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Hamburger and Hamilton Stage 27

HH27 (5-5.5 days).
Contour of digital plate angular in region of first digit.
Digits 1, 2, 3 separated by grooves.
Grooves between toes distinct on outer and inner surfaces of toe plate.
First toe projects over tibial part at an obtuse angle.
Tip of third toe not yet pointed.
Mandibular process has broadened ventrally and grown forward.
'a' and 'b' project over surface.
'd' and 'e' flat.
'b' and 'e' close to fusion, but separating line still distinct.
The 'collar' ('f') has broadened and rises above the surface.
Groove between 'c' and 'f' has widened.
Beak: barely recognizable.


  1. TXT - Text Format
    The ABSTRACT ONTOLOGY (NOT Staged/Timed) with all pathways to child nodes materialised, in Plain Text only, as a Tree Report.

  2. OBO - OBO Format
    The ABSTRACT ONTOLOGY (NOT Staged/Timed) in OBO Flat File Format, version 1.2, available for viewing/editing using OBO-Edit.


  1. H. Eyal-Giladi and S. Kochav
    From cleavage to primitive streak formation: A complementary normal table and a new look at the first stages of the development of the chick : I. General morphology
    Developmental Biology, Volume 49, Issue 2, April 1976, Pages 321-337

  2. V. Hamburger and H.L. Hamilton
    A series of normal stages in the development of the chick embryo
    Journal of Morphology, 1951, Volume 88, Pages 49-92 (reprinted in Developmental Dynamics, December 1992, Volume 195, Issue 4, pages 231-72)

  3. R. Bellairs and M. Osmond
    The Atlas of Chick Development
    Academic Press, ISBN 0-12-084790-6, 1998

  4. C.D. Stern and P.W.H. Holland (Ed.s)
    Essential Developmental Biology: A Practical Approach
    Oxford University Press, ISBN 0-19-963423-8, 1993

  5. M.A.J. Selleck and C.D. Stern
    Fate mapping and cell lineage analysis of Hensen's node in the chick embryo
    Development, Volume 112, Pages 615-626, 1991