RURAL ECONOMY. 



CHAPTER I. 



PHYSICAL PHENOMENA OF VEGETATION. VEGETABLE PHYSIOLOGY. 



The operations of agriculture having for their object the produc- 

 tion of plants which are either essential as food, or useful in the arts 

 and industrial processes of man, it is well to begin with a summary 

 view of the principal organs of which vegetables are composed ; and 

 by the instrumentality of which, under certain influences which we 

 shall seek to appreciate, all the phenomena of their existence are 

 manifested. 



Plants fixed in the soil by their roots, live in the atmosphere by 

 the concurrence of their green parts under the combined actions of 

 light, heat, and moisture. We shall by and by ascertain at the cost 

 of what elements, and under what conditions, their growth and com- 

 plete development are accomplished. 



The seed, which is the final result of vegetable life, and of which 

 the aim is the reproduction and multiplication of the species, should 

 first receive our attention. The seed is, if we may so speak, the 

 starting point of all husbandry ; it is with very few exceptions the 

 first point on which the industry of the farmer exerts itself. 



Nature, to ensure the preservation of seeds, has had recourse to 

 infinite care and foresight, which are in some measure an assurance 

 of their importance. The seed is often placed in the middle of an 

 abundant fleshy pulp, which serves to afford it nourishment or ma- 

 nure at the time of its future development. Sometimes, as in legu- 

 minous plants, it is lodged between thick and tough membranes, or 

 is covered with hard but flexible scales, as in the gramineous plants ; 

 or again it is enveloped in a woody substance of extreme hardness, 

 as in stone fruits. 



Nature does not show herself less provident in furnishing means 

 for scattering seeds, and propagating vegetable species at great dis- 

 tances. There are, indeed, seeds which, furnished with light silky 

 plumes or wings, flutter in the air, and are transported afar by the 

 winds. Others, by means of a viscous, hard, impermeable envelope, 

 float on rivers, and descend their courses without suflTering the slight- 

 est change, or losing their germinating power. There are seeds 

 again of a sufficiently coherent texture to resist the digestive action 



