39. Do birds digest all they eat?--To determine whether seeds would lose their vitality in passing through the digestive organs of birds, Kerner von Marilaun fed seeds of two hundred and fifty different species of plants to each of the following: blackbird, song thrush, robin, jackdaw, raven, nutcracker, goldfinch, titmouse, bullfinch, crossbill, pigeon, fowl, turkey, duck, and a few others; also to marmot, horse, ox, and pig, making five hundred and twenty separate experiments. As to the marmot, horse, ox, and pig, almost all the fruits and seeds were destroyed. From the ox grew a very few seeds of millet, and from the horse one or two lentils and a few oats; from the pig a species of dogwood, privet, mallow, radish, and common locust. Under ordinary conditions, no seed was found to germinate after passing through the turkey, hen, pigeon, crossbill, bullfinch, goldfinch, nutcracker, titmouse, and the duck. Ravens and jackdaws passed without injury seeds of stone fruits and others with very hard coats. Of seeds that passed through the blackbird 75 per cent germinated, 85 per cent in the case of the thrush, 80 per cent in the case of the robin.[4] [Footnote 4: It should be noted that the blackbird here mentioned is not the same as either of our blackbirds, but a thrush much like our robin; that the robin mentioned is a ground warbler nearly related to our bluebird. It should also be noted that jackdaws, ravens, thrushes, and probably many others eject thousands of seeds by the mouth for one which passes through the intestines.]