147 



Not only were great differences discovered between different lots of the 

 same old varieties but within each lot was often to be found a " motley collec- 

 tion of quite distinct types." When the pedigree method came to be applied 

 to this crop, as it did about the year 1892, it quickly served to isolate a large 

 number of these types, which, on further investigation, were found to possess 

 qualities of varying practical values. Much workfromthat time on was devoted 

 to the isolation of distinct strains which would be suitable for growing under 

 different conditions of soil and climate and which would possess constant 

 and well denned botanical characters. As the work proceeded it was found 

 that the morphological differences which characterize many strains, while 

 often small, are usually quite constant. This, as in the cereals, is a matter 

 of great importance as it not only provides a means of keeping under control 

 those sorts which have been placed on the market, but at the same time 



Photo by L. H. N. 

 FIG. XLIII. Dr. Tedin crossing Pease. 



affords protection against misrepresentation and fraud in the ordinary 

 course of business. 



While experience showed it to be possible to separate out a large number 

 of different strains from the common varieties by means of the pedigree 

 method, yet it was not long before other methods came to be included. Thus 

 artificial hybridization was introduced on an extensive scale and as we shall 

 see later, occupies a prominent place in the improvement of this crop. 

 Unfortunately many promising crosses have had to be laid aside owing to the 

 absence of proper facilities for testing at different local centres. 



The difference between Pea sorts as regards such matters as earliness 

 is considerably greater than in the case of cereals, while the influence of soil 



