THE ASSOCIATION OF CHARACTERS 269 



has taken years to arrive at a sufficient degree of knowledge 

 of all these correlations, and the investigations, though cov- 

 ering more than ten years, have as yet not nearly been 

 exhausted. But the general result has been that the indus- 

 trial worth of any individual plant can now be estimated by a 

 thorough inspection of its panicles or ears and with a degree 

 of certainty which is wholly sufficient for all purposes of 

 selection. 



As an illustration of the high significance of these corre- 

 lations, I will now return to the example of the Primus-barley, 

 of wliich I spoke in a previous lecture. As already pointed 

 out, all endeavors to breed a race of Chevalier-barley with 

 stiff culms had led to no appreciable ameUoration, and 

 the cultures in this direction had to be given up. The 

 principle of correlation, however, pointed to another way 

 of solving the problem. Instead of trying to breed a Cheva- 

 lier-barley with rigid halms, a stiff variety was chosen, and 

 it was proposed to give to this the quahties of a fine brewer's 

 barley. In Sweden a kind of barley is largely cultivated 

 which bears the name of Imperial barley and belongs to 

 the subspecies of Hordeum erectum with stiff culms, hairy 

 scales, and coarse kernels. This variety, the good qualities 

 of which were duly appreciated, was taken for a starting- 

 point in order to produce the desired barley for the brewers. 

 The study of the correlations between morphological and 

 industrial features had led to the discovery of a coincidence 

 of some marks of the hairs on the base of the scales with the 

 composition of the albumen of the grains. Long and 

 straight ones are correlated with coarse kernels, but short 

 and crisp, more or less woolly hairs are indicative of those 

 quahties which stamp a barley as a good kind for the 

 brewery. 



On the basis of this correlation, combined with the dis- 

 covery of the existence of innumerable individual variations, it 



