1902.] OF HORNS AND ANTLERS. 219 



II h. Terminal, further development of type II a. Epichon- 

 di'otic growths prolifei'ating fieely and with broad bases, 

 so that they form intrapei-iosteal growths, separated fi-om 

 the cranial bones, and consequently ossifying independently 

 of them, ultimately fusing with them. Crunial apophyses 

 or exostoses, or pedicles, much reduced in height. Disuse 

 of the outgrowths, implying cessation of the irritation 

 upon the basal periost {i. e. between the growth and the 

 cranial bone), explains diminution of the pedicles and 

 their late fusion and the long delayed process of ossification. 

 But the development of the ecchondrotic mass, inherited 

 from the ancesti-al stock, and subsequent ossification still 

 go on, although without a purpose, and they produce 

 organs which, owing to their late fusion with the ciunium, 

 their original home, now appear as osteoderms, although in 

 reality they are pseudo-primitive organs. The integument 

 remains hairy, except on the top where the epidei-m 

 proliferates and cornifies a little. Example, the Giraffe. 

 (Text-fig. 25, II h.) 



II c. Apparent loss of all these armaments, the last remnants 

 being frontal bosses: Okapi. (Text-fig. 25, lie, p. 216.) 



It is worth noting that, while the females of Sivatherium and 

 Samotherium &TQ,hj geneva! consent, not credited with "antlers," 

 the Girafie makes an exception in this respect. This fits in with 

 the view, expressed in this paper, that Giraifes represent a 

 terminus of one line of development. There are some typical 

 Cervince of which both sexes ai'O antlered. The acquisition of 

 secondary sexual oi-gans by the females is mainly a question 

 of time. It is an illustration of simple, direct inheiitance fi-om 

 the other sex, so common in oi-gans which are connected with 

 sexual activity, e. g. clitoris, mammae, spurs. These things are of 

 not the slightest good to their new possessors, but they do no 

 harm either. They are therefore neglected, i-ather not discovered, 

 by natural selection. 



III. The same initial stage as type II. A long pedicle with a 

 simple broach, covered with haiiy skin, but the epidei'mal 

 portion of this tegumentaiy sheath proliferates, glues the 

 hairs together and embeds them. The hoi'ny sheath 

 is an efiicient protection against injury ; the extei'nal or 

 cutaneous and the internal vascular supply remain, and 

 the simple antler is shed no longer. Immature specimens 

 still show a thickened, burr-like swelling at the junctui'e 

 of the pedicle and antler. We assume that the horn-sheath 

 consisted oi'iginally of an imperfectly welded material still 

 liable to fraying, until it became effective enough to pie- 

 vent any necrosis and subsequent shedding cf the antler, 

 which thereby becomes an os coi'nu» So long as the hair 

 preponderates in the deeper strata, the shedding and 



15* 



