still more by your paper in the Annals, a year or more ago.  I can plainly see that we have thought much alike and to a certain extent have come to similar conclusions....  I agree to almost every word of your paper; and I dare say that you will agree with me that it is very rare to find oneself agreeing pretty closely with any theoretical paper.”  He concludes:  “You have my very sincere and cordial good wishes for success of all kinds, and may all your theories succeed, except that on Oceanic Islands, on which subject I will do battle to the death.”

The three years from 1855 to 1858 were for Wallace crowded with hard work, and perilous voyages by sea and hardships by land.  January, 1858, found him at Amboyna, where, in all probability, he found a pile of long-delayed correspondence awaiting him, and among this a letter from Bates referring to the article which had appeared in print September, 1855.  In reply he says:  “To persons who have not thought much on the subject I fear my paper on the ‘Succession of Species’ will not appear so clear as it does to you.  That paper is, of course, merely the announcement of the theory, not its development.  I have prepared the plan and written portions of a work embracing the whole subject, and have endeavoured to prove in detail what I have as yet only indicated....  I have been much gratified by a letter from Darwin, in which he says that he agrees with ‘almost every word’ of my paper.  He is now preparing his great work on ‘Species and Varieties,’ for which he has been preparing materials for twenty years.  He may save me the trouble of writing more on my hypothesis, by proving that there is no difference in nature between the origin of species and of varieties; or he may give me trouble by arriving at another conclusion; but, at all events, his facts will be given for me to work upon.  Your collections and my own will furnish most valuable material to illustrate and prove the universal application of the hypothesis.  The connection between the succession of affinities and the geographical distribution of a group, worked out species by species, has never yet been shown as we shall be able to show it.”

“This letter proves,” writes Wallace,[22] “that at this time I had not the least idea of the nature of Darwin’s proposed work nor of the definite conclusions he had arrived at, nor had I myself any expectations of a complete solution of the great problem to which my paper was merely the prelude.  Yet less than two months later that solution flashed upon me, and to a large extent marked out a different line of work from that which I had up to this time anticipated....  In other parts of this letter I refer to the work I hoped to do myself in describing, cataloguing, and working out the distribution of my insects.  I had in fact been bitten by the passion for species and their description, and if neither Darwin nor myself had hit upon ’Natural Selection,’ I might have spent the best years of my life in this comparatively profitless work.  But the new ideas swept all this away.”