280 THE PRINCIPLES OF [Part II. 



prong-horned antelope, 26 in which species the horns, though 

 present in both sexes, are almost rudimentary in the 

 female, they do not appear until about five or six months 

 after birth. With sheep, goats, and cattle, in which the 

 horns are well developed in both sexes, though not quite 

 equal in size, they can be felt, or even seen, at birth, or 

 soon afterward. 26 Our rule, however, fails in regard to 

 some breeds of sheep, for instance, merinos, in which the 

 rams alone are horned ; for I cannot find on inquiry, 27 that 

 the horns are developed later in life in this breed than in 

 ordinary sheep in which both sexes are horned. But with 

 domesticated .sheep the presence or absence of horns is 

 not a firmly-fixed character ; a certain proportion of the 

 merino ewes bearing small horns, and some of the rams 

 being hornless ; while with ordinary sheep hornless ewes 

 are occasionally produced. 



In most of the species of the splendid family of the 

 Pheasants, the males differ conspicuously from the females, 

 and they acquire their ornaments at a rather late period of 

 life. The eared pheasant (Crossvjytilon aurituni), how- 

 ever, offers a remarkable exception, for both sexes possess 



25 Antilocapra Americana. Owen, ' Anatomy of Vertebrates,' vol. 

 iii. p. 627. 



26 1 have been assured that the horns of the sheep in North Wales 

 can always be felt, and are sometimes even an inch in length, at birth. 

 With cattle Youatt says (' Cattle,' 1834, p. 277) that the prominence of 

 the frontal bone penetrates the cutis at birth, and that the horny matter 

 is soon formed over it. 



27 1 am greatly indebted to Prof. Victor Carus for having made in- 

 quiries for me, from the highest authorities, with respect to the merino 

 sheep of Saxony. On the Guinea coast of Africa there is a breed of 

 sheep in which, as with merinos, the rams alone bear horns ; and Mr. 

 Winwood Reade informs me that in the one case observed, a young ram 

 born on February 10th first showed horns on March 6th, so that in this 

 instance the development of the horns occurred at a later period of life, 

 conformably with our rule, than in the Welsh sheep, in which both sexes 

 are horned. 



