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THE FORMATION AND GROWTH 
OF THE WOOL FIBRE 
Wool fibre is composed of the following elementary 
Ausus. — Carbon, Hydrogen, Nitrogen, Sulphur, 
xygen. 
These five components are obtained from the blood, 
which in part derives them from the food, and in part 
from the atmosphere, in the process of breathing. 
To understand how the wool fibre is formed it is 
necessary to learn something about the structure and 
functions of the skin, from which it isan outgrowth. 
The mechanism by which a wool fibre is produced is 
of some complexity. Here is a diagram representing a 
section of the skin of a sheep, from which two wool fibres 
are seen growing out. The skin is composed of two main 
layers, the epidermis or outer skin, (subdivided into two 
. Separate layers) which constitutes a protective covering to 
the animal, and the dermis or inner skin, in the substance 
of which are contained those organs which contribute to 
the production of the wool fibre. 
Referring to the diagram it will be seen that the wool 
і fibres grow out from pear-shaped structures, which are 
termed “follicles.” (A.) Their counterparts are familiar 
to everyone in the bulb-like so-called “roots ,” that are seen 
at the end of a hair that has been pued from the head. 
The part played by the follicle is the “manufacture” of 
the wool fibre from the materials mentioned above. - 
In addition to these follicles the skin contains numerous 
' sweat glands (E) opening to the surface of the skin by 
