rather than with stimulating manures, escape the disease. If the
ground is poor, however, and the growth feeble, barnyard manure or
its equivalent is needed as a mulch. The apple-blight is another
kindred and equally obscure disease. No better remedy is known
than to cut out the infected part at once.

In coping with insects we can act more intelligently, and
therefore successfully. We can study the characters of our
enemies, and learn their vulnerable points. The black and green
aphides, or plant-lice, are often very troublesome. They appear in
immense numbers on the young and tender shoots of trees, and by
sucking their juices check or enfeeble the growth. They are the
milch-cows of ants, which are usually found very busy among them.
Nature apparently has made ample provision for this pest, for it
has been estimated that "one individual in five generations might
be the progenitor of six thousand millions." They are easily
destroyed, however. Mr. Barry, of the firm of Ellwanger & Barry,
in his excellent work "The Fruit Garden," writes as follows: "Our
plan is to prepare a barrel of tobacco juice by steeping stems for
several days, until the juice is of a dark brown color; we then
mix this with soap-suds. A pail is filled, and the ends of the
shoots, where the insects are assembled, are bent down and dipped
in the liquid. One dip is enough. Such parts as cannot be dipped
are sprinkled liberally with a garden-syringe, and the application
repeated from time to time, as long as any of the aphides remain.
The liquid may be so strong as to injure the foliage; therefore it
is well to test it on one or two subjects before using it
extensively. Apply it in the evening."

The scaly aphis or bark-louse attacks weak, feeble-growing trees,