Feather These barbules have minute hooks called barbicels for cross-attachment. Down feathers are fluffy because they lack barbicels, so the barbules float free of each other, allowing the down to trap air and provide excellent thermal insulation. At the base of the feather, the rachis expands to form the hollow tubular "calamus" (or quill) which inserts into a follicle in the skin. The basal part of the calamus is without vanes. This part is embedded within the skin follicle and has an opening at the base (proximal umbilicus) and a small opening on the side (distal umbilicus). Hatchling birds of some
Calamus, Iowa a more favorable location in what is now the town of Calamus. The present day location of Calamus, a small village on the Union Pacific Railway, was platted in 1860 by R. S. Dickinson, who owned the land on the north side of the railroad, and Col. Milo Smith, who owned that on the south. James Keith opened the first store here containing a small stock of groceries and accessories, located about where the present day Faith Lutheran Church stands. In 1861, R.S. Dickinson and his son A.L. built the first general store, and opened a large and complete stock