London: C. Kegan Paul & Co., 1879. First Edition. First printing. Octavo (23cm) in two vols. In purple cloth with black-stamped frame to boards, titled in gilt on spines; black coated endpapers; vol. I: [i]-[xviii], -pp; vol. II: vi, 571, , pp; 32-page publisher's catalogue at rear. Sound copies, rubbed, vol. I sunned at spine, internally lightly browned and shaken: Good. A study of animal intelligence and human "mental disease," though Lindsay (1829-1880) was primarily an expert on lichens (ODNB).