PRIMARY TISSUES S-SIMPLE FIBROUS TISSUES. 
37 
merely to the physical actions of the framework; as, for ex¬ 
ample, by holding its parts together, by communicating motion, 
or by giving them mechanical support and protection.—The 
several parts of the body, even to the very minute divisions 
of its organs, are held together by what may be termed, in 
contradistinction to Muscular and Nervous fibre, the simple 
fibrous tissues; and these are merely endowed, like ordinary 
cords, with the power of resisting tension or strain, either 
without themselves yielding to it at all, or with a certain 
amount of elasticity, which enables them first to yield to 
a certain degree, and then to recover their previous state. 
These two qualities are characteristic of two distinct forms of 
simple fibrous tissue, the white and the yellow . 
23. The White fibrous tissue presents itself under various 
forms, being sometimes composed of fibres so minute as to be 
scarcely distinguishable, but 
more commonly presenting 
itself under the aspect of 
flattened bands, which are 
but imperfectly divided into 
fibres, and have more or less 
of a wavy aspect (fig. 1). This 
tissue is resolved, by long 
boiling, into gelatine; and 
when treated with acetic acid, 
it swells up and becomes *** l-white fibrous tissue. 
transparent, by which peculiarity it can be readily dis¬ 
tinguished from the other kind, to be next described. The 
Yellow fibrous tissue presents 
itself in the form of long, 
separate, clearly defined fibres, 
which sometimes branch, and 
which break short off when 
overstrained, their extremi¬ 
ties being disposed to curl up 
(fig. 2). They are, for the most 
part, between 1-5,000th and 
1-1 0,000th of an inch in 
diameter; but they are often 
met with both larger and smaller. This kind of tissue un¬ 
dergoes but very little change from long boiling, and it is 
