Origin of Peloric Toadflax 465 



stances the desired evidence might easily be 

 gathered. Or, to put it in other words, we must 

 try to arrange things so as to be present at the 

 time when nature produces another of these 

 rare changes. 



There was still another reason for choosing 

 this plant for observational work. The step from 

 the ordinary toad-flax to the peloric form is 

 short, and it appears as if it might be produced 

 by slow conversion. The ordinary species pro- 

 duces from time to time stray peloric flowers. 

 These occur at the base of the raceme, or rarely 

 in the midst of it. In other species they are 

 often seen at the summit. Terminal pelories 

 are usually regular, having five equal spurs. 

 Lateral pelories are generally of zygomorphic 

 structure, though of course in a less degree than 

 the normal bilabiate flowers, but they have un- 

 equal spurs, the middle one being of the ordi- 

 nary length, the two neighboring being shorter, 

 and those standing next to the opposite side of 

 the flower being the shortest of all. This curi- 

 ous remainder of the original symmetrical 

 structure of the flower seems to have been over- 

 looked hitherto by the investigators of peloric 

 toad-flaxes. 



The peloric variety of this plant is character- 

 ized by its producing only peloric flowers. No 

 single bilabiate or one-spurred flower remains. 



