These small butterflies lay tiny though beautiful eggs upon a variety of plants. The eggs hatch into curious little caterpillars that have the appearance of slugs with small heads which can be extended as if the little creature had really a rubber neck. The object of this extensile head is seen when one finds the larvae feeding upon the fruits or the seed-pods of its various food plants--hawthorn, hop, hound's-tongue, and St. John's-wort. The caterpillar is able to thrust its jaws into the interior of the seed-pods and devour their contents. There seem to be generally two broods in a season, even in the more northern parts of its range, while toward the south there are probably at least three broods. The butterflies are found upon the wing almost any time in summer, especially from early June until late in August. =The Banded Hair-streak= _Thecla calanus_ This is one of the most familiar of the delicate little butterflies grouped in the genus _Thecla_. It occurs rather commonly in a great stretch of territory extending from Maine, west to Nebraska, south to New Mexico and Texas, and east to Alabama and Georgia. It also occurs in a limited area on the coast of California. The general color of the upper surface is a dark brown, which in the male is marked near the front edge of the fore wings with a distinct gray patch of scent scales. The under side is similar in color to the upper except that the outer half of the wing is marked by two series of broken lines in white, blue, and brown and a brilliant bit of coloring just in front of the tail projection of the hind wings; this coloring shows beautiful tones of red, blue, and black. These little butterflies may often be seen visiting the midsummer flowers but are fully as likely to be found along the sides of a shady road, where they rest upon the leaves of trees, shrubs, and herbaceous plants. When disturbed, they fly up in small companies but soon settle back again into their previous positions. They are lovers of sunshine and may often be seen upon a leaf, with fully expanded wings, taking a sun-bath. There is but one brood a year, butterflies appearing early in summer and remaining for several weeks. They lay their tiny pale green eggs upon the leaves of various trees, especially oaks and hickories, and probably hawthorns. It is not known whether these eggs remain unhatched as a rule until the following spring, or whether they soon hatch and the young caterpillars hibernate without feeding. It is probable that both conditions occur. In spring the larvae eat holes in the leaves of their food plant and grow rather slowly, gradually becoming brown or green slug-like caterpillars about half an inch long. They finally change into greenish brown chrysalids from which the butterflies emerge in early summer. =The Striped Hair-streak= _Thecla liparops_