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
Lattice of subgroups lattice of subgroups can sometimes be used to infer information about the original group, an idea that goes back to the work of . For instance, as Ore proved, a group is locally cyclic if and only if its lattice of subgroups is distributive. If additionally the lattice satisfies the ascending chain condition, then the group is cyclic. The groups whose lattice of subgroups is a complemented lattice are called complemented groups , and the groups whose lattice of subgroups are modular lattices are called Iwasawa groups or modular groups . Lattice-theoretic characterizations of this type also exist for solvable