210 Heredity. 



even among birds, the male differs from the female by 

 the possession of numerous secondary sexual characters 

 besides brilliant plumage, and that many of these, like 

 the spurs of male Gallinacese, are not at all conspicuous. 

 Bechstein {JSfaturgesch Deutschland) says that a breed of 

 fowls formerly existed in Germany in which the hens 

 were furnished with spurs, but that they could not be 

 allowed to sit on their own eggs, as, although they were 

 good layers, the spurs disturbed the nest and broke the 

 eggs ; and it might perhaps be urged that the absence of 

 spurs in the females of wild species of Gallus may be due 

 to the selection, for this reason, of females without 

 spurs, but we must recollect that natural selection acts 

 upon every part of the organism, and would, if the fe- 

 male were as liable as the male to give rise to hereditary 

 variations, have acted, during the evolution of spurs, to 

 bring the structure and habits of the female into 

 harmony with these new weapons, so that she could en- 

 joy their protection without injury to her eggs. 



Darwin says that when we think of the multitude of 

 birds which with impunity gladden the country with 

 their songs during the spring, it does not seem probable 

 that the females have been saved from acquiring this 

 power on account of the danger to which they would 

 have been exposed by attracting the attention of birds 

 and beasts of prey. 



If female birds have had the power of song, it would 

 certainly seem simpler for them to have acquired the 

 habit of restraining their voices in dangerous places than 

 to suppose that the power has been removed by natural 

 selection. 



Wallace's view fails to account for the fact that the 

 plumage of allied species of females is, as a rule, much 

 more alike than that of the males ; and this fact is quite 



