200 POPULAR SCIENCE MONTHLY. 



led the same men from different points of view. How much more 

 confusing if each chanced to hit upon an entirely different set of 

 ten thousand men! This, be it noted, is generally the case in 

 practice. Nevertheless, although there is always danger in such 

 inferences, we are fortunate in possessing so many parallel inves- 

 tigations that they check one another, and the tendencies all 

 point in one direction. 



These tendencies we may discover by means of curves drawn 

 as we have indicated above in our diagram. By them we may 

 analyze each group in detail. Every turn of the lines has a mean- 

 ing. Thus, the most noticeable feature of the Sardinian curve of 

 statures is its narrowness and height ; the Ligurian one is broader 

 at the base, with sloping sides ; and the Scotch one looks as if 

 pressure had been applied at the apex to flatten it out still 

 farther. The interpretation is clear. In Sardinia we have a 

 relatively unmixed population. Nearly all of the people are 

 characterized by statures between five feet one inch (1*56 metres) 

 and five feet five inches (1*65 metres). They are homogeneous, in 

 other words: and they are homogeneous at the lower limit of 

 human variation in stature. The curve is steepest on the left side. 

 This means that the stature has been depressed to a point where 

 neither misery nor chance variation can stunt still further ; so 

 that suddenly from seven per cent of the men of a height of five 

 feet one and a half inches [more frequent than any given stature 

 in Scotland] we drop to two per cent at a half inch shorter stat- 

 ure. A moment's consideration will show that the narrower the 

 pyramid, the higher it must be. One hundred per cent of the 

 people must be accounted for somewhere. If they do not scatter 

 sidewise, their aggregation near the center will elevate the apex, 

 or the shoulders of the curve at least. So that a sharp pyra- 

 mid points to a homogeneous people. If they were all precisely 

 alike, a single vertical line one hundred per cent high would 

 result. On the other hand, a flattened curve indicates the intro- 

 duction of some disturbing factor, be it an immigrant race, en- 

 vironment or what not. In this case the purity of the Sardin- 

 ians is readily explicable. They have lived in the greatest isola- 

 tion, set apart in the Mediterranean. A curve drawn for the Irish 

 shows the same phenomenon. Islands demographically tend in 

 the main to one or the other of the extremes. If unattractive, 

 they offer examples of the purest isolation, as in Corsica and Sar- 

 dinia. If inviting or on the cross-paths of navigation, like Sicily, 

 their people speedily degenerate into mixed types. For if incen- 

 tive to immigration be offered, they are approachable alike from 

 all sides. The Scotch, as we have observed, are more or less 

 mixed in type, and unequally subjected to the influences of envi- 

 ronment ; so that their curve shows evidence of heterogeneity. 



