Gilbert: The Science of Genetics 



241 



this done? These are the ever-present 

 questions which have been worn thread- 

 bare by biologists and evolutionists 

 who have based their so-called argu- 

 ments upon philosophical speculations 

 and have not arrived at these conclu- 

 sions as the result of experimentation. 

 The present tendency of genetics, how- 

 ever, is to base its conclusions upon the 

 results of controlled experimentation 

 only, and the empirical method is being 

 applied to this time-honored contro- 

 versy with the hope of obtaining some- 

 thing tangible and definite. 



To prove experimentally the inheri- 

 tance of acquired characters, suggests 

 Walter, three things are necessary: 

 first, a particular variation must be 

 called forth by a known external cause; 

 second, it must be something new and 

 not merely the awakening of latent 

 qualities; and third, this induced varia- 

 tion must exist and reappear in subse- 

 quent generations after the original 

 exciting cause has been removed. Up 

 to the present the so-called "acquired 

 characters" which seem to be inherited 

 have failed to fulfill all of the require- 

 ments. 



COMMERCIAL VALUE OF GENETICS. 



The thrill of discovery is not dulled 

 by a suspicion that the discovery can 

 be commercially applied. "With rarest 

 exception the discoveries which have 

 formed the basis of physical progress 

 have been made without any thought 

 but for the gratification of curiosity. 

 Of this there are few examples more 

 conspicuous than the work of Gregor 

 Mendel. Untroubled by any itch to 

 make potatoes larger or bread cheaper, 

 he set himself in the quiet of a cloister 

 garden to find out the laws of hybridity, 

 and so struck a mine of truth, inex- 

 haustible in brilliancy and profit." 



Nevertheless, the work of Mendel 

 had very great practical application. 

 The discovery known as Mendel's Law 

 enables the breeder, if given sufhcient 

 time, to construct an animal or plant 

 almost at will. He can take a bit here 

 and a bit there and by hybridization 

 unite them to produce whatever is 

 desired. For example, suppose there is 

 desired on the market a plant with a 

 red flower, dwarf stature and smooth 



leaves. A breeder goes about the pro- 

 duction of this plant by taking a 

 variety containing the red color 'and 

 another variety having the dwarf stat- 

 ure and crossing them together. When 

 the hybrid is produced, he crosses that 

 with a third parent having smooth 

 leaves. As a result, he will have brought 

 together in some one of the offspring all 

 of the qualities desired. 



You will see that the claims put forth 

 by students of genetics are high, but I 

 hope to be able to show you that their 

 claims are not unfounded. Any body 

 of science has immediately an added 

 fascination when its supporters are 

 aware that their labors are somewhat 

 in the main stream of progress. The 

 science of genetics can boast of this 

 position. 



With an understanding of the facts of 

 transmission of plant characters from 

 generation to generation, we are enabled 

 to control the forces of heredity almost 

 at will. Biologists are learning how to 

 harness and use heredity as electricians 

 are learning how to harness and use 

 electricity. The one uses the great 

 network of heredity by taking a bit 

 here and a bit there and putting them 

 together, creating a valuable new plant 

 or animal, the other takes our water- 

 falls which have little use and converts 

 them into greater sources of power for 

 the benefit of mankind. 



Hays says, "It is fair to estimate that, 

 of the twenty-seven billion dollars of 

 our annual national production, elec- 

 tricity and breeding may each be 

 credited with one billion dollars. It is 

 also reasonable to expect that each will 

 have added another billion annually by 

 the time our total production reaches 

 thirty-seven billion dollars. As count- 

 less waterfalls along our streams are 

 waiting for the electrical engineer to 

 bring them into service of man, so the 

 choicest blood streams of heredity in 

 the various species of plants and of 

 animals are waiting for the plant breeder 

 or the animal breeder to segregate them 

 and make them available." 



Scientific breeders beheve that every 

 species is amenable to improvement by 

 breeding; that every species has in it 

 individuals with rare value for produc- 

 ing progeny along desired lines. Breed- 



