Leipzig: Verlag von Wilhelm Engelmann 1875. First Edition. iv, 94,  pages plus 2 chromolithographed plates of butterflies. Spine and corners leather (worn, spine rebacked), over marbled boards. An ex-library copy with institutional bookplates, remainder of pocket in rear, and a few embossed stamps. Plates are bright, but have handwritten annotations in many places. A treatise about studies on the theory of evolution PART ONE ONLY on the seasonal dimorphism of butterflies. Text in German. Good. Hard Cover.