116 



Racial Studies in Fishes 



is such that the uninitiated might well take it as representing two 

 distinct species, and j^et as a matter of fact we have here only to deal 

 with two populations living within the same area of sea, and, as far as 

 we are aware, under uniform external conditions. 



St. 52. Gulf of Bothnia (Sweden). 



120 

 118 

 116 

 114 



a • • • 9 



Population 



io»*9»»*0eo«oo3o«roo«9«e* 



9 9 U « 



• • e ^ 



(1 = 116-40 (±0-i7). 



St. 57. Scotland ( Anstruther). 



120 

 118 

 116 

 114 

 112 



Population 





a = 116-10 {±0-i5). 



l''ig. 9. Zoctrces vivijyanix, L. Number of vertebrae. Two population analyses from 

 St. 57 (Anstruther, Scotland) and St. .')2 (Hudiksvall, Gulf of Bothnia). .M St. .57 

 the salinity of the water is about SI "/j,,^; at St. .52 only about -5 °/,-,^. 



Our investigations thu.s by no means support the hypothesis that 

 the racial characters are determined exclusively by environment. On 

 the contrary, they seem rather to indicate that differences of environ- 

 ment are not sufficient to explain the structural differences between 

 the races, and that the importance of the salinity especially has doubt- 

 less been greatly over-estimated. 



