plumulaceous

plumulaceous

1. Feathers can have a pennaceous vane and a plumulaceous base.

单一支羽毛也可以由顶端为正羽、基部为绒羽组合而成。

2. Likewise, a plumulaceous tuft of barbs evolved before the pennaceous feather with a rachis because the rachis is formed by the fusion of barb ridges.

同样的，绒羽的羽枝簇比拥有羽轴的正羽更早演化出来，因为羽轴是由羽枝脊接合而成。

3. In a plumulaceous feather, barb ridges grow straight without any helical movement.

在绒羽上，羽枝脊则直直生长，不做螺旋形移动。