OF ORGANIC NATURE. 



11 



then the kidneys, and the organs of reproduction, and 

 so on. Let us now endeavor to reduce this notion of a 

 horse that we now have, to some such kind of simple 

 expression as can be at once, and without difficulty, re- 

 tained in the mind, apart from all minor details. If I 

 make a transverse section, that is, if I were to saw a dead 

 horse across, I should find that, if I left out the details, 

 and supposing I took my section through the anterior 

 region, and through the fore-limbs, I should have here 

 this kind of section of the body (Fig. 1). Here would 

 be the upper part of the 

 animal — that great mass 

 of bones that we spoke 

 of as the spine (a, Fig. 

 1). Here I should have 

 the alimentary canal (5, 

 Fig. 1). Here I should 

 have the heart (<?, Fig. 1) ; 

 and then you see, there 

 would be a kind of double 

 tube, the whole being in- i 

 closed within the hide ; 

 the spinal marrow would be placed in the upper tube 

 (a, Fig. 1), and in the lower tube (J, Fig. 1), there would 

 be the alimentary canal and the heart ; and here I 

 shall have the legs proceeding from each side. For 

 simplicity's sake, I represent them merely as stumps 

 (e e, Fig. 1). Now that is a horse — as mathematicians 

 would say — reduced to its most simple expression. 

 Carry that in your minds, if you please, as a simplified 

 idea of the structure of the Horse. The considerations 

 which I have now put before you belong to what we 

 technically call the ' Anatomy ' of the Horse. Now, 



Fig. 1. 



