conditions prevailing in 1951, incubation periods of about six weeks were recorded. Incubation may be shortened by retention of ova in the oviducts in early stages of embryonic development. Hatching may occur from the first week of July to mid-August, but in any one year most clutches hatch within two weeks of each other. Hatching of eggs in a clutch extends over a day or two. The hatchling gradually becoming active inside the egg, slits the leathery shell with its egg tooth, and spends several hours in the early stages of emergence. After resting with head and shoulders protruding, becoming adjusted to the outside environment and gaining strength, it lunges from the egg. For a day or two after hatching, the young remains in the nest, being slow and feeble, and handicapped in its movements by the protruding belly distended by the yolk mass. The female usually remains in the nest cavity for a day or two after the eggs hatch, showing affinity for the young by curling around them protectively. Family ties are broken as soon as the young leave the nest, and they do not return. Hatchlings average a little less than an inch in snout-vent length, and have a sharply defined five-lined pattern on a black ground color, and vivid blue tail. Hatchlings make rapid growth in late summer, and by the time of their retirement into hibernation, the more successful may have doubled in length, and may have increased their original weight, of approximately .3 or .4 grams, more than eight-fold. After emergence from their first hibernation the young continue their rapid growth. When they are a year old, some of them are as large as small adults. However, they can usually be distinguished from adults by the more sharply defined pattern. These grown young retain the hatchling pattern but the contrast between stripes and ground color, and between body and tail is not quite so sharp. Especially in those with regenerated tails, the vivid blue of the hatchling's tail has become much dulled. By the time they retire to their second hibernation, the young have mostly grown to small adult size. A small percentage are retarded in their growth and fail to mature. Upon emergence from their second hibernation, the grown young mature sexually and participate in the annual breeding season, in early May, and they may comprise the majority of breeding adults. The ratio of new adults to old adults however varies from year to year depending on the varying fortunes of successive annual broods. The new adults overlap older ones in size, but are usually distinguishable on the basis of their coloration, as they retain the striped body pattern (dulled, especially on the head) and with distinctly blue color on the tail. In skinks that are three years old or more, the dorsal stripes have become obscured and partly blended with the ground color, which becomes progressively paler with advancing age. Metamorphosis is most complete