MENDELISM AND SEX. 



An Address delivered to the Mendel Society, 

 29th March, 1909. 



BY 



C. C. HURST. 



The question of the determination of sex is an old 

 one. It is a problem which has been much debated 

 along various lines of inquiry. Until recently it not 

 only eluded all solution, but gave no promise of 

 solution. 



Recent Mendelian experiments, commenced about 

 the year 1900, had not, however, been very long 

 in operation before the conclusions to which they 

 led afforded clear suggestions that the problem of 

 sex could be investigated by the same methods 

 and with the aid of the same directing principles. 

 Mendelism, in fact, has provided the key by which 

 the question can be accurately and experimentally 

 answered. Much however remains to be done, 

 for the knowledge which we now possess is to be 

 regarded as in the nature of a right beginning rather 

 than as a final solution. 



Until quite recently it was generally believed 

 that external conditions determined the sex of 



