Birds
In birds with webbed feet, retia mirabilia in the legs and feet transfer heat from the outgoing (hot) blood in the arteries to the incoming (cold) blood in the veins. The effect of this biological heat exchanger is that the internal temperature of the feet is much closer to the ambient temperature, thus reducing heat loss. Penguins have them also in the flippers and nasal passages.
Read more about this topic: Rete Mirabile
Famous quotes containing the word birds:
“It is not a piece of fine feminine Spitalfields silk—but is of the horrible texture of a fabric that should be woven of ships’ cables & hausers. A Polar wind blows through it, & birds of prey hover over it. Warn all gentle fastidious people from so much as peeping into the book—on risk of a lumbago & sciatics.”
—Herman Melville (1819–1891)
“When you have shot one bird flying you have shot all birds flying. They are all different and they fly in different ways but the sensation is the same and the last one is as good as the first.”
—Ernest Hemingway (1899–1961)
“May! Be thou never graced with birds that sing,
Nor Flora’s pride!
In thee all flowers and roses spring,
Mine only died.”
—William Browne (1591–1643)