£52 THE ZOOLOGIST. 



with the rapid disappearance of hornless ungulate families ; and 

 that, in the later Tertiaries (Pliocene) and onwards, the develop- 

 ment of horns and antlers follows an ascending scale which is 

 parallel, on the one hand, with the survival, multiplication and 

 lasting numerical preponderance of horned and antlered ungulate 

 genera (deer, antelopes, oxen), and, on the other hand, with the 

 decrease in a diminishing ratio to all but ultimate extinction of 

 perissodactyle genera not similarly endowed, though starting in 

 the race for life with a not less marked majority.* 



In reaching the implied conclusion that horns and antlers 

 were aboriginally protective weapons, we may reinforce our 

 argument with the fact that these weapons have suffered a 

 gradual yet continuous loss of calibre throughout the human 

 period. Among various causes which have contributed to this 

 effect it must not be forgotten that, with advancing civilisation, 

 the conditions to which such weapons owe their origin must 

 inevitably cease to exist. Carnivores, great and small, are slowly 

 but surely disappearing in their unequal struggle with new 

 masters of the world; and the cranial armature of ruminants, 

 which proved a solid defence against teeth and claws at close 

 quarters, avails nothing against more cunning foes who fight with 

 missile weapons, whether flint, spear, or bullet. Horns and 

 antlers have declined with the declining influence of natural 

 selection, and illustrate the fundamental truth that " not only 

 does the survival of the fittest select the best, but it also main- 

 tains it" (Weismann), the most elaborately adjusted adaptation 

 being " handed over to a process of gradual destruction the 

 moment it ceases to be essential to the life of the species." 



(To be continued.) 



* The predilection of the Puma for horseflesh leads Mr. Hudson to 

 suggest that the indigenous horses of America were exterminated by Pumas 

 (' Naturalist in La Plata,' p. 33). 





