Die Klassen und Ordnungen des Thier-Reichs, Leipzig, C.F. Winter, 1859-1901, Woodshole, This illustration presents a detailed anatomical study of amphibian hearts and circulatory systems, featuring various labeled diagrams. The layout includes multiple specimens showing different heart structures, illustrating the complexity and diversity among amphibian species. Key components such as atria, ventricles, and related blood vessels are depicted, alongside numerical labels that correspond to a descriptive key. This educational representation highlights the evolutionary adaptations of amphibians regarding their cardiovascular systems, providing insights into their biology and physiology.