Specimens of Archaeopteryx The end of the feather has an obtuse angle of 110°, while the barbs branch off from the rachis at an angle of around 25°. The barbs branch noticeably into barbules, as in the feathers of modern birds. The base of the feather consists of plumulaceous barbs which are unconnected to one another and result in a down-like appearance. This tuft of down led Griffiths to conclude that "Archaeopteryx" might have been endothermic in that it implies the use of thermal insulation. The feather is clearly asymmetrical, which has been interpreted by many scientists to be a clear indication of
Acorus calamus Karpos, of Zephyrus (the West Wind) and Chloris (Spring). When Karpos drowned in a swimming race, Kalamos also drowned and was transformed into a reed, whose rustling in the wind was interpreted as a sigh of lamentation. The plant was a favorite of Henry David Thoreau (who called it "sweet flag"), and also of Walt Whitman, who added a section called the "Calamus" poems, to the third edition of "Leaves of Grass" (1860). In the poems the calamus is used as a symbol of love, lust, and affection. Lewis Carroll uses the plant in "Through the Looking-Glass" as a symbol