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 produces 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 unequal spurs, the middle one being of the ordinary length, the two neighboring being shorter, and those standing next to the opposite side of the flower being the shortest of all. This curious remainder of the original, symmetrical structure of the flower seems to have been overlooked hitherto by the investigators of peloric toad-flaxes. The peloric variety of this plant is characterized by its producing only peloric flowers. No single bilabiate or one-spurred flower remains. [466] I once had a lot of nearly a hundred specimens of this fine variety, and it was a most curious and beautiful sight to observe the many thousands of nearly regular flowers blooming at the same time. Some degree of variability was of course present, even in a large measure. The number of the spurs varied between four and six, transgressing these limits in some instances, but never so far as to produce really one-spurred flowers. Comparing this variety with the ordinary type, two ways of passing over from the one to the other might be imagined. One would entail a slow increase of the number of the peloric flowers on each plant, combined with a decrease of the number of the normal ones, the other a sudden leap from one extreme to the other without any intermediate steps. The latter might easily be overlooked in field observations and their failure may not have the value of direct proof. They could never be overlooked, on the other hand, in experimental culture.