A feather is a cornea structure that grows in the body of a bird . It consists of a tube (he canon or quill ) which is embedded in the skin and of a axis that stands out, which has chins .
The feathers are appendages of the integumentary system , like the horns or the hairs in other species. These formations fulfill several functions: they protect against the cold, they are insulating, they are used for camouflage, they are used during courtship and they contribute to flight, for example.
The set of an animal's feathers is called plumage . Although each pen, at the individual level, is very light, the plumage can weigh up to three times more than the skeleton .
It is important to mention that birds change feathers through a process known as change . Since the feathers deteriorate due to the presence of parasites, frictions and other causes, the specimen is sequentially detached from a part or all of them and replaces them with new ones that grow in them. follicles .
In ancient times, the feathers of the largest birds were used to to write . When introducing the calamus in a inkwell , the ink entered the hollow tube and then flowed through capillarity .
By extension, today various pen is called writing instruments , as the fountain pen (pen ) and the atomic pen (pen or birome ). There is also talk of a pen to refer to the ability or style to write or as synonym of writer : “This author is recognized for his satirical and sharp pen”, “Mario Vargas Llosa is among the best feathers in the world”, "The most promising feathers of the continent will meet in a new literary festival".