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entirely developed inferiority of the mesenchyme, the examination 

 of the other members of the family enables us to follow the 

 development of all the phases of our disease and to observe the 

 precursors of the outbreak. 



Indeed the inferiority of the bloodvessels is not seen exclusively in the 

 presence of haemophily, a congenital defect of the heart shows in what 

 a labile equilibrium the constitution of this organic system is found. 

 Osteopsathyrosis does not yet occur, but the skeleton already shows 

 signs here and there of abnormal design, the rachischisis and the 

 split palate are there to prove it. Blue sclerotics, although less 

 iutensive than in my patients are already found in several 

 individuals, and one of them shows moreover a congenital cornea- 

 abnormality (embryotoxon). 



The catastrophe first take place in the person of my patient and 

 his daughters; what had been threatening for some generations 

 is realised : the mesenchyme shows its insufficient design in an 

 unmistakable inferiority. 



II. The significance of this hypothesis is of for greater general 

 scope than to explain the origin of these abnormalities in my patients. 



In this family we had to do with a hereditary inferiority in 

 design of one of the 4 great groups into which the embryonal cells 

 are differentiated in the very first phase of the development of the 

 germ. It seems to me that it is of great interest for the doctrine of 

 hereditary abnormalities that it is possible that germinal defects 

 exist affecting the individual already at so early a stage, and set 

 their stamp upon him. 



Do such inferiorities of the whole mesenchyme or of the greater 

 part of it occur more? Can they likewise be restricted to the 

 exclusion of the mesenchyme and of the two other germinal layers to 

 one germinal layer? Do they likewise occur hereditarily ? Numerous 

 facts indeed seem to point that way. Innumerable are the questions 

 rising with regard to this hypothesis. It is really a luorking hypothesis. 

 And it seems to me that it is a very important undertaking to 

 examine, guided by this hypothesis, the combinations of hereditary 

 abnormalities in connection with other degenerations in one and 

 the same family. For what is known of these combinations or 

 correlations is, almost without any exception, limited to the mere 

 statement of the facts as such, and a dominant idea, if there was 

 one, in the explanation of these correlations, has not been succesful. 



