. The doctrine of descent and Darwinism. Evolution. LOWEST VERTEBRATE ANIMALS. 2SS direct offspring of the present apes; neither do they infer from these observations on the Ascidian larva that vertebrate animals are descended from the Ascidians. Their accordance much rather forces us to assume an unknown primordial vertebrate family, springing from some branch of the heterogeneous division of the Annulosa. From these diverged on one side the Tes- tacea, who might perhaps be called mischanced vertebrata, and on the other the true vertebrate animals.'" The Amphioxus which lives in the sand
. The doctrine of descent and Darwinism. Evolution. LOWEST VERTEBRATE ANIMALS. 2SS direct offspring of the present apes; neither do they infer from these observations on the Ascidian larva that vertebrate animals are descended from the Ascidians. Their accordance much rather forces us to assume an unknown primordial vertebrate family, springing from some branch of the heterogeneous division of the Annulosa. From these diverged on one side the Tes- tacea, who might perhaps be called mischanced vertebrata, and on the other the true vertebrate animals.'" The Amphioxus which lives in the sand in shallow places on various coasts, and is daily caught by thou- sands at Messina for example, is five or six centimetres in length, and is compressed after the manner of a fish, pointed at both ends, and semi- transparent whilst alive. It pos- sesses no trace of limbs, at the posterior end only a pair of minute membranous margins, the indication of dorsal and caudal fins, and is so simple in its internal structure that it is usually, though inaccurately, termed a fish. Its skeleton is limited to the noto-chord, and some minute cartilaginous rods at the mouth and gills. It has no brain, and, except a small ciliated sac, perhaps to be in- terpreted as an olfactory organ, no sensory apparatus; the heart is tubular. And thus between the lancelet and other true fishes there exists so wide a difference that the possibility remains open that the fishes passed through some other course of development than phases like that of the FIG. 24.—Full-grown Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original Schmidt, Dr. (Eduard Oskar), 1823-1886. New York, Appleton
Size: 1156px × 2162px
Photo credit: © The Book Worm / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookauthorschmidtdreduardoskar1, bookcentury1900, bookdecade1900
