==============+===============+===============+=============== | Snout-vent | Sizes of | Age Date | length in mm. | testes in mm. | class --------------+---------------+---------------+--------------- May 6, 1951 | 76 | 7.0 × 4.0 | old adult May 20, 1951 | 77 | 5.0 × 2.8 | old adult May 20, 1951 | 74 | 6.2 × 3.2 | old adult May 20, 1951 | 74 | 5.5 × 3.0 | old adult May 20, 1951 | 66 | 5.0 × 2.8 | young adult May 20, 1951 | 65 | 4.2 × 3.2 | young adult May 20, 1951 | 64 | 5.3 × 3.1 | young adult May 20, 1951 | 45 | 2.5 × 1.0 | juvenile May 20, 1951 | 40 | 1.5 × .3 | juvenile June 3, 1951 | 65 | 5.0 × 2.5 | young adult June 10, 1951 | 67 | 4.0 × 1.8 | young adult June 25, 1951 | 75 | 4.0 × 2.0 | old adult June 25, 1951 | 70 | 3.5 × 1.8 | young adult June 25, 1951 | 51 | 2.0 × .5 | juvenile --------------+---------------+---------------+--------------- From the time of emergence in spring, males show some tendency to seek out females, and frequently a pair may be found together under the same rock, weeks before the onset of the breeding season. There is no satisfactory evidence that such associations have any permanence. At the time of emergence from hibernation the males rarely have even a trace of reddish coloration on their heads, and more than a month normally elapses before attainment of breeding coloration. Each year that observations were made activity of the skinks was interrupted by cold weather in April, so that the lizards were fully active for only part of the time between their earliest emergence and their attainment of breeding condition five to eight weeks later. The reddish suffusion of the breeding season, hardly showing in the first few weeks after emergence, appears suddenly within a few days in all adult males of the population. The best indication of the time necessary to attain breeding condition was provided by an adult male whose hibernation was interrupted on December 15 by bringing him into a warm room where he was kept at 80° F. or more in the daytime, and approximately 70° F. at night. Thirteen days later, on December 28, the male had developed a noticeable reddish suffusion. On January 3, nineteen days after hibernation terminated, the suffusion was near its maximum. When an adult female was placed with the male on this date, he showed sexual interest but the courtship was not consummated. On January 6, the 22nd day, the male's colors had reached their maximum, and when the female was placed with him, pursuit and copulation occurred promptly.