



immediately preceding season ; also the average pro- 

 duce of each plot over the first half, the second half, 

 and the total period up to date, commencing with the 

 ninth crop, that of 1852. The results so recorded are, 

 however, given numerically only, that is without com- 

 ment or discussion. 



A selection of the results is annually given, and 

 discussed, in a letter published in the chief Daily, 

 Agricultural, and some other Journals, as the basis of 

 an estimate of the average Wheat crop of the United 

 Kingdom. 



The field results have been discussed more or less 

 fully, and sometimes in reference to special points of 

 interest, in the papers, the titles of which are given in 

 the list, Series 1 in the "Appendix" and there numbered 

 1, 5, 7, 8, 9, 10, 18, 23, 24, 26, 27, 28, 29,31,38, 40, 43, 

 48, 49, 54, 60, 64, 65, 66, 68, 72, and 73. 



The results have been the more fully given, and the 

 more systematically discussed, in Nos. 23 and 66 ; the 

 first of these giving, and discussing, the results of each 

 of the first twenty, and the second those of each of the 

 second twenty years, of the continuous growth. 



It is to be supposed that occasions may arise for 

 partial discussions in reference to special points of 

 interest ; but that further sj^stematic discussion will be 

 postponed until the conclusion of the third period of 

 twenty years of the experiments (1903), or possibly 

 only until the conclusion of the first 50 years of their 

 duration (1893). 



2. The Composition of the Continuous Wheat Crops. 



The plots now under experiment are numbered 2 

 to 20 inclusive ; but 3 of these are each divided into 

 2 separate experiments, raising the number to 22, and 

 12 of the remainder are each divided into 2, which are 

 now only duplicates, but which have a slightly different 

 manurial history in earlier years, and hence separate 

 samples have hitherto been taken for dry matter, ash, 



