CONTENTS. 



xxiii 



planation of phenomena and in the solution of questions 

 connected with trees — its uses to the gardener and the 

 forester. Apology and protest. Suggestions. — I. Cautions 

 as to pruning and precautions as to planting and thinning. 

 II. The fact of the tree-plants of each year being essentially 

 independent of those of past and subsequent years, aground 

 of hope to the landowner that a disease affecting his plan- 

 tations for one or even for a series of years,, may be but 

 temporary and not permanently injurious. Disease in its 

 own nature essentially temporary. Eecovery of diseased 

 larch plantations. Probable final recovery of the potato, 

 the h.op, the vine, and other plants from their " disease." 

 Possibly some qualification of this expectation requisite in 

 the case of trees — the timber produced by diseased plants 

 perhaps unsound, and may affect the adjacent sound timber. 

 '^Dry rot " in timber. 



LETTER XX 213 



Application of the theory to questions in natural theology. 

 Laws of Nature : what they are ; various definitions given 

 of them — Dr Alison's, Dr Thomas Reid's, Plato's, (Ersted's. 

 ' Illustrations. What the law written upon trees ; what 

 the language which they speak. Conclusion. 



POSTSCRIPT 223 



Annual and prospective money-value of larch and Scotch fir 

 plantations. 



APPENDIX 229 



