1906.] 



Improvement of Cereals. 



735 



•one mother plant or ear, increase being obtained strictly from 

 the produce of this one foundation stock. Under this system 

 the main point was to obtain as a mother plant a natural varia- 

 tion presenting desirable qualities, whose variation from the 

 normal was of an hereditary character. This method proved 

 very successful, and the produce of the carefully selected 

 mother plants showed a surprising homogeneity in their 

 botanical and physiological properties, with the result that a 

 number of new varieties of grains were produced and placed on 

 the market. 



A special feature of the Svalof method was a system of classi- 

 fication depending on certain fixed botanical characteristics, by 

 means of which the plants under cultivation were divided into 

 certain minor classes or species. The system by which this 

 principle is worked has been very carefully devised. Each 

 person engaged at the .station has only one, or at the most two, 

 sorts of plants to deal with, and thus becomes so familiar with 

 their characteristics that the slightest deviation from the normal 

 type can hardly pass unnoticed. In order to classify the plants 

 systematically they are grouped in a number of fixed types ; 

 thus in the case of barley there are four sub-species of the three 

 species generally cultivated, viz., Hordeum distichum nutans, 

 H. distichum erectum, and H. tetrastichum, so that there are 

 twelve classes in which the seed may be grouped. The four 

 sub-species depend in each case on small, and to a large 

 extent microscopical, differences in the seed, which, however, 

 have been found to be completely hereditary ; thus the grain 

 of H. distichum nutans has seed with an oblique or sloping 

 base, but may have either long or short hairs or bristles on 

 the rachilla, and each description may have either smooth or 

 indented nervures. The seed of the other species is similarly 

 classified. Wheat is divided into seven types, oats into ten, 

 peas into nine, and vetches into nine. The cultivation of rye 

 and potatoes has only recently been taken up, and the types 

 have not yet been fixed. 



In view of the great number of foundation stocks in cultiva- 

 tion, it is naturally not sufficient to class them merely in one or 

 other of these sub-species, and a further step towards identifica- 

 tion is necessary, so that all the characteristics of a mother plant 

 maybe satisfactorily established, and by following its subsequent 



