I will now give the description of my own experiment. Of course this did not give the expected result in the first year. On the contrary, it was only after eight years' work that I had the good fortune of observing the mutation. [469] But as the whole life-history of the preceding generations had been carefully observed and recorded, the exact interpretation of the fact was readily made. My culture commenced in the year 1886. I chose some plants of the normal type with one or two peloric flowers besides the bilabiate majority which I found on a locality in the neighborhood of Hilversum in Holland. I planted the roots in my garden and from them had the first flowering generation in the following summer. From their seeds I grew the second generation in three following years. They flowered profusely and produced in 1889 only one, and in 1890 only two peloric structures. I saved the seeds in 1889 and had in 1890-1891 the third generation. These plants likewise flowered only in the second year, and gave among some thousands of symmetrical blossoms, only one five-spurred flower. I pollinated this flower myself, and it produced abundant fruit with enough seeds for the entire culture in 1892, and they only were sown. Until this year my generations required two years each, owing to the perennial habit of the plants. In this way the prospects of the culture began to decrease, and I proposed to try to heighten my chances by having a new generation yearly. With this intention I sowed the [470] selected seeds in a pan in the glasshouse of my laboratory and planted them out as soon as the young stems had reached a length of some few centimeters. Each seedling was put in a separate pot, in heavily manured soil. The pots were kept under glass until the beginning of June, and the young plants produced during this period a number of secondary stems from the curious hypocotylous buds which are so characteristic of the species. These stems grew rapidly and as soon as they were strong enough, the plants were put into the beds. They all, at least nearly all, some twenty specimens, flowered in the following month. I observed only one peloric flower among the large number present. I took the plant bearing this flower and one more for the culture of the following year, and destroyed all others. These two plants grew on the same spot, and were allowed to fertilize each other by the agency of the bees, but were kept isolated from any other congener. They flowered abundantly, but produced only one-spurred bilabiate flowers during the whole summer. They matured more than 10 cu. cm. of seeds. It is from this pair of plants that my peloric race has sprung. And as they are the ancestors of the first closely observed case of peloric mutation, [471] it seems worth while to give some details regarding their fertilization.