46 Veterinary Medicine. 



roused to more rapid and often more forcible contractions, which 

 modify the pulse both in number and rythm. 12. The circulating 

 blood is found to have received a great increase in the fibrine for- 

 mers, the fibrine in the shed blood amounting to 6, 8, or 10 parts 

 per 1000 in place of 3 parts as is normal. The contraction of 

 this causes a depression on the surface of the clot. 13. The red 

 globules become viscous and adhere together by their flat surfaces 

 to form rolls, which precipitate much more rapidly than single 

 globules and leave the coagulated blood with a straw-colored up- 

 per stratum (bufly coat). 14. Increase of waste products, urea, 

 uric acid, hippuric acid, etc. 



Other changes in the blood are alleged, like lessening of the al- 

 bumen, as balancing the increase of fibrine, and lipaemia, but 

 the constancy of these in all cases of inflammation is uncertain. 



By way of comment and explanation of the above changes in the 

 circulation the following may be advanced : The primary con- 

 traction of the capillaries is by no means a necessary condition of 

 inflammation, and contractions and dilatations within certain lim- 

 its occur in health and as a purely physiological act. The dilata- 

 tion of the capillaries and the increased flow of blood to the part 

 are related to each other as in part cause and effect, yet both are 

 due to a reflex act from the seat of irritation which inhibits con- 

 traction in the capillaries and determines a more rigid contraction 

 in the walls of the arteries running to the part. A rigid inelastic 

 vessel of the same calibre and under the same pressure transmits 

 more liquid than the one with elastic walls. The movement of 

 the white globules to the walls of the vessel depends in part on 

 their levity, light bodies passing into the outer slow moving layer, 

 which is less dense, from the central stream where the force and 

 density are greater. The epithelial cells of the intima undergo 

 cloudy swelling and are often detached, allowing the readier mi- 

 gration of the globules through the openings of the lymphatics 

 and the softened and friable walls. When the capillaries are 

 blocked the pressure necessarily increases on the arterial side, fa- 

 voring laceration of the friable walls and the escape of minute 

 masses of blood. The formation of the buffy coat is characteristic 

 of the normal equine blood ; in inflammation it becomes more 

 abundant. In the other genera a buffy coat apart from inflamma- 

 tion may be shown in : (a) anaemia or oligocythsemia in which 



