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:
“While he hears in every spring
How the birds do chirp and sing:
Or before the hounds in cry
See the hare go stealing by:
Or along the shallow brook,
Angling with a baited hook,
See the fishes leap and play
In a blessed sunny day:”
—Nicholas Breton (1542–1626)
“I would that we were, my beloved, white birds on the foam of the sea!
We tire of the flame of the meteor, before it can fade and flee;
And the flame of the blue star of twilight, hung low on the rim of the sky,
Has awaked in our hearts, my beloved, a sadness that may not die.”
—William Butler Yeats (1865–1939)
“...here he is, fully alive, and it is hard to picture him fully dead. Death is thirty-three hours away and here we are talking about the brain size of birds and bloodhounds and hunting in the woods. You can only attend to death for so long before the life force sucks you right in again.”
—Helen Prejean (b. 1940)