To the goose genus belong also the chenalopex,[1] and the cheneros,[2] a little smaller than the common goose, and which forms the most exquisite of all the dainties that Britannia provides for the table. The tetrao[3] is remarkable for the lustre of its plumage, and its extreme darkness, while the eyelids are of a scarlet colour. Another species[4] of this last bird exceeds the vulture in size, and is of a similar colour to it; and, indeed, there is no bird, with the exception of the ostrich, the body of which is of a greater weight; for to such a size does it grow, that it becomes incapable of moving, and allows itself to be taken on the ground. The Alps and the regions of the North produce these birds; but when kept in aviaries, they lose their fine flavour, and by retaining their breath, will die of mere vexation. Next to these in size are the birds which in Spain they call the "tarda,"[5] and in Greece the "otis:" they are looked upon however as very inferior food; the marrow,[6] when disengaged from the bones, immediately emits a most noisome smell.