Dr. Arthur Evans thinks that the older, or Hallstatt, culture of Central Europe was gradually modified and transformed into the La Tène, Marnian, and Late-Celtic stages of culture, in consequence of the foreign influence exercised by the continual flow of Greek commerce into eastern Gaul from the sixth century B.C. onwards. Ample evidence of this commercial intercourse is afforded by the discovery of tripods, hydrias, œnochœs, and painted vases of Greek workmanship associated with Gaulish burials,[36] as at Grækwyl, near Berne in Switzerland, at Somme-Bionne (Marne), at Rodenbach in Bavaria, and at Courcelles-et-Montagne (Haute-Marne). [36] A. Bertrand’s _Archéologie Celtique et Gauloise_, pp. 328 to 347; see also L. Lindenschmit’s _Die Alterthümer unserer heidnischen Vorzeit_, Mainz, 1858, etc. The great difficulty in understanding the evolution of Celtic art lies in the fact that although the Celts never seem to have invented any new ideas, they professed an extraordinary aptitude for picking up ideas from the different peoples with whom war or commerce brought them into contact. And once the Celt had borrowed an idea from his neighbour, he was able to give it such a strong Celtic tinge that it soon became something so different from what it was originally as to be almost unrecognisable. Polybius gives the following picture of the Cisalpine Gauls:— “These people camp out in villages without walls, and are absolutely ignorant of the thousand things that make life worth living. Knowing no other bed than straw, only eating flesh, they live in a half-wild state. Strangers to everything which is not connected with war or agricultural labour, they possess neither art nor science of any description.” The tendency of the Celt to copy rather than invent is brought out most clearly in their coinage. M. A. Bertrand[37] says:—