When ready to transform, this caterpillar spins a delicate gauze-like cocoon, Fig. 25, e, made of white, silken threads, on the under side of a cabbage leaf.  The pupa, Fig. 25, d, and i, the end of a pupa, is commonly white, sometimes shaded with reddish brown, and can be distinctly seen through the silken case.

The first brood is more injurious than the second, as it feeds on the young cabbage leaves before the head is formed, and this must surely stunt the growth and make weak, sickly plants; while the second brood feeds only on the outside leaves.  The caterpillars are very active, wriggling violently when disturbed, and falling by a white silken thread.

Hot dry weather is favorable to them and enables them to multiply rapidly.  Advantage has been taken of this fact, and spraying the plants thoroughly with water is strongly recommended.  Prof.  Riley states that the insects are very readily destroyed by pyrethrum.  There are two species of spiders and a species of ichneumon fly that destroy them.

THE GARTERED PLUME MOTH.

Oxyptilus periscelidactylus (Fitch.)

The caterpillars of this species draw together the young grape leaves, Fig. 26, a, in the spring, with fine silken threads, and feed on the inside, thus doing much damage in proportion to their size.  These caterpillars, Fig. 26, a, and e, a segment greatly enlarged, are full grown in about two weeks, when they are about one-fourth of an inch long, pale green with whitish hairs arising from a transverse row of warts on each segment.

Early in June they transform to pupae, Fig. 26, b, which are pale green at first and change to dark brown.  The surface is rough and the head is cut off obliquely, while on the upper side near the middle are two sharp pointed horns, Fig. 26, c.  They remain in this stage from a week to ten days, when the moths emerge.

[Illustration:  FIG. 26.]

The moths, Fig. 26, d, belong to the family commonly known as plume moths or feather wings (Pterophoridae), from having their wings divided into feather-like lobes.  When the wings are expanded they measure about seven-tenths of an inch across.  They are yellowish brown with a metallic luster, and have several dull whitish streaks and spots.  The fore wings are split down the middle about half way to their base, the posterior half having a notch in the outer margin.  The body is somewhat darker than the wings.

It is not known positively in what stage the winter is passed, but it is supposed to be the perfect, or imago stage.  The unnatural grouping and spinning of the leaves together leads to their detection, and they can be easily destroyed by hand picking and then crushing or burning them.

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THE BREEDS OF DOGS.

The dog exhibitions that have annually taken place for the last eight years at Paris and in the principal cities of France have shown how numerous and varied the breeds of dogs now are.  It is estimated that there are at present, in Europe, about a hundred very distinct and very fine breeds (that is to say, such as reproduce their kind with constant characters), without counting a host of sub-breeds or varieties that a number of breeders are trying to fix.