In earlier conceptions of kidney biology, the nephrotome was a section of the mesoderm that gives rise to the pronephros and eventually to the rest of the kidney. Older texts describe the pronephros as forming through the fusion of multiple nephrotomes.Modern visualization methods, such as scanning electron microscopy, in situ hybridization, and confocal microscopy, combined with the simple approach of peeling off the epidermis to see the forming kidney, have shown that this is not the case.