GENERAL PRINCIPLES. 181 



disturbances may not arise ; hence the necessity for chap- 

 ters on disease, which disease as a matter of fact exists 

 and carries off many of the finest specimens of the canine 

 race. 



In a large proportion of disturbances inflammation 

 and altered conditions play a very prominent part, and to 

 these, in the briefest way, attention is now invited. 



An organ may contain an excess of arterial blood, 

 owing mostly to enlargement of its arterioles, and is then 

 said to be hypercemic ; if the organ contain an excess of 

 venous blood, from the latter not being removed as rap- 

 idly as usual, the part is possibly congested, or there is 

 stasis, though the latter term is applied mostly to slowed 

 current in the smallest vessels or capillaries. 



When the vascular (circulatory) and associated disturb- 

 ances constitute inflammation, we have dilatation of blood- 

 vessels, afflux of blood, slowing of the blood-current, 

 changes in the walls of the vessels, in the blood within 

 them, and in the tissues around them. 



The small blood-vessels dilate, the colorless corpus- 

 cles become more actively amoeboid, the vessel-walls are 

 changed, and, in consequence of the relations between the 

 blood, the vessels, and the tissues being altered, the cor- 

 puscles pass through to a greater or less extent, especially 

 the colorless ones (leucocytes), and also a fluid derived 

 from the liquor sanguinis, or plasma. 



The tissues around the vessels may enter on a more 

 active condition and produce immature cells. 



These changes are accompanied by heat, pain, redness, 

 and swelling in most instances, and may give rise to con- 

 stitutional disturbance of varying degrees of severity, 



