forming the next circle, were lieallliy, all beincf of the same age. In all cases where 

 the destruction was goin^ on I found the Scolytus in great profusion : on mentioning 

 this circumstance to the Curator, the old stereotyped answer came in due form, 'that 

 this beetle always attacked sickly and deceased elms, and were since to he found in all 

 places where this timber had fallen or had been conveyed, either decaying along the 

 road-side or drawo into the timber-yard.' Now, in the first place, I was uot satisfied 

 iu my own mind that the trees were perishinsi from the assi<;ned causes; the coinci- 

 dence was too remarkable not to be noticed, and I felt sure that there was something 

 more than the embanking and gravel to account for the rapid death of so many young 

 trees in different parts of the belt, more especially as my attention had been called, in 

 ]842, to the state of the trees in St. James' Park ; with a very little reflection I felt 

 convinced that insects had something at least to do with the matter, and that among 

 them, if the Scolytus destructor were not the first and absolute cause, their presence 

 acted most injuriously by still more disabling the already imjieded circulation of the 

 sap: being fully impressed, after further close and most attentive examination into 

 the subject, of their powerful influence, I made it my business to study their habits, 

 and soon became so far master of them that I was induced, in 1843, to read a paper 

 upon the subject before the Royal Botanic Society, and detailed a mode of treatment 

 I felt almost certain would succeed : as the trees iu the park belong to Her Majesty's 

 Woods and Forests, the Council of the Society applied for permission to allow me to 

 experiment upon some, and a row of eighteen, fiiirly selected, were placed at my 

 disposal. 



" The following eighteen trees were granted by the Commissioners of Woods and 

 Forests in 1843 : — 



No. Scolytus. Cossus. 



* The presence of either Scolytus destructor or Cossus larvae is indicated by „ 

 according to the heading of the column iu which they appear. 



