A Significant Morphogenetic Variant of Dictyostelium Mucoroides

(WITH 4 FIGURES) Genetic variation within a species is a commonly recognized occurrence generally not warranting special consideration. Variants of possible phylogenetic significance, however, deserve a more detailed examination. The variant of Dictyostelium mucoroides Brefeld described in this paper appears to be of such significance. It was isolated from rotting wood of Citrus sinensis collected in Turrialba, Costa Rica, on December 31, 1961. This variant, hereafter referred to as CR17, represents a modification of the morphogenetic development found in typical material of D. mucoroides and has several features common to other species. In the earliest description of D. mucoroides by Brefeld (1869), a brief explanation of sorocarp development was included, and in a later