14 
DAVIS : PEO. THILLIPS. 
and proceeded to adapt it to already existing theories, or new ones 
were originated to account lationally for the phenomena of nature 
during the long past ages. Professor Phillips wrote in 1837,* 
" From a mass of crude speculations fitted to inaccurate observa- 
tions, it (i.e. geology) has gradually grown up to a system of sound, 
though limited inferences, connected by some very probable 
generalizations, and supported by independent mathematical rea- 
soning. The laws of phenomena are unfolded to a considerable 
extent, and in the opinion of eminent men of science, the time is 
at hand for effectual researches into the lai09 of causation. Not 
that the labours of observation should, for an instant, be suspend- 
ed ; ^/ie?/ are the most important of all the means of advancing 
geology ; on the contrary, they ought to be continually excited by 
new impulses, and turned into more profitable directions by the 
first, however rude, indications of theory. The state of geology is 
so prosperous, that its numerous cultivators may well agree to 
divide their forces so as to accomplish combined movements ; to 
advance on the one hand, the mass of generalized phenomena, and 
on the other, to multiply the points of contact between dynamical, 
chemical and vital laws and the results of geological inquiry." 
It would be impossible within the limits of this paper to 
trace the various theories which have finally resulted in the great 
work of Darwin on the Development of Species by Natural Selec- 
tion. It is a little more than twenty-one years since the " Origin of 
Species" was issued from the press, and in that short period the work 
has created a complete revolution in all modern scientific thought. It 
is not to be supposed that the origin of this great discovery rested 
solely with Darwin: many minds had been working at the problem. 
It was the natural outcome of all the accumulated thought for years 
previously, and solved the problem which was the great stumbling ■ 
block to all advance. The belief in " special creations" had long 
been undermined by well establislied facts, and many naturalists 
* Treatise on Geology, by John Philhps, F.R.S., &c., 1837. 
