THE METHODS AND 



closed to the physicist or the astronomer; 

 for the glory of the celestial is one and the 

 glory of the terrestrial is another. But I will 

 say that for once to the man of ordinary 

 power who cannot venture into those heights 

 beyond, Mendel's clue has shown the way into 

 a realm of nature which for surprising novelty 

 and adventure is hardly to be excelled. 



It is no hyperbolical figure that I use 

 when I speak of Mendelian discovery leading 

 us into a new w r orld, the very existence of 

 which was unsuspected before. 



The road thither is simple and easy to 

 follow. We start from a common fact, 

 familiar to everyone, that all the ordinary 

 animals and plants began their individual 

 life by the union of two cells, the one male, 

 the other female. Those cells are known as 

 germ-cells or gametes, that is to say, " marry- 

 ing" cells. 



