[Reconstruction of the metanephros of a human embryo of 20 millimeters. Study of the origin of the renal artery].

The authors have reconstructed by the Born's method, the uretero-pyelo-calycial system of a 20 mm human embryo, the aortic axis and the branches given off, at a magnification of 400. This reconstruction shows two antero-lateral branches which are the only mesonephrotic arteries persisting at this stage, and two arteries issued from the aorta at the level of the second lumbar arteries; these are undoubtedly the renal arteries; this is supported by their lateral origin formerly observed on a 17 mm embryo and by their termination at the level of the future renal hilum. This renal artery which is directly metanophrotic, weakens certain classical affirmations considering the renal artery as a mesonephrotic artery, secondarily picked up by the metanephros at the end of its migration.