36 
COMPARATIVE ZOOLOGY. 
are condensed into sheets or parallel cords, having a wavy, 
glistening appearance. Such structures are the fasciae and 
tendons. Connective tissue is not very sensitive. It con¬ 
tains gelatin — the matter which tans when hide is made 
into leather. In this tissue the intercellular substances 
take the form of fibres. The white fibres are inelas¬ 
tic, and from - 4 tf to of an inch in diameter. 
They are best seen in the tendons. The yellow fibres are 
elastic, curled at the ends, very long, 
and from o o fo ■^inro" of an inch in 
diameter. They are shown in the 
hinge-ligament of an Oyster. Connec¬ 
tive tissue appears areolar, i. e., shows 
interspaces, only under the microscope. 
(3) Cartilaginous Tissue. —This tissue, 
Fig. 5.—Hyaline Cartilage, 
Diagram: a , cartilage 
cell; 6, cell about to di- . 
vide; c, ceil divided into known also as “gristle, is composed 
two; d, into four parts. n • i_ j j j • i i 
The space between the of cells imbedded in a granular or hy- 
parent hiteroeiiaiarTab- aline substance, which is dense, elastic, 
stance; highly magni- bluish-’white, and translucent. It 
fled. 
IS 
found where strength, elasticity, and 
insensibility are wanted, as at the 
joints. It also takes the place of the 
long bones in the embryo. When 
cartilage is mixed with connective tis¬ 
sue, as in the ear, it is called fibro-car- 
tilage. 
(4) Osseous Tissue. —This hard, opaque 
tissue, called “ bone,” differs from the 
former two in having the intercellular 
spaces or meshes filled with phosphate 
of lime and other earths, instead of a 
~ d hyaline or fibrous substance. It may 
be called P etrified tissue-the quantity 
ceils, passing into com- 0 f earthy matter, and therefore the brit- 
pact bone, c, and then 47 7 
spongy bone, e. tleness of the bone, increasing with the 
