primitive node n.
A knotlike thickening at the anterior end of the primitive streak of the blastoderm at the point of origin of the embryonic head. Also called Hensen's node, primitive knot.
:10
:09
:08
:07
:06
:05
:04
:03
:02
:01
| the offspring of a zebra and a donkey. |
| an arrangement of five objects, as trees, in a square or rectangle, one at each corner and one in the middle. |