18 
DAVIS : PRO. PHILLIPS. 
" This question of development might be safely left to the 
prudent researches of physiology and anatomy, were it not the 
case that palaeontology furnishes a vast range of evidence on the 
real succession in time of organic structures, which on the whole 
indicate more and more variety and adaptation, and in certain 
aspects a growing advance in the energies of life. Thus at first only 
invertebrate animals appear in the catalogues of the inhabitants of 
the sea ; then fishes are added, and reptiles and the higher verte- 
brata succeed; man comes at last to contemplate and in some degree 
to govern the whole. 
" The various hypothetical threads by which many good 
naturalists hoped to unite the countless facts of biological change 
into a harmonious system have culminated in Darwinism, which 
takes for its basis the facts already stated, and proposes to explain 
the analogies of organic structures by reference to a common origin, 
and their differences to small, mostly congenital, modifications 
which are integrated in particular directions by external physical 
conditions, involving a 'struggle for existence.' Geology is inte- 
rested in the question of development, and in the particular 
exposition of it by the great naturalist whose name it bears, because 
it alone possesses the history of the development iii time, and it is 
to inconceivably long periods of time, and to the accumulated efl"ect 
of small but almost infinitely numerous changes in certain direc- 
tions, that the full eff'ect of the transformations is attributed. 
For us therefore, at present it is to collect with fidelity the 
evidence which our researches must certainly yield, to trace the 
relation of forms to time generally, and physical conditions locally, 
to determine the life periods of species, genera and families in dif- 
ferent regions, to consider the cases of temporary interruption and 
occasional recurrence of races, and how far by uniting the results 
obtained in difi*erent regions the alleged 'imperfection of the geolo- 
gical record' can be remedied." 
I have, perhaps, dwelt longer on the important question of 
Darwinism than the nature of my subject will warrant, but it is 
