Page:The Effect of Research in Genetics on the Art of Breeding (1912).djvu/3



knowledge of breeding has advanced so rapidly in recent years that few of us realize the great change that has taken place in our understanding of the fundamental principles, and the effect that this change has had on the methods of practical breeding which we advocate. I had the good fortune to begin my studies and experiments in breeding in 1890, ten years before the rediscovery of Mendel’s now famous principles of heredity, or the publication of de Vries’s mutation theory. I have thus had the opportunity to follow this change through all its ramifications. From a condition of ignorance and largely of chaos, where all advance was taken as a lucky chance, we have developed to a position where practically each step may be taken intelligently. True, we touch the limits of knowledge on every hand and many of the most fundamental problems still remain unsolved, yet our understanding to-day, which enables us to analyze a plant into its component parts or characters, and then in turn by synthesis to build up a new structure by the combination of different characters into a new race or variety, is to our former understanding as light to darkness. The knowledge of breeding has developed into the science of genetics, and is fast assuming through the orderly presentation and classification of facts, the form of an exact science. Yet with all this advance in our understanding, the methods of breeding that can be recommended for the use of practical breeders have changed but little in the last twenty years, the greatest change being primarily in the greater surety with which we now make recommendations. It is the speaker’s purpose in this address to emphasize certain salient features of the advance that has been achieved, and point out what he conceives to be some of the most important problems awaiting solution.

Twenty years ago our understanding of the principles of breeding was derived largely from Knight’s physiological papers and Darwin’s “Origin of Species” and “Plants and Animals under Domestication.” Verlot’s admirable pamphlet “On the Production and Fixation of Varieties of Ornamental Plants” gave a general outline of the best methods then followed, and we derived our knowledge of the use of hybrids largely from Focke’s excellent text, “Die Pflanzenmischlinge,” published in 1880, and the work of the French experimenter Naudin.

At that time breeders clearly understood the fact that hybrids segregated in the second generation and gave new combinations of characters, and the suggestion was even then present in the minds of scientific