The American Naturalist, Vol. 41, No. 485 (May, 1907), pp. 287-302 (16 pages) ...
THIN-WALLED expansions of the tracheæ known as air sacs occur in those insects which have well-developed powers of flight. Misconception as to the function of these structures is common. They have ...
The human middle ear—which houses three tiny, vibrating bones—is key to transporting sound vibrations into the inner ear, where they become nerve impulses that allow us to hear. Embryonic and fossil ...
Some results have been hidden because they may be inaccessible to you
Show inaccessible results
Feedback