!^^:^^ 



1>£AB BUQUT. 



soils we fiiul the tree to grow anil flourish in. It may be queslionoil, if a tree, which 

 finds the proper constituent particles in a soil fur its licallhy growth, can ever exhaust 

 any part of it to such an extent as to produce death, if the natural sources of growth 

 continue to yield their supply from the atmosphere. A forest does not wear out the 

 soil and die ; on the contrary, we are indebted to its agency for the virgin soil we find 

 under its boughs. It is the opinion of writers of high authority, that among our mod- 

 ern forest trees, there are some which have attained the great age of four thousand 

 years ; and it is said that " investigation of coal and lignite strata lias proved the 

 existence of trees of the same order as those now existing." If this be true, it j>roves 

 positively that trees do not draw on the soil, so as to destroy themselves, or to impair 

 the perfect development of their seed and fruit. But it may be said this is applicable 

 to a state of nature. Well, this is just what I am endeavoring to show ; that we have 

 run contrary to this ; and, from that cause, have produced an enfeebled race, which 

 we are exposing to an uncongenial climate, and charging it (improperly, as I think), 

 to the soil. 



The reason why soils are worn out, is because of injudicious cultivation, a continued 

 removal of its products without a proper restoration of the properties thus removed. 

 This is not applicable to trees, only so far as the removal of fruit is concerned, and 

 the obstruction of the natural supply from decayed leaves, branches, &c. This may 

 be larger or smaller, and of course it is wise to see that the soil is well supplied with 

 all the particles thus drawn from it. You may, however, feed the Pear tree as much 

 as you please, and still it will die in the midst of a luxurient growth ; and it is, there- 

 fore, to other causes that we must look for its destruction, not to the want of proper 

 food. 



The advocates of the insect theory have not been very successful in proving its truth. 

 They are bound to show something more plausible for its support, than the simple 

 fact that insects are found in connection witli the diseased parts. They are bound to 

 show that these insects are really tha cause, and not there as a result of the blight. 

 And, moreover, to show some reason why it is that they discriminate, pass by certain 

 unmolested Pear trees, and do not make a clean sweep of all within their reach ; and 

 also, why it is that their destructive influence is sometimes suspended for years 

 together. 



Prof. Harris' description of the Scolyius pjri, in his invaluable work on Insects, 

 which is mainly relied on as the support of this theory, fully defines its regular periods 

 of change and operations. I am very sure that it will not apply to our blight, all the 

 reasons for which I cannot here enumerate. SuflBce it to say, that the injury of that 

 insect " ends with the death of the branch, down to a certain point, but does not extend 

 below the seat of attack, and does not eff'ect the health of other parts of the tree." 

 (Second edition Harris^ Treatise on Insects). A comparatively harmless insect, whose 

 effects all cultivators in this region will have observed on their trees. 



I will here very briefly give what I deem the cause and the reason for the blight, 



are not materially different from those given elsewhere. Long observatio 

 ifirmed my judgment that the disease is chargeable mainly to atmospheric 



