xv MAN 165 



as well as by the numerous cases of able families 

 brought together by Galton and others. But when 

 we come to inquire more precisely what it is that is 

 transmitted we are baffled. A distinguished son 

 follows in the footsteps of a distinguished father. Is 

 this due to the inheritance of a particular mental apti- 

 tude, or is it an instance of general mental ability 

 displayed in a field rendered attractive by early 

 association ? We have at present very little definite 

 evidence for supposing that what appear to be 

 special forms of ability may be due to specific 

 factors. Hurst, indeed, has brought forward some 

 facts which suggest that musical sense sometimes 

 behaves as a recessive character, and it is likely 

 that the study of some clean-cut faculty such as the 

 mathematical one would yield interesting results. 



The analysis of mental characters will no doubt 

 be very difficult, and possibly the best line of attack 

 is to search for cases where they are associated with 

 some physical feature such as pigmentation. If an 

 association of this kind be found, and the pigmenta- 

 tion factors be determined, it is evident that we 

 should thereby obtain an insight into the nature of 

 the units upon which mental conditions depend. 

 Nor must it be forgotten that mental qualities, such 

 as quickness, generosity, instability, etc. qualities 

 which we are accustomed to regard as convenient 

 units in classifying the different minds with which 

 we are daily brought into. contact are not neces- 

 sarily qualities that correspond to heritable units. 

 Effective mental ability is largely a matter of tem- 

 perament, and this in turn is quite possibly dependent 

 upon the various secretions produced by the different 



