etermination was now fixed to devote his own labours to the
task of working out the geological results of the voyage, and that
he was prepared to leave to more practised hands the study of his
biological collections, is clear from the letters he sent home at this
time. From St Helena he wrote to Henslow asking that he would propose
him as a Fellow of the Geological Society; and his Certificate, in
Henslow's handwriting, is dated September 8th, 1836, being signed from
personal knowledge by Henslow and Sedgwick. He was proposed on November
2nd and elected November 30th, being formally admitted to the Society
by Lyell, who was then President, on January 4th, 1837, on which date he
also read his first paper. Darwin did not become a Fellow of the Linnean
Society till eighteen years later (in 1854).

An estimate of the value and importance of Darwin's geological
discoveries during the voyage of the "Beagle" can best be made when
considering the various memoirs and books in which the author
described them. He was too cautious to allow himself to write his first
impressions in his Journal, and wisely waited till he could study his
specimens under better conditions and with help from others on his
return. The extracts published from his correspondence with Henslow and
others, while he was still abroad, showed, nevertheless, how great was
the mass of observation, how suggestive and pregnant with results were
the reasonings of the young geologist.

Two sets of these extracts from Darwin's letters to Henslow were
printed while he was still abroad. The first of these was the series of
"Geological Notes made during a survey of the East and West Coasts of
South America, in the years 1832, 1833, 1834 and 1835, with an account
of a transverse section of the Cordilleras of the Andes between
Valparaiso and Mendoza". Professor Sedgwick, who read these notes to
the Geological Society on November 18th, 1835, stated that "they were
extracted from a series of letters (addressed to Professor Henslow),
containing a great mass of information connected with almost every
branch of natural history," and that he (Sedgwick) had made a selection
of the remarks which he thought would be more especially interesting to
the Geological Society. An abstract of three pages was published in the
"Proceedings of the Geological Society" (Vol. II. pages 210-12.), but so
unknown was the author at this time that he was described as F. Darwin,
Esq., of St John's Col