gill-arches

He makes the retrograde step of admitting only three aortic arches, and he is not inclined to consider the three visceral arches as equivalent to the gill-arches of fish -- in his opinion they have more analogy with ribs, though differing somewhat from ribs in their later modifications.

Form and Function A Contribution to the History of Animal Morphology

Following up his discovery of gill-slits and arches in the embryos of birds and mammals, Rathke in two papers of 1832 [199] and 1833 [200] worked out the detailed homologies of the gill-arches in the higher

Form and Function A Contribution to the History of Animal Morphology

Between these two arches he found an opening, just as between two gill-arches a gill-slit.

Form and Function A Contribution to the History of Animal Morphology

He did not, however, let this distinction hinder him from asserting the substantial homology of all the gill-arches _inter se_, the first two included.

Form and Function A Contribution to the History of Animal Morphology

But Rathke could not altogether shake himself free from the transcendental notion of the homology of jaws with ribs, and this led him to draw a certain distinction between the first two and the remaining gill-arches, by which the homology of the former with the ribs was asserted and the homology of the latter denied.

Form and Function A Contribution to the History of Animal Morphology

The other, "true," gill-arches appeared to him to be formed in the mucous layer, in the lining of the alimentary canal.

Form and Function A Contribution to the History of Animal Morphology

Examples of the second fact -- that individuals of higher classes or orders in former states of their embryonic development represent an organization which corresponds to the full-grown individuals of the lower classes -- are: the tail of the human embryo, the gill-arches of the embryos of reptilia, of birds, of mammalia, and of man.

The Theories of Darwin and Their Relation to Philosophy, Religion, and Morality Rudolf Schmid

He listened attentively to my brief rehearsal of the structure of parts whose names were still unknown to me: the fringed gill-arches and movable operculum; the pores of the head, fleshy lips and lidless eyes; the lateral line, the spinous fins and forked tail; the compressed and arched body.

Louis Agassiz as a Teacher; illustrative extracts on his method of instruction Lane Cooper

He discovered also three pairs of aortic arches in close relation with the gill-arches, so close indeed, that he did not hesitate to call them gill-arteries, and to recognise their resemblance with the aortic arches of fish.

Form and Function A Contribution to the History of Animal Morphology

He derives gill-slits from segmental organs, fins and limbs from gills, ribs from gill-arches, and so on, instead of admitting that these organs might quite as well have arisen independently.

Form and Function A Contribution to the History of Animal Morphology