392 REVIEWS—ON THE ORIGIN OF SPECIES. 
their original condition, and to be accounted different species. If our 
inquiries lead us to the former conclusion, every species in nature has 
come into existence at some time and place, and it is an important 
inquiry how long each can be proved by good evidence to have ex- 
isted, and within what geographical limits it has, been confined ; but 
there is scarcely any place for inquiry respecting the act of creation 
since it is not easy to perceive how it could be effected by the opera- 
tion of second causes, and if we can conceive of such causes they are 
out of the field of natural science, and if ever determined it must be 
by other means than the observation of nature and the study of the 
relations between differing structures. If, on the other hand, we con- 
clude that such distinctions, as properly mark species, are liable to 
change with the progress of time, and can produce good evidence that 
even any one distinct species has been derived from any other in the 
course of ages, then it may be reasonable to admit the possibility of 
all varying forms having been derived from one primitive germ, and 
the manner in which such changes have been effected, the causes. 
upon which they depend, become subjects of intense interest, and fur- 
nish the most important inquiries in which a naturalist can be en- 
gaged. Butit seems to us most unreasonable, to expect that the 
believer in the immutability of species should want a theory as to 
their origin. He sees throughout nature the abundant evidence of 
the operation of an intelligent designing mind, the great first cause of 
all things. He sees every species adapted to its condition and enabled 
to supply its wants, and the conception of a creative act, as the expres- 
sion of an almighty volition, is sufficient to account to him for the 
existing order of things—objects may have been created simulta- 
neously or successively, ; all in one place on the earth’s surface, or in 
various localities ; but as long as they are acknowledged to be essen- 
tially distinct objects, and to have no natural tendency to intermix 
and modify each other, they admit of no inquiry into the nature of 
the modifying causes, and consequently of no theory of the formation. 
of species. It is quite true that we recognise a common plan of struc- 
ture in a variety of objects ; on examination this plan is found to con- 
sist ina certain arrangement of elementary organs, which, in some 
form, are always present, whilst the characteristics of species seem to 
be really found in the tendencies to comparative development of cer- 
tain parts, which, in all of the same genus tribe or sub-kingdom, are at 
least rudimentally present, bearing to each other certain common rela- 
