Origin of Species Variorum

races may differ much in some one organ from the other races of the same species, yet the remaining parts of the organisation will always be found in some degree different. Professor Bronn likewise asks with striking effect how, for instance in the mouse or hare genus, can natural selection account for the several species (descended, I may remark, from a parent of unknown character) having longer or shorter tails, longer or shorter ears, and fur of different colours; how can it account for one species of plant having pointed and another species blunt leaves? I can give no definite answer to such questions; but I might ask in return, were these differences, on the doctrine of independent creation, formed for no purpose? If of use, or if due to correlation of growth, they could assuredly be formed through the natural preservation of such useful or correlated variations. I believe in the doctrine of descent with modification, notwithstanding that this or that particular change of structure cannot be accounted for, because this doctrine groups together and explains, as we shall see in the later chapters, many general phenomena of nature.

A distinguished botanist, Mr. H. C. Watson, believes that I have overrated the importance of the principle of divergence of character (in which, however, he apparently believes), and that convergence of character, as it may be called, has likewise played a part. This is an intricate subject which need not be here discussed. I will only remark that if two species of two closely allied genera produced a number of new and divergent species, I can believe that these new forms might sometimes approach each other so closely that they would for convenience' sake be classed in the same new genus, and thus two genera would converge into one; but from the strength of the principle of inheritance, it