"Looking back through the prodigious vista of the past, I find no record of the commencement of life, and therefore I am devoid of any means of forming a definite conclusion as to the conditions of its appearance. Belief, in the scientific sense of the word, is a serious matter, and needs strong foundations. To say, therefore, in the admitted absence of evidence, that I have any belief as to the mode in which the existing forms of life have originated, would be using words in a wrong sense. But expectation is permissible where belief is not; and if it were given to me to look beyond the abyss of geologically recorded time to the still more remote period when the earth was passing through physical and chemical conditions which it can no more see again than a man can recall his infancy, I should expect to be a witness of the evolution of living protoplasm from non-living matter. I should expect to see it appear under forms of great simplicity, endowed, like existing fungi, with the power of determining the formation of new protoplasm from such matters as ammonium carbonates, oxalates, and tartrates, alkaline and earthy phosphates, and water, without the aid of light. That is the expectation to which analogical reasoning leads me; but I beg you once more to recollect that I have no right to call my opinion anything but an act of philosophical faith." Huxley was the Apostle Paul of the Darwinian movement, and one main result of his active propagandism was to so effectively prepare the way for the reception of the profounder issues involved in the theory of the origin of species, that the publication of Darwin's Descent of Man in 1871 created mild excitement. And the weight of his support is the greater because he never omitted to lay stress on the obscurity which still hides the causes of variation which, it must be kept in mind, natural selection cannot bring about, and on which it can only act. He insists on the non-implication of the larger theory with its subordinate parts, or with the fate of them. The "doctrine of Evolution is a generalisation of certain facts which may be observed by any one who will take the necessary trouble." The facts are those which biologists class under the heads of Embryology and Palæontology, to the conclusions from which "all future philosophical and theological speculations will have to accommodate themselves."