42 Lloyd's natural history. 



along the ground or runs towards her supposed enemy with 

 drooping wings and halting gait to attract attention, while the 

 young disappear as by magic, and vanish among the crevices 

 of the stones. Ptarmigan depend greatly for safety on the per- 

 fect harmony of their plumage with their natural surroundings, 

 and it is astonishing to see how they will sometimes rise all 

 round one, almost from under one's feet, on comparatively bare 

 ground, without any previous evidence of their presence. 



Nestling, Nest, and Eggs. — Similar to those of the Red Grouse, 

 but the eggs of the latter are rather smaller, less thickly covered 

 with blotches, and more buff in general appearance. 



IV. THE ROCK PTARMIGAN. LAGOPUS RUPESTRIS. 



Tetrao rupestris, Gmel. S. N. i. pt. ii. p. 751 (1788). 

 Lagopus riipesiris^ Leach, Zool. Misc. ii. p. 290 (18 17); Ben- 

 dire, Life Hist. N. Am. B. p. 75, pi. ii. figs. 11-15 (1892) \ 

 Ogilvie-Grant, Cat. B. Brit. Mus. xxii. p. 48 (1893). 

 Lagopus riipestris reinhardti^ p. 78; L. ?'. nelsoni^ p. 80; Z. 

 r. atkhensis^ P- 81 ; Z. ivelchi^ p. 82 ; Bendire, Life Hist. 

 N. Am. B. (1892). 



^.Plate IV.) 

 It appears to me more and more doubtful whether this 

 so-called species should be considered more than a mere 

 climatic variety of the Ptarmigan. In typical examples, the 

 summer and autumn plumages are certainly more rufous 

 in birds from Iceland, Greenland, Arctic America, Japan, 

 and Asia ; but in Newfoundland we find a greyer form, 

 apparently scarcely to be distinguished from the European 

 bird, and similar forms are recorded from some of the islands 

 to the north of Arctic America. Insufficient material pre- 

 vents us at present from settling this point, but we believe 

 that the most reasonable way of treating the matter is to regard 

 all as climatic variations of one circum-polar species. It is 

 obviously useless to give endless names to slight cHmatic varie- 

 ties because they occur in different parts of the globe, when, 



