156 A Manual of Veterinary Physiology. 



The amount of faeces produced in 24 hours varies with the 

 quantity and nature of the food given. I have observed 

 that on a diet consisting of 12 lbs. of hay, 6 lbs. of oats, and 

 3 lbs. of bran, that the average amount of faeces passed by 

 fifteen horses during an experiment lasting seven days, 

 amounted to 29 lbs. 13 ozs. in 24 hours, the frcces being 

 weighed in their natural condition, viz., containing 70 per 

 cent, water ; the dry material of this bulk of faces is about 

 7| lbs. More faeces are passed during the night than 

 during the da} 7 . In the above experiment, during the 

 12 hours (6 p.m. to 6 a.m.), the average amount of f;eces 

 per horse was 18 lbs. 3 ozs., whilst from a.m. to G p.m. 

 the amount was 11 lbs. 10 ozs. The largest amount of 

 faeces I have known a horse produce was an average of 

 73-3 lbs. (weighed in their natural state) for the 24 hours ; 

 the diet consisted of 12 lbs. of oats, 3 lbs. of bran, and 

 2cS lbs. of hay. 



In an experiment carried out for several months with 

 different horses all receiving 12 lbs. hay and varying pro- 

 portions of bran and oats, the average daily amount of 

 faeces, weighed in their natural state, amounted to 24 lbs. 



A horse will evacuate the contents of the bowels about 

 ten or twelve times in the 24 hours, and the food he con- 

 sumes will take at least four days to pass through the body. 



In the ox the amount of fleces in 24 hours is about 

 66 lbs. per diem, containing about 10 lbs. of dry material. 



The odour of faeces is distinctly unpleasant, due to the 

 presence of indol and skatol. In disease the faeces are 

 often extremely fostid ; the odour probably depends upon 

 the indol and skatol and the decomposing unabsorbed pro- 

 teid. 



The act of defaecation is performed by a contraction of 

 the rectum, assisted by the abdominal muscles, the glottis 

 being closed. In the horse the contraction of the rectum 

 alone is sufficient to expel its contents ; this is well shown 

 by the fact that this animal can defeecate while trotting. 

 The anal sphincter dilates under the pressure of the faeces, 

 the tonic contraction of the muscle — the centre for which 



