74 THE PALM -STEM : 



stem, and founds his answer on the following considera- 

 tions. His Date-palm was 18 '60 meters high, the base, 

 clothed with roots, 34 centimeters in diameter ; above the 

 root-bearing part the surface of the stem had suffered 

 from the influence of the atmosphere, and its diameter 

 here amounted to 25 centimeters; the upper part was 

 covered with leaf-scars, and almost cylindrical. Mirbel 

 then concludes, that if the fibres originated in the leaves, 

 and all reached down to the base of the stem, or, on the 

 other hand, if all the fibres originated at the base of the 

 stem, and ascended up into the leaves, the stem must 

 necessarily have a conical form, on account of the accu- 

 mulation of the fibres at its lower end. In like manner 

 is opposed to either of these views a circumstance, which 

 was undoubtedly known to me, namely, the spindle-shaped 

 expansion of many Palm-stems in the middle, which I 

 could not explain according to my theory, but which 

 affords nothing remarkable now he has found that the 

 fibres originate at all heights in the stem. The most 

 certain evidence, however, against the opinion that the 

 fibres run from the leaves to the base of the stem, is 

 furnished by the following exact measurements. In the 

 Date-stem he examined there were 337 leaf-scars on a 

 length of one meter, the entire stem had, therefore, borne 

 about 6268 leaves. At the base of one petiole Mirbel 

 found 500 fibres 1 millimeter thick, and 400 fibres ^th 

 of a millimeter, which he estimated equal to 44 of the 

 larger fibres ; for the vagina of the leaf he reckoned 100 ; 

 therefore, altogether, 644 for a leaf, and for all the leaves 

 of the stem added together, 4,036,592 fibres. Besides 

 these, account must also be taken of the fibres which run to 

 the spathes and flower-stalks, and, moreover, the enormous 

 number of capillary fibres which occupy a considerable 

 space in the hard and firm crust of the oldest portions of 

 the stem. Leaving these last out of sight, the fibres 

 running to the leaves furnish a sufficient proof against 

 my theory, since, if these fibres ran down to the base of 

 the stein, the cone formed by them at the bottom would 



