Brown: Apogamy in Phegopteris polypodioides 33 



kept in the laboratory. The percentage of male prothallia 

 was much higher in cultures on the modified solutions, while 

 on the unmodified solutions female prothallia predominated. 



4. Both monecious and dioecious prothallia occurred in all 

 the cultures, but the percentage of monoecious prothallia was 

 low, even in young cultures on the modified solutions. 



5. Apogamous sporophytes were observed in cultures on 

 Prantl's solution with NH4NO3 omitted. 



6. Apogamous outgrowths and structures intermediate be- 

 tween mere outgrowths and apogamous sporophytes were 

 observed in cultures on the Knop's full nutrient solution. 



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