CONCLUSION. 153 



passage of the water, are thereby rendered in a 

 fit state to act as the pabulum of the grass, by 

 furnishing an increased supply of carbon. 



That the fertilizing effects of irrigation are 

 due to the presence of something more than 

 mere water, may be proved from the fact, that 

 stagnant water produces the very reverse of a 

 running stream, which is quite contrary to 

 what should be the case, was water the only 

 requisite for a luxuriant vegetation. 



CONCLUSION. 



We have thus completed the task originally 

 contemplated, we have traced the organization 

 of the vegetable structure and the functions al- 

 lotted to each part of the plant, from the period 

 of the germ's first appearance to the completion 

 of its allotted purpose— -the ripening of the 

 seed. 



The subject of the composition of the goil 

 has also come under our notice, and we have 

 endeavoured to point out the conditions neces- 

 sary to be observed, for the perfection of the 

 crops growing on its surface; and, lastly, the 

 matter composing the structure of the plant 

 itself, the sources from which it is derived, and 

 the manner in which it is assimilated, have 

 been fully entered into, leaving, it is hoped, 

 little in the present state of our knowledge on 

 this subject to be desired. This with the spe- 

 cific action of the various manures, completes 

 the subject, which it is hoped will be found 

 practically useful to those employed in the cul- 

 tivation of the soil. 



