in support of the proposition. Assuming that
they are true, are they pertinent to the proposition?

Certain species of these army ants which inhabit tropical America, Mr.
Belt considered to be the most intelligent of all the insects of that part
of the world. On one occasion he noticed a wide column of them trying to
pass along a nearly perpendicular slope of crumbling earth, on which they
found great difficulty in obtaining a foothold. A number succeeded in
retaining their positions, and further strengthened them by laying hold of
their neighbors. They then remained in this position, and allowed the
column to march securely and easily over their bodies. On another occasion
a column was crossing a stream of water by a very narrow branch of a tree,
which only permitted them to go in single file. The ants widened the
bridge by a number clinging to the sides and to each other, and this
allowed the column to pass over three or four deep. These ants, having no
permanent nests, carry their larvae and pupae with them when marching. The
prey they capture is cut up and carried to the rear of the army to be
distributed as food.

--Robert Brown: _Science for All_.

+Theme C.+--_Present all the evidence you can either to prove or disprove
one of the following propositions:_--

Select some question of local interest as:--
1. The last fire in our town was of incendiary origin.
2. The football team from ---- indulged in "slugging" at the last game.
3. Our heating system is inadequate.
4. It rained last night.

If you prefer, choose one of the following subjects:--
1. The Stuart kings were arbitrary rulers.
2. The climate of our country is changing.
3. Gutenberg did not invent the printing press.
4. The American Indians have been unjustly treated by the whites.
5. Nations have their periods of rise and decay.

(Are the facts you use true? Are they pertinent? Do you know of facts
that would tend to show that your proposition is not true?)

+182. Number and Value of Reasons.+--Although a statement may be true and
pertinent it is seldom sufficient for proof. We need, as a rule, several
such statements. If you are trying to convince a friend that one kind of
automobile is superior to another, and can give only one reason for its
superiority, you no doubt will fail in your attempt. If, however, you can
give several reasons, you may succeed in convincing him. Suppose you go to
your principal and ask permissio