436 The Systematic Value of the New Species. 



LENGTHS OF THE FRUITS OF THREE SPECIES OF OENOTHERA IN MILLI- 

 METERS. 



{O. muricata 1894, the rest in 1893.) 

 Millimeters Larnarckiana Biennis Muricata 



Number 568 356 228 



polycentric, each individual species forming a perfectly 

 definite group. The character of each group is given by 

 the center of greatest frequency, independently of the 

 apparent absence of definite limits. 



