Kelvin, Lord, [84]

Knowledge and authority, [104], [105]

Kölliker, [49], [59]

Kowalevsky, [57]

[L]

Laboratory work, [177], [179], [180]

Labyrinthodonts, [69]

Lamarck, [90], [91], [97]

Lamarckism and Darwinism, [94], [97]

Languages, modern, [6], [7]