Page - 394 - in The Origin of Species

394 ORIGIN OF SPECIES The inhabitants of the world at each successive period in its histor> have beaten their predecessors in the race for life, and are, in so far, higher in the scale, and their struc- ture has generally become more specialised; and this may account foi the common belief lield by so many palaeontolo- gists, that organisation on the whole has progressed. Extinct and ancient animals resemble to a certain extent the embryos of the more recent animals belonging to the same classes, and this wonderful fact receives a simple explanation accord- ing to our views. The succession of the same types of structure within the same areas during the later geological periods ceases to be mysterious, and is intelligible on the principle of inheritance. If then the geological record be as imperfect as many be- lieve, and it may at least be asserted that the record cannot be proved to be much more perfect, the main objections to the theory of natural selection are greatly diminished or dis- appear. On the other hand, all the chief laws of palaeontology plainly proclaim, as it seems to me, that species have been produced by ordinary generation : old forms having been sup- planted by new and improved forms of life, the products of Variation and the Survival of the Fittest.