2 4 



Introductory 



the brow-tined deer (Cervus, Cervulus, and Elaphodus), which agree in the 

 retention of the upper extremities of the lateral metacarpal bones, are 

 essentially Old World types. 



Much more difficulty exists with regard to the relationship of the fork- 

 antlered section, which includes the roes (to which the Chinese water-deer 

 appears nearly related), the Asiatic milou deer, the extinct Old World genus 

 Anoglochis, and the modern American deer. These present two distinct 

 types of metacarpal structure, namely, one in which the upper ends of the 

 lateral bones are retained, and another in which the lower ends remain ; the 

 condition existing in the extinct forms being unfortunately unknown. 

 Assuming Mr. A. Gordon Cameron to be correct in regarding all the antlers 

 of the forked type as indicative of a common ancestry, it is obvious that 

 in such ancestors the lateral metacarpals must have been complete. 



With regard to the roes, there is no definite information beyond the fact 

 that they date from the earlier portion of the Pliocene epoch ; but they are 

 doubtless Old World types, and not improbably trace their ancestry to 

 some of the extinct hornless muntjacs (Dremotherium) , from which both 

 types of antlers may have originated. Their metacarpal structure is the 

 same as in the American deer. Nothing definite can be said with regard to 

 the milou deer, in which the opposite type of metacarpal structure obtains, 

 and the extinct Anoglochis, except that both are of Old World origin. 



The American deer are usually regarded as the descendants of the two 

 extinct North American genera B/astomeryx and Cosoryx, the former of 

 which is regarded as the descendant of the extinct European Dremotherium} 

 Even on this view, the American deer are ultimately of Old World origin. 

 But it is difficult to believe that antlers of such essentially similar general 

 structure as are those of the modern American deer and the extinct European 

 Anoglochis have originated independently ; and there seems, therefore, to be 

 a considerable probability that the American deer have taken origin from 

 ail Old World type allied to or identical with Anoglochis. The question is 

 again discussed in the sequel, but it may be mentioned that Cosoryx is con- 

 sidered to be the ancestor of the American prong-buck (Ant/locapra) , and 

 if this be correct, is it probable that it also gave rise to the American deer ? 



Before proceeding further, it may be well to mention that the geo- 

 logical formations of the Tertiary period, or those newer than the Chalk, 



1 Sec Scott and Osborn, Bull. Mm. Harvard, vol. xx. p. 76 et scq. (1890). 



