528 Short Commimications : -^ 



groups of living ones, where the wound in the bark was large 

 enough to admit a group to pasture together. Nearly the 

 whole of the flies were of the common blow-fly species (Musca 

 vomitoria), but a not uncommon brassy-green species was 

 there, and another small species or two, and a few wasps, and 

 always one or more hornets : at one time I saw three, and I 

 think four, of the latter animal. Of the seven trees into 

 which the parent Scoly ti had perforated, out of which the sap 

 had extravasated, and upon which the flies, wasps, and hornets 

 have been and are (Sept. 10.) feasting, I think I may state 

 that, although their leaves are not, as I have already stated, 

 strikingly dissimilar to those upon neighbouring healthy trees, 

 they yet, to a close inspection, seem somewhat flaccid and 

 drooping, and as if tending to earlier sereness than those of 

 their neighbours. 



To return to the Scolytus. Those who will have it that 

 this poor pretty little beetle is the formidable foe to healthy 

 living trees, and to the interests and wishes of man, that it 

 is represented to be, have now, to account for the facts I have 

 stated, it seems to me, only to say, that " the perforations of 

 the Scolytus induced the extravasation of the sap, and the per- 

 forations and the extravasation have brought the trees into 

 the dying condition in which you describe them to be." To 

 this conclusion, should any one incline to it, there are these 

 objections : — First, as to Scolytus perforating healthy trees at 

 all ; none of the healthy trees neighbouring to those whose 

 roots have been, as I have argued, injured, are at all per- 

 forated. And, were it admitted that the Scolytus does perforate 

 into healthy growing trees, and occasion their death, it would 

 surely be too much to admit that the symptoms of mortality 

 would be induced, in trees healthy and growing, within the 

 very same year or season in which the perforations were made. 

 The erosions of the numerous larvae (which, it is said in IV. 

 152., are hatched, in September, from the eggs introduced by 

 the perforating parent in June and July) subsisting upon the 

 inner bark, and, perhaps, alburnum, of the tree, and eating 

 their way out, might induce, in the year following, death in- 

 deed. Under this view, the particular trees I have cited, 

 should live through, at least part of, 1835, which I anticipate 

 they will not. Next, as to the perforations of the Scolytus 

 inducing the extravasation of sap. The period at which the 

 parent Scolytus bores into trees is intimated, in IV. 152., to 

 be June and July. From the decayed state of the remains 

 of some of the dead flies observed on August 22., it is not 

 too much to infer, that the flies had drunk of the sap of the 

 trees by about this time, and that, this admitted, it was effused 



