Q.Distinguish between vanes, barbs and barbules.

Step 1. A quill feather's stem has a solid upper portion, the rachis, and it is to this rachis that the flat, blade-like part of the feather is attached.

Step 2. That flat blade-like part as a whole is called the vane, or vexillum; it is made up of many parallel filaments called barbs, which branch off the rachis on either side.

Step 3. Each barb is, in turn, fringed with its own finer processes called barbules, arranged obliquely along the barb. …

Work from the largest structure down: vane (whole blade) is made of barbs (filaments), and barbs are fringed by bar …

• Using 'vane' and 'barb' interchangeably, when the vane is the whole blade and a barb is just one of the many filaments that make it up. …