IXTRODUCTIOX INTO GREAT BRITAIN. 1 7 



January i 847 by Mr. Pillaiis Xewton, and for January 

 1863 by Mr. ^Morrison. The rot attacks trees in all 

 situations and on every variety of soil, seldom ap- 

 pearing till the trees are from twelve to twenty years 

 of age. It commences at the root and proceeds upward 

 generally, but not always : sometimes it begins at the 

 top. Our own experience of the somewhat similar 

 disease that has attacked the vine, leads to the 

 belief that it is caused by the spores of a fungus tha,t 

 enters the system of the tree through the roots and 

 develops itself there, causing the disorganisation of the 

 tissues wherever it enters. We should expect the 

 decaying roots and branches of trees cut down, or the 

 prunino: of those left standincr, to breed this fungous in 

 abundance. We have known beech-mast amongst the 

 soil of a vine border breed a functus that entered the 

 system of the vines and killed them, and we think 

 the larch suffers from a similar cause. 



The larch blight {Coccus Lciricis) is a disease that 

 was observed by the Duke of Athole in 1795. It 

 had, however, been previously seen in old trees at 

 Eaith in Fifeshire, in 1785 ; and, like all insect attacks 

 when on a large scale, nothiug can be done to pre- 

 vent it. 



