VOMITING. 147 



milk. Though nourishing when carried into the stomachs 

 of the young birds, it is doubtless most useful in moistening 

 grain and preparing it for effectual digestion. The crop of 

 the domestic fowl is seen at 4, Fig. 77, and the guizzard, 7, 

 is a muscular organ destined to grind the food, compensating 

 for the want of teeth. It is connected with the secreting 

 stomach, 6, which is technically called ventriculus succen- 

 turiatus. 



Returning to the simple stomachs of our domestic quad- 

 rupeds, we find that the muscular fibres are destined to cause, 

 Istly, A movement of the contents from left to right, or 

 vice versa; 2ndly, A rolling movement; Srdly, A mixed 

 movement. Thus the food is exposed most freely to the 

 action of the gastric juice. 



None of the monogastric animals ruminate. Instances 

 have been recorded of human beings becoming addicted to 

 the habit, or suffering from the tendency to ruminate, as a 

 symptom of a morbid state of the alimentary canal. The 

 regurgitation of food in all animals, with a simple stomach, 

 constitutes the act of 



VOMITING. 



This is the simple means by which an animal discharges 

 that which the stomach refuses to digest, or is likely to be 

 injured by. The act is under the control of the nervous 

 system, and in order to be induced, the phenomena included 

 under the name nausea or sickness must be observed. All 

 animals are not equally susceptible to nauseating agents, or 

 to substances capable of causing the evacuation of the 

 stomach. This is regarded by my brother, Mr J. Sampson 

 Gamgee, as the true cause of the difficulty of the act in the 

 horse, and in other animals who manifest but rarely the 

 tendency, and, never in health, the power to vomit, A very 



