Pin feather protective peripheral sheath, longitudinal barb ridges, and growth plates. Over time these barb ridges lengthen helically, branch to create barbs and barbules, and fuse to form the rachis or central shaft. Moreover, the barb plate further differentiate into hooklets and cilia, while the marginal and axial plate die to form the intervening space within the feather structure. During moulting, a bird may get careless and begin to chew at its feathers and might accidentally damage a blood feather. To prevent this, it is necessary that the bird is given chewing toys so that it does not chew at its own
Calamus (poems) sequence as written celebrates many aspects of "comradeship" or "adhesive love," Whitman's term, borrowed from phrenology to describe male same-sex attraction. This attraction is presented in its political, spiritual, metaphysical, and personal phases—Whitman offering it as the backbone of future nations, the root of religious sentiments, the solution to the big questions of life, and as a source of personal anguish and joy. The 1860 edition contains three poems that Whitman would later edit out of the sequence, including the very personal Calamus 8, "Long I thought that knowledge alone would suffice me," and Calamus 9, "Hours continuing long, sore