The development of the centrum of Hypogeophis rostratus (Amphibia, Apoda) with special reference to the notochordal (intravertebral) cartilage

The development of the centrum and the notochordal (intravertebral) cartilage in Hypogeophis is described. The notochordal cartilage is produced in each vertebra by certain areas of the notochordal epithelium and there is no indication of the invasion of the notochordal sheath by mesenchyme cells. The bands of cartilage are of constant occurrence and persist in the adult vertebrae. The vertebrae are autocentral and the centrum is produced (independently of the neural arches) by a tube of circumnotochordal mesenchyme cells.