232 GENETICS 



yet undergone the careful analysis demanded by 

 modern genetics which deals in unit characters rather 

 than in lump inheritance. 



Musical, literary, or artistic ability, for example, 

 mathematical aptitude and inventive genius, as well 

 as a cheerful disposition or a strong moral sense are 

 probably all gifts that come in the germplasm. 



They may each be developed by exercise or re- 

 pressed by want of opportunity, nevertheless they 

 are fundamentally germinal gifts. 



A genius must be born of potential germplasm. 

 No amount of faithful plodding application can com- 

 pensate for a lack of the divine hereditary spark at 

 the start. 



6. HEREDITARY DEFECTS 



Undesirable hereditary traits are usually defects 

 due to the absence of some character. For instance, 

 albinism, which occurs in several kinds of animals 

 and also in man in one out of every 20,000 individuals 

 (according to Elderton), is due to the absence of pig- 

 ment in the skin, hair and eyes. Albinic individuals 

 have poor eyesight because they are unable to stand 

 strong light, being without protective pigment in the 

 eyes. This peculiarity of albinism behaves as a 

 recessive character both in man and in other animals. 

 An albinic individual may, therefore, marry a normal 

 individual without fear of producing albino children, 

 although the children of such a mating would carry 

 heterozygous germplasm with respect to albinism, 



