He developed a system of heredity which was similar to Darwin's hypothesis of pangenesis. This contradicted both Darwin's pangenesis and Lamarckian inheritance. Charles Darwin tried unsuccessfully to explain inheritance through a theory of pangenesis. Darwin believed in a mix of blending inheritance and the inheritance of acquired traits (pangenesis). Darwin's own concept of pangenesis implied soft inheritance. Mendel's laws of inheritance eventually supplanted most of Darwin's pangenesis theory. Towards this end, Darwin developed his provisional theory of pangenesis. Conversely, the neo-Lamarckians of the time seized upon pangenesis as evidence to support their case. This led to new ideas on telegony, referred to as pangenesis by Charles Darwin. If correct, this made Darwin's pangenesis wrong and Lamarckian inheritance impossible. One area where Darwin and Gray disagreed was Darwin's theory of pangenesis. If correct, this made Darwin's pangenesis wrong, and Lamarckian inheritance impossible. Darwin advocated a hypothesis of pangenesis in the third edition of "Zoonomia". This made Pangenesis popular among the neo-Lamarckian school of evolutionary thought. De Vries called these units "pangenes" ("Pangens" in German), after Darwin's 1868 pangenesis theory.