546 Rot in Larch. 



the appearance of so many pea-green cones, several of which still 

 remain ; and in none of those so clothed with side branches did 

 the red wood appear to indicate a precocious maturity. I men- 

 tion this, to direct attention to the state of the diseased tree, the 

 section of which I have been describing. This tree had stood 

 near a walk, and had had its branches pruned off up to the height 

 of 8 ft. or 10 ft. 



In going over from three to four acres of larch trees, where 

 the soil was a strong deep black loam approaching to clay 

 (see the Quarterly Journal of Agriculture, vi. 550., where Mr. 

 Knight's opinion is quoted by G. I. T. as to argillaceous loam), 

 mostly on a moderately retentive subsoil, the trees generally 

 measured from 1 ft. to 1 5 in. in diameter, when cut near the 

 ground. Here I found, in general, an approximation to early 

 maturity : the red wood appearing in many of a dark colour, 

 and extending to within 1 in. or 2 in. of the outside; apparently 

 having nearly arrived at that period when, according to a quo- 

 tation from Mr. Knight's letter, in the communication alluded to 

 bv G. I. T., the heart wood not receiving new matter, it might 

 be said " to live no longer," yet it was such as is denominated 

 sound by joiners. These trees were planted, I should have 

 said, in 1805. In another two acres of larch trees, of the same 

 age, which had grown in a strong black loam from 8 in. to 10 in. 

 deep, but upon a dry and porous subsoil, and where the trees 

 exhibited such strong symptoms of premature old age as to 

 render their removal advisable, I found the red or heart wood 

 generally extend to within five or six annular layers oJ the 

 bark; and, of sixty of these trees, I found three completely 

 infected ; the section of one of which I shall describe, pre- 

 mising that the other two specimens present almost similar 

 phenomena. Here I have again to beg Mr. Munro's attention 

 to the facts, that, in each of the diseased specimens, the annu- 

 lar layers are comparatively narrow ; and, in each, the central 

 layers for the first ten years are sound. G. I. T. will also please 

 to observe, that, in this instance, "a" very "dry soil" appears 

 conducive to " decay at the heart." [Quart. Journ., vi. 551.) 

 The trees were planted, as I have said before, in 1805; and the 

 three annular layers of 1805, 1806, and 1807 amount in breadth 

 to 4 decimal parts of an inch. The deposit in 1808 measures 

 •]5; in 1809, *20 ; and, in the three following seasons, about 

 •3 of an inch each year. For 1813, the annular deposit measures 

 only '15 of an inch : this was a dry season. In 1814* and 1815, 

 about *2 of an inch each season. Up to this period, all the 

 central layers are sound : but the disease in an inveterate shape 

 begins to encroach inwards from the four following annular 

 layers, which are all around quite rotten. In 1820, the wood 

 was of a diseased colour, but firm ; in 1823, the annular layer, 



