Comparative Integrative Anatomy era
Karl Gegenbaß established the core comparative anatomy approach by linking homologous structures to shared developmental plans and adaptive function across vertebrates. Santiago Ramón y Cajal, using Golgi staining and meticulous neural mapping, produced cross‑species neuroanatomical illustrations that tied microstructure to reflex and systemic function. August Krogh advanced comparative physiology of microvasculature, articulating principles of capillary networks and tissue oxygen delivery across species. Walter Cannon synthesized autonomic innervation, vascular regulation, and tissue homeostasis into a systemic framework that explained organ and reflex function across taxa.