356 Darwin and Geology 
1835, stated that “they were extracted from a series of letters 
(addressed to Professor Henslow), containing a great mass of informa- 
tion 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 Pro- 
ceedings of the Geological Society}, but so unknown was the author 
at this time that he was described as “F. Darwin, Esq., of St John’s 
College, Cambridge”! Almost simultaneously (on November 16th, 
1835) a second set of extracts from these letters—this time of a 
general character—were read to the Philosophical Society at Cam- 
bridge, and these excited so much interest that they were privately 
printed in pamphlet form for circulation among the members. 
Many expeditions and “scientific missions ” have been despatched 
to various parts of the world since the return of the Beagle in 
1836, but it is doubtful whether any, even the most richly endowed 
of them, has brought back such stores of new information and 
fresh discoveries as did that little “ten-gun brig”—certainly no 
cabin or laboratory was the birth-place of ideas of such fruitful 
character as was that narrow end of a chart-room, where the 
solitary naturalist could climb into his hammock and indulge in 
meditation. 
The third and most active portion of Darwin’s career as a 
geologist was the period which followed his return to England at the 
end of 1836. His immediate admission to the Geological Society, 
at the beginning of 1837, coincided with an important crisis in the 
history of geological science. 
The band of enthusiasts who nearly thirty years before had 
inaugurated the Geological Society—weary of the fruitless conflicts 
between “Neptunists” and “ Plutonists”—had determined to eschew 
theory and confine their labours to the collection of facts, their 
publications to the careful record of observations. Greenough, 
the actual founder of the Society, was an ardent Wernerian, and 
nearly all his fellow-workers had come, more or less directly, under 
the Wernerian teaching. Macculloch alone gave valuable support to 
the Huttonian doctrines, so far as they related to the influence of 
igneous activity—but the most important portion of the now cele- 
brated Theory of the Earth—that dealing with the competency of 
existing agencies to account for changes in past geological times— 
was ignored by all alike. Macculloch’s influence on the development 
of geology, which might have had far-reaching effects, was to a great 
extent neutralised by his peculiarities of mind and temper ; and, 
1 Vol. m. pp. 210—12. 
