Slide showing diagram of 'Diabetes Insipidus'. Slide shows black and white pedigree diagram of 'Diabetes Insipidus'. Title under image reads 'Fig. 16 - Pedigree of diabetes insipidus, showing the effects of low penetrance on the part of the gene. II1 and II4 must have possessed the gene since they produced affected offspring yet they themselves did not exhibit the character.' Late 19th - early 20th century