Another kind of Ptarmigan of which we have secured good photographs 

 from life is the Lagopus scoticus, the so-called "Grouse" of the British Isl- 

 ands (Figs. 44 and 45). This is preeminently a bird of the heather, and it is 

 gratifying to see how subtilely and significantly its markings differ from those 

 of the American species which nest among grasses. It is completely covered 

 with wonderful heather-pictures, recognizable as such even when the bird is 

 examined away from its true environment. The more complex forms of the 

 crowded and delicately branching heather plants, with their twigs and leaves 

 and blossoms, are copied by various modifications of the bird's pattern. Rel- 

 atively to that of the grass-ptarmigans this pattern is characterized by the 

 multiplicity of its small, light-colored forms, which are also greatly more var- 

 ied both in shade and color, to simulate the complexer surface-pattern and in- 

 terior-vistas of the heather plants, with their variously illuminated details. 

 (Technically, the difference consists chiefly in the wider and wavier marginal 

 bands, and in a copious speckling of darker brown upon the fuscous ground- 

 color within these bands.) The bird shown in Fig. 40 was unfavorably ar- 

 ranged as to obliterative shading, but certain features of its obliterative pat- 

 tern are shown off to consummate advantage. The pattern of its rump and 

 back is scarcely recognizably different from that of the heather around its tail 

 and nearer wing, while the picturing of heather-bells by its breast-pattern is 

 astonishingly close. The obliterative shading of this species is so extremely 

 slight that we must infer that it is wont to lie very deeply settled into the heath, 

 and often more or less overarched by it, so that the preponderance of direct 

 top-light is reduced to a minimum. The dark area on the actual belly, which 

 this species shares with several other gallinaceous birds of different genera, 

 has little or no bearing on the case, as it is invariably out of sight when the 

 bird is "lying close." (The use of such markings will be discussed in a later 

 chapter.) The ptarmigans which resort often to bare ground and rock, as 

 also the arboreal Gallinse, lack this 'squatting-patch,' and light bellies are 

 essential factors of their concealment. Even some of the rock-haunting 

 ptarmigans, however, have a somewhat weak obliterative shading, and this is 



47 



