ee eels 
t 
7 
the trunk is convex or obconical, and is usually buried for a depth of 
hardly more than 50 centimeters. Its surface underground is almost 
entirely covered with the bases of the roots. The latter are remarkably 
uniform, about 1 centimeter in diameter, radiating from the tree on all 
sides, each without much variation in its direction, and, so far as my 
observations justify a general conclusion, for a normal distance of about 
5 meters in firm soil and 7 meters in sand. ‘he lateral branches, what- 
ever direction they may take with regard to the action of gravity, leave 
the main roots with surprisingly uniform exactness at right angles and 
are likewise on the whole straight, though less so in detail than the main | 
roots. ‘ 
The old main roots are notable for the combination of elasticity * and 
tensile strength shown by their powerful central steles, the cylinder of 
xylem inclosing a “pith” with thick, lignified walls. The most con- 
spicuous feature of the branches is their stiffness, for which the stele is 
not more responsible than the hypodermis.. I have never before, in any 
plant, seen a rigidity on the part of the fine, absorbing roots which will 
compare with that possessed by those of the coconut. The intimate 
contact between the hard, firm roots and the soil is responsible for the 
rigidity of the Cocos, as of other trees, but while in most, this contact is 
centered about the base of the trunk, the Cocos has it disseminated equally 
through the ground to a radius of 5 meters or more. The main roots act 
as so many taut strands between the base of the trunk and the multitude 
of fine points of attachment. The effectiveness of the coconut’s system 
of anchorage is perfect. The tree’s favorite habitat is the seashore, where 
it receives the unbroken force of the fiercest storms. Because of its 
elasticity, the trunk very rarely breaks, and I have never seen one instance 
of an uprooted coconut, the roots of which had not either previously been 
killed or undermined by waves. 
Kighty centimeters is not a very exceptional diameter for a well-grown 
bole, though a majority fall below this size. The buried part of a stem 
of this thickness will afford attachment for nearly 8,000 bases of roots 
1 centimeter in diameter. Some of the main roots bear few or no 
branches at all like themselves; others have 10 to 20, which rarely reach 
a length of 1 meter or a diameter of 4 millimeters. The main roots 
and these major branches bear numerous fine ones, 1 to 2 millimeters 
in diameter, springing forth at right angles and having a rigidity which 
has already been noted. These may be the ultimate divisions; or they 
in turn may bear finer branches, at most a very few centimeters long, 
about 0.5 millimeter in diameter; the life of the latter is transitory like 
that of root hairs. A less ample system of branches is formed in sand 
than in firmer ground. 
Dead, distal parts of roots are replaced from the bases of the same roots 
' Pfeffer, Pflanzenphysiologie, 11, page 60, cites Sonntag, Landw. Jahrb. (1892), 
21, 839 as authority for a stretching of 20 per cent by Cocos fibers, without 
exceeding their limit of elasticity. 
