Darwin and Descent IQ! 
diminished or disappear. On the other hand, all the chief 
laws of palzontology plainly proclaim, as it seems to me, 
that species have been produced by ordinary generation.” 
Here again the claim to the theory of descent with 
modification is unmistakable ; it cannot, moreover, but 
occur to us that if species ‘“‘ have been produced by ordinary 
generation,”’ then ordinary generation has as good a claim 
to be the main means of originating species as natural 
selection has. It is hardly necessary to point out that 
ordinary generation involves descent with modification, for 
all known offspring differ from their parents, so far, at any 
rate, as that practised judges can generally tell them apart. 
Again :— 
“ We see in these facts some deep organic bond, prevailing 
throughout space and time, over the same areas of land 
and water, and independent of their physical condition. 
The naturalist must feel little curiosity who is not led to 
inquire what this bond is. 
“This bond, on my theory, 1s simply inheritance, that 
cause which alone,”’ &c. (p. 350). 
This passage was altered in 1869 to “ The bond is simply 
inheritance.” The paragraph concludes, “ On this principle 
of inheritance with modification, we can understand how 
-it is that sections of genera . . . are confined to the same 
areas,’ &c. 
Again :— 
““ He who rejects it rejects the vera causa of ordinary 
generation,” &c. (p. 352). 
We naturally ask, Why call natural selection the “ main 
means of modification,” if ‘‘ ordinary generation” is a 
vera causa ? 
Again :— 
“In discussing this subject, we shall be enabled at -the 
same time to consider a point equally important for us, 
namely, whether the several distinct species of a genus, 
which on my theory have all descended from a common ances- 
