4 ORIGIN OF SPECIES. 
that of ordinary generation. He says: “If I am 
asked whether I believe that every separate species 
has been a separate creation—not born, but sepa- 
rately made—-I must answer that I do not believe 
it.” (236) “There is one idea which has been com- 
mon to all theories of Development, and that is, the 
idea that ordinary generation has somehow been pro- 
ducing, from time to time, extraordinary effects, and 
that a new species is, in fact, simply an unusual 
birth.” (214). 
' We see that animal creation as it goes on under 
our observation, is by the ordinary process. _ From 
this we are able to evolve, not merely the general, 
but the invariable rule, that every living organism, 
within historic times, has required a receptacle or 
matrix, for its conception, gradual development, and 
final birth. Surely, from what we thus see, we 
should be able to find a general law for the pro- 
duction of new species. If species are reproduced 
by this ordinary process—then it is fair to con- 
clude that they must have originated, not by ‘‘an 
unusual birth,” but by an extraordinary generation ; 
and herein, I apprehend, will be found the key to 
‘the whole mystery. 
In the first place, let us be clearly understood as 
to what we definitely mean by Creation ; and then 
on certain admitted facts, and fair deductions, we 
may gain some knowledge of the extraordinary gen- 
eration under which new species have originated. 
