240 PLANT-BREEDING 



proposed to look for tne same qualities among other sorts 

 with resistant halms. A minute study of the botanical char- 

 acters of the ears, of their spikelets and scales led him to the 

 discovery of a relation between the form and the hairiness 

 of the latter and the practical qualities of the grains. On 

 the ground of this relation tens of thousands of individual 

 barley plants were scrupulously investigated, and some sixty 

 were chosen out of this number for a comparative trial of 

 their progeny. Among these the continued study during 

 subsequent years led to the selection of the one which best 

 answered the proposed question, inasmuch as it combined 

 the qualities of a fine brewers' barley with strong and resist- 

 ant halms. From this one plant a race has been derived, 

 which received the name of Primus-barley and has already 

 supplanted large parts of the cultures of the original Cheva- 

 lier kinds all through the middle parts of Sweden. 



These examples may suffice to convince us of the useful- 

 ness of a thorough study of the association of qualities and 

 characters of cultivated plants. Evidently such a study is 

 a very difficult one, but it opens new and broad lines of re- 

 search. In order to build upon a scientific basis, it is nec- 

 essary not to confine ourselves to cultivated plants, but to 

 take as large a view of the whole vegetable kingdom as possi- 

 ble. Only in this way is there a chance of discovering the 

 great laws of nature which govern this most intricate group 

 of phenomena. 



Broadly speaking, the characters of plants may be con- 

 sidered from a systematic or from a physiological point of 

 view. The systematist explains the affinity by means of 

 the laws of inheritance, assuming thereby a common cause 

 for every character which remains unchanged throughout 

 a large group of closely related species. The flower heads 

 of all the composites must have one and the same cause, and 

 so it is with their inferior ovary, their connate stamens, and 



