THE STEM 151 



plants to the tall graceful palms which Endlicher called 

 Principes, i.e. the princes of the vegetable world. Their 

 trunks grow upwards as straight vertical pillars with a 

 crown of leaves at the top like the very columns for 

 which it is believed they served as model. But the 

 trunks of the palms represent only a one-sided develop- 

 ment — development in length ; they are very tall and 

 graceful, but they do not usually branch or increase 

 in thickness. A totally different aspect as well as the 

 greatest development in size is seen in the trunks of our 

 broad-leaved trees and our fir-trees. They, throughout 

 their existence, increase in thickness and throw out 

 branches, and may thus reach very great dimensions. 

 Thus, for instance, within the circle of the bark of a 

 Californian Wellingtonia, there would even be room for 

 dances ; a small chapel has been fitted up within the 

 hollow of a huge chestnut tree on Mount Etna ; while 

 travellers tell us that whole caravans find shelter under 

 the green shade of the baobab. Although such giants 

 do not exist in Russia even in the forests, we can still 

 find hoary denizens of the past like the oak of Kunzewo. 

 Its mighty trunk, of the thickness of four horse-girths, 

 rises from the bottom of a deep ravine, while its summit 

 towers above the lime and aspen trees that are crowded 

 all along the edges of the ravine. 



Such are the dimensions that can be attained by a 

 stem in the fulfilment of its destiny, bearing a canopy of 

 foliage, the large leafy surface for the absorption of 

 the rays of the sun ; and one cannot fail to see how 

 well it is adapted to this purpose. We have only to 

 remember the partial obscurity which reigns in a pine 

 wood, even on a sunny day, to realise that the needles 

 must be distributed on the stem in the most advan- 

 tageous way if, in spite of their insignificant breadth, they 

 are to arrest as many rays of light as possible. Indeed, 

 although the distribution of the leaves on a stem seems 

 at a first glance entirely hap-hazard, a closer investiga- 



