OF ORGANIC NATURE. 13 



If I were to make a section of a piece of the skin of 

 my hand, I should find that it was made up of these 

 cells. If I examine the fibres which form the various 

 organs of all living animals, I should find that all of 

 them, at one time or other, had been formed out of a 

 substance consisting of similar elements ; so that you 

 see, just as we reduced the whole body in the gross t<> 

 that sort of simple expression given in Fig. 1, bo we 

 may reduce the whole of the microscopic .structural 

 elements to a form of even greater simplicity ; just as 

 the plan of the whole body may be BO represented in a 

 sense (Fig. 1), so the primary structure of (jvltv tissue 

 may be represented by a mass of cells (Fig. 2). 



Having thus, in this Bort of general way. sketched 

 to you what I may call, perhaps, the architecture of 

 the body of the Horse (what we term technically its 

 Morphology), I must now turn to another aspect. A 

 horse is not a mere dead structure : it is an active, 

 living, working machine. Hitherto we have, as it 

 were, been looking at a steam-engine with the fires out, 

 and nothing in the boiler; but the body of the living 

 animal is a beautifully-formed active machine, and 

 every part has its different work to do in the working 

 of that machine, which is what we call its life. The 

 Horse, if you see him after his day's work is done, is 

 cropping the grass in the fields, as it may be, or munch- 

 ing the oats in his stable. What is he doing ? His 

 jaws are working as a mill — and a very complex mill 

 too — grinding the corn, or crushing the grass to a pulp. 

 As soon as that operation has taken place, the food is 

 passed down to the stomach, and there it is mixed with 

 the chemical fluid called the gastric juice, a substance 

 which has the peculiar property of making soluble and 



