Nerve net Nerve net A nerve net consists of interconnected neurons lacking a brain or any form of cephalization. While organisms with bilateral body symmetry are normally associated with a central nervous system, organisms with radial symmetry are associated with nerve nets. Nerve nets can be found in members of the Cnidaria, Ctenophora, and Echinodermata phyla, all of which are found in marine environments. Nerve nets can provide animals with the ability to sense objects through the use of the sensory neurons within the nerve net. The nerve net is the simplest form of a nervous system found in multicellular organisms. Unlike
Libbie Hyman masterly integration of information." Declining health did not allow her to finish the entire subject. In it she developed her scientific theory that the Phylum Chordata, including all vertebrates, was evolutionarily related to the apparently very different and very much more primitive Echinodermata, such as starfish. This group is now known as the deuterostomes. Her theory was based upon the morphological data of classical embryology, and has since been confirmed by molecular sequence analysis. In addition to her major project, Hyman extensively revised "A Laboratory Manual for Comparative Vertebrate Anatomy" in 1942 into a textbook as well as laboratory manual;