290 THE ZOOLOGIST* 



which are described as horned by Major Pinto on the upper Chobe, 

 but were found to be hornless by Mr. Selous on the lower reaches 

 of the same river. Among horned females, again, while a majority 

 carry horns which, though well developed, are of generally lesser 

 calibre than those carried by their males, we find, at the two 

 extremes of a graduated series, that some have horns of equal 

 calibre, as in the Hippotragine Antelopes, which show ancestral 

 affinities with the oxen ; and that others have horns which are 

 rudimentary or disappearing, as in the Pronghorn, the females of 

 which are usually horned, but occasionally hornless; or in the 

 Blackbuck, the females of which are usually hornless, but 

 occasionally horned. 



The comparative proportion of horned and antlered females 

 in their respective families is, however, by far the most striking 

 fact relative to the physiological interference of the maternal 

 function with the development of cranial weapons. Among 

 surviving ruminants with antlers (Cervidce) a single genus repre- 

 sented by a single species exhibits these weapons in both sexes ; 

 whereas among surviving ruminants with horns (Bovidce) horned 

 females appear in a majority of genera and in an overwhelming 

 majority of species. Seeking an explanation of these different 

 results in the history of frontal weapons, we find it in the fact 

 that antlers arose from the intermittent fracture and renewal of 

 antecedent structures which otherwise remained permanent as 

 horns. There can be no question that the physiological cost of 

 maintenance in the case of cranial outgrowths which were periodi- 

 cally lost and renewed, must have been immensely greater than 

 in the case of outgrowths which were developed once for all, and 

 permanently retained thereafter. Hence we may conclude that 

 the reserve of vital force necessitated by the complete fulfilment 

 of the maternal function, though generally compatible with the 

 development of horns, was generally incompatible with the de- 

 velopment of antlers. The occasional and abnormal presence in 

 female Deer of simple antlers which retain their velvet (the 

 primitive hairy skin), are not shed, and exhibit a rudimentary 

 coronet (the point of primitive fracture) or none at all, appears 

 to be a remarkable reversion to the Miocene ancestry in which 

 similar weapons were aboriginal, permanent, and probably common 

 to both sexes. 



The absence of defensive weapons on the maternal side found 





