[Illustration: FIG. 9. Adult male skinks fighting. A. Menacing approach. B. One has lunged and secured a grip on the other's side, holding it at right angle. The one caught is unable to flex its body and neck enough to secure a retaliatory grip on the attacker, and must break away by violent thrashing.] On May 12, 1950, my attention was attracted by a rustling in dry leaves. Within a few inches of my foot two adult males were struggling fiercely with jaws interlocked. Sudden violent twisting and thrashing alternated with quiet periods of a few seconds duration, in which the lizards scarcely moved except for heavy panting and twitching of their tails. After perhaps two minutes of fighting, one broke away and ran. For a distance of several feet it was closely pursued by the other, which, however, soon lost contact with it in the rough terrain and surface litter. On May 12, 1951, rustling in dry leaves attracted my attention to two large adult males fighting. For about fifteen minutes that they were observed, they struggled, with neither yielding ground, though they thrashed and rolled about over an area of several square feet. Sometimes they were disengaged for short intervals. Then facing in opposite directions, with their heads side by side, they would snap at each other's necks and shoulders (Figure 9). Part of the time both males had grips and were biting each other simultaneously, but more frequently one or the other had a temporary advantage. When one secured a grip it would strain to the utmost, biting as hard as it could and lunging forward with frequent short jerks, meanwhile striving to keep out of reach of the other's jaws. The one caught in the attacker's grip was usually unable to flex its body sharply enough to reach its opponent at all, or could barely reach it at such an oblique angle that its jaws slipped off the smooth body. Sometimes the one held did succeed in catching the other's front foot. The one caught in the other's jaws always succeeded in tearing loose after a short time. In the interval while the attacker rested with jaws partly relaxed, the victim had an opportunity to break away. Even when both were free, they did not obtain grips easily, but often made several unsuccessful lunges and bites, the jaws of each slipping off the firm, smooth sides of its opponent. Sometimes the attacker seized a fold of skin, or sometimes obtained a wide grip on its body. One which had obtained a grip sometimes rolled rapidly, spinning the other around and dashing it against the ground. As these rotations stopped, the victim might come to rest on its back in such a position that it was temporarily helpless, but always broke loose after further struggles. Neither showed any inclination to retreat until finally, when they were interlocked, rolling about almost at my feet, I attempted to catch them. Then they instantly disengaged and rushed away, and one escaped.