The first half of the eighteenth century brought us the Aubretia and the sweet pea from southern Europe, the first Pelargoniums (scarlet geraniums) from the Cape, the camellia and Kerria japonica from the far east. The West Indian heliotrope was introduced in 1713; the better-known Peruvian species not till 1757. Phloxes began to be imported from North America. Two or three foreign orchids were already known, and the number now began to increase; but it was not till the nineteenth century that they came over in crowds. Our list gives no notion whatever of the number of new species added now and subsequently. Of the accessions made during the latter half of the eighteenth century we must at least mention the mignonette from North Africa, white arabis from the Caucasus, the common rhododendron from Asia Minor, Rosa indica and Hydrangea hortensis from China, South African gladioli, which now begin to be numerous, and chrysanthemums from China and Japan. The first calceolarias were brought from great heights on the Andes, the first begonias from Jamaica, and the first fuchsia from Chili. We can make only one remark about the multitudinous accessions of the nineteenth century. It is surprising to note how recently many established favourites have been brought to the knowledge of English gardeners. Anemone japonica (Japan) and Jasminum nudiflorum (China) date from 1844, while the Freesias (Cape Colony) are as recent as 1875. The dahlia, after two unsuccessful attempts, was established here as recently as 1815; Nemophila insignis came over from North America in 1822; the common musk and the monkey-plant a few years later; the chionodoxas (Crete and Asia Minor) in 1877. The first of the foliage-begonias (Begonia rex from Assam) dates only from 1858, and the first of the tuberous species from 1865. Importation of foreign species has not been the only method by which English gardens have been enriched. New varieties and hybrids have been produced in bewildering numbers by the gardeners of Europe, and many of these far surpass in beauty the wild originals. Botanists and nurserymen could relate in great detail the steps by which our favourite roses, calceolarias, begonias, and cinerarias have been developed from a few natural stocks, sometimes of uninviting appearance. Horticulture has repaid the debt which it owed to the explorations of botanists by furnishing countless observations and experiments bearing upon inheritance. When these have been properly co-ordinated, they will yield precious knowledge, not only to botanists but to all students of biology. Humboldt as a Traveller and a Biologist.