This view is again given in Volume II., page 569, where he asks whether we should believe that "at the first production of a genus, when it first grew into existence, some slight modification in the productive causes stamped it originally with all these specific diversities? Or is it most probable that the modification was subsequent to its origin, and that the genus at its first creation was one and uniform, and afterwards became diversified by the influence of external agents?" He concludes that "the former of these suppositions is the conclusion to which we are led by all that can be ascertained respecting the limits of species, and the extent of variation under the influence of causes at present existing and operating." In spite of the fact that Prichard did not carry his ideas to their logical conclusion, it may perhaps excite surprise that Mr. Darwin should have spoken of him as absolutely on the side of immutability. We believe it to be partly accounted for (as Poulton suggests) by the fact that Mr. Darwin possessed only the third edition (1836 and 1837) and the fourth edition (1841-51). (14/7. The edition of 1841-51 consists of reprints of the third edition and three additional volumes of various dates. Volumes I. and II. are described in the title-page as the fourth edition; Volumes III. and IV. as the third edition, and Volume V. has no edition marked in the title.) In neither of these is the evolutionary point of view so strong as in the second edition. We have gone through all the passages marked by Mr. Darwin for future reference in the third and fourth editions, and have been only able to find the following, which occurs in the third edition (Volume I., 1836, page 242) (14/8. There is also (ed. 1837, Volume II., page 344) a vague reference to Natural Selection, of which the last sentence is enclosed in pencil in inverted commas, as though Mr. Darwin had intended to quote it: "In other parts of Africa the xanthous variety [of man] often appears, but does not multiply. Individuals thus characterised are like seeds which perish in an uncongenial soil.") "The variety in form, prevalent among all organised productions of nature, is found to subsist between individual beings of whatever species, even when they are offspring of the same parents. Another circumstance equally remarkable is the tendency which exists in almost every tribe, whether of animals or of plants, to transmit to their offspring and to perpetuate in their race all individual peculiarities which may thus have taken their rise. These two general facts in the economy of organised beings lay a foundation for the existence of diversified races, originating from the same primitive stock and within the limits of identical species." On the following page (page 243) a passage (not marked by Mr. Darwin) emphasises the limitation which Prichard ascribed to the results of variation and inheritance:--