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:
“We must not make a scarecrow of the law,
Setting it up to fear the birds of prey,
And let it keep one shape, till custom make it
Their perch and not their terror.”
—William Shakespeare (1564–1616)
“... to a poet, the human community is like the community of birds to a bird, singing to each other. Love is one of the reasons we are singing to one another, love of language itself, love of sound, love of singing itself, and love of the other birds.”
—Sharon Olds (b. 1942)
“So near to paradise all pairing ends:
Here loveless birds now flock as winter friends,
Content with bud-inspecting. They presume
To say which buds are leaf and which are bloom.”
—Robert Frost (1874–1963)