CHAPTER IX 

 PHYSIOLOGICAL 1 



THE value of meat as an article of diet depends upon its con- 

 taining concentrated nourishment in a form which can be easily 

 dealt with by the organs of digestion, and so as to yield only 

 a minimal amount of faecal residue. With meat-eaters the 

 nutritive processes consist in a conversion of the flesh and blood 

 of herbivorous animals into the flesh and blood of those con- 

 suming them, the constituents of the tissues being approximately 

 the same in the two classes of animals. An elementary study 

 of the comparative physiology of Carnivora and Herbivora is 

 sufficient to convince one of the general truth of these statements. 



In carnivorous animals, such as the dog and cat, the digestion 

 and absorption of the foodstuffs are practically confined to the 

 stomach and small intestine. The caecum or "blind-gut" is 

 reduced to a mere vestige, and the colon (which together with 

 the caecum and rectum constitutes the large intestine of 

 mammals) is small and short and without any of the complica- 

 tions found in the horse and other Herbivora. In man the 

 caecum is likewise vestigial, consisting of little more than the 

 appendix vermiformis, so often removed surgically and without 

 any subsequent detriment to the powers of digestion. 



On the other hand in the Herbivora the digestive apparatus 

 is enormously developed. In the horse the caecum is so immense 

 as to occupy the greater part of the abdominal cavity, while its 

 length may be greater than that of the body. At the same time 

 the colon is a vast structure, five or six times as large as the 

 stomach, and double throughout part of its length. In the 

 rabbit and many other rodents also the large intestine is of 

 enormous dimensions relative to the size of the animal, and the 

 same may be said of the herbivorous marsupials. 



In the ruminants, of which the ox, the sheep and goat are 

 examples, the large intestine relative to the size of the animals 



1 By F. H. A. Marshall, So.D. 



