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Webster 1913 Edition
Water tube
Wa′ter tubeˊ
(wa̤′tẽr tūbˊ)
. 1.
(Zool.)
One of a system of tubular excretory organs having external openings, found in many invertebrates. They are believed to be analogous in function to the kidneys of vertebrates. See Illust. under
Trematodea
, and Sporocyst
.