242 



The Journal of Heredity 



ing power, projected efficiency, or the 

 power of the individual plant or animal 

 to beget valuable progeny, has come 

 forward as a central idea in plant and 

 animal breeding. Careful breeders arc 

 searching each species for the occasional, 

 the phenomenal individual — when that 

 one in many thousands is found, all the 

 rest are discarded. This individual of 

 superior blood is then multiplied and 

 sent to the growers to take the place 

 of their half-civilized kinds, and thus 

 these varieties are superseded by the 

 improved kind. This is the method of 

 improving plants and animals by simple 

 selection. 



Breeders have worked out a yet more 

 radical method of producing improved 

 varieties, the method of crossing or 

 hybridization, followed by selection. 

 Once those rare forms with heredity 

 strongest in the lines in which improve- 

 ment is desired are secured, new and 

 more pronounced varieties are created 

 by bringing together from widely sep- 

 arated sources, those of the same 

 variety, and crossing or hybridizing 

 them. The resulting progeny diverge, 

 or vary, more widely than the progeny 

 of forms more closely related. The 

 exceptional individuals among these are 

 searched out and tested, in the hope of 

 securing an unusual or phenomenal 

 individual of much stronger breeding 

 ability than any foimd in either of the 

 stocks used as parents of the cross. 

 Thus is created an occasional plant or 

 animal which combines the best in each 

 ])arent stock and has the rare power of 

 projecting this new combination of 

 values into its progeny. To illustrate. 

 Dr. William Saunders, of Canada, by 

 crossing the two varieties of wheat 

 known as Fife and Lagoda, produced 

 Preston wheat, more valuable than 

 either of its parents; Webber and 

 Swingle, by crossing the sweet oranges 

 with their wild relatives, produced 

 vakiable new species called citranges 

 and tangelos; and Burbank, by hyl)ri(l- 

 izing the l)lack walnut and the English 

 walnut produced hybrid walnuts of 

 great value. 



CHANCE FOR PRACTICAL MAN. 



In the case of nvtmerous species of 

 plants, as wheat, flax, carnations and 



sugar beets, scientific breeders have 

 already devised effective plans for 

 ferreting out individuals with rare 

 breeding ability along desired lines, and 

 for thus creating new types or improv- 

 ing existing forms by using the subtle 

 forces of heredity. 



Such results are not beyond the 

 practical breeder, as the history of 

 countless varieties attests. In the 

 middle of the last century, in France, 

 Louis Vilmorin set out to increase the 

 value of field beets as a forage crop. 

 With strong faith in the unity of Nature, 

 and the underlying principles of organic 

 development, he seized upon some of 

 the methods already in use in the pro- 

 duction of blooded live stock, and 

 adapted them to the production of 

 "blooded" beets. This was a great 

 departure in plant-breeding, and this 

 method, elaborated and adapted by 

 modem breeders, is one of fundamental 

 importance in the creation of new 

 types or the improvement of existing 

 forms of life. \'ilmorin's work with 

 beets resulted in raising the sugar con- 

 tent of the sap from seven per cent, to 

 15 per cent. This change in the heredity 

 of an humble plant was the basis of a 

 new industry in France and in other 

 Eiiropean countries — the beet-sugar 

 industr}' — and one which has now 

 become thoroughly established in this 

 country. The potency of that subtle 

 character in Vilmorin 's selected beet 

 ]3lants, chosen for their peculiar power 

 to increase the sugar in the sap of their 

 progeny, has added millions to the 

 wealth of the world. 



There is no lack of utiUty and direct 

 application in the study of genetics. If 

 we want to raise mangels that will not 

 run to seed, or to produce a cow that 

 will give more milk in less time, or milk 

 with more butter and less water, we 

 can turn to genetics with every hope 

 that something can be done in these 

 directions. 



But the science of genetics is con- 

 cerned with another field to which I 

 have but briefly alluded — the field of 

 eugenics, the improvement of the human 

 stock, luigenics is the appHcation, to 

 the human race, of the principles about 

 which I have been speaking. This 

 subject will be so well covered in the 



