526 Short Communications : -^ 



extended farther west, a length of about 1 50 yards : it was 

 opposite the interval included between the street which leads 

 off the Oxford Road into Connaught Square, and the Hano- 

 ver Square burying-ground, and extended, perhaps, even a 

 little farther west than the frontage of the burying-ground 

 does. This length of wall was, in about August, 1832, 

 taken down ; the foundation of it was cleared away, and 

 a new wall, dwarfer, and surmounted by an iron palisade, 

 has been erected in its site and stead, and uniform with the 

 fence (using this term to imply both wall and palisade) which 

 had been previously erected at each end of it. Of the trees 

 contiguous to the specified length of wall, there are twenty- 

 two (twenty elm trees, one oak tree, one ash tree), standing 

 within from 5 ft. to 8 ft. of the foot of it. In digging out 

 scope of access to the foundation of the old wall, in removing 

 the old materials, and providing scope for the foundation of 

 the new wall, it will be plain, on reflection, that no small in- 

 jury must be occasioned to trees growing so near as this, from 

 both the exposure and the mutilation to which their roots 

 must be subject. The erection of the new fence was com- 

 pleted in about October, 1832; when I presume that the 

 soil was levelled down at its foot, and all left finished as we 

 now find it. Of the twenty-two trees standing so near to the 

 wall as I have stated, fourteen are now (Sept. 1834) so 

 mortally affected that most of this number will, when their 

 present leaves have fallen, never more bear others. The crop 

 of leaves which they this year bear is a full one ; and to the 

 passing eye their leafy heads exhibit so little dissimilarity to 

 those of the neighbouring trees, that, up to August 22., I had 

 not observed, in passing them occasionally, any difference in 

 their condition. On this day my attention was drawn, in 

 passing, to first one, and then another of them, by the buzz- 

 ing and the bustling of numerous large flies upon and about 

 the stems of some of them. Since that time I have examined 

 the trees several times, and acquired the following facts and 

 notions respecting them. The bark of fourteen of them (all 

 elm trees) has been perforated by the Scolytus destructor ; 

 the perforations in some of them are rather numerous, but in 

 nearly all of them have been made by the parent female 

 Sc61yti, to effect their ingress for the purpose of depositing 

 their eggs. The holes of ingress made from without by the 

 entering female Scolyti are usually most readily distinguish- 

 able from those made from within by the Scolyti developed 

 from the introduced eggs in gnawing their way out; those 

 made by the former are larger, less uniform in figure, and 

 less definite in outline, than those made by the latter : the 



