HYBRIDS OF THE GENUS EPILOBIUM 



R. HOLDEN 



Newnham College 



That hybridism and sterility are closely related has 

 been long recognized in a general way, but it is only 

 within the last few years that a systematic and com- 

 prehensive investigation, at least of the plant kingdom, 



has been attempted. Professor Jeffrey and his students, 1 

 working on the flora of eastern North America, have 



1 Jeffrey, E. C, « < The Mutation Myth, ' » Science, N. S., 39 : 488-491, 1914 ; 

 "Spore Conditions in Hybrids and the Mutation Hypothesis of De Vries," 

 Sot. Gaz., Vol. LVIII, No. 4, Oct., 1914; "Some Fundamental Morpholog- 

 ical Objections to the Mutation Theory of De Vries," Amer. Nat., 1915; 

 Holden, E., "Anatomy as a Means of Diagnosis of Spontaneous Plant 

 Hybrids," Science, N. S.,38: 932-933, 1913; "Anatomy of a Hybrid Equise- 

 tmn," Amer. Jour. c f Bot., May, 1915. 



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