Darwin and Descent 197 
Again :— ; 
“On my view of descent with modification, the origin of 
rudimentary organs is simple ”’ (p. 454). 
“On my view ” became “‘ on the view ”’ in 1869. 
Again :— 
“ On the view of descent with modification,” &c. (p. 455). 
Again :— 
“On this same view of descent with modification all the 
great facts of morphology become intelligible ’’ (p. 456). 
Again :— 
“That many and grave objections may be advanced 
against the theory of descent with modification through 
natural selection, 1 do not deny ”’ (p. 459). 
This now stands, ‘“‘ That many and serious objections 
may be advanced against the theory of descent with modifica- 
tion through variation and natural selection, I do not deny.” 
Again :— 
“ There are, it must be admitted, cases of special difficulty 
on the theory of natural selection’’ (p. 460). 
“On” has become “‘ opposed to ;”’ it is not easy to see 
why this alteration was made, unless because “opposed to ”” 
is longer. 
Again :— 
“Turning to geographical distribution, the difficulties 
encountered on the theory of descent with modification are 
grave enough.” 
“ Grave ’’ has become “ serious,” but there is no other 
change (p. 461). 
Again :— 
“As on the theory of natural selection an interminable 
number of intermediate forms must have existed,” &c. 
‘“‘On’”’ has become “ according to ’’—which is certainly 
longer, but does not appear to possess any other advantage 
over “on.” It is not easy to understand why Mr. Darwin 
should have strained at such a gnat as “on,” though 
