SPECIES. 149 



but it in a great measure disappears, when the internal cha- 

 racters are chiefly relied on. 



In a domesticated state, it sometimes happens, that fe- 

 male birds assume the plumage of the male, when they 

 have ceased, from old age, to be capable of producing eggs. 

 This was first distinctly determined by JOHN HUNTER, in 

 the case of the pheasant and peacock *. Sir E. HOME like- 

 wise records an example of the same change taking place 

 in a duck, at the age of eight years -f-. Mr TUCKER, and 

 more recently, Dr BUTTER, have recorded similar occur- 

 rences in the common fowl J. The females of the last species 

 in the absence of the cock, may frequently be observed as- 

 suming the attitudes of the male, and even, according to 

 ARISTOTLE, acquiring small spurs. The same illustrious 

 observer adds, that the cock has been known to make up 

 the loss of the mother to the brood, by devoting himself 

 entirely to the supply of their wants |j. 



" Account of an extraordinary Pheasant." Phil. Trans. 1780, and 

 republished in An. Econ. p. 63. 



f- Phil, Trans. 1799, p. 174, where some cases of sexual monstrosity in 

 quadrupeds are noticed. 



Mem. Wern. Soc. vol. iii. p.183. In addition to all these species which 

 thus change, BLUMENBACH (Phys. p. 369.) refers to the Pigeon, Bustard, 

 and Pipra rupecola; and BECKSTEIN records the Turkey. 



|| Hist. Anim. ix. 49. The following singular change of character in the 

 Turkey-cock, came under my own observation four years ago. While two fe- 

 male birds, his companions, were sitting on their eggs, he was in the habit of 

 frequenting the nests occasionally. Even after the females were removed, 

 along with their young, he resorted to one of the nests, and continued sit- 

 ting for several days in succession, scarcely moving away to take food. At 

 length a dozen of hens' eggs were put into the nest, and on these he sat 

 regularly until they were hatched. When, however, the young chickens 

 began to make a noise, and to break open the shell, he endeavoured to kill 

 them with his bill, and throw them out. Only one, indeed, was saved 

 from his fury. After performing this tedious task of incubation, he rturn- 

 fd to his ordinary habils. 



