288 



THE THEORY OF THE GENE 



one miglit anticipate that identical conditions would tend 

 to bring each toward a neutral or intermediate condition 

 or one only toward the other. In fact, something like this 

 seems to take place, for on a carpellate plant stamens 



Fig. 149. 



Female plant, to left, and male plant, to right, of hemp. (After 



Pritchard, in Journal of Heredity,) 



appear; conversely, on a staminate plant, pistils may 

 appear. It is in this sense, in the main, that ' ' sex rever- 

 sal" occurs, although there are other cases still in which 

 a new branch of a pistillate plant may develop only sta- 

 mens, and a new branch of a staminate plant develop only 

 pistils. In these extreme cases "sex reversal" may almost 

 be said to take place in those new parts that develop 



