JF Ptak Science Books  Post 268

These two wonderful and unexpected sets of data come from Sir John Lubbock’s article On Leaves, appearing in the Popular Science Monthly for July 1885.  Sir John was a very keen and astute observer of nature, and was one of a long line of gentleman/noble scientists naturalists and the fourth Sir John in the Lubbock line.  The idea that Lubbock was running here with was the the size and shape of the leaf of a tree was determined by the diamter of the twig leading to the sixth leaf of the tree, with size determining form and function.   This gets much more complicated than this, once you throw in a bunch of the other factors that he treid to account for, and I’m not qualified to respond to this work.  What I liked though was the thickness indicator (below) of twigs of twelve different trees and the thickness of their twigs at Lubbock’s decribed sixth leaf, which is something I’ve not scene before (though I’m hardly a naturalist, I have seen hundreds of thousands of scientific and natural history images, and I’ve not seen one like this).  It is glorious in its own quiet way.  The chart that he provides correlating leaf size (the square footage of leaf in the last six leaves with twig thickness) is seen in the table at bottom. 

I’m aware that I haven’t said very much about this, but I just couldn’t pass on the opportunity to post this iamge on twig thickness.                                                               
(Click to enlarge to readable size.)