gill-clefts

None the less, if the transition from a gilled tadpole to the adult with lungs means an evolution of amphibia from fishlike ancestors, then the change of a chick embryo with gill-clefts into the fledgling without them is most reasonably interpreted as proof that birds as well as amphibia have had ancestors as simple as fishes.

The Doctrine of Evolution Its Basis and Its Scope Henry Edward Crampton

This is not so, for like the adult fish, the larval tadpole, and the embryo chick, an embryo of a cat or a man is at one time constructed with a series of gill-clefts and with blood-vessels and skeletal supports of fishlike nature that are everywhere associated with gills.

The Doctrine of Evolution Its Basis and Its Scope Henry Edward Crampton

Land Vertebrates, including man, have in their early embryonic life gill-clefts, heart and circulation, and in some respects skeleton and other organs of the type found in fishes, and this can only be explained on the assumption that they are descended from aquatic fish-like ancestors.

Recent Developments in European Thought Various

In gill-bearing animals the closing membranes disappear, and the grooves become complete clefts, the gill-clefts, opening from the pharynx on to the exterior; perforation, however, does not occur in birds or mammals.

I. Embryology. 12. The Branchial Region 1918

When the human embryo is only a quarter of an inch in length, it has gill-clefts and gill-arches in the throat like a fish, and no limbs.

The World's Greatest Books — Volume 15 — Science Various 1909

But these embryonic gill-clefts are not used for respiration and show no trace of gills except in a few embryonic reptiles and birds where their dwindled vestiges have been recently discovered.

The Outline of Science, Vol. 1 (of 4) A Plain Story Simply Told J. Arthur Thomson 1897

It is a suggestive fact that the embryos of all reptiles, birds, and mammals show gill-clefts -- _a tell-tale evidence of their distant aquatic ancestry_.

The Outline of Science, Vol. 1 (of 4) A Plain Story Simply Told J. Arthur Thomson 1897

As to the gill-clefts, they are of no use in higher Vertebrates except that the first becomes the Eustachian tube leading from the ear-passage to the back of the mouth.

The Outline of Science, Vol. 1 (of 4) A Plain Story Simply Told J. Arthur Thomson 1897

At the branchial section of the gut in front the two canals are connected by a number of branches, which rise in arches between the gill-clefts.

The Evolution of Man — Volume 1 Ernst Heinrich Philipp August Haeckel 1876

A week later (or after the twenty-first day) the human embryo has doubled its length; it is now about one-fifth of an inch long, and, when seen from the side, shows the characteristic bend of the back, the swelling of the head-end, the first outline of the three higher sense-organs, and the rudiments of the gill-clefts, which pierce the sides of the neck (Figure 1.179, III).

The Evolution of Man — Volume 1 Ernst Heinrich Philipp August Haeckel 1876