166 NATURAL SELECTION vil 
what, on Darwin’s theory, the ancestors of existing animals 
ought to be; and this, it must be remembered, is the evidence 
of one of the strongest opponents of the theory of natural 
selection. 
Conclusion 
I have thus endeavoured to meet fairly, and to answer 
plainly, a few of the most common objections to the theory of 
natural selection, and I have done so in every case by refer- 
ring to admitted facts and to logical deductions from those 
facts. 
As an indication and general summary of the line of 
argument I have adopted, I here give a brief demonstration 
in a tabular form of the Origin of Species by means of Natural 
Selection, referring for the facts to Mr. Darwin’s works, and 
to the pages in this volume, where they are more or less fully 
treated. 
A Demonstration of the Origin of Species by Natural Selection 
PROVED FACTS NECESSARY CONSEQUENCES 
(afterwards taken as Proved Facts) 
STRUGGLE FOR EXISTENCE, the 
deaths equalling the births on 
the average, p. 24 (Origin of 
Species, chap, iii.) 
Rapip INCREASE OF ORGANISMS, 
pp. 28, 142 (Origin of Species, 
p. 75, 5th ed.) 
ToraL NuMBER oF INDIVIDUALS 
STATIONARY, p. 23. 
STRUGGLE FoR EXISTENCE. SURVIVAL OF THE FITTEST, or 
HEREDITY WITH VARIATION, or Natural Selection; meaning, 
general likeness with individual | simply, that on the whole those 
differences of parents and off- die who are least fitted to main- 
springs, pp. 142, 156,179 (Origin | tain their existence (Origin of 
of Species, chaps. i. ii. v.) Species, chap. iv.) 
( CHANGES or Oreanio Forms, to 
keep them in harmony with the 
Changed Conditions ; and as the 
SURVIVAL OF THE FITTEST. changes of conditions are perman- 
CHANGE OF EXTERNAL Conpitrons, | ent changes, in the sense of not 
universal and unceasing.—See) reverting back to identical pre- 
Lyell’s Principles of Geology. vious conditions, the changes of 
organic forms must be in the 
same sense permanent, and thus 
_ originate Sprcizs, 
