Feather development non-nervous. They have a tubular central shaft called the rachis; coming off either side of the rachis are the veins, which have a series of barbs with interlocking connections that are called barbules. The rachis and attached veins make up the spathe. The opposite of the rachis is the calamus, which anchors the feather to the body and is moved by attached dermal muscles. There are many different types of feathers that mostly follow this basic design with few variations based on evolutionary needs. Feathers are sometimes referred to as “elaborate reptile scales” just as birds are sometimes viewed as
Rachis achieved pachytene and are attached to the walls of the gonadal tube. The rachis is filled with cytoplasm. In plants, a "rachis" is the main axis of a compound structure. It can be the main stem of a compound leaf, such as in "Acacia" or ferns, or the main, flower-bearing portion of an inflorescence above a supporting peduncle. A ripe head of wild-type wheat is easily shattered into dispersal units when touched or blown by the wind. A series of layers forms that divides the rachis into dispersal units consisting of a small group of flowers (a single spikelet) attached