Co 
368 
NALURE 
[JUNE 13, ro12 
books, first and foremost those of Lyell, as noted 
above, then of Humboldt in his ‘‘ Personal Narra- 
tive’? (1814-18), of Robert Chambers in his 
‘“Vestiges of the Natural History of Creation ”’ 
(1844), of Malthus in his ‘‘ Essay on the Principle 
of Population ’’’ (1798). It was, however, Dar- 
win’s own “‘ Journal,’’ published in 1845, and 
read by Wallace at the age of twenty-three, which 
determined him to invite Bates to accompany him 
on his journey to the Amazon and Rio Negro, 
which filled the four years 1848-52. In this 
wondrous equatorial expanse, like Darwin, he | 
was profoundly impressed with the forests, the 
butterflies, and birds, and with his first meeting 
with man in an absolute state of nature. Bates, 
himself a naturalist of high order, was closely 
observing the mimetic resemblances among 
insects to animate and inanimate objects and 
introducing Wallace to a field which was subse- 
quently made his own. Bates remained several 
years after Wallace’s departure, and published 
his classical memoir on mimicry in 1860-61. 
Wallace’s ‘‘ Narrative of Travels on the 
Amazon,”’ published in 1853 when he was thirty 
years of age, does not display the ability of his 
later writings, and shows that his powers were 
slowly developing, to reach maturity during his 
eight years of travel between 1854 and 1862 
in the Indo-Malay islands, the Timor Group, 
Celebes, the Moluccas, and the Papuan Group. 
It is apparent that his prolonged observations 
on the natives, the forests, the birds, and mam- 
mals, and especially on the butterflies and beetles, 
were gradually storing his mind for one of those 
discharges of generalisation which comes so un- 
expectedly out of the vast accumulation of facts. 
““The Malay Archipelago’’ of 1869, published 
seven years after the return, is Wallace’s 
““Journal of Researches.’’ Its fine breadth of 
treatment in anthropology, zoology, botany, and 
physiography gives it a rank second only to 
Darwin’s ‘“‘ Journal”? in a class of works re- 
peatedly enriched by British naturalists from the 
time of Burchell’s journey in Africa. 
Wallace’s first trial at the evolution problem 
was his essay sent to the Annals and Magazine | 
of Natural History in 1855, entitled ‘‘ On the Law 
Which has Regulated the Introduction of New 
Species.’’ This paper suggested the when and 
where of the occurrence of new forms, but not 
the how. 
“It has now been shown,’’ he concludes, 
“though most briefly and imperfectly, how the 
NO. 2224, VOL. 89] 
law that ‘Every species has come into existence 
coincident both in time and space with a pre- 
existing closely allied species,’ connects together 
and renders intelligible a vast number of inde- 
pendent and hitherto unexplained facts.’’ 
In February, 1858, during a period of inter- 
mittent fever at Ternate, the how arose in his 
mind with the recollection of the ‘‘Essay”’ of 
Malthus, and there flashed upon him all the pos- 
sible effects of the struggle for existence. In two 
days the entire draft was sketched and posted 
to Darwin, who had been working upon the veri- 
fication of the same idea for twenty years. The 
noble episode which followed of the joint publica- 
tion of the discovery was prophetic of the con- 
tinued care for truth and carelessness of self, of 
the friendship, mutual admiration, and coopera- 
tion between these two high-minded men, which 
affords a golden example for our own and future 
ages. Each loved his own creations, yet under- 
valued his own,work; each accorded enthusiastic 
praise to the work of the other. 
This discovery again turned the course of 
Wallace’s life. In his autobiography he 
writes :— 
““T had, in fact, been bitten with the passion 
for species and their description, and if neither 
| Darwin nor myself had hit upon ‘ natural selec- 
| new ideas swept all this away... . 
tion,” I might have spent the best years of my 
life in this comparatively profitless work, but the 
‘This\ eae 
will perhaps enable my readers to understand 
the intense interest I felt in working out all 
these strange phenomena, and showing how they 
could almost all be explained by that law of 
‘Natural Selection’ which Darwin had discovered 
many years before, and which I also had been so 
fortunate as to hit upon.”’ 
It is a striking circumstance in the history of 
biology that Wallace’s rapidly produced sketch 
of 1858 ‘* On the Tendencies of Varieties to Part 
Indefinitely from the Original Type’’ not only 
pursues a line of thought parallel to that of 
Darwin, except in excluding the analogy of 
natural with human selection, but embodies the 
permanent substance of the selection theory as 
it is to-day after fifty-four years of world-wide 
research. It may be regarded as his masterpiece. 
The attempt has been made by De Vries and 
others to show that Wallace in his ‘‘ Darwinism ”’ 
of 1889 differed from Darwin on important points, 
but whatever may be true of this final modi- 
fication of the theory, a com- 
parison the Darwin-Wallace sketches of 
1858 shows that they both involve the principle 
very careful 
of 
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