40 . H. LLNDBORG 



On the basis of what has now been said it must be recognized that 

 UcHERMANN's figures agree very well with the values to be theoreti- 

 cally expected. At all events they are far too high to correspond 

 to a dihybrid course of descent. 



Bergh, who has compared the statistics of his own observations 

 with those of Lemcke and Uchermann, finds that the number of 

 children born deaf in the consanguineous marriages amounts to 

 275 out of 1084, a percentage of 25,37. It should perhaps be men- 

 tioned that both Lemcke'S and Uchermanns works were published 

 in the nineties of the last century, consequently in the pre-Mendelian 

 period. * 



From what has now been adduced it is obvious that we must 

 reject Plate's hypothesis that the deaf-mutism resulting from geno- 

 typical causes is a dihybrid factor. On the contrary, there is every 

 probability that the view I advanced in 1912 is the correct one. 

 Accurate genealogical investigations should be able, sooner or later, 

 to prove this exactly. Ebbe Bergh certainly seems to incline to 

 the same opinion, but he has not been quite capable of estimating 

 the value of his own evidence, nor of making a sufficiently careful 

 analysis of the literature in this field of research, and for this reason 

 he has irresolutely avoided expressing any positive opinion on a point 

 of such importance. 



