Neurobiology. — "A hypothesis concerning the mutual relation 

 between some hereditary abnormalities that occurr combined". 

 By Dr. N. Voorhoevk. (Communicated bj Prof. Dr. I. K. A. 

 Wertheim Salomonson). 



(Communicated in the meeting of May 26, 1917). 



In the following lines I intend : 



1. to explain the grounds on which my hypothesis rests that a 

 hereditary inferiority of the mesenchyme occurs, 



2. to elucidate the significance and the scope of this hypothesis. 



I. I was induced to state this hypothesis in consequence of 

 considerations concerning the results of an examination of three 

 patients, whilst an examination of the family relations afforded strong 

 proofs for the validity of this liypothesis. 



It appeared, that a father and his two daugljters were troubled 

 with blue sclerotics and brittle hones, a combination which, though 

 very rare, has already several times been described, and the heredity 

 of which has been proved. 



The father was moreover suffering from haemophily, an abnormality, 

 which is likewise exceedingly hereditary. 



If we account for the anatomical substratum oï ihe^.e, ohxiOvra^iWÜQQ, 

 then it appears : 



a. that the blue colour of the sclerotics is caused by their 

 congenital excessive thinness; 



b. that the brittle bones which in my cases proved to be the 

 consequence of osteopsathyrosis infantilis, is a consequence of an 

 inferiority of the ossificating elements ; 



c. that so much may be stated with certainty concerning haemo- 

 phily, though its pathogenesis may not yet be perfectly clear, that 

 it is a consequence of an inferiority of blood resp. bloodvessels. 



Consequently there existed in these individuals a hereditary 

 inferiority of 3 systems of oi-gans : sclerotics, skeleton and blood resp. 

 bloodvessels. Their hereditary transmission pointed to an endogenous 

 cause, or in other words, to a defect in design. 



