352 THE HISTORY OF CREATION. 
Tf all the phenomena of the geographical and topographi- 
cal distribution of organisms are examined by themselves, 
without considering the gradual development of species, and 
if at the same time, following the customary superstition, the 
individual species of animals and plants are considered 
as forms independently created and independent of one 
another, then there remains nothing for us to do but to gaze 
at those phenomena as a confused collection of incompre- 
hensible and inexplicable miracles. But as soon as we 
leave this low stand-point, and rise to the height of the 
theory of development, by means of the supposition of a 
blood-relationship between the different species, then all 
at once a clear light falls upon this strange series of 
miracles, and we see that all chorological facts can 
be understood quite simply and clearly by the supposition of 
a common descent of the species, and their passive and 
active migrations. 
The most important principle from which we must start 
in chorology, and of the truth of which we are convinced by 
due examination of the theory of selection, is that, as a rule, 
every animal and vegetable species has arisen only once in 
the course of time and only in one place on the earth—its 
so-called “ centre of creation”—hby natural selection. I share 
this opinion of Darwin’s unconditionally, in respect to the 
great majority of higher and perfect organisms, and in 
respect to most animals and plants in which the division of 
labour, or differentiation of the cells and organs of which 
they are composed, has attained a certain stage. For it 
is quite incredible, or could at best only be an exceedingly 
rare accident, that all the manifold and complicated circum- 
stances—all the different conditions of the struggle for life, 
