8 ]May, 1908.] Iniprovciuoit of Cereals by Selecfioit and Crossing. 291 



been engaged in the cross-breeding of wheats, in which he has achieved 

 considerable success, experimenting largely in conjunction with the late Mr. 

 Farrer. The work of raising and distributing impro\ed wheat is now 

 being placed on a permanent footing by the Department of Agriculture 

 and selection combined with crossing is being carried out at the four experi- 

 mental stations to begin with — Dookie, Longerenong, Rutherglen. and 

 Wyuna. Standard varieties will also be grown for seed purposes in what 

 may be called " Stud Plots." It is confidently hoped that by means of well 

 selected varieties suited to the different wheat-growing districts, there may 

 be a perceptible increase in the yield, for it is only by the combination of 

 good methods of cultivation and the best strains of approved varieties, that 

 the present relatively low average can be raised. 



Elementary Species. 



The " new breeds " of cereals which have recently been introduced into 

 cultivation as the result of selection may be accounted for in various ways. 

 In some cases a variety may unwittingly have been imported, such as 

 Ward's Prolific, which was brought into this country as a stray grain in 

 some wheat from Egvpt. Others are undouljtedly the result of the selec- 

 tion of the best tvpes, such as Squarehead wheat and Chevalier barley, and 

 although it is sometimes stated that such selected types are not permanent, 

 there is one of the earliest selection, such as Talavera, still in existence. And 

 this leads me to explain how by a process of selection new and permanent 

 varieties may be obtained. It has been known for some time that among 

 the ordinary species of plants there are often minor or elementary species, 

 and sometimes asi many as two hundred constant forms have been distin- 

 guished wuthin the limits of a single systematic species. 



It was discovered at Svalcif that our agricultural cro])s are particularly 

 rich in these elementary species. The ordinary varieties of cereals are 

 built up of hundreds of these elementarv forms, although hitherto mostly 

 unrecognized, and are quite as constant as the variety itself. These 

 sharply defined tvpes are distinguished from one another by their botanical 

 characters and various properties, so that they afford rich material for 

 selection. These distinct marks have to be carefully studied in the field, 

 particularly in the early stages of grow'th, and then they have only to be 

 st-lected once in order to be quite pure and constant. From all these con- 

 siderations it will be seen that selection can isolate forms which may be 

 an improvement on those already existing and suited for a greater variety 

 of conditions. It was formerly supposed that improvements made by selec- 

 tion alone were temporary and unstable, and that the improvements had to 

 be kept up bv continuous selection. This view led some to neglect this 

 means of improvement altogether and confine their attention to crossing as 

 the only way to reach permanent stabilitv. Xo doubt when additional 

 vigor is required and a greater amount of variability to choose from, then 

 the shock of crossing, after long continued in-breeding, affords the necessary 

 reaction, but selection alone by means of elementary species and by sports 

 may lead to permanent improvement. 



{To he confi lined.) 



