FIBROUS TISSUE, 35) 
canals are formed through which the vessels pass to supply the parts 
which are too far removed from the perichondrium. In articular carti 
lages no vessels enter. When cartilage is removed by mechanical means, 
or by absorption, it is not regenerated, and when fractured, as in the ribs, 
there is no reunion by cartilage, but by fibrous, or most frequently by 
osseous deposition. 
CuemicaL Composition.—True cartilage contains three-fifths of its 
weight of water. It is ascertained that the cells and the intermediate 
substance are composed of different materials. The membranes of the 
cartilage cells are not resolved by boiling, and offer a lengthened resistance 
to alkalies and acids. The contents of the cells coagulate in water and 
dilute acids, and are dissolved by alkalies. The intermediate substance 
consists of chondrin, which differs from gelatine in not being precipitated 
by the mineral acids, 
FIBROUS TISSUE. 
FrBrovs TISSUE exists very generally throughout the body, being com- 
posed of fibres of extreme minuteness. It is found under three forms, as 
white fibrous tissue, yellow fibrous tissue, and red fibrous tissue. 
WHITE FIBROUS TISSUE is composed of cylindrical fibres of exceeding 
minuteness, transparent, and undulating. They are collected first into 
small fasciculi and then into larger bundles, which, according to their 
arrangement, compose thin layers or membranes, ligamentous bands or 
tendons. Zhe membraneous form is seen in the periosteum and _ peri- 
chondrium, the fasciz covering various organs, the membrane of the 
brain, &e.—Zigaments are glistening and inelastic bands, composed of 
fasciculi of fibrous tissue generally ranged side by side, sometimes inter- 
woven with each other. These fasciculi are held together by separate 
fibres, or by areolar tissue. They are of all forms, from the round band to 
the expanded membrane known as a capsular ligament.—Z'endons are 
constructed like ligaments, but usually in larger and more rounded 
bundles. Sometimes they are spread out in the form of aponeuroses. 
YELLOW FIBROUS TISSUE is also known as elastic tissue, from its most 
prominent physical characteristic, in which it differs from white fibrous 
tissue. It is so elastic that it may be drawn out to double its naturai 
length, without losing its power of returning to its original dimensions. 
Its fibres are transparent, brittle, flat or polyhedral in shape, colourless 
when single, but yellowish when aggregated in masses. When this tissue 
is cut or torn, the fibres become curved at their extremities in a peculiar 
manner. It is met with in the ligamenta subflava of the vertebra, the 
ligamentum colli, the chord vocales, and membranes of the larynx and 
trachea, and the middle coat of the arteries. 
RED FIBROUS TISSUE, also called contractile tissue from its possessing 
the power of contracting under certain stimulants, is intermediate between 
yellow fibrous tissue and muscular fibre. Its fibres are cylindrical, trans- 
parent, of a reddish colour, and collected in bundles. It has no connexion 
with the joints, but is met with in the iris, around certain excretory ducts, 
and in the coats of the veins. 
Chemical Composition.—The flexibility of fibrous tissue is owing to 
the presence of water in it, of which it contains about two-thirds of its 
weight. A tendon or ligament will readily dry and become brittle. 
Acetic acid causes it to swell up, and here the acid discloses the existence 
of nuclei and elastic fibres. It is chiefly composed of gelatine, which is 
extracted by boiling. 
