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causes of disease will be better ascertained, and every 

 one is aware that to know the cause of an evil is the 

 most important step towards its prevention. 



It is a very important preliminary to the study for 

 which we would gain the attention of practical men, 

 that they understand the nature of plants ; of those 

 organic creatures whose diseases they would obviate ; 

 for an ignorance of, or an inattention to this, is one 

 of the causes that so little progress has been made in 

 this branch of natural philosophy. It is absolutely 

 necessary and important for them to understand fully 

 that this part of the creation, the very grass they 

 trample upon, is so highly organized, so exhibiting 

 intimations of the functions more highly developed in 

 the superior animals, that it is not possible to point 

 out where animal life terminates, and where vegetable 

 life begins : the zoophyte connects the two kingdoms. 

 It is absolutely necessary, we think, for this to be 

 understood and felt by those who enter upon the 

 investigation of vegetable diseases, because we have a 

 strong opinion that these in many, very many in- 

 stances, are caiised by the plants which they infect 

 being treated as if they were totally insensible, inor- 

 ganic matters, scarcely more susceptible of injury at 

 some periods of their growth than the soil from whence 

 they partly derive their sustenance. 



To determine the question whether plants possess 

 a degree of sensation is not so easy as many persons 



