Organic Selection.

"Origin of Species", first draft of the.--geological chapter in the.

Orthogenesis.

Ortmann, A.E.

Osborn, H.F.--"From the Greeks to Darwin" by.

Osthoff and Brugmann.

Ostwald, W.

Ovibos moschatus.

Owen, Sir Richard.

Oxford, Ashmolean Museum at.

Packard, A.S.

Palaeontological Record, D.H. Scott on the.--W.B. Scott on the.

Palaeopithecus.

Paley.

Palitzch, G.

Palm.

Pangenesis.

Panmixia, Weismann's principle of.

Papilio dardanus.

Papilio meriones.

Papilio merope.

Papilio nireus.

Paramoecium, Jennings on.

Parker, G.H., on Butterflies.

Parkin, J. and E.A.N. Arber, on the origin of Angiosperms.

Parthenogenesis, artificial.

Paul, H. and Wundt.

Pearson, K.

Peckham, Dr and Mrs, on the Attidae.

Penck.

Penzig.

Peripatus, distribution of.

Peridineae.

Permanence of continents.

Perrier, E.

Perrhybris pyrrha.

Perthes, B. de.

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.

R