FIG. 1 is a perspective view of a lamp and modular heat sink according to the present invention. FIG. 2 is a side elevation view of the lamp and modular heat sink illustrated in FIG. 1. FIG. 3 is a top plan view of the lamp and modular heat sink illustrated in FIG. 1; and, FIG. 4 is a bottom plan view of the lamp and modular heat sink illustrated in FIG. 1.