356 



least they are not obligatory apogainous. The constancy of liis new 

 forms in the F, might find their explanation in apoganiy. The 

 intermediate hybrid formation in the F, and the singular appearance 

 of the F, on the other hand, are not explained, and in respect to 

 this a special theory would have to be applied to explain the sudden 

 occurrence of apoganiy. 



Utrecht, March 1923. Botanical Laboratory. 



