... colony(slime molds being equivalent to dusk and dawn), living and nonliving(ditto for viruses), endo- and ectotherm, adult and infant, male and female,sexual and asexual.In like manner, that species ... up species, in-exorably demand genera and families and orders to fall, and classestottering. We ought to stop only when clear unity of type, independent ofuse and adaptation, ceases” (49). ... (62), and even more favorably on the topic of perfectfertility in interspecific hybrids in the genera Crinum and Hippeastrum16 DARWIN AND THE NATURE OF SPECIES21Chapter 2Taxon, Category, and...