698 MAMMALIA. 



annular absorption occurs near the base. Then the antlers are 

 shed, leaving a stump, from which a fresh but larger growth 

 takes place in the next year. The earliest (Lower Miocene) 

 deer had no antlers, thus resembling young stags of the first 

 year ; the Middle Miocene deer had simple antlers with not 

 more than two branches, thus resembling two-year-old stags. 

 Thus there is a parallelism between the history of the race and 

 the individual development. 

 Examples -.—Cei-Lnis, most Old World deer ; Kangifer, the reindeer ; 

 Alces, the elk or moose ; Capreohts, the roe deer ; Hydropotes, 

 the water deer, without antlers ; Moschus, the musk deer, with- 

 out antlers, with long sharp upper canines in the males, with 

 large musk glands. 

 Giraflklae, represented solely by the giraffe ( Giraffa camelopardalis), a 

 tall Ethiopian animal, notable for its enormously elongated cervi- 

 cal vertebra:, and for its long limbs. It is gregarious in its habits, 

 and feeds on the leaves of trees. The lateral digits are entirely 



absent. The dental formula is '^^^. On both sexes there are on 



3133 

 the forehead short erect prominences, over the union of panetals 

 and frontals, which arise from two distinct centres of ossification, 

 but afterwards fuse with the skull. In front of these there is 

 median protuberance. 



Antilocapridse, represented solely by the prongbuck {Antilocapra 

 atnericana), a North American animal, with most of the char- 

 acteristics of Buvidcc, but with deciduous and branched horns. 



Bovidce, the hollow-horned Ruminants, widely distributed throughout 

 the world, but without indigenous representatives in Australia, 

 South or Central America. The second and fifth digits may be 

 completely absent, but are often represented by minute hoofs and 

 supporting nodules of bone. The frontal appendages, if present, 

 consist of a solid bony core growing from the frontal, and a much 

 longer sheath of horn, which grows at the base as it is worn away 

 at the tip. They are not deciduous, and are usually present in 

 both sexes, though larger in the males. 

 Examples : — Aiitilope, Gaze/la, Capra, Oz'i's, Bus. 



Sub-Order Perissodactyl.\. 



Horses, Tapirs, Rhinoceros, and their extinct Allies. 



The middle or third digit of fore and hind feet is larger 

 than the others, and symmetrical on itself. It may be the 

 only complete digit, as in the horse, or it may be accom- 

 panied by a second and a fourth, and in the fore foot of 

 Tapirs and some extinct forms, by a fifth digit. No modern 

 forms have any trace of a first digit. The astrao^alus 

 has a pulley-like surface above for articulation with the 

 tibia ; its distal surface is flattened and unites to a much 



