268 NATURAL HISTORY. [CH. XIX. 



on the 27th of June, it was found to be inhabited by 

 living larvae, and they were supposed to be the cause 

 of the tumour. Sorpe branches were placed in a 

 vial, to observe their progress to maturity. On the 

 6th of July, the observer perceived that the larvse 

 had left the tumour, and were uneasy in tKe bottom 

 of the vial. A vessel of earth was immediately 

 prepared: the larvae, when turned into it, buried 

 themselves instantly. On the 30th of the same 

 month the perfect insects began to rise. They 

 proved to be insects which had long been known to 

 occasion the fall of peaches, apricots, and plums, 

 by the larvae eating into the kernel of those fruits 

 long before they had acquired half their growth. 

 The evil produced by this insect cannot be wholly 

 remedied ; but something may be done to diminish 

 the mischief by cutting off the diseased branches, 

 provided this be done at the right season, and by the 

 joint labour of the whole neighbourhood at the same 

 time. Those insects which furnished the data above 

 set down, ceased to feed on the 6th of July, rose 

 from the earth on the 30th, and were soon ready to 

 deposite their eggs in healthy branches ; but, if the 

 diseased branches are cut off before the end of June, 

 a great number may be most effectually destroyed 

 by burning the branches on which the tumours are 

 seen. It is possible that in some situations they 

 may be disclosed earlier ; it will therefore be neces- 

 sary to prune away the tumours as soon as they ap- 

 pear. The insects which cause this mischief belong 1 

 to the Linnaean genus Curculio. 



The elm-trees of St. Jameses and Hyde Park 

 were attacked, in 1824, by an insect known to en- 

 tomologists by the name of Hylesinus destructor, 

 which caused great havoc, especially in the Mall and 

 Birdcage walk. The elm-trees in both parks, and 

 particularly in St. James's Park, were being rapidly 

 destroyed ; and unless decisive measures had been 

 taken to resist the progress of the contagion, we 



