Rachis Rachis Rachis is a biological term for a main axis or "shaft" (from the Greek "ράχις, backbone, spine"). In vertebrates a "rachis" can refer to the series of articulated vertebrae, which encase the spinal cord. In this case the "rachis" usually forms the supporting axis of the body and is then called the spine or vertebral column. "Rachis" can also mean the central shaft of pennaceous feathers. In the gonad of the invertebrate nematode "C. elegans", a "rachis" is the central cell-free core or axis of the gonadal arm of both adult males and hermaphrodites where the germ cells have
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