premise: He injected one of two cells of a two-cell starfish embryo with antibodies  to myosin, and allowed the embryo to develop to the blastula stage.
hypothesis: Invertebrates (and higher animals) can also be placed in one of two groups based on how they develop as embryos.
hypothesis_graph_structure: Invertebrates (and higher animals<>can be placed<>$$$two groups<>based<>on how they develop as embryos$$$they<>develop<>