Besides them a single plant was seen to bear only peloric flowers; it produced racemes on several stems and their branches. All were peloric without exception. I kept it through the winter, taking care to preserve a complete isolation of its roots. The other plants were wholly destroyed. Such annihilation must include both the stems and roots and the latter of course requires considerable labor. The following year, however, gave proof of the success of the operation, since my plant bloomed luxuriously for the second time and remained true to the type of the first year, producing peloric flowers exclusively. Here we have the first experimental mutation of a normal into a peloric race. Two facts were clear and simple. The ancestry was known for over a period of four generations, living under the ordinary care and conditions of an experimental garden, isolated from other toad-flaxes, but freely fertilized by bees or at times by myself. This ancestry was quite constant as to [474] the peloric peculiarity, remaining true to the wild type as it occurs everywhere in my country, and showing in no respect any tendency to the production of a new variety. The mutation took place at once. It was a sudden leap from the normal plants with very rare peloric flowers to a type exclusively peloric. No intermediate steps were observed. The parents themselves had borne thousands of flowers during two summers, and these were inspected nearly every day, in the hope of finding some pelories and of saving their seed separately. Only one such flower was seen. If there had been more, say a few in every hundred flowers, it might be allowable to consider them as previous stages, showing a preparation of the impending change. But nothing of this kind was observed. There was simply no visible preparation for the sudden leap. This leap, on the other hand, was full and complete. No reminiscence of the former condition remained. Not a single flower on the mutated plant reverted to the previous type. All were thoroughly affected by the new attribute, and showed the abnormally augmented number of spurs, the tubular structure of the corolla and the round and narrow entrance of its throat. The whole plant departed absolutely from the old type of its progenitors. [475] Three ways were open to continue my experiment. The first was indicated by the abundant harvest from the parent-plants of the mutation. It seemed possible to compare the numerical proportion of the mutated seeds with those of normal plants. In order to ascertain this proportion I sowed the greatest part of my 10 cu. cm. of seed and planted some 2,000 young plants in little pots with well-manured soil. I got some 1,750 flowering plants and observed among them 16 wholly peloric individuals. The numerical proportion of the mutation was therefore in this instance to be calculated equal to about 1% of the whole crop.