Blue-green algae are fascinating microorganisms which have an astounding cellular complexity all of their own. An illustrated discussion of cell structure, spores, and reproduction in blue-green algae is presented. Fossil remains of blue-green algae are quite similar to living forms. Arguments from homology or parallelism show that in different aspects blue-green algae variously resemble red algae, green algae, Zea mays, or bacteria! Most evolutionists believe, however, that bacteria and bluegreen algae have evolved from a close common ancestry. Much evidence is presented here from writings of Pringsheim and other workers to show that there are great differences in spores, pigments, biochemistry, and movement between bacteria and blue-green algae. These differences are strong evidence in support of the view that the various kinds of blue-green algae and bacteria were separately created.