740 



THE CIECULATIOK 



Now it is evident that the object should be, when there is such 

 disturbance, to equalize the circulation again, or force it back to 



its natural chan- 

 i^^~T^\^r'^\^NO^^'-'^>]^l."SJH ii^ls as quickly 



as possible, and 

 that treatment 

 by which this 

 can be done 

 most easily and 

 quickly will be 

 the best. The 

 circulation is 

 really controlled 

 by the nervous 



Fig. G31. — Portion of the web of a frog's foot, largely magui- system. it the 



fie(|, after a drop of strong alcohol had been placed upon nervOUS system 



it. The black spots are caused by the congestion js from a n V 

 induced by the alcohol. i 



cause weaken- 

 ed, so that it is unable to act with the usual vigor, there is less 

 ability to resist the influence of disturbing changes, and the horse 



Fig. 632. — ^Irregular contraction of small vessels in the web of a frog's foot 

 after the application of stimuli. 



is, as it is termed, more liable to take cold, which means a disturb- 

 ance of the circulation. 



Hence a horse, when warm and exhausted after a drivi ,, if 

 given a little too much cold water would be liable to have colic, 



