KINETOGENESIS. 317 



less it is probable that the death of the horn would be 

 associated with the deposit of the burr in this case 

 also, were the conditions the same. What those con- 

 ditions were we can only surmise. It was very prob- 

 ably the death of the integument which invested and 

 nourished the horn that produced that result ; and 

 this would more readily occur in the exposed antlers 

 than in the more protected basal portion of the beam. 

 It is very probable that this result would follow blows 

 and laceration of the surface received during combat, 

 or accidental contact with hard substances. The in- 

 tegument would be stripped up to near the junction of 

 the antlers with each other, or of the beam with the 

 cranium, and the arteries would be constricted or 

 closed at those points. It is near these junctions that 

 all of the burrs are found. But as such lesion would 

 be necessarily less complete at the point where the 

 horn has greatest circumference, so the entire death 

 of the horn might be less usual than that of the 

 branches. Should such lesions have occurred for a 

 long period at the breeding season, nature's efforts to 

 repair by redeposit of bony tissue might as readily be- 

 come periodical as the increase in size and activity of 

 the reproductive organs and other growths which char- 

 acterize the breeding season in many animals. The 

 subsequent death of the horn would be at some time 

 followed by its shedding by the ordinary process of 

 sloughing." 



Cosoryx is not the true ancestor of the Cervidse, as 

 its teeth have already attained the prismatic type of 

 the higher Bovidae. But Blastomeryx is most prob- 

 ably the ancestor of the deer. The remains of this 

 genus occur with those of Cosoryx, but the burr has 

 not yet been observed on its horns. 



