During the summer time the Fen Ducks live almost entirely on vegetable substances; bulbous roots, buds, and tender shoots of trees, succulent leaves, blossoms and seeds of water-plants, constitute the staple of their diet; they will, however, likewise catch aquatic insects, fishes, and pond mollusca; in fact, they seem to like variety. During their migrations they appear more partial to animal food, and when they indulge in this to any extent, their flesh, at other times excellent food, acquires a somewhat disagreeable flavour. Their breeding-time begins late in the season, generally about the middle of May, when they usually construct their nests among the sedges and reeds that grow upon the margins of the marsh or pond which they may have selected for their residence. Whether this be fresh water or salt seems to be to them a matter of no consequence. Sometimes they will build in situations frequented by man, sometimes by the side of very small ponds, but in the latter case they soon remove their young ones to a more roomy locality. After their first arrival they spend a long time in the society of other species of Ducks, apparently without ever thinking of the great object of their visit. Towards the end of April they become restless and lively, and the males begin to utter their amorous call, the flock separates into pairs, which at once set to work in earnest to construct their nests. There does not seem to be any fighting amongst the males; the females quietly select their mates, and the espoused couple immediately resort to their building ground. The nest is usually a mere pile of sedges, stalks of reeds, hay, straw, and leaves, slightly hollowed at the top, and warmly lined with feathers. The eggs, eight or ten in number, sometimes in exceptional cases more, sometimes fewer, are moderately large, roundish, and of a dull grey or olive-green. So long as the female continues to lay, her mate remains true to his duty, and carefully watches over her safety. When, however, she begins to sit upon her eggs, the male deserts his charge, leaves her while he amuses himself in the society of other roving males, and finally troubles himself no more about either mother or eggs. After the lapse of twenty-two or twenty-three days, the young ones make their appearance, and on the very day of their birth are to be seen paddling about upon the surface of the water, but at first they do not venture beyond the shelter of the floating herbage at the side of the pond. Soon, however, their parent, by the pressure of her body, crushes down the reeds and water-plants, so as to make a sort of bed, to be used as a sleeping or resting place, and here she may be found sitting, closely surrounded by her little flock, as they sun themselves and preen their feathers. If disturbed in their snug retreat, they endeavour to save themselves by repeatedly diving, and if the threatened danger continues, the mother hastens to lead them to a more secluded spot,