Microvascular corrosion casts of chicken embryos between four and 19 days after fertilization have been prepared. The developing kidney was investigated with scanning electron microscopy (SEM). The injection technique and resin composition were modified in order to facilitate the complete replication of native blood vascular systems of specimens as small as 15 mm body length. The development of the opisthonephros was followed from near the beginning of its function until a vascular development comparable to the adult situation was reached. Critical point dried glomeruli show the differentiation of the glomerular visceral epithelium (podocytes) from initially epithelioid to highly branched forms. The embryonic kidney (cranial part of the opisthonephros - mesonephros) shows a construction principle resembling amphibians that is entirely different from the definitive excretory organ (caudal part of the opisthonephros - metanephros).
Ditrich, H. and Splechtna, H.
"The Opisthonephric Blood Vascular System of the Chicken Embryo as Studied by Scanning Electron Microscopy of Microvascular Corrosion Casts and Critical Point Dried Preparations,"
Scanning Microscopy: Vol. 3
, Article 19.
Available at: https://digitalcommons.usu.edu/microscopy/vol3/iss2/19