Its existence must be regarded as one of the most remarkable results of my researches upon the elasmobranch nervous system.
In this layer nuclei appear, which are equivalent to those in the elasmobranch ovum.
The development of the elasmobranch ovary has recently formed the subject of three investigations.
The development of the elasmobranch excretory system has been mainly studied by Semper and myself.
This difference no doubt depends upon the greater quantity of yolk particles present in the elasmobranch ovum.
It develops in elasmobranch embryos in two sections, one situated in the head, and the other in the trunk.
In the higher types the earlier changes are precisely the same as those in elasmobranch Fishes.
Next in point of time to the paper of Schenk, is my own preliminary account of the development of the elasmobranch Fishes.
One of the most interesting features in the elasmobranch development is the formation of the notochord from the hypoblast.
elasmobranch fishes may be taken as the type to illustrate the mode of formation of the spinal nerves.
Any of numerous cartilaginous fishes of the subclass Elasmobranchii, having five to seven gill slits on each side, dermal denticles for scales, and a small respiratory opening (spiracle) behind each eye. The pectoral fins of elasmobranchs are often greatly enlarged. Elasmobranchs include the sharks, rays, and skates.