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
USS Calamus (AOG-25) USS Calamus (AOG-25) USS "Calamus" (AOG-25) was a "Mettawee"-class gasoline tanker acquired by the U.S. Navy for the dangerous task of transporting gasoline to warships in the fleet, and to remote Navy stations. "Calamus" was launched 4 May 1944 by East Coast Shipyard, Inc., Bayonne, New Jersey, under a Maritime Commission contract; sponsored by Mrs. A. H. Moore; transferred to the Navy 7 July 1944; and commissioned the same day, Lieutenant W. Hord, USCGR, in command. "Calamus" sailed from Norfolk, Virginia, 13 September 1944, bound for Pearl Harbor and Ulithi, where she arrived in mid-December and began her work as