Mais cette hypothèse est corroborée par une lettre de Tolkien (L.247 du 20 septembre 1963), p.334: "But I can foresee one action that they (the Ents) took (...). It was in Ossiriand, a forest country, secret and mysterious before the west feet of the Ered Luin, that Beren and Lúthien dwelt for a whike after Beren's return from the Dead. Beren did not show himself among mortals again, except once. He intercepted a dwarf-army that had descended from the mountains, sacked the realm of Doriath and slain King Thingol (...). There was a battle about a ford across one of the Seven Rivers of Ossir, and the Silmaril was recovered (...). It seems clear that Beren, who had no army, received the aid of the Ents"
Par contre, il n'est fait aucune mention de leur rôle dans l'Anneau de Melian, même si plus haut dans cette même lettre, il dit d'eux: "they were not quite the same: less wise, less strong, shyer and more uncommunicable (their own language simpler, but their knowledge of other tongues very small)", ce qui tendrait à montrer qu'ils n'avaient guère de relations avec les autres espèces inteligentes...
Iarwain