18 SCIENCE BULLETIN, No. 22. 



His second objective was to get a prolific grain-yielding early maturing variety ; and 

 o he crossed Rymer with Maffra. The result was Bunyip, which for a time was the 

 most prolific grain yielder of all the very early maturing varieties, although it has been 

 recently surpassed by newer varieties like Canberra. 



It does not appear that Farrer was conversant with Mendel's work until 

 about 1905, when it was too late for him to work on Mendelian lines. A 

 few extracts from correspondence he carried on in 1905 with Professor R. H. 

 Biffen, of Cambridge, will throw some light on Farrer's views on the subject. 

 Writing under date 8th March, 1905, he says : 



In your letter you speak of " the old, bugbear of fixing varieties." This work for the 

 last twelve or fourteen years has given me no trouble whatever. It seems to me from 

 what I can see of Mendel's theory of heredity, that the consideration I then gave to the 

 matter of fixing varieties led me to adopt the system, which, for all practical purposes, 



Mendel's theory indicates as being the best The practice was adopted from 



what appeared to me to be common-sense considerations ; I certainly had not Mendel's 

 theory to work upon. 



In a subsequent letter dated 14th April, 1905, he remarks : 



There is one point in connection with Mendel's law that it seems to me not to provide 

 for. It is that when varieties, which differ sufficiently in type, are crossed, the variable 

 generation seems to produce individuals which differ in all the qualities in which 

 varieties differ : e.g., by crossing two late sorts of different types, it is quite possible to 

 get early sorts. I cannot recall just now an instance in which I have got a very early 

 variety in this manner, but I have made from such crosses varieties which are distinctly 

 earlier than either parent. Mendel's law, I fear, is not likely to be of great use to me 

 in enabling me to improve my methods, because in nearly all the crosses I make, one of 

 the parents is an unfixed crossbred, and frequently a plant of the first generation from 

 the cross. . 



In connection with the above quotation from Farrer as to the use of unfixed 

 cross-breds as parents, the following remarks by Mr. J. P. Shelton, holder of 

 the Farrer Scholarship, who has recently returned from England and 

 America, and has had the opportunity of studying, especially at Cambridge, 

 with Professor Biffen, the present developments of wheat-breeding, are of 

 special interest : 



The practice, adopted so largely by Mr. Farrer, of mating unfixed cross-breds, and 

 indeed using first generation cross-bred plants as parents, was based upon the old 

 nineteenth century conception that crossing was of value because it induced variations. 

 It is diametrically opposed to the modern methods based on the knowledge of Mendelism, 

 and ia indeed in strange contrast and opposition to Farrer's own views and knowledge of 

 the segregation of "unit characters." 



It is not suggested that Farrer could not obtain valuable recombinations of characters 

 by crossing Fj plants. The pedigrees of some of his best productions show that such 

 recombinations were obtained fortunately for Australia. But the mathematical aspect 

 of Mendelism based on the laws of chance shows that Farrer undoubtedly reduced, in a 

 very large degree, the chances of obtaining any desired recombination by crossing Fj 

 plants, as compared with the crossing of fixed strains, or pure lines, that had the 

 necessary characters. On the other hand, when no fixed or pure line strains were 

 available, any success resulting from Farrer's system saved several years of patient 

 labour, and expedited results by so much time as would have been necessary to first 

 create and fix such varieties. 



The statement that Mendel's law does not provide for cases in which the progeny of a 

 cross includes individuals which possess characters not found in either parent was 

 undoubtedly true, as Mendel's law was then stated and understood. Subsequent 

 research, however, has shown that some characters depend, for their full expression, 

 upon the presence of more than one Mendelian factor. Thus late varieties are differen- 

 tiated from early varieties by the presence of several factors. Where two late varieties 

 are crossed, it is evident that different recombinations of the several factors for lateness 

 may occur in the variable generation. Some plants will then contain less than the full 

 number of factors for lateness, and will show a degree of earliness in correspondence 

 with the decrease in the factors. 



Farrer's case of the appearance of early wheats as the result of crossing two late 

 wheats of different type is therefore not really at variance with Mendel's theory as now 

 understood ; although at the time his objection was perfectly valid. 



