296 POPULAR SCIENCE MONTHLY. 



ters in the Alpine highlands, running up to the north ; the other, 

 in Auvergne, extends away toward the Spanish frontier. At 

 the present time let us note that this intrusive strip of long heads 

 cutting the Alpine belt in two follows the exact course of the 

 canal which has long united the head waters of the Loire with the 

 Rhone. It is an old channel of communication between Marseilles 

 and Orleans. Foreigners, immigrating along this highway, are 

 the cause of the phenomenon beyond question. %,^ 



The long-headed populations therefore seem Xo follow the 

 open country and the river valleys. The Alpine broad-headed 

 type, on the other hand, is always and everywhere aggregated in 

 the areas of isolation. Its relative purity, moreover, varies in 

 proportion to the degree of such isolation enjoyed or suffered. 

 In Savoy and Auvergne it is quite unmixed ; in Brittany only a 

 few vestiges of it remain. And yet these few remnants are 

 strictly confined within the inhospitable granitic areas, so that 

 the boundaries of the two correspond very closely. The spoken 

 Celtic tongue has also lingered here in Brittany for peculiar rea- 

 sons, which we shall soon discuss. The main one is the isolation 

 of the district, which has sheltered the Alpine race in the same 

 way. For it is now beyond question that the Breton, the Au- 

 vergnat, and the Savoyard are all descendants of the same stock. 

 In nearly every case the Alpine race is found distributed, as Dr. 

 Collignon says, " by a mechanism, so to speak, necessary, and 

 which by the fatal law of the orographic condition of the soil 

 ought to be as it is." In the unattractive or inaccessible areas 

 the broad-headedness centers almost exclusively ; in the open, fer- 

 tile plains the cephalic index falls as regularly as the elevation. 

 So closely is this law followed that Dr. Collignon aflSrms of the 

 central plateau that wherever one meets an important river eas- 

 ily ascended, the cephalic index becomes lower and brachycephaly 

 diminishes. 



The two-hundred-metre line of elevation above the sea seems 

 most nearly to correspond to the division line between types. 

 This contour on our geographical map is the boundary between 

 the white and first shaded areas. Compare this map with that of 

 the cephalic index, following round the edge of the Paris basin, 

 and note the similarity in this respect. There is but one break in 

 the correspondence along the eastern side. This exception it is 

 which really proves the law. It is so typical that it will repay us 

 to stop a moment and examine. We have to do, just south of 

 Paris, with that long tongue of dark tint, that is of relative 

 broad-headedness, which reaches away over toward Brittany. It 

 nearly cuts the main axis of Teutonic racial traits (light tinted) 

 in two. This is the department of Loiret, whose capital is Or- 

 leans. It is divided from its Alpine base of sujjplies by the long- 



