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improved within the last year or two through the investigations 

 which have followed on the rediscovery of Mendel's law of inheri- 

 tance. Wheat as a normally self-fertilized plant is particularly 

 suited to the investigation of Mendel's law and the work of 

 Biffen shows that, with a few possible exceptions, the characters 

 of the parent varieties are inherited strictly in accordance with 

 the expectations derived from a consideration of that law. Ex- 

 treme strength shown in any particular wheat can then be 

 picked out and combined with any other essential qualities, 

 such as the yield and the character of the straw, which distinguish 

 our present varieties of wheat. Biffen's work among the wheat 

 hybrids touches also upon another point of special importance to 

 South African farming, where the incidence of "rust " forms the 

 greatest obstacles to extensive and successful wheat-growing. It 

 is generally recognized that relative immunity or susceptibility to 

 an attack of yellow rust is characteristic of particular varieties, 

 and Biffen finds that such " immunity" is a true Mendelian charac- 

 ter, recessive and therefore only appearing in the second generation 

 of hybrids between a rusting and a rust-proof parent. It is not 

 correlated with shape or character of the leaf, but is transmitted 

 from one generation to another quite independently, and can there- 

 fore be picked out of a desirable parent and combined with other 

 qualities of value in different parents. Here, again, we are deal- 

 ing with a character that is only relative, for no wheat can be 

 called either absolutely rust-proof or entirely susceptible ; the off- 

 spring that have inherited immunity will still vary a trifle among 

 themselves in the degree of their resistance to attack, and in this 

 possibility of variation lies the chance of the plant-breeder to 

 improve upon the rust-resisting powers of the varieties we now 

 possess. The whole work of the plant-breeder is of singular 

 importance in a country like South Africa, whose agricultural 

 history is so recent. Our European crops represent the culminat- 

 ing points of a tradition, and are the fruit of the observation and 

 judgment of many generations of practical men working, as a rule, 

 with chance material. The products are eminently suited to 

 European conditions, but, as has been seen so often, they fail 

 comparatively when brought into other climates and soils. It 

 follows then, that, in a new country, the work of the acclimatizer 

 is one of the necessary foundations for agriculture, and this 

 involves a careful study of climatology, and of the influence that 

 the distribution of rainfall and temperature in various parts of the 

 country has on the character of the crop. Then the cross- 

 breeder's work begins ; acclimatization alone is hardly likely to 

 yield the ideal plant, but by it are found plants possessing the 

 features, one here and one there, that are desiderated ; and starting 

 with this ground material, the hybridizer can eventually turn out 

 an improved plant. 



