ccess to the flowers.

In illustration of the first case I may refer to many alpine plants, the
well-known Edelweiss, for instance, where the woolly covering of hairs
prevents the "stomata," or minute pores leading into the interior of the
leaf, from being clogged up by rain, dew, or fog, and thus enable them
to fulfil their functions as soon as the sun comes out.

As regards the second case many desert and steppe-plants are covered
with felty hairs, which serve to prevent too rapid evaporation and
consequent loss of moisture.

The woolly hairy leaves of the Mulleins (Verbascum) doubtless tend to
protect them from being eaten, as also do the spines of Thistles, and
those of Hollies, which, be it remarked, gradually disappear on the
upper leaves which browsing quadrupeds cannot reach.

I have already alluded to the various ways in which flowers are adapted
to fertilisation by insects. But Ants and other small creeping insects
cannot effectually secure this object. Hence it is important that they
should be excluded, and not allowed to carry off the honey, for which
they would perform no service in return. In many cases, therefore, the
opening of the flower is either contracted to a narrow passage, or is
itself protected by a fringe of hairs. In others the peduncle, or the
stalk of the plant, is protected by a hedge, or chevaux de frise, of
hairs.

In this connection I might allude to the many plants which are more or
less viscid. This also is in most cases a provision to preclude creeping
insects from access to the flowers.

There are various other kinds of hairs to which I might refer--glandular
hairs, secretive hairs, absorbing hairs, etc. It is marvellous how
beautifully the form and structure of leaves is adapted to the habits
and requirements of the plants, but I must not enlarge further on this
interesting subject.

The time indeed will no doubt come when we shall be able to explain
every difference of form and structure, almost infinite as these
differences are.

INFLUENCE OF SOIL

The character of the vegetation is of course greatly influenced by that
of the soil. In this respect granitic and calcareous regions offer
perhaps the best marked contrast.

There are in Switzerland two kinds of Rhododendrons, very similar in
their flowers, but contrasted in their leaves: Rhododendron hirsutum
having them hairy at the edges as the name indicates; while in R.
ferrugineum they are rolled, but not hairy, at t