not try for things which we believe to be beyond our reach, hence one would expect that the fortunes, as it were, of animals should have been built up gradually. Our own riches grow with our desires and the pains we take in pursuit of them, and our desires vary and increase with our means of gratifying them; but unless with men of exceptional business aptitude, wealth grows gradually by the adding field to field and farm to farm; so with the limbs and instincts of animals; these are but the things they have made or bought with their money, or with money that has been left them by their forefathers, which, though it is neither silver nor gold, but faith and protoplasm only, is good money and capital notwithstanding. I have already admitted that instinct may be modified by food or drugs, which may affect a structure or habit as powerfully as we see certain poisons affect the structure of plants by producing, as Mr. Darwin tells us, very complex galls upon their leaves. I do not, therefore, for a moment insist on habit as the sole cause of instinct. Every habit must have had its originating cause, and the causes which have started one habit will from time to time start or modify others; nor can I explain why some individuals of a race should be cleverer than others, any more than I can explain why they should exist at all; nevertheless, I observe it to be a fact that differences in intelligence and power of growth are universal in the individuals of all those races which we can best watch. I also most readily admit that the common course of nature would both cause many variations to arise independently of any desire on the part of the animal (much as we have lately seen that the moons of Mars were on the point of being discovered three hundred years ago, merely through Galileo sending to Kepler a Latin anagram which Kepler could not understand, and arranged into the line—“_Salve umbistineum geminatum Martia prolem_,” and interpreted to mean that Mars had two moons, whereas Galileo had meant to say “_Altissimum planetam tergeminum observavi_,” meaning that he had seen Saturn’s ring), and would also preserve and accumulate such variations when they had arisen; but I can no more believe that the wonderful adaptation of structures to needs, which we see around us in such an infinite number of plants and animals, can have arisen without a perception of those needs on the part of the creature in whom the structure appears, than I can believe that the form of the dray-horse or greyhound—so well adapted both to the needs of the animal in his daily service to man, and to the desires of man, that the creature should do him this daily service—can have arisen without any desire on man’s part to produce this particular structure, or without the inherited habit of performing the corresponding actions for man, on the part of the greyhound and dray-horse.