520 Philippine Journal of Science 1919 
average circumference of 47.8 centimeters at 1.36 meters (4.5 
feet) above the ground. However, even this rate of growth is 
exceeded by certain selected trees in Basilan. The best group 
of three consecutive trees in block 18 (Nos. 79, 80, 81) shows 
an average girth of 57.7 centimeters (22.7 inches) at the age 
of 51 months, which is equivalent to about 54.24 centimeters 
(21.3 inches) at the age of 4 years. 
Willis *° presents the measurements of some trees in Ceylon. 
The original trees, planted at Henaratgoda in 1876 when prob- 
ably about 1 year old, attained a girth of 35.6 centimeters (14 
inches) two years later, and in 1882 the largest tree was 63.5 
centimeters (25 inches) in circumference 1 yard from the 
ground. The girth of this tree was measured annually there- 
after and in 1886, when 10 years of age, its girth was 124.5 
centimeters (49 inches). Even this growth appears to be in- 
ferior to that attained by the best tree measured at Basilan, 
No. 12 in block 2, which attained a circumference of 142 centi- 
meters (55.9 inches) at an age of 124 months. 
In the same paper Willis gives the average measurements 
of trees at Edangoda and Yattipowa, Ceylon. Willis’ figures 
are given in Table XV. 
TABLE XV.—Growth of trees in Ceylon. 
Locality. Age. Trees. Circumference. 
Years. cm. tn. 
| Edangoda _._...___. ae 4 100 32.9 12.96 
Do ...___ 3 50- eae 
D6 oss esse oi See Se ee ee 2 20 12.6 4.96 
Sathipe was 26 os ee eC via 3 108 23.8 9.37 
ppc ews MIN SR nO a a ae el eA 3 108 23.2 9.13 
The trees were measured 3 feet above the ground and so are 
closely comparable with measurements in the Philippines made 
at a height of 1 meter. These measurements indicate a de- 
cidedly slower growth than is shown by trees of the same age 
in Basilan. At an age of 4 years the circumference attained 
by trees at Edangoda was 2.7 centimeters (1.1 inches) less 
than that of trees of the same age in the Philippines. Other 
measurements of Para rubber trees recorded from Ceylon in- 
* Cireular and Bull. Roy. Bot. Gard. Ceylon 5 (1910) 17 and 18. 
