CONTRIBUTIONS FROM THE WISLEY LABORATORY. gi 



outer rows, and in only six of the eighty-eight opportunities did it 

 exceed that of the lower of the outer rows. Taking the combined 

 weights of tops and roots, in only two plots did the total weight of 

 an inner row exceed one or other of the corresponding outer rows, 

 and in none was the highest yield given by an inner row. In every 

 case but one (the foliage in Plot C II.) the lowest yield on the plot, 

 whether of tops, roots, or total, was in an inner row. 



Possibly the diagram given in figures 41 and 42 will emphasize 

 even more clearly the influence of crowding on yield. The longer 

 line in every case represents the average yield of all the plants in 



(a) (b) (a) (b) (a) (b) 



Whole plant. Tops only. Roots only. 



Fig. 41. — Average Weights of Turnips in (a) Outer Rows and 

 (b) Inner Rows in Series I. Compared. 



the outer rows on the plots; the shorter, of all the plants in the 

 inner rows on the plots. The first diagram (fig. 41) corresponds with 

 Table I., the second (fig. 42) with Table II. 



The first diagram (fig. 41) represents the comparison between 



(1) the average weights of the whole plants from the two outer rows 

 (2,127 plants) and from the one inner row (1,086 plants) ; (2) average 

 weight of the tops; and (3) average weight of the roots, in the first 

 series of plots. In the same way the second diagram (fig. 42) repre- 

 sents the comparison between the average weights of (1) whole plant, 



(2) tops, (3) roots of 1,763 plants from the outer rows and 1,738 plants 

 from the inner rows of the plots in the second series. 



