2 EARLY DAYS 
medicine sprang the organised knowledge both of botany and 
of animal life : first the herbal and the history book of animals, 
full of strange lore ; then the gradual searching out of living 
framework and vital processes, which finally took rank and 
order as the anatomy and physiology of animals and plants. 
That these researches aw^akened doubts of the conventional 
creeds as apphed to nature is evidenced by the famihar sneer at 
the dangerous folk who recognised the constancy of natural law 
in the workings of the human frame — uU ires medici, ihi duo 
athei. Chemistry began to emerge experimentally from the 
mists of alchemy some half-century before Hooker's birth. 
Geology took operative shape yet later : with Ly ell's * Principles ' 
in 1839 the first step Vv^as built of the stairway that actually led 
to the theory of evolution. The succession of differmg forms 
of similar creatures in a fossil state provoked challenge of the 
doctrine of immutability of species ; indeed, as has been well 
said, if the theory of evolution had not existed. Geology 
would have had to invent it. By the fifties, also, botany, 
in its search for a natural system of classification, was ripe 
for the acceptance of an evolutionary explanation. 
If the interest awakened by scientific men is proportioned 
to the degree in which their researches and discoveries come 
home to ' men's business and bosoms,' giving new colour or 
shape to the eternal questions of the making of the heavens 
and the earth, the nature of matter, the play of subtle forces, 
the laws of life and disease, man's place in the miiverse, his 
origin and his destiny, then in every province of physics and 
astronomy, in medicine and its fellow sciences, the nineteenth 
century saw great and memorable figures stand out : but most 
memorable the central group, who, touching most nearly upon 
life and its place in the universe, awoke the loudest opposition 
and achieved the greatest triumph. 
Charles Lyell pointed the way to Darwin : after the appear- 
ance of the ' Origin of Species,' Thomas Henry Huxley was 
chief champion in the support and spread of evolution on the 
one hand, and, on the other, of freedom of scientific thought 
and speech. It was Hooker's privilege to be Darwin's sole 
confidant for near fifteen years, his generous friend, his unstint- 
