REPORT ON LARCH FORESTS. 411 



other cause, look at the two margins of the drain : on the one 

 side is the earth, with its luxuriant crop ; on the other, with 

 only a three feet drain between them, is a poor stinted growth, 

 with no loose earth to grow in. 



Some persons maintain that dry soils are as injurious to larch 

 as wet ones are. This is not borne out in the writer's experience. 

 It is true larches die on dry soils, but it is not simply on account 

 of the soils being dry that they die, but because of some dele- 

 terious or obstructive substance being in the way of the roots. 

 Either the subsoil is pan, or the soil may have been exhausted 

 by preceding crops of similar or different kinds. One descrip- 

 tion of exhausted soil is met with in moorlands which is fatal to 

 larch ; it is termed a deaf soil, and in it the roots at an early age 

 lose their vitality. The manner in which larch decays in this 

 sort of soil gives rise to the belief of its contracting disease, 

 through fungi, of the spongioles of the roots. Such soils are 

 impure, hence unfit for larch. Lime applied to such soils pre- 

 vious to planting might be of some benefit, but in the meantime 

 it is much safer to plant spruce or poplar. 



Larch as a succeeding crop succeeds much the same as others 

 do. But as ground cleared of a crop of trees requires in general 

 both draining and trenching, it is after this is done that the 

 ground is in readiness for another crop. 



Wet clay soils are admitted without dissent to be fatal to larch, 

 and yet upon such soils larch is not only planted, but promises 

 to do well for a time, and then speedily dies off. The cause of 

 this is pretty clear. In the first stage of growth the roots are 

 upon the surface, and the under herbage thin, so that they have 

 the advantage of solar heat. Afterwards the roots dip into the 

 cold and wet soil, and those roots that extend upon the surface 

 are matted over with a rank, deep-rooted herbage, which herbage 

 probably also impoverishes the soil and obstructs the roots of the 

 trees. Whether the manner in which a wet clay soil proves fatal 

 to larch be fully understood or not, experience shows that it is 

 inexpedient to plant larch upon it, however well it may grow at 

 first. 



The preceding are the principal theories and opinions enter- 

 tained respecting the causes of failures of the larch ; but without 

 following in detail the various forms of disease, and tracing them 

 through their various stages, the writer will conclude this part of 

 the subject by adding briefly, that it is his opinion that all the 

 diseases embracing what is generally known as the larch disease, 

 are either due to low temperature in the soil, the result generally 

 of superabundant water — a soil too compact, stiff, or hard for the 

 roots to spread or dip in — the sudden transition of the roots pass- 

 ing through a o;ood strata of soil into an inferior one, or entering 

 a soil either naturally destitute, or exhausted of those elements 



