In the far northern climate of Labrador there is but one brood a year and the butterflies belong to what I have been calling the spring form. The butterflies appear on the wing in early summer, lay their eggs upon the aster leaves, and die. The eggs hatch into caterpillars that feed for several weeks, then become dormant and remain in such shelters as they can find until the following spring. They then change to chrysalids to emerge as butterflies a little later. There is thus but one brood a year and the only form of the butterfly is the small, darker colored variety. As far south as southern Canada there is a slight variation in this yearly cycle. The spring form of the butterflies appears in May and lays eggs. The eggs hatch into caterpillars; part of these caterpillars mature within a few weeks, change to chrysalids, and come out in July or August as the larger summer form of the butterfly, which in turn lays eggs for the caterpillars that are to winter over in a dormant condition and mature the following season. But the significant fact is that not all of the caterpillars which thus have hatched in spring go through this cycle. Part of them become dormant when partially grown and continue dormant through summer, autumn, and winter, just as they did in Labrador. Then in spring they develop into the spring form of the butterfly, along with the caterpillars that have hatched from the eggs laid in summer. There is thus what is called an overlapping of the broods. Farther south, in southern New England, the life-history is more definitely two-brooded each year, as already described in an earlier paragraph. Still farther south, in the region of the Virginias, it is definitely three-brooded, there being at least two summer broods during the year. How is it that the instinct to become lethargic lies dormant in the summer broods of caterpillars and shows itself only in the autumn brood? Is it perhaps due to a reaction to the colder nights of the later season? If so, possibly one could get interesting light upon the subject by experimenting with placing the summer caterpillars temporarily in an ice chest. _Synopsis of the Crescent-spots_ _Baltimore Checker-spot_ (_Euphydryas phaeton_ or _Melitaea phaeton_). Expanse 1 3/4 inches. General color purplish black with the upper surface marked thus: a marginal row of red-brown spots between the veins; two rows of creamy yellow spots inside of the row just mentioned; two or three small red and two or three small white spots near front border of each front wing. Under surface checkered in red-brown and creamy yellow on a blackish background.