At the same time, so great was his enthusiasm and interest, in spite of the hard work and ill-health, that all through this period he was making fresh observations whenever an opportunity occurred. Thus we find him writing to Hooker about the thistle-down blown out to sea and then back to shore again; about the migrations of slave-making ants which he had been watching; about the bending of the pistil into the line of the gangway leading to the honey when this latter “is secreted at one point of the circle of the corolla,” etc. And on March 2nd, 1859, he writes about “an odd, though very little, fact”:--Large nuts had been found in the crops of some nestling Petrels at St. Kilda, which he suspected the parent birds had picked up from the Gulf Stream. He arranged for one of these to be sent, and asked Hooker for the name and country. He asks forgiveness for the trouble, “for it is a funny little fact after my own heart.” The nuts turned out to be West Indian. When the proposal for publication had been accepted by Murray and the manuscript was assuming its final form, the letters to Hooker were more frequent than ever. Writing on May 11th, 1859, Darwin again raises the question of the relative importance of variation and selection. “I imagine from some expressions ... that you look at variability as some necessary contingency with organisms, and further that there is some necessary tendency in the variability to go on diverging in character or degree. _If you do_, I do not agree.” Darwin’s splendid confidence in the future appears in a letter written about this time (September 2, 1859) in which he begs Lyell not to commit himself “to go a certain length and no further; for,” he says, “I am deeply convinced that it is absolutely necessary to go the whole vast length, or stick to the creation of each separate species.” He asks Lyell to remember that his verdict will probably be of more importance than the book itself in influencing the present acceptance or rejection of the views. “In the future,” he continues, “I cannot doubt about their admittance, and our posterity will marvel as much about the current belief as we do about fossil shells having been thought to have been created as we now see them.” And again writing to Lyell a few days later (September 20th), he says, “I cannot too strongly express my conviction of the general truth of my doctrines, and God knows I have never shirked a difficulty.” I have thought it well to bring strong evidence of Darwin’s entire confidence in his conclusions, because his writings were so extraordinarily balanced and judicial, and the weight he gives to opposing considerations so great, that a superficial student might imagine that he wrote and argued without any very strong convictions.