it has no such action if the fibre is of animal origin. This test is known as
2. The Source of Hairs.It is extremely difficult to determine whether
the hairs sent for examination belong to a particular individual or not,
though it may be easy to ascertain the source (part of the human body)
from which they are derived. This may be easily done by observing the
following characteristic features :
Hairs from the head are usually long and soft, and taper gradually from
root to point. Hairs from the female head are generally thinner and much
longer than those from the male head.
Hairs from the beard and moustache are usually thicker than those
derived from any other part of the body.
Hairs from the chest, axillas and pubic region are short, stout and curly.
Those from the axillae and pubic region also show split ends.
Hairs from the eyebrows, eyelashes and nostrils are stiff and thick, taper
to a point and are \ to | inch long.
Hairs from the body surface are generally fine, short and flexible, and
do not show pigment cells in the cortex. The medullary canal is also apt to
be relatively small, or may be altogether absent. The downy hairs of the
new-born infant have no medullary canal or pigment cells.
Fig. 28. (1) Human Hair:
(5) Silk Fibre:
(6) Wool Fibre:
AH x 150 (B. y. Patel).
A. Medulla; B. Cuticle; C. Cortex with cuticular
A. Portions of fibre ; B. Apex.
A. Portion of fibre ; B. Apex ; C. Transverse markings.
A. Portion of fibre; B. Apices.
A. Fragment from sericin layer (silk glue).
A. Medulla; B. Cuticle; C. Cortex.