5/193 And it is natural that in later life he should have felt that conviction was wanting till that cause was made out. See "Charles Darwin, his Life told, etc." 1892, page 165.) For the purposes of the present chapter the point is not very material. We know that in 1842 he wrote the first sketch of his theory, and that it was greatly amplified in 1844. So that, at the date of the first letters of this chapter, we know that he had a working hypothesis of evolution which did not differ in essentials from that given in the "Origin of Species." To realise the amount of work that was in progress during the period covered by Chapter II., it should be remembered that during part of the time--namely, from 1846 to 1854--he was largely occupied by his work on the Cirripedes. |