86o 
Journal of Agricultural Research 
Vol. XXI, No. II 
line from left to right if the lengths of the laterals formed a regularly 
descending geometrical series. As mentioned above, the descent is by 
no means uniform. The logarithms of the first seven values of S descend 
rapidly and somewhat uniformly, but from that point on the descent is 
less rapid and more irregular. In the language of the horticulturist, the 
first few buds formed shoots and the rest formed fruit spurs. The 
formation of these two classes of laterals is of great importance in horti¬ 
cultural practice, and their regulation is one of the principal objects of 
pruning. A discussion of the physiological aspects of the problem will, 
however, be postponed until other data have been presented. 
Fig. 4. —Mean length and variability of laterals I to XV on pruned mother shoots. The circles indi¬ 
cate the observed mean lengths of laterals; the dots and dashes, the standard deviation; the broken 
line, the coefficient of variability of laterals; and the solid line, the mean length of laterals I to X 
calculated from ^=93.47+4.1931—136.907 log x. 
The length of the first io laterals when plotted as in figure 4 indicates 
that they follow a curve of a type frequently encountered in biological 
data. By the aid of tables given by Pearl and McPheeters ( 8 ) the equa¬ 
tion for this curve was computed and found to be 
^ = 9347 + 4 -193^-136.907 log*, 
when y represents length of lateral and x represents its ordinal position 
on the mother shoot. The path of this curve is shown in figure 4. 
That it is more representative of the laterals than of the fruit spurs is 
shown both by its shape and by the fact that it gives values of zero or 
less from lateral X and below. 
