absence of crescent fit _cafer_ to the conditions of the more southern and
western territory. But, as the author we are quoting points out, when we
think of the wide range of conditions in the country occupied by
_auratus_, extending from Florida to the Arctic, it is impossible to
believe that there is any common element in the conditions which demands a
scarlet nuchal patch in _auratus_, while the equally varied conditions in
the _cafer_ area do not require that character. It may be added that the
same objection is equally valid whether we apply it to the utility of such
a character or to the supposition that the character has been caused by
external conditions; in other words, whether we attempt to explain the
facts by selection or by the Lamarckian principle.

Another case quoted by Bateson is that of the two common British Wasps,
_Vespa vulgaris_ and _Vespa germanica_. Both usually make subterranean
nests, but of somewhat different materials. That of _V. vulgaris_ is of a
characteristic yellow colour, because made of rotten wood, while that of
_V. germanica_ is grey, from the weathered surface wood of palings or
other exposed timber which is used in its construction. In characters the
differences of the two forms are so slight as to be distinguishable only
by the expert. _V. vulgaris_ often has black spots on the tibiae, which
are wanting in _germanica_. A horizontal yellow stripe on the thorax is
enlarged downwards in the middle in _germanica_, not in _vulgaris_. There
are distinct though slight differences in the genital appendages of the
males in the two species. Here there are differences of habit, and slight
but constant differences of structure; but it is impossible to find any
relation between the former and the latter.

Mendelism in itself affords no evidence of the origin of new characters,
since it deals only with the heredity of the characters which it finds
usually in the varieties of cultivated animals and plants. But indirectly