MIRACLES OF SCIENCE 



also of Cambridge University. Professor Biffin's 

 experiments have had to do with the different races 

 of wheat. England, in common with other countries, 

 has suffered tremendously from the pest known as 

 rust. This is a fungus growth, which attacks the stem 

 of the wheat plant and saps its vitality. It has been 

 estimated that the annual loss to the wheat crops of 

 the world from this little fungus is not less than five 

 hundred million dollars. But no method of combat- 

 ting the pest proved effective. 



It has long been observed, however, that there are 

 certain varieties of wheat that are practically im- 

 mune to the attack of a given variety of rust fungus. 

 But unfortunately this immune variety of wheat, 

 while having a strong stalk, produces very little grain, 

 and that of an inferior quality. On the other hand, 

 the varieties producing the finest qualities of grain 

 have shown peculiar susceptibility to the rust. It 

 occurred to Professor Biffin that it might be possible 

 to hybridize these two races, along Mendelian lines. 

 His tests soon convinced him that susceptibility and 

 immunity to rust are a pair of Mendelian characters, 

 of which susceptibility is dominant. When, therefore, 

 he hybridized a susceptible and an immune wheat 

 plant, he produced seed from which grew plants that 

 were all susceptible to the rust. But in the following 

 generation appeared the expected proportion, one- 

 fourth, of plants showing the recessive quality, 

 which in this case was the desired immunity. So 

 the upshot of his experiments was that he developed 

 in the course of a few years' experimentation a race 

 of wheat producing a larger yield of grain of fine 



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