38 WOODLANDERS AND FIELD FOLK 



between those two forms of sport, though the parallel 

 must not be pushed too far. Opinions differ as to 

 the number of white grouse existing now and formerly, 

 though the general verdict is that the species is 

 increasing. 



The inclination of naturalists has been to multiply 

 species by a process of hair-splitting, though doubt- 

 less in the near future scientists will admit that the 

 red grouse, the ptarmigan, and the Scandinavian 

 willow grouse are each varietal forms of one parent 

 stock. The length to which inherent variability 

 may go is yet but little understood, and its furthest 

 possibilities can only be demonstrated on domestic 

 animals. Nature of course works on similar lines, 

 but her processes are slower and less tangible, as 

 applied to any one generation. 



The willow grouse is the white bird which in winter 

 adorns the game shops, and is usually set down as 

 the ptarmigan. It is a large and robust bird, conse- 

 quent upon its wide range and abundant food 

 supply, and acquires almost purely white plumage 

 in winter. 



