在動物世界中，鹿是唯一能再生完整的身體零部件的哺乳動物。當(dāng)鹿角長到最大尺寸后，骨頭開始變硬，像天鵝絨一樣柔軟的鹿茸開始脫落。一旦鹿茸掉光，就剩下赤裸的骨頭，就可成為角斗中的強(qiáng)大武器。在交配期結(jié)束時，鹿角脫落以保存能量，等到春天來臨，在其頭頂上就能長出一對新的隆起的組織骨結(jié)節(jié)。

Deer shed their antlers annually as apreludeto the regeneration, or re-growth, of new ones.

The entire shedding process takes a mere two to three weeks to complete, and the re-growth phase takes place over the summer. Thedocilemale deer that, with the exception of the male and the female reindeer, solelysportsantlers, sheds them between January and April, after the autumnmatingseasondraws to a close. He can do without antlers at this time, because his need for them in prior months, to attract and to impress females for hisharemof mates, and to fight with his competitors for the females' affections, no longer exists.

The antlers themselves differ from the hollow horns of cattle, in that they comprise solid bone tissue with a honey combed structure.Pedicles, orknobby, skin-coverednubsprotruding from the skull, support the deer's antlers, or points, which range in number from one shaft to eleven branches. The pedicles are a permanent fixture on the deer's forehead, and are the point from which the antlers annually break off.

During the first year the pedicles appear on the young deer's forehead. The following year, the youngster sprouts straight, spike-like shafts, and in the third year, the first branch appears. In successive years, as the deer matures, his antlers lengthen and, in most species, he acquires additional branches. One can actually determine the age of the deer from the number of branches on his antlers, as their number increases with age.

During the growth phase of the bony antlers, they are covered with a sensitive skin referred to as "velvet", which is filled with blood vessels that feed the antlers the vitamins and the minerals necessary to build up the bone, and to promote normal antler growth. Antler growth spans two to four months, after which time the velvet is no longer needed, and a ring, which effectively serves as a shutoff valve, forms at the base of the antlers and cuts off the blood supply to the velvet. As a result, the velvet withers, dries up, and falls off, often assisted by the deer, which rubs his antlers against tree bark. The antler regeneration is complete, and the shedding cycle will resume once mating season in the fall concludes.

prelude: 前奏
docile: 溫順的
sport: 炫耀，賣弄
mating: 交配
draw to a close: 漸近結(jié)束
harem: 一群雌動物
pedicle: 肉莖
knobby: 多節(jié)的
nub: 小塊
velvet: 天鵝絨

（來源：coolquiz.com 英語點津 Annabel 編輯）

我想了解更多趣味百科知識