THE THEORY OF NATURAL SELECTION. 277 



satisfactorily explains the method in which species have 

 been produced by evolution from other previously existing 

 forms. No naturalist at the present day, it may safely 

 be said, doubts that the theory of the origin of species 

 by means of natural selection is true so far as it goes, 

 and that it satisfactorily explains the principal difficulties 

 which it can be legitimately called upon to explain. 

 'Natural Selection' is, in other words, universally recog- 

 nised as a vera causa. The chief point that can be 

 said now to be at issue among naturalists is not whether 

 it be a genuinely active cause, but only as to the extent 

 to which it can be applied some regarding it as the 

 sole factor in the production of 'species,' while others 

 look upon it as being only one of many concurrent 

 factors. 



Darwin's life need only be referred to here in the 

 briefest way, and only for the purpose of showing 

 how thoroughly it qualified him for the task of elabor- 

 ating and establishing his great theory. Charles Darwin 

 was born at Shrewsbury, on the i2th of February 1809. 

 His father was Dr Robert Waring Darwin, a physician 

 of Shrewsbury, and his grandfather was the celebrated 

 Dr Erasmus Darwin, whose life and writings have been 

 previously noticed. At sixteen years of age, Charles 

 Darwin went to Edinburgh to study medicine ; but 

 he soon made up his mind that the pursuit of medicine 

 as a profession would not be in accordance with his 

 tastes, and he accordingly betook himself in 1828 to 

 Cambridge, with a view to studying theology. The 

 influences of the place, however, combined, we may 

 presume, with his own unconscious bent and aptitudes, 



