The following are a few cases of strong seeds or fruits:--Cotton seed bears a weight of 19 to 20 lb.; the hard fruits of the Dogrose, 33 lb.; Castor-oil seed, 17 lb.; Hornbeam nuts, 27 lb.; Pine seed (various sorts), from 11 to 22 lb.; Yew seeds, 16 lb.; Peas, 50 to 56 lb. In every case they are not at all hurt by these pressures. As regards the animals for whom fruit or seeds are of great importance, birds are of course the commonest. The following is part of the bill-of-fare of a few of our common birds:--Thrushes eat blaeberries (bilberries), brambles and mulberries. Missel-thrush (or mavis) is especially fond of the mistletoe. Now the berry of the mistletoe is exceedingly sticky and glutinous, and in the course of the bird's meal these sticky strings get on to the bill and feathers, so that the mavis wipes its bill on the branch of a tree. When it does so the seed becomes attached to the branch, and is drawn close to the latter when the viscous matter dries up, and so takes root on the branch. Nightingales and robins eat strawberries and elderberries; blackbirds are very fond of strawberries, gooseberries, and raspberries. Wood-pigeons eat beechmast, acorns, and, according to Pliny, mistletoe-berries also, but this latter author has not been confirmed by later observers. Some of the wild African pigeons are exceedingly fond of castor-oil seeds. When travelling through the Central African bush, it is often necessary to shoot your dinner (if you are to have any at all), and castor-oil bushes can be relied upon to produce pigeons, if you are content with and are able to shoot them. There is a widely-spread belief in the country that a great quantity of berries means that a very severe winter is going to follow. But as a matter of fact the winter of 1904 was not a severe one, and yet there were enormous quantities of berries. We are still ignorant of many details about birds and berries. It is not quite clear how the seeds are not destroyed, though experiments have shown that they are not injured, by passing through the body of a bird. Kerner von Marilaun, for instance, tried the fruits and seeds of 250 different plants which were offered to seventeen birds, as well as to marmots, horses, cattle, and pigs. He found that from seventy-five to eighty-eight per cent. of the seeds germinated afterwards so far as regards the blackbird, song-thrush, rock-thrush, and robin. Quail also bring seeds from Greece and the Ionian Islands to Sicily. Mr. Clement Reid says: "Some years ago I found ... in an old chalk-pit the remains of a wood-pigeon which had met with some accident. Its crop was full of broad-beans, all of which were growing well, though under ordinary circumstances they would have been digested and destroyed."[110] Such accidents are common. [110] Reid, _Origin of the British Flora_.