Feather development grows, its spathe, which is where the rachis and vanes attach, continues to form. When spathe is finished developing, the calamus begins to form within the base of the spathe. The calamus is the quill of the feather, which is the bottom portion that stays mainly within the pulp cavity. From there, the feather is fully developed and will remain as such until molting occurs, causing it to fall off. Feathers fall off during molting, which occurs in the at different times through the year depending on the type of bird. Birds can molt for seasonal, reproductive and many other
Calamus (poems) This cluster of poems contains a number of images and motifs that are repeated throughout. The most important is probably the Calamus root itself. "Acorus calamus" or Sweet Flag is a marsh-growing plant similar to a cat-tail. Whitman continues through this one of the central images of "Leaves of Grass"--Calamus is treated as a larger example of the grass that he writes of elsewhere. Some scholars have pointed out, as reasons for Whitman's choice, the phallic shape of what Whitman calls the "pink-tinged roots" of Calamus, its mythological association with failed male same-sex love and with writing (see Kalamos), and