[Footnote 130: In his stimulating book, _Comment la route crée le type Social_, Edmond Desmolins submits an ingenious hypothesis to explain the pre-eminence of the Gauls in the growing and making of pork, and how that pre-eminence was itself the explanation of their early success in cultivating the cereals. He describes their migrating ancestors, the Celts, pushing their way up the Danube as hordes of nomad shepherds with their vast flocks and herds of horses and cattle, on the milk of which they had hitherto subsisted. So long as they journeyed through prairie steppes, the last of which was Hungary, they maintained their shepherd character, but when they once passed the site of the present city of Vienna and entered the plateau of Bavaria, they found new physical conditions which caused them to reduce and to separate their herds of large cattle--an unbroken forest affording little pasture of grass. Here they found the wild boar subsisting upon the mast of the forest, and him they domesticated out of an economic necessity, to take the place of their larger cattle as a basis of food supply. Until then they had not been meat eaters, and so had known no necessity for cereals, for milk is a balanced ration in itself. But this change of diet required them also to take to agriculture and so to abandon their nomad life. 'By reason of the habits of the animal, swine husbandry has a tendency in itself to confine those engaged in it to a more or less sedentary life, but we are about to see how the Celts were compelled to accomplish this important evolution by an even more powerful force. Meat cannot be eaten habitually except in conjunction with a cereal ... and of all the meats pork is the one which demands this association most insistently, because it is the least easily digested and the most heating of all the meats.... So that is how the adoption of swine husbandry and a diet of pork compelled our nomad Celts to take the next step and settle down to agriculture.'] [Footnote 131: This Gallic _tomacina_ was doubtless the ancestor of the _mortadella_ now produced in the Emilia and known to English speaking consumers as "Bologna" sausage.]