FUNDAMENTAL PRINCIPLES OF DISEASE. 
By Russ SHIppEN HvuipeKoper, M. D., Vet. 
[Revised by Leonard Pearson, B. S., V. M. D.] 
ANIMAL TISSUES. 
The nonprofessional reader may regard the animal tissues, which 
are subject to inflammation, as excessively simple structures, as simi- 
lar, simple, and fixed in their organization as the joists and boards 
which frame a house, the bricks and iron coils of pipe which build a 
furnace, or the stones and mortar which make the support of a great 
railroad bridge. Yet while the principles of structure are thus sim- 
ple, for the general understanding by the student who begins their 
study the complete appreciation of the shades of variation, which 
differentiate one tissue from another, which define a sound tendon or 
a ligament from a fibrous band—the result of disease filling in an old 
lesion and tying one organ with another—is as complicated as the 
nicest jointing of Chinese woodwork, the building of a furnace for 
the most difficult chemical analysis, or the construction of a bridge 
which will stand for ages and resist any force or weight. 
All tissues are composed of certain fundamental and similar ele- 
ments which are governed by the same rules of life, though at first 
glance they may appear to be widely different. These are (a) amor- 
phous substances, (0) fibers, and (c) cells. 
(a) Amorphous substances may be in liquid form, as in the fluid 
of the blood, which holds a vast amount of salts and nutritive matter 
in solution; or they may be in a semiliquid condition, as the plasma 
which infiltrates the loose meshes of connective tissue and lubricates 
the surface of some membranes; or they may be in the form of a glue 
or cement, fastening one structure to another, as-a tendon or muscle 
end to a bone; or, again, they hold similar elements firmly together, 
as in bone, where they form a stiff matrix which becomes impreg- 
nated with lime salts. Amorphous substances, again, form the pro- 
toplasm or nutritive element of cells or the elements of life. 
(6) Fibers are formed of elements of organic matter which have 
only a passive function. They can be assimilated to little strings, or 
cords, tangled one with another like a mass of waste yarn, woven 
regularly like a cloth, or bound together like a rope. They are of two 
27 
