air-sacks

Updated: July 6, 2025

Material can be more profitably invested in brain or muscle. Air is carried to all parts of the body by a special system of air-sacks and tubes. This is a very advantageous structure for small animals with an external skeleton.

John Mason Tyler - The Whence and the Whither of Man : A Brief History of His Origin and Development through Conformity to Environment; Being the Morse Lectures of 1895