e 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:--

"Even those physiologists who contend for what is termed the indefinite
nature of species admit that they have limits at present and under
ordinary circumstances. Whatever diversities take place happen without
breaking in upon the characteristic type of the species. This is
transmitted from generation to generation: goats produce goats, and
sheep, sheep."

The passage on page 242 occurs in the reprint of the 1836-7 edition
which forms part of the 1841-51 edition, but is not there marked by Mr.
Darwin. He notes at the end of Volume I. of the 1836-7 edition: "March,
1857. I have not looked through all these [i.e. marked passages], but I
have gone through the later edition"; and a similar entry is in Volume
II. of the third edition. It is therefore easy to understand how he came
to overlook the passage on page 242 when he began the fuller statement
of his species theory which is referred to in the "Life and Letters" as
the "unfinished book." In the historical sketch prefixed to the "Origin
of Species" writers are named as precursors whose claims are less strong
than Prichard's, and it is certain that Mr. Darwin would have given an
account of him if he had thought of him as an evolutionist.

The two following passages will show that Mr. Darwin was, from his
knowledge of Prichard's books, justified in classing him among those who
did not believe in the mutability of species:

"The various tribes of organised beings were originally placed by
the Creator in certain re