the Duke of Argyll.
-on physiological selection.
-review of Roux's book.
-on heliotropism.
-lecture on animal intelligence by.
-lecture on evolution of nerves.
-letter to "Times" from.
-"Life and Letters" of.
-on minds of animals.

Roots, heliotropism of.
-sensitive tip of.

Roses, N. American species.
-bud-variation.
-raising from seed.
-resemblance of seedling moss-rose to Scotch.
-varieties of.

Ross, Sir J.

Rosse, Lord.

Round Island, fauna and flora of.

Roux's "Struggle of Parts in the Organism."

Royal Commission on Vivisection.

Royal Institution, lectures at.

Royal medals.

Royal Society, council meeting of.

Royer, Mdlle., translatress of the "Origin."

Royle, John Forbes (1800-58): was originally a surgeon in the H.E.I.C.
Medical Service, and was for some years Curator at Saharunpur. From 1837-
56 he was Professor of Materia Medica at King's College, London. He wrote
principally on economic and Indian botany. One of his chief works was
"Illustrations of the Botany and other branches of the Natural History of
the Himalayan Mountains and of the Flora of Cashmere." (London, 1839.)
-letters to.
-mentioned.

Rubiaceae, dimorphism in.
-fertilisation in.

Rubus, N. American species.
-variation in.
-F. Darwin on roots of.

Rubus and Hieracium, comparison of variability of N. American and
European species.

Rucker.

Rudimentary organs.
-in frogs.
-nascent and.
-variation of.
-in man.
-use in classification.

Rudinger, Dr., on regeneration.

Rue, flowers of.

Ruffs, polygamy of.

Rumex, germination of old seeds.

Russia, forms of wheat cultivated in.

Rutaceae, A. St.-Hilaire on difference in ovary of same plants of.

Sabine, General Sir E. Sabine (1788-1883): President of the Royal
Society 1861-71. (See "Life and Letters," III., page 28.)
-address to Royal Society.
-award of Copley medal to Darwin during presidency of.
-recognition by Government.
-mentioned.

Sabrina, elevation of.

Sagitta.

St. Dabeoc's heath, in Azores.

St. Helena, Darwin suggests possibility of finding lost plants in earth
from.
-extinction in.
-Hooker on flora of.
-land-birds of.
-plants of.
-trees of.
-Darwin on craters of.
-geology of.
-subsidence in.
-White on hemiptera of.

St.-Hilaire, A.F.C.P. de, on affaiblissement.
-erect and suspended ovules in same ovary.
-"Lecons de Botanique."
-Life of