THE COMMON LARCH. 515 



sand, and in cold wet clays, where no previous crop of 

 Pine has existed, we are inclined to think, with Mr. 

 Matthew, that " there must be some constitutional ten- 

 dency to corruption in the Larch, which is excited by 

 a combination of circumstances, and that we must limit 

 our knowledge, for the present, to the fact, that certain 

 soils, perhaps slightly modified by other circumstances, 

 produce sound, and others unsound Larch." 



The canker is another disease which has been found 

 affecting the Larch in some plantations at Athol and 

 Dunkeld, formed since the commencement of the present 

 century upon land that had previously borne crops of 

 corn, as well as in wet situations ; it is described by 

 Mr. Munro, in the ninth volume of the " Gardener's 

 Magazine,' 1 '' as a malignant distemper, resembling the 

 canker in apple-trees. " First, 11 he says, " a branch gives 

 way, then a black liquid issues from the point of union 

 with the trunk, the regular ascent of the sap seems 

 impeded, and the albumen is disposed in rather large 

 quantities on each side of the affected part, which gives 

 the tree a very unsightly and gibbous appearance. 11 Of 

 this disease we are able to give no further details, as it 

 seems to have been unnoticed by other writers, and has 

 not come under our own observation in any of the Larch 

 plantations in this immediate neighbourhood. 



Of the insects which infest the Larch, the coccus, or 

 eriosoma laricis, commonly known by the name of Larch 

 blight, is by far the most injurious, though seldom to 

 such extent as to destroy the tree, which in the case of 

 the Silver Fir is often done by a nearly allied congener. 

 This insect was first observed by Sang, upon the Larch 

 at Raith, in Fifeshire, about 1785; and in 1795 the Duke 

 of AthoFs attention was directed to it, in consequence 



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