Feather by exposure to emulsifying agents due to human pollution. Feathers can then become waterlogged, causing the bird to sink. It is also very difficult to clean and rescue birds whose feathers have been fouled by oil spills. The feathers of cormorants soak up water and help to reduce buoyancy, thereby allowing the birds to swim submerged. Bristles are stiff, tapering feathers with a large rachis but few barbs. Rictal bristles are found around the eyes and bill. They may serve a similar purpose to eyelashes and vibrissae in mammals. Although there is as yet no clear evidence, it has been
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