In essence, all feathers are variations on a tube produced by proliferating epidermis with the nourishing dermal pulp in the center.

 
  • 基本上,所有的羽毛都来自一根管子的各种变化,这根管子由表皮增生而来,其中央则是位于皮肤上负责提供养份的羽髓。
今日热词
目录 附录 查词历史