Peter, on sea urchin's eggs.

Petunia violacea.

Pfeffer, W.

Pfitzner, W.

Pflueger.

Phillips.

Philosophy, influence of the conception of evolution on modern.

Phryniscus nigricans.

Phylogeny, embryology as a clue to.

--Palaeontological evidence on.

Physiology of plants, development of.

Piccard, on Geotropism.

Pickering, spectroscopic observations by.

Piranga erythromelas.

Pisum sativum.

Pithecanthropus.

Pitheculites.

Planema epaea.

Plants, Darwin's work on the movements of.

--geographical distribution of.

--Palaeontological record of fossil.

Platanthera bifolia.

Plate.

Plato.

Playfair.

Pliopithecus.

Pocock, R.I.

Poincare.

Polarity, Vochting on.

Polymorphic species.

--variability in cereals.

Polypodium incanum.

Porthesia chrysorrhoea.

Potonie, R.

Pouchet, G.

POULTON, E.B., on "The Value of Colour in the Struggle for Life".

--experiments on Butterflies by.

--on J.C. Prichard.

--on Mimicry.

--various.

Pratt.

Pratz, du.

Premutation.

Preuss, K. Th.

Prichard, J.C.

Primula, heterostylism in.

Primula acaulis.

Primula elatior.

Primula officinalis.

Promeces viridis.

Pronuba yuccasella.

Protective resemblance.

Protocetus.

Protohippus.

Psychology.

Pteridophytes, history of.

Pteridospermeae.

Pucheran.

Pusey.

Quatrefages, A. de.

Quetelet, statistical investigations by.

Rabl, C.

Radio-activity.

Radiolarians.

Raimannia odorata.

Ramsay, Sir W. and Soddy.

Ranke.

Rau, A.

Ray, J.

Reade, Mellard.

Recapitulation, the theory of.

Reduction.

Regeneration.

Reid, C.

Reinke.

Religion, Darwin's attitude towards.

--Darwin's influence on the study of.

--and Magic.

Religious thought, Darwin's influence on.

Renard, on Darwin's work on volcanic islands.

Reproduction, effect of environment on.

Reptiles, history of.

Reversion.

Rhinoceros, the history of the.

Ridley, H.N.

Riley, C.V.

Ritchie.

Ritual.

Roberts, A.

Robertson, T.B.

Robinet.

Rolfe, R.A.

Rolph.

Romanes, G.J.

Rothert.

Roux.

Rozwadowski, von.

Ruskin.

Rutherford, E.

Rutot.

Sachs, J.

St Hilaire, E.G. de.

Salamandra atra.

Salamandra maculosa.

Saltatory Evolution, (see also Mutations).

Sanders, experiments on Vanessa by.

Saporta, on the Evolution of Angiosperms.

Sargant, Ethel, on the Evolution of Angiosperms.

Savigny.

Scardafella inca.

Scent, in relation to Sexual Selection.

Scharff, R.F.

Schelling.

Schlegel.

Schleicher, A., on language.

Schleiden and Schwann, Cell-theory of.

Schmarda, L.K., on geographical distribution.

Schoetensack, on Homo heidelbergensis.

Schreiner, K.E.

Schubler, on cereals.

Schultze, O., experiments on Frogs.

Schur.

Schutt.

SCHWALBE, G., on "The Descent of Man".

Sclater, P.L., on geographical distribution.

SCOTT, D.H., on "The Palaeontological Record (Plants)".

--elsewhere.

SCOTT, W.B., on "The Palaeontological Record (Animals)".

Scrope.

Scyllaea.

Sechehaye, C.A.

SEDGWICK, A., on "The Influence of Darwin on Animal Embryology".

Sedgwick, A., Darwin's Geological Expedition with.

Seeck, O.

Seed-plants, origin of.

Segregation.

Selection, artificial.

--germinal.

Selection, natural (see Natural Selection).

--organic.

--sexual.

--social and natural.

--various.

Selenka.

Semnopithecus.

Semon, R.

Semper.

Senebier.

Senecio vulgaris.

Sergi.

Seward, A.C.

--and S.O. Ford.

--and J. Gowan.

Sex, recent investigations on.

Sharpe, D.

Sherrington, C.S.

Shirreff, P.

Shrewsbury, Darwin's recollections of.

Sibbern.

Sinapis alba.

Smerinthus ocellata.

Smerinthus populi.

Smerinthus tiliae.

Smith, A.

Smith, W.

Snyder.

Sociology, Darwinism and.

--History and.

Soddy.

Sollas, W.J.

Sorley, W.R.

Species, Darwin's early work on transmutation of.

--geographical distribution and origin of.

--immutability of.