Segmental tubes

Segmental \Seg*men"tal\, a.
   1. Relating to, or being, a segment.
      [1913 Webster]

   2. (Anat. & Zool.)
      (a) Of or pertaining to the segments of animals; as, a
          segmental duct; segmental papillae.
      (b) Of or pertaining to the segmental organs.
          [1913 Webster]

   {Segmental duct} (Anat.), the primitive duct of the embryonic
      excretory organs which gives rise to the Wolffian duct and
      ureter; the pronephric duct.

   {Segmental organs}.
      (a) (Anat.) The embryonic excretory organs of vertebrates,
          consisting primarily of the segmental tubes and
          segmental ducts.
      (b) (Zool.) The tubular excretory organs, a pair of which
          often occur in each of several segments in annelids.
          They serve as renal organs, and often, also, as
          oviducts and sperm ducts. See Illust. under
          {Sipunculacea}.

   {Segmental tubes} (Anat.), the tubes which primarily open
      into the segmental duct, some of which become the urinary
      tubules of the adult.
      [1913 Webster]