The Origin of Vertebrates

Abstract

TWENTY years ago the author of this interesting book was led by his studies on the innervation of the heart to make a comparison between the central nervous system in vertebrates and that in appendiculate invertebrates. This led him to a highly original theory of the derivation of vertebrates from an arthropod stock, and the researches of twenty years have strengthened his confidence in this conclusion. Encouraged by what Huxley wrote to him in 1889, “There is nothing so useful in science as one of those earthquake hypotheses, which oblige one to face the possibility that the solidest-looking structures may collapse,” Dr. Gaskell has published paper after paper in support of the view that the infundibulum may represent the old œsophagus, the ventricles of the brain the old cephalic stomach, the canal of the spinal cord the long straight intestine, the cranial segmental nerves the infra-œsophageal ganglia, the cerebral hemispheres and optic and olfactory nerves the supra-œsophageal ganglia, and the spinal cord the ventral chain of ganglia.

The Origin of Vertebrates.

By Dr. Walter Holbrook Gaskell Pp. iv+537; 168 figures (London: Longmans, Green and Co., 1908.) Price 21s. net.