the "organization and generation of voluntary movement". in 1941, cécile and oskar vogt simplified the nomenclature by proposing the term striatum for all elements in the basal ganglia built with striatal elements: the caudate nucleus, the putamen, and the fundus striati, which is the ventral part linking the two preceding together ventrally to the inferior part of the internal capsule. the term neostriatum was forged by comparative anatomists comparing the subcortical structures between vertebrates, because it was thought to be a phylogenetically newer section of the corpus striatum. the term is still used by some sources, including medical subject headings. other animals in birds the term used was the paleostriatum augmentatum, and in the new avian terminology listing (as of 2002) for neostriatum this has been changed to the nidopallium. in non-primate species, the islands of calleja are included in the ventral striatum.