MENDELIAN INHERITANCE IN MAN 365 



Hurst found that the eye with two layers of visible pigment 

 (duplex) is dominant and the eye with one layer of visible 

 pigment (simplex) recessive. Or, putting it in another way, 

 the presence of the brown front layer is dominant to its absence. 

 Practically the same conclusion was reached independently by 

 Professor and Mrs. Davenport. 



The Davenports and Major Hurst have also brought forward 

 some evidence illustrating in typical Caucasians the dominance 

 of dark to fair skins, their segregation in the same family, and the 

 apparent purity of the extracted fair individuals. Hurst also 

 gives evidence that " fiery red " hair behaves as a recessive to 

 brown, and that the musical sense or temperament is also reces- 

 sive. It seems as if an individual is non-musical owing to the 

 presence of an inhibitory factor preventing the expression of the 

 musical temperament which is potentially present in every one 

 (Hurst, 1912). 



It would be interesting to have precise information as to the 

 progeny of Eurasians who intermarry, for here the original 

 hybrids result from the mixture of two very distinct races. 



5. Mendel's Discovery in Relation to Other Conclusions 



Conception of the Organism. A keen critic has pointed out 

 that the Darwinian or Selectionist theory of evolution is obviously 

 a projection on nature of anthropomorphic ideas partly due to the 

 keen competition of the industrial age, partly due to a temporary 

 pressure of over-population, partly due to the process by which 

 mechanical devices, such as spinning and weaving machinery 

 on the one hand and. bicycles on the other, are improved by the 

 addition of one patent after another. Taking the last point, 

 the critic asks if we can seriously believe that organisms have 

 evolved by piecemeal variation and selection of particular parts, 

 comparable to improvements now in the gear, again in the 

 steering, and again in the chain of the bicycle ? Is it not one 



