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 can never see Christianity from the catechism:Mfrom the pastures, from a boat in the pond, from amidst the songs of wood- birds we possibly may.”
—Ralph Waldo Emerson (1803–1882)
“I sowed the seeds of love,
It was all in the spring,
In April, May, and June, likwise,
When small birds they do sing.”
—Mrs. Fleetwood Habergham (d. 1703)
“Thou waitest late and com’st alone,
When woods are bare and birds are flown,”
—William Cullen Bryant (1794–1878)