Money doesn’t grow on trees, but the barnacle goose does.
This strange bird is mentioned only scantily in bestiaries, but Sir John Mandeville proudly boasted of it as a British wonder to compare to the incredible creatures he met on his travels:
“I told them of as great a marvel to them, that is amongst us, and that was of the Bernakes. For I told them that in our country were trees that bear a fruit that become birds flying, and those that fell in the water live, and they that fall on the earth die anon, and they be right good to man’s meat. And hereof had they as great marvel, that some of them trowed it were an impossible thing to be.” (Travels Ch.29)
Barnacle Geese, from British Library Harley MS 4751 f. 36 r.
Giraldus Cambrensis wrote of birds in Ireland “called barnacles, which nature produces in a wonderful manner, out of her ordinary course. They resemble the marsh-geese, but are smaller. Being at first gummy excrescences from pine-beams floating on the waters, and then enclosed in shells to secure their free growth, they hang by their beaks, like seaweeds attached to timber. Being in process of time well covered with feathers, they either fall into the water or take their flight in the free air, their nourishment and growth being supplied, while they are bred in this very unaccountable and curious manner, from the juices of the wood in the sea-water.” Incase you’re skeptical, Giraldus assures his readers that “I have often seen with my own eyes more than a thousand minute embryos of birds of this species on the seashore, hanging from one piece of timber, covered with shells, and already formed.”
The barnacle geese are quite handy, as “Irish bishops and men of religion make no scruple of eating these birds on fasting days, as not being flesh, because they are not born of flesh”.
Giraldus disapproves of this practice: “if anyone had eaten part of the thigh of our first parent [Adam], which was really flesh, although not born of flesh, I should think him not guiltless of having eaten flesh”. This assertion draws a parallel between the curious fleshless birth of these birds and that of Adam. For Giraldus, eating flesh on fast days is close to cannibalism!
Minatures of Barnacle Geese often depict the geese forming on a log, looking like…well, barncacles. As T.H. White notes, the goose was probably “invented to account for the facts that (a) some geese, being migratory, were not seen to breed in the south and (b) shellfish like mussels do have the general tulip shape and some of the coloration of wild geese with their wings folded. There was also an etymological muddle about wings, for translators had been liable to render the two shells of an oyster as ‘wings'” (White, Book of Beasts 267).
If you’re about to go off chuckling at the ignorance of the Middle Ages, have a look at the image below to see what folks were on about. Use your imagination!
For the record, Mandeville did also encounter lambs growing on trees in his travels; the tree branches were flexible, so that they would bend down and let the lambs graze on the grass below, thus giving them nourishment until they were ready to drop off.
No idea where the notion of vegetable lambs came from… But that’s a matter for another post.
The tree-climbing goats of Morocco
And since we’ve got onto the topic of sheep in trees:
Marginalia 