As regards the organism’s being guided throughout its development to maturity by an unconscious memory, Dr. Creighton says that “Professor Bain calls reproduction the acme of organic complication.” “I should prefer to say,” he adds, “the acme of organic implication; for the reason that the sperm and germ elements are perfectly simple, having nothing in their form or structure to show for the marvellous potentialities within them. “I now come to the application of these considerations to the doctrine of unconscious memory. If generation is the acme of organic implicitness, what is its correlative in nature, what is the acme of organic explicitness? Obviously the fine flower of consciousness. Generation is implicit memory, consciousness is explicit memory; generation is potential memory, consciousness is actual memory.” I am not sure that I understand the preceding paragraph as clearly as I should wish, but having quoted enough to perhaps induce the reader to turn to Dr. Creighton’s book, I will proceed to the subject indicated in my title. Chapter V Statement of the Question at Issue OF the two points referred to in the opening sentence of this book—I mean the connection between heredity and memory, and the reintroduction of design into organic modification—the second is both the more important and the one which stands most in need of support. The substantial identity between heredity and memory is becoming generally admitted; as regards my second point, however, I cannot flatter myself that I have made much way against the formidable array of writers on the neo-Darwinian side; I shall therefore devote the rest of my book as far as possible to this subject only. Natural selection (meaning by these words the preservation in the ordinary course of nature of favourable variations that are supposed to be mainly matters of pure good luck and in no way arising out of function) has been, to use an Americanism than which I can find nothing apter, the biggest biological boom of the last quarter of a century; it is not, therefore, to be wondered at that Professor Ray Lankester, Mr. Romanes, Mr. Grant Allen, and others, should show some impatience at seeing its value as prime means of modification called in question. Within the last few months, indeed, Mr. Grant Allen {70a} and Professor Ray Lankester {70b} in England, and Dr. Ernst Krause {70c} in Germany, have spoken and written warmly in support of the theory of natural selection, and in opposition to the views taken by myself; if they are not to be left in possession of the field the sooner they are met the better.