The unexpected results from an investigation into hereditary congenital anorectal malformations of pig embryos have demonstrated the weakness of earlier interpretations and constructions and underlined the need for a new inquiry into the normal development of the area in human embryos. It demonstrated that although data from malformations may offer extra information about the normal development of the area, great care has to be taken in using that information for the reconstruction of its normal development which should be firmly based on the observation of the evolving microscopic anatomy of...

When Budge in the eighth decade of the nineteenth centlll'Y, started his investigations into the origin and development of the lymphatic system, he probably did not expect that these would be the starting-point for disputes that would continue well into our time. But rather than by his results were these disputes intensified by the controversial conclusions of some papers published by Gulland (1894), Ranvier (1897) and Sala (1900), and above all by some new investigations by Sabin (1902-1913) and Huntington (1908-1914) during the first decades of the twentieth century. The most important...