Rhine; and next, that delicate orchid, the Spiranthes aestivalis,
which is known only in a bog near Lyndhurst and in the Channel
Islands, while on the Continent it extends from Southern Europe all
through France. Now, what do these two plants mark? They give us a
point in botany, though not in time, to determine when the south of
England was parted from the opposite shores of France; and whenever
that was, it was just after the Gladiolus and Spiranthes got hither.
Two little colonies of these lovely flowers arrived just before
their retreat was cut off. They found the country already occupied
with other plants; and, not being reinforced by fresh colonists from
the south, have not been able to spread farther north than
Lyndhurst. Thus, in the New Forest, and, I may say in the Bagshot
moors, you find plants which you do not expect, and do not find
plants which you do expect; and you are, or ought to be, puzzled,
and I hope also interested, and stirred up to find out more.

I spoke just now of the time when England was joined to France, as
bearing on Hampshire botany. It bears no less on Hampshire zoology.
In insects, for instance, the presence of the purple emperor and the
white admiral in our Hampshire woods, as well as the abundance of
the great stag-beetle, point to a time when the two countries were
joined, at least as far west as Hampshire; while the absence of
these insects farther to the westward shows that the countries, if
ever joined, were already parted; and that those insects have not
yet had time to spread westward. The presence of these two
butterflies, and partly of the stag-beetle, along the south-east
coast of England as far as the primeval forests of South
Lincolnshire, points, as do a hundred other facts, to a time when
the Straits of Dover either did not exist, or were the bed of a
river running from the west; and when, as I told you just now, all