68 



The Irish Naturalist. 



June. 



BELFAST NATURALISTS' FIELD CLUB. 



March 15. — The President (S. A. Bennett, B.A.) in the chair. Canon 

 VV. P. Carmody lectured on " Lisburn in the Olden Days," tracing the 

 town's history from the early seventeenth century. The President, 

 |. S. Killen, R. S. Lepper, M.A., and the Secretary took part in the 

 subsequent discussion. 



REVIEWS. 



THE ANTLERS OF DEER. 



The Growth and Shedding of the Antler of the Deer. The Histological 



Phenomena and their Relation to the Growth of Bone. By Sir 

 William Macewen, F.R.S. Glasgow : MacLehose, Jackson and Co. 

 1920. Pp. xviii. and no. 109 photograph figures. Price los. 6d. 

 net. 



This monograph contains a detailed account of the author's observa- 

 tions of the processes attending the growth and shedding of the antlers 

 in the Cervidae. The observations have an important bearing upon the 

 general question of the growth of bone, and tend to support the author's 

 recently published work.^ 



The antlers of stags are among the most remarkable of the structures 

 known as secondary sexual characters, being found, as is well known, 

 only in the male (except in the Reindeer). The antler arises from a base 

 or pedicle which persists from year to year. At the commencement of 

 growth, this pedicle becomes very highly vascular, and a cap of cartilage 

 is formed on its extremity. This cap commences to ossify rapidly and 

 continues to reproduce cartilage distally as its proximal region is con- 

 verted into bone — a process analogous to the primary diaphyseal ossifi- 

 cation of a mammalian long bone. 



Both antler and " velvet " are highly vascular, and the shedding 

 of th^. antler is a result of withdrawal of the blood supply. This becomes 

 effected in the velvet by compression of the vessels through proliferation 

 of bone at the base of the antler forming a corona which stretches and may 

 break the skin. The dead velvet is rubbed off, leaving the bone naked. 

 The same proliferation of osseous tissue cDmpresses and occlude; the 

 nutrient vessels of the bony antler, and it too becomes a dead structure. 

 Resorption of bone at the base of the antler takes place pari passu and 

 a layer of granulation tissue is laid down between the antler and the 

 pedicle. At this " absciss layer " separation of the antler eventually 



1 W. Macewen, " Growth of Bone." Glasgow, 191 2. 



