The habits of a people and the consequent demands which they make upon their environment must be taken into account in judging whether or not a restricted geographical location is indicative of a retrograde process. The narrow marginal distribution of the Haida, Tlingit, and Tsimshean Indians on the islands and coastal strips of northwestern America means simply the selection of sites most congenial to those inveterate fisher tribes. The fact that the English in the vicinity of the Newfoundland Banks settled on a narrow rim of coast in order to exploit the fisheries, while the French peasants penetrated into the interior forests and farmlands of Canada, was no sign of territorial decline. English and French were both on the forward march, each in their own way. The scattered peripheral location of the Phoenician trading stations and later of the Greek colonies on the shores of the Mediterranean was the expression of the trading and maritime activity of those two peoples. Centuries later a similar distribution of Arab posts along the coast of East Africa, Madagascar and the western islands of the Sunda Archipelago indicated the great commercial expansion of the Mohammedan traders of Oman and Yemen. The lack came when this distribution, normal as a preliminary form, bore no fruit in the occupation of wide territorial bases. [See map page 251.] [Sidenote: Prevalence of ethnic islands of decline.] In general, however, any piecemeal or marginal location of a people justifies the question as to whether it results from encroachment, dismemberment, and consequently national or racial decline. This inference as a rule strikes the truth. The abundance of such ethnic islands and reefs--some scarcely distinguishable above the flood of the surrounding population--is due to the fact that when the area of distribution of any life form, whether racial or merely animal, is for any cause reduced, it does not merely contract but breaks up into detached fragments. These isolated groups often give the impression of being emigrants from the original home who, in some earlier period of expansion, had occupied this outlying territory. At the dawn of western European history, Gaul was the largest and most compact area of Celtic speech. For this reason it has been regarded as the land whence sprang the Celts of Britain, the Iberian Peninsula, the Alps and northern Italy. Freeman thinks that the Gauls of the Danube and Po valleys were detachments which had been left behind in the great Celtic migration toward the west;[287] but does not consider the possibility of a once far more extensive Celtic area, which, as a matter of fact, once reached eastward to the Weser River and the Sudetes Mountains and was later dismembered.[288] The islands of Celtic speech which now mark the western flank of Great Britain and Ireland are shrunken fragments of a Celtic linguistic area which, as place-names indicate, once comprised the whole