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:
“My weary limbs are scarcely stretched for repose, before red dawn peeps into my chamber window, and the birds in the whispering leaves over the roof, apprise me by their sweetest notes that another day of toil awaits me. I arise, the harness is hastily adjusted and once more I step upon the tread-mill.”
—“E. B.,” U.S. farmer. As quoted in Feminine Ingenuity, by Anne L. MacDonald (1992)
“Beauty sat bathing by a spring,
Where fairest shades did hide her;
The winds blew calm, the birds did sing,
The cool streams ran beside her.
My wanton thoughts enticed mine eye
To see what was forbidden:
But better memory said Fie;
So vain desire was chidden—”
—Anthony Munday (1553–1633)
“The kiss of the sun for pardon,
The song of the birds for mirth,—
One is nearer God’s heart in a garden
Than anywhere else on earth.”
—Dorothy Frances Gurney (1858–1932)