ains about four and one half million particles).
Clay is made from crushed rocks, chiefly feldspars. Mix clay with a
little water and note sticky character. Compare with sand in this
respect. Which makes the best road in wet weather, gravel, sand, or
clay? Note how hard the clay bakes after being moistened. Uses of
clay--pottery, bricks, tile. Pupils should visit a brick- or tile-yard
and watch the process of manufacture. In many parts of the world there
are beds of clay of extreme fineness and whiteness, from which beautiful
china is made.

_Humus_ is decayed vegetable matter. Pupils should gather soil from the
forest, bog, or marsh. Note dark colour. Examine carefully and see what
you can find in it that is not in sand or clay.

Most of our farm land consists of these four soils mixed in various
proportions, and it gets its name from the one that preponderates. Thus
we have our sandy, gravelly, or clay _loams_. Humus is likely to be
present in all fields, because vegetable matter grows, to some extent,
everywhere; but freshly broken land, reclaimed swamps, and prairie lands
are likely to be especially well supplied. The great value of humus in
the soil will appear in later studies.

ANIMAL STUDIES

BIRD MIGRATION

(Consult _Bird Life_ by Frank M. Chapman, and _Bird Studies_
by G. A. Cornish.)

In the autumn, direct attention to the flight of wild ducks and geese
and to the gathering into flocks of robins, crows, bronze grackles,
blue herons, sparrows, and other birds in preparation for migration.

Discuss with the pupils the reasons for migration, namely, scarcity of
food, the cold, the snow. In the spring, the return is stimulated by the
nesting instinct.

Note how the birds are guided--some, for example the ducks and geese, by
their leaders, while others have no guides but their instincts.

In winter, require the pupils to observe the kinds of birds that are to
be seen in the gardens, fields, orchards, and woods, having them note
the scarcity of birds and the absence of many forms that are with us in
the summer.

CORRELATIONS

Geography: By pointing out on the map the countries into which the birds
go, namely, Central America, Brazil, etc.

Reading and literature: By interpreting

Where did you spend the dreary winter?
In a green and sunny land,
By the warm sea-breezes fanned,
Where orange trees with fruit are bent,
There the dreary time I've spent.

COMMON WILD A