The comparative size of the penguin's egg is shown in some of my photographs. Ninety-six eggs averaged 4·56 ounces apiece. They vary in size from about 6·45 cm. to 7·2 cm. in length, and from 5·0 cm. to 5·5 cm. in breadth, on an average. Both ends are nearly equally rounded, and of a white chalky texture without, and green within. This green colour is plainly shown by transmitted light. When the two have been laid the sitting bird places them one in front of the other. The rearmost egg is tucked up on the outspread feet, the foremost lies on the ground, and is covered by the belly of the bird as it lies forward upon it. (Fig. 31.) By many of the birds a strong inclination to burrow was displayed, and they seemed very fond of delving in the soft shingle ledges that were to be found on some parts of the beach. They did this ostensibly to get small stones for their nests, but certainly burrowed deeper than they need have done, and occasionally squatted for some time in little caves that they made in this way. I noticed the same thing in the drifts when they went to eat snow, and thought at times that they were going to make underground nests, but they never did so, though some of the little shingle caves would have made ideal nesting sites. By November 7, though many nests were still without eggs, a large number now contained two, and their owners started, turn and turn about, to go to the open water leads about a third of a mile distant to feed, and as a result of this a change began gradually to come over the face of the rookery. Hitherto the whole ground in the neighbourhood of the nests had been stained a bright green. This was due to the fasting birds continually dropping their watery, bile-stained excreta upon it. (The gall of penguins is bright green.) These excreta practically contained no solid matter excepting epithelial cells and salts. The nests themselves are never fouled, the excreta being squirted clear of them for a distance of a foot or more, so that each nest has the appearance of a flower with bright green petals radiating from its centre. Some of the photographs show this well, especially Fig. 30. Even when the chicks have come and are being sat upon by the parents, this still holds good, because they lie with their heads under the old bird's belly and their hindquarters just presenting themselves, so that they may add their little decorative offerings, petal by petal! Now that the birds were going to feed, the watery-green stains upon the ground gave place to the characteristic bright brick-red guano, resulting from their feeding on the shrimp-like euphausia in the sea; and the colour of the whole rookery was changed in a few days, though this was first noticeable, of course, in the region of those knolls which had been occupied first, and which were now settled down to the peaceable and regular family life which was to last until the chicks had grown.