258 



THE DOG IN DISEASE. 



^dth redness, tumefaction, exudation, etc., owing to the 

 usual changes in vessels and tissues at the seat of inflam- 

 mation, as before described. Of course, the effects of 



[brain above medulla I 



»y CENTRE"""^ "(-"I 1- •■'■^ /"^INHIBITORY CENTRE 



O 7 SENSORY CEUL AND 

 AFFERENT NERVE 



MOTOR CELL.AND 

 EFFERENT NERVE 



MOTOR CELL WITH 

 EFFERENT NERVE 



Fig. 16.— Diagram intended to illustrate nervous mechanism of— 1, automatism ; 2, 

 reflex action ; and 3, how nervous impulses in the latter case may pass into the 

 higher parts of brain and affect consciousness, or be wholly inhibited. A reflex 

 or automatic center may, for the sake of simplicity, be reduced to a single cell, 

 as above on the left. The arrows indicate the course of the nervous impulses. 



irritating products formed at the site of the disease, and 

 absorbed or acting locally, must not be forgotten. 



Common Causation. — Apart from poisons and such 

 like irritants, unhygienic surroundings, especially damp 

 with cold; unsuitable food, either too coarse and bulky 

 or too exciting, too hot, too cold, or putrescent; blows, 

 nervous shock, as from harsh treatment, etc. 



