30 
Indian Forest Records. 
[Vol. Ill 
bamboo appear, in a microscopic cross-section, arranged in groups of 
four in the form of a rhomboid square. The groups are about 1 mm. 
distant from each other, and, in the groups, the tubes are about 
05 mm. apart. Their diameter is 0T mm., mostly circular in shape 
though an occasional one is found of oval contour. None are flattened 
or collapsed. In old bamboo, one tube (occasionally two) in each 
group is wholly or partially filled up with infiltrated pectous matter. 
In a bamboo of three inches in diameter with walls half an inch in 
thickness there are about 8,000 of them. Each group forms a weak 
place in the tissue, which splits and breaks down under pressure, and, 
if the crushing is thoroughly done, it is possible to obtain fibre bundles 
with a cross-section diameter no greater than the distance between the 
groups, i.e., 1 mm. 
35. The individual or ultimate fibres strongly resemble those of straw 
in their appearance and colour reactions, which are blue with iodine and 
sulphuric acid, and violet with iodo-zinc-chloride. They are, however, 
nearly twice the average length of straw, and are, in the main, narrow 
and slender, and taper to fine points. About a fifth of the whole are from 
0*6 to 1'2 mm. in length, the remainder being from 1*5 to 3*0 with a few 
running up to 4 0 mm. The proportion of short to long fibres is about 
the best possible for producing a closely woven well felted sheet of paper, 
and this quality is aided by their tapering pointed shape and their dis¬ 
tinctively soft and silky texture and entire absence of harshness. Their 
dimensions for the five species are as per the following table 
TABLE IX. 
Dimensions of ultimate fibres (in mm.). 
1 
Length. 
Diameter. 
Maxi¬ 
mum. 
Mini¬ 
mum. 
Aver¬ 
age. 
Maxi¬ 
mum. 
Mini¬ 
mum. 
Aver¬ 
age. 
B. Tulda 
3-96 
•70 
2-60 
•036 
•009 
•027 
B. arundinacea 
3-76 
•60 
2-40 
•034 
•008 
•024 
B. polymorpha 
2-88 
•60 
2-45 
•036 
•009 
027 
C. pergracile 
3-87 
•60 
2-30 
•027 
007 
•020 
Melocanna 1. 
2*90 
•80 
2-20 
•022 j 
•007 
•018 
t 210 ] 
