In Middle English pertriche «partridge,» was derived from Perdix, one of Athena’s sacred kings, thrown in the seas from a tower, and carried to heaven in the form of a bird by his Goddess. He was the partridge, she the pear tree.
Athena was worshipped in Boeotia as Once, the Pear Tree, mother of all pear trees. Perdix, whose name originally meant «the Lost One,» was a form of Vishnu-Narayana, called Lord of the Pear Trees in his holy city of Badrinath in the Himalayas (from badri, «pear tree»).
The pear tree had a feminine-masculine significance through Eurasia. It was also sacred to Hera, whose oldest image at Heraeum in Mycenae was made of pear wood. European peasants considered the pear a favorite «life-tree» for a girl. In Russia pears were used as protective charms for cows.
It seems that when the partridge in a pear tree was made into a Christmas carol the symbol of Christ was substituted for Perdix. A.G.H.