But the story itself is hardly distinguishable in kind from _Libeaux Desconus_. It is not easy to say how far this treatment of Jason may be due to the Welsh example of similar stories, and how far to the general medieval disrespect for everything in the classics except their matter. The Celtic precedents can scarcely have been without influence on this very remarkable detection of the "Celtic element" in the voyage of the Argonauts, while at the same time Ovid ought not to be refused his share in the credit of medieval romantic adventure. Virgil, Ovid, and Statius are not to be underrated as sources of chivalrous adventure, even in comparison with the unquestioned riches of Wales or Ireland. There is more than one distinct stage in the progress of the Celtic influence in France. The culmination of the whole thing is attained when Chrestien makes the British story of the capture and rescue of Guinevere into the vehicle of his most finished and most courtly doctrine of love, as shown in the examples of Lancelot and the Queen. Before that there are several earlier kinds of Celtic romance in French, and after that comes what for modern readers is more attractive than the typical work of Chrestien and his school,--the eloquence of the old French prose, with its languor and its melancholy, both in the prose _Lancelot_ and in the _Queste del St. Graal_ and _Mort Artus_. In Chrestien everything is clear and positive; in these prose romances, and even more in Malory's English rendering of his "French book," is to be heard the indescribable plaintive melody, the sigh of the wind over the enchanted ground, the spell of pure Romance. Neither in Chrestien of Troyes, nor yet in the earlier authors who dealt more simply than he with their Celtic materials, is there anything to compare with this later prose.