. THE LEAF-CUTTERS.

It is not enough that animal industry should be able, to a certain
extent, to adapt itself to casual exigencies when choosing the site of
a nest; if the race is to thrive, something else is required, something
which hide-bound instinct is unable to provide. The Chaffinch, for
instance, introduces a great quantity of lichen into the outer layer of
his nest. This is his method of strengthening the edifice and making
a stout framework in which to place first the bottom mattress of moss,
fine straw and rootlets and then the soft bed of feathers, wool and
down. But, should the time-honoured lichen be lacking, will the bird
refrain from building its nest? Will it forgo the delight of hatching
its brood because it has not the wherewithal to settle its family in the
orthodox fashion?

No, the chaffinch is not perplexed by so small a matter; he is an expert
in materials, he understands botanical equivalents. In the absence of
the branches of the evernias, he picks the long beards of the usneas,
the wartlike rosettes of the parmelias, the membranes of the stictises
torn away in shreds; if he can find nothing better, he makes shift with
the bushy tufts of the cladonias. As a practical lichenologist, when one
species is rare or lacking in the neighbourhood, he is able to fall back
on others, varying greatly in shape, colour and texture. And, if the
impossible happened and lichen failed entirely, I credit the Chaffinch
with sufficient talent to be able to dispense with it and to build the
foundations of his nest with some coarse moss or other.

What the worker in lichens tells us the other weavers of textile
materials confirm. Each has his favourite flora, which hardly ever
varies when the plant is easily accessible and which can be supplemented
by plenty of others when it is not. The bird's botany would be worth
examining; it would be interesting to draw up the industrial herbal of
each species. In this connection, I will quote just one instance, so as
not to stray too far from the subject in hand.

The Red-backed Shrike (Lanius collurio), the commonest variety in my
district, is noteworthy because of his savage mania for forked gibbets,
the thorns in the hedgerows whereon he impales the voluminous contents
of his game-bag--little half-fledged birds, small Lizards, Grasshoppers,
caterpillars, Beetles--and leaves them to get high. To this passion for
the gallows, which has passed unnoticed by the country-folk