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Celibacy, unknown among the savages of South Africa and South America. Centipedes. Cephalopoda, absence of secondary sexual characters in. Cephalopterus ornatus. Cephalopterus penduliger. Cerambyx heros, stridulant organ of. Ceratodus, paddle of. Ceratophora aspera, nasal appendages of. Ceratophora Stoddartii, nasal horn of. Cerceris, habits of. Cercocebus aethiops, whiskers, etc., of.
As well expect to find a palæolithic man quietly chipping flints on a Pacific atoll, or to discover the ancestor of all horses on the isolated and crag-encircled summit of Roraima, as to unearth a real live Ceratodus from a modern estuary. In 1870, however, Mr.
The idea that a Ceratodus could still be living, far less that it formed an important link in the development of all the higher animals, could never for a moment have occurred to anybody.
But in most other features they approach nearer to the fishes, and are inferior to the amphibia. Externally they are entirely fish-like. Young ceratodus, shortly after issuing from the egg, magnified ten times. k gill-cover, l liver. Young ceratodus six weeks after issuing from the egg. s spiral fold of gut, b rudimentary belly-fin. In the Dipneusts the head is not marked off from the trunk.
This is confirmed by a number of interesting facts that have lately come to our knowledge in connection with the embryonic development of the Ceratodus and Lepidosiren; they give us important information as to the stem-history of the lower Vertebrates, and therefore of our early ancestors of the paleozoic age.
Ceratodus is particularly interesting on account of the primitive build of its skeleton; the cartilaginous skeleton of its two pairs of fins, for instance, has still the original form of a bi-serial or feathered leaf, and was on that account described by Gegenbaur as a "primitive fin-skeleton." At the same time the gills also are developed as water-breathing organs in all these lung-fishes.
On the other hand, according to the opinion lately advanced by Dr. Gunther, on the paddle of Ceratodus, which is provided with articulated bony rays on both sides of a central chain of bones, there seems no great difficulty in admitting that six or more digits on one side, or on both sides, might reappear through reversion. I am informed by Dr.
When the skeletons of fishes of the Ceratodus type were discovered in the Devonian rocks, it was felt that we had found the fish-ancestor of the land Vertebrates, but a closer anatomical examination has made this doubtful. The Devonian lung-fish has characters which do not seem to lead on to the Amphibia.
He ought rather to come out in the character of a ceratodus or a labyrinthodon. Again, another adult toad crawls into the hollow of a tree, and there hibernates. The bark partially closes over the slit by which he entered, but leaves a little crack by which air can enter freely. The grubs in the bark and other insects supply him from time to time with a frugal repast.
The Ceratodus of certain Queensland rivers has one lung; though, I was told by the experts in Queensland, it is not a "mud-fish," and never lives in dry mud. However, the Protopterus of Africa and the Lepidosiren of South America have two lungs, as well as gills, and can live either in water or, in the dry season, on land.
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