Mayhew 1952 Mallard 43. June 6 Gray Lodge Refuge, Sutter Co., Calif. Nest 21 (cont.) - (ponds nearby had dried up). Temp. - 35°C.; R.H. - 50%. Nest 22 - This nest was deserted. There were 8 eggs present. 3 of these eggs were opened: - 1 showed no development, 2 showed a primitive streak, so that the nest had been deserted very early in incubation. Nest 29 - This nest was deserted. There were 8 eggs present. 3 of these eggs were opened: - 2 had blood rings + very small embryos, the other showed no development. Nest 30 - This nest, containing 6 eggs, was deserted. There was 1 very tiny egg present that, on opening, was found to contain no yolk. 2 of the others were opened, but showed little development. Nest 27 - This nest had been destroyed by some predator, as egg shells remained that were smeared with egg yolk. Nest 8 - This nest was also deserted, but it was decided to take readings to see how such a nest compared with active nests. There were 7 eggs in the nest. 2 of these were opened, + showed a very early stage of incubation. This nest was about 10 feet from water. Temp. - 23°C., R.H. - 65%. Nest 28 - This nest was also deserted. It contained 3 eggs, all of which were opened: 1 early embryo (about 1 week), 2 with no development.