtuse angle permitting the trap to rotate rearward when activated by the movement of the animal inside. The heated conductive elements conduct heat to the tooling blocks, which then conduct heat to the cells to cure the composite and adhesive.