The Inheritance of Acquired Characteristics.--The belief in the inheritance of acquired characteristics was generally accepted up to the middle of the nineteenth century, but the reaction against it started by Galton and others has assumed great proportions. Discussions in this line have been carried on extensively, and frequently in the spirit of great partizanship. These discussions cluster very much about the name and the work of Weismann, the man who has consistently stood against the idea of acquired characteristics. More in reference to this phase of the question is given in the chapter dealing with Weismann's theory of evolution (see p. 398). Wherever the truth may lie, the discussions regarding the inheritance of acquired characteristics provoked by Weismann's theoretical considerations, have resulted in stimulating experiment and research, and have, therefore, been beneficial to the advance of science. The Application of Statistical Methods and Experiments to the Ideas of Heredity. Mendel.--This feature of investigating questions of heredity is of growing importance. The first to complete experiments and to investigate heredity to any purpose was the Austrian monk Mendel (1822-1884) (Fig. 95), the abbot of a monastery at Brünn. In his garden he made many experiments upon the inheritance, particularly in peas, of color and of form; and through these experiments he demonstrated a law of inheritance which bids fair to be one of the great biological discoveries of the nineteenth century. He published his papers in 1866 and 1867, but since the minds of naturalists at that time were very much occupied with the questions of organic evolution, raised through the publications of Darwin, the ideas of Mendel attracted very little attention. The principles that he established were re-discovered in 1900 by De Vries and other botanists, and thus naturalists were led to look up the work of Mendel. [Illustration: Fig. 95.--Gregor Mendel, 1822-1884. Permission of Professor Bateson.]