354 THE EETUEN FROM INDIA 
Darwin and Wallace's ^ joint communication on Natural 
Selection was read before the Linnean Society in July 
1858 ; the ' Origin ' was not published till November 1859. 
The Introductory Essay to the Flora of Tasmania, appear- 
ing between the two, did not thus early proclaim Natural 
Selection as a proven theory and philosophic principle, what- 
ever effect on his trend of thought Hooker confessed the 
publication of the ' Origin ' might produce. He frankly 
employed the theory as a working hypothesis to see whether 
it did not explain the perplexing questions of botanical affinity 
and distribution better than its predecessor, which he had 
still accepted as the working hypothesis for the New Zealand 
Essay. Applied to the vast material over which his mind 
had ranged, the hypothesis ' worked ' in striking fashion. 
So far as plant life was concerned, the Tasmanian Essay 
offered in advance a strong buttress for the ' Origin,' which 
dealt with hfe in both animals and plants. 
Discussion of this progress in scientific views is most 
profitably postponed to a Darwinian chapter. For the present 
it is enough to bear in mind that the species question was 
constantly before him ; and that while working on the ordinarily 
accepted lines until he could see more clearly, he was ready, when 
fuller conviction came, to avow openly his change of attitude. 
With the publication of the Flora of Australia and Tasmania 
(1855-60) the Botany of Ross's Voyage was completed, the 
New Zealand Flora having been pubhshed between 1853- 
55. The next important work of this decade was the beginning 
of his magnum o^us, the Flora Indica. The first year after 
his return in March 1851, ' sHghtly fatter, three years younger, 
and much stronger than when I left England in '47,' was mainly 
1 Alfred Russel Wallace (1822-1913), the joint discoverer of the principle 
of Natural Selection, gave up his profession as land-surveyor and architect 
to travel and study nature, visiting the Amazon with Bates, 1848-52, and the 
Malay Archipelago, 1854-62. It was from here that he sent Darwin in 1858 
the paper which was read at the Linnean with Darwin's own, and led to the 
speedy publication of the Origin. Besides his two great books of travel, his 
most important scientific books are those on Geographical Distribution of 
Animals, Tropical Nature, Island Life, and Darwinism. He received the 
Royal Medal of the R.S. in 1868. Keenly interested in social reform, he wrote 
a volume on Land Nationalisation. He wrote also against compulsory vac- 
cination and became a strung supporter of spiritualism. 
