2 34 THE LARCH. 



If the theory of hereditary disease be correct, a crop 

 would occupy the ground as various as were the 

 diseases of the seeds — one tree affected with dry-rot, 

 another with blister, another with Coccus laricis, and 

 in the centre of a group which had died off suddenly 

 one or two in perfect health. The reverse of all this 

 is the case. However mixed the trees are when 

 planted, subtle disease attacks them all alike or in 

 groups. 



Many hold the opinion that sound trees can only 

 be grown from imported seed, and contend that the 

 action of the pollen in local plantations is such as to 

 corrupt the seed ; that the pollen of diseased trees is 

 conveyed to those that are sound, and thereby con- 

 taminate the seed. They, too, point to the first intro- 

 duced larches — at least as good as any yet grown — in 

 support of their views. It is, however, an undeniable 

 fact that thousands of trees grown from foreis^n seed 

 become diseased, and many of the Duke of Athole's 

 first planted larches were affected with blight and 

 other diseases. 



D.eep planting is also looked upon by many as the 

 cause of disease, and they point out trees where the 

 roots are near the surface as the soundest and most 

 healthy, while others whose roots are deeper in the 

 ground are affected with ground-rot. The benefit of 

 shallow over deep planting is doubtless twofold : first, 

 the roots are larger and of better quality when near 

 the surface, beine^ better carbonised, and second, the 

 admission of air and light to that part termed the neck 



