52 



LETTERS ON TREES. 



reason of the successive production of distinct palm 

 plants growing year after year one above another. In 

 most species of Palm there are no branches. In most 

 the trunk towers upwards singly and alone, — some- 

 times to an elevation of 150 or 180 feet, and is naked 

 throughout, save only at the summit, where it is sur- 

 mounted with large and numerous leaves, with flowers 

 and fruit ; and likewise, in the very centre, and form- 

 ing its highest point, with a fleshy bulb or bud for 

 the evolution of next year's palm plant. This trunk, 

 in fact, may not inaptly be likened to a stately monu- 

 mental column, on the top of which an embryo palm 

 plant is every year placed by the hand of Nature, — 

 the column itself, however, serving to this plant simply 

 the purpose of a stand-point, and having as little to do 

 with its germination and growth as it manifestly would 

 have nothing, were it the " Monument" in Fish Street 

 Its offices are purely mechanical, not vital. It gives 

 support to the young plants ; and by the porosity of 

 its substance, it gives scope for the roots to strike a 

 short way down into it, while it also allows fluids to 

 pass upwards from the earth beneath for the growth 

 and nourishment of the plant. 



4. The trunk of the Palm-tree is fixed to the soil by 

 means of a strictly fibrous root resembHng that of the 

 grasses ; and this root appears to be derived from the 

 woody bundles of the earHest set of plants, — those of 

 the plants subsequently formed never reaching the 



