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Having two modes of embryonic development.

A lack of common possessions, properties, or relationship. Community of embryonic structure reveals community of descent; but dissimilarity of embryonic development does not prove discommunity of descent. Darwin.

See under Embryonic.

Embryonic.

Embryonic; undeveloped. [R.]

An embryonic form having its origin in the invagination or pushing in of the wall of the planula or blastula (the blastosphere) on one side, thus giving rise to a double-walled sac, with one opening or mouth (the blastopore) which leads into the cavity (the archenteron) lined by the inner wall (the hypoblast). See Illu…

The process of invagination, in embryonic development, by which a gastrula is formed.

The primitive cell in certain embryonic forms. Balfour.

ed homoplasy to denote any superinduced correspondence of position and structure in parts embryonically distinct (other writers using the term homoplasmy). Thus, there is homogeny between the fore limb of a mammal and the wing of a bird; but the right and left ventricles of the heart in both are only in homoplasy with…

Developing, in the case of multicellular organisms, from the same embryonic systems into which the secondary unit (gastrula or plant enbryo) differentiates.

in those that are strong on both sides. Bacon. Indifferent tissue (Anat.), the primitive, embryonic, undifferentiated tissue, before conversion into connective, muscular, nervous, or other definite tissue.

The middle one of the three pairs of embryonic renal organs developed in most vertebrates; the Wolffian body.

The most posterior of the three pairs of embryonic renal organs developed in many vertebrates.

Of, pertaining to, or discovered by, Johannes Müller. Müllerian ducts (Anat.), a pair of embryonic ducts which give rise to the genital passages in the female, but disappear in the male. -- Müllerian fibers (Anat.), the sustentacular or connective-tissue fibers which form the framework of the retina.…

ned to become a part of the muscular system; -- applied to structural elements in certain embryonic forms.

One of the embryonic muscular segments arising from the protovertebræ; also, one of the protovertebræ themselves.

of or pertaining to the nose and the front of the head; as, the embryonic nasofrontal process which forms the anterior boundary of the mouth.

An opening at either end of the embryonic neural canal.

An analogous mass of protoplasm in the ovule of a flowering plant; an embryonic vesicle. Goodale.

one tissue; the residue after removal of the mineral matters from bone by dilute acid; in embryonic tissue, the substance in which the mineral salts are deposited to form bone; -- called also ostein. Chemically it is the same as collagen.