DAKWIN'S ESTIMATE OF HOOKER 489 
bond between them was as strong as ever. In 1881 Darwin 
writes : 
Your letter has cheered me, and the world does not look 
a quarter so black as it did when I wrote before. Your 
friendly words are worth their weight in gold. 
One of the starting points of Darwin's ' presumptuous work' 
had been the striking impression made on him by the distri- 
bution of the Galapagos organisms ; hence his eager desire 
to know whether the botany of this isolated group was as 
suggestive as the zoology. 
The correspondence began in December ; by January the 
momentous confession was made : 
At last gleams of light have come, and I am almost con- 
vinced (quite contrary to the opinion I started with) that 
species are not (it is like confessing a murder) immutable. 
He had instantly recognised Hooker's capacity. * I am 
pleased to think,' he writes on Hooker's rejection at Edinburgh 
in 1845, * that after having read a few of your letters, I never 
once doubted the position you will ultimately hold among 
European Botanists.' And in the next letter, * It is absurdly 
unjust to speak of you as a mere systematist.' More than this, 
he recognised that Hooker also beheved, as he put it in the 
Preface to his Flora Antarctica, that ' Geographical Distribution 
will be the key which will unlock the mystery of the species.' 
But true views of geographical distribution were impossible 
without full and accurate Floras. Here no doubt was a re- 
doubled motive for the ardour with which Hooker flung him- 
self into his unending labours, the extent of which called forth 
the first of many anxious warnings from Darwin as early as 
1845, to beware of overwork, doctor though he be,' and a novel 
prescription, * You ought to have a wife to stop your working 
too much, as Mrs. Lyell peremptorily stops LyelL' The per- 
fecting of liis great Floras involved the re- examination of 
his vast materials and the more or less incomplete work of 
his predecessors, so as to sweep away the existing synonymy 
and overlapping, and to readjust the systematic details by 
