26 ANATOMY OF THE RABBIT. 
it is found to yield up to a certain point, beyond which it is tough 
and resistant. It tends to regain its original shape when the 
tension is removed. 
Fibrous connective tissue may be greatly modified through the 
concentration of either one of the fibrous elements. Concentration 
of white fibres is most common. This con- 
dition is illustrated in the thick connective 
tissue layer forming the true skin or corium 
(Fig. 5), but is more conspicuous in the 
glistening white tendons (Figs. 7,34) by which 
muscles are attached to bone surfaces, in the 
ligaments uniting bones with one another, 
and in the thin, broad aponeuroses which 
serve for muscular attachment. The struc- 
tures known anatomically as fasciae are 
special sheets of connective tissue covering 
chiefly individual muscles or muscle groups. 
Conceniration of yellow fibres occurs in the 
dorsal ligament of the neck (ligamentum 
muchae) where greater elasticity is required. 
The ligament is not so conspicuous in the 
rabbit as in larger mammals where the 
Fic. 7: Ftom a section Yellow coloration is very noticeable. 
of the tendon of origin of Fat or adipose tissue is a soft form of 
the biceps muscle: m.f., E : E 
muscle fibres ending on the - connective tissue in which the cells are greatly 
tendon; t., fibrous con- 
nective: Aseuevot the ten: enlareedsand icontamatatty. material athe 
form of globules. It tends to occur in certain 
situations and in particular association with the bloodvessels, but 
otherwise is found in situations where areolar connective tissue - 
might be expected to occur. Special fat masses, sometimes 
distinguishable by their darker coloration, occur at the side of the 
neck in the rabbit. In the foetus (cf. Plate VI) large masses of 
vascular connective tissue are found in this situation, and are 
probably similar in origin to the storing or hibernating glands of 
certain other mammals. ! 
Coloration or pigmentation of certain portions of the body, 
especially of the skin and hairs, and of the retina, ciliary body, and 
iris of the eye, is due partly to the presence of special connective 


