title: [Reciprocal homology of the preotic mesodermal segments of representatives of different classes of vertebrates].
abstract: The data of the literature and those of the author on the origin of preotic mesodermal segments are discussed. Only in Cyclostomata all preotic segments are formed from the wall of archenteron and are larval segments. In all the gnathos tomata, the primary gastral segments are substituted, to different degrees, by postlarval peristonal mesoderm. The preotic mesomeres of Cyclostomata are homologous to II--IV mesomeres of Branchiostoma lanceolata. The anterior cephalic cavity and the premandibular segment of the elasmobranchia are homologous to I and II segments of Branchiostoma lanceolata. The mandibular mesoderm of the elasmobranchia includes the gastral mesoderm (homologous to III and some subsequent segments of Brachiostoma lanceolata) and peristomal mesoderm. The mandibular mesoderm in higher vertebrates has the same composition, but their anterior larval segments disappear and are substituted by gastral part of the mandibular mesoderm.
mesh_terms: D000663:Amphibians / Q000196:embryology; D000818:Animals; D005399:Fishes / Q000196:embryology; D006257:Head / Q000196:embryology*; D008322:Mammals / Q000196:embryology; D008648:Mesoderm; D010802:Phylogeny; D012104:Reptiles / Q000196:embryology; D014714:Vertebrates / Q000196:embryology*
vernacular_title: O vzaimnoĭ gomologii preoticheskikh mezodermal'nykh segmentov u predstaviteleĭ razlichnykh klassov pozvonochnykh.