588 PRACTICE OF AGRICULTURE. Part III. 



3726. Interior rotting, arising from the dampness of the soil, cannot by the art of man 

 be cured; though it might have been prevented by timous draining. The hearts of trees 

 frequently rot, where there is no excess of moisture, and especially such as have been 

 produced from old roots left in the ground by a previous felling. Such roots when in 

 good ground, send up very great shoots, with few leaves in proportion to their sizes ; by 

 the absence of a profusion of these, properly to concoct the juices so abundantly supplied 

 by the roots, the fibre of the wood is loose and imperfect ; the next season will produce 

 more leaves in proportion to the supply of juices, yet not a sufficient number for making 

 timber ; several years may pass before this event will arrive : thus crude and ill-digested 

 timber disposed to premature decay is the foundation over which subsequent coatings of 

 wood are laid: yet, however perfect these may be, they do not prevent the progress of 

 decomposition going on in the interior. Nature teaches how necessary numerous leaves 

 are to the proportion of the solid wood ; the cotyledons and subsequent leaves of a one- 

 year old tree, are a thousand times greater, compared to its solid contents, than are 

 leaves to the solid contents of the first year's shoots from roots like the above. 



3727. Shakes often arise from the weight and multiplicity of top branches, and might 

 have been prevented by timous pruning. Shakes or rents in the boles of trees, however, 

 often happen where there is no excess of tops. Sometimes the rain running down from 

 the branches, wets one part of the bole, while the rest is comparatively dry. If this cir- 

 cumstance is succeeded by an intense frost, before the wetted side become dry, the bole 

 may be rent for a length, and perhaps to the depth of the core. Shakes or rents, like 

 the above, are difficult to cure. The best method of helping them, is to trace out their 

 upper extremity, caulk it up with oakum, and pitch it over, to prevent the rain descend- 

 ing that way in future. {Sang. ) 



3728. In cases of hoUownesSf Pontey recommends probing to the bottom, letting out 

 the water, if any, with an auger, drying the cavity with a cloth, filling it with dry sand, 

 plugging it with wood and oakum, and then painting it over. 



3729. Decorticated stems or branches by ligntning, or otherwise, if the soft wood is not 

 much injured, will heal over and become covered with bark ; and this the more certainly 

 and rapidly if the air be excluded by a coating of adhesive matter, as cow dung and quick 

 lime, or tying on moss or bandages of mat or cloth. Pontey gives an instance in which 

 such treatment was successful in the case of an apple tree. [Pruner, 230.) We have 

 witnessed it on an extensive scale on the trunk of a pear tree ; and we are informed, on 

 the best authority, of other cases now under progress, in the government garden of the 

 Luxemberg, at Paris. 



3730. Withered or decayed tops, may arise from age and incipient decay ; but also, as 

 Pontey states, from improper pruning, or the want of it. We often see it from improper 

 pruning elms, which, after having been close pruned to their summits for many years, are 

 left entirely to nature; in that case they branch out luxuriantly below, and the top 

 withers. By neglecting to thin out the branches dn the,stems of non-resinous trees the 

 same effect may be produced. 



3731. Stinted bushy tops on very tall naked stems, show a deficiency of nourishment, 

 from these circumstances ; and on short stems from defects of the soil. Obliquely 

 placed misshapen heads, in detached trees, commonly proceed from the same causes and 

 want of shelter. Stinted growth, both in tops and stems, is also produced by ivy, and 

 by lichens, mosses, miseltoe, and other parasites. Ivy compresses the bark, precludes its 

 expansion, as well as excludes air and moisture, by which the outer bark becomes rigid 

 and corky. Happily, both men and trees will live a long time under the influence both 

 of deformity and disease. 



3732. Excessive exudations of gum and resins are peculiar to resinous and some other 

 trees when over pruned, or pruned at improper times. Mildew, honeydew, and blight ; 

 three popular names applied to the effects of certain insects of the aj)his kind, attack the 

 oak, beech, poplar, and many trees; all that can be said is, if proper regimen has been 

 regularly attended to, trees will overcome these and all other enemies. 



3733. Insects and vermin. Almost every tree has its particular insect of the hemip- 

 terous and dipterous families, and many of the coleoptera are common to all. The foli- 

 age of the small leaved elm of hedges is often almost entirely destroyed in the early part 

 of the season by tenthredinidse ; and those of the larch and Scotch pine have suffered ma- 

 tei-ially in some seasons from aphides. The ap)his laricea, L. {Eriosomata, of Leach,) 

 increased to an alarming extent from 1800 to 1802, on the larch, on account of three dry 

 seasons following each other ; but, though it retarded their growth, it ultimately destroyed 

 very few trees. Sang says, he has known it since 1785; that it dirties more than in- 

 jures the tree, and is now (1819) thought little of. Indeed, almost every species of tree 

 has been known to have suffered in some one or more seasons, and in particular districts 

 from insects ; for which, on so large a scale, there seems to be no applicable remedy, but 

 patiently waiting till their excess, or the increase of other vermin, their natural enemies, 



