At about this time, Hugo de Vries and Carl Erich Correns began similar plant-breeding experiments. But, unlike Bateson, they were familiar with the extensive plant breeding experiments of Gregor Mendel in the 1860s, and they did not cite Bateson's work. Critically, Bateson gave a lecture to the Royal Horticultural Society in July 1899, which was attended by Hugo de Vries, in which he described his investigations into discontinuous variation, his experimental crosses, and the significance of such studies for the understanding of heredity. He urged his colleagues to conduct large-scale, well-designed and statistically analysed experiments of the sort that, although he did not know it, Mendel had already conducted, and which would be "rediscovered" by de Vries and Correns just six months later.