MAMMALS 



99 



the females, and the species is unique among the Cavicornia 

 or sheath-horned ungulates in shedding, not the bony core, 

 but the horny covering every year. The horns are also 

 unique in being forked instead of simply pointed. The 

 regular periodical shedding of the horns was regarded as so 



f^ 



Fig. S. Head of the Prong-Buck, Antilocapra americana. From a stuffed specimen 

 in the British Museum of Natural History. 



extraordinary a phenomenon, that for a long time naturalists 

 refused to believe it when sportsmen asserted that it occurred. 

 Yet from the Lamarckian point of view it is possible to 

 understand and explain it, for the simple reason that the 

 shedding of the entire horn occurs occasionally in domesti- 

 cated cattle in consequence of definite external irritation. 

 J. D. Caton has described at length, and I believe 



