Observations upon some Noteworthy Leaf Variations. 285 



spective positions indicated), the intermediates presenting 

 graduated sizes. As will be seen, these leaves are ovate in 

 form and they have a distinctly cordate base. The leaves of 

 the entire branch show an average area of about 41.61 sq. 

 cm., ranging from 25.85 sq. cm. to 57.37 sq. cm. From this it 

 appears that the same plant produces two sets of leaves under 

 the same general conditions of growth, in which the extreme 

 variation is in the ratio of 1 :5o.32, the average variation 

 being in the ratio of 1 :8. 17. While we are familiar with 

 the fact that many trees exhibit very striking differences 

 under essentially the same general conditions of growth, the 

 present case appears to be of a most extraordinary nature in- 

 asmuch as the different forms appear to be wholly localized 

 and confined to particular regions of the plant ; while the 

 the differences in form and size particularly, are such as, in 

 the case of the basswood, are usually associated with extremes 

 of light and shade. To complete our description of this par- 

 ticular shrub, it should be noted that in addition to growing 

 on that side of the clump which only received the afternoon 

 sum as greatly modified by the proximity of a high building 



Fig. 4. I,onicera tartarica. Leaves from the plagiotropic branches of 

 a much pruned shrub, reduced through correlation, x \ 



