544 Mot in Larch. 



Art. V. On the Rot in Larch ; ivith Information on the Dimensions 

 of the Layers of Wood -produced in the Annual Growth of the Larch 

 Tree, in a Series of Years, in connection with a Statement of the 

 Quantity of Rain which fell in each of those Years. By Mr. A. 

 Gorrie, F.H.S. C.S. &c. 



Agreeably to your request, I send you the following remarks 

 on the rot in larch : a subject which, I am glad to observe, 

 begins to excite attention. 



My former note on this subject (VII. 374.), stating some rea- 

 sons for the inference that, where the larch succeeds the Scotch 

 pine (Pinus sylvestris), " the rotting roots of Plnus sylvestris 

 form at least one powerful agent in promoting this disease," has 

 been noticed in a scientific communication, by a gentleman 

 signing himself G. I. T., in the Quarterly Journal of Agricul- 

 ture, vi. 552. Every line in that excellent communication 

 evinces an ardent desire in the author to discover the nature of 

 the malady ; an ardour every arboriculturist must approve, and 

 many, I trust, will be induced to imitate. As I have frequent 

 opportunities of investigating the subject in different situations, 

 I, for one, shall, from time to time, transmit to you such facts 

 as may come under my observation connected with this capricious 

 disease, in the hope that they may meet the eye, and engage the 

 criticism, of G. I. T. and others of your intelligent readers. 



Although I cannot altogether agree with the theory advanced 

 by your ingenious correspondent Mr. Munro (IX. 551.), and 

 although I believe few can admire, or feel disposed to imitate, 

 the flippant style in which he treats his practical brethren at 

 p. 555., yet I feel thankful for his attempts to direct attention to 

 an evil, the baneful effects of which it requires the union of 

 practical men to counteract. In the remarks I have now to 

 submit, I shall allude to such parts of his and of G. I. T.'s com- 

 munication as the facts I may have to offer shall appear to con- 

 firm or contradict. 



Having been lately engaged in cutting down several acres of 

 larch (interspersed with other forest trees), of twenty-two and 

 twenty-eight years' standing, I have retained specimens of a 

 few that appeared diseased, sections of which I shall endeavour 

 to describe. No. 1. is a transverse cutting of a larch tree 

 planted by me in the spring of 1811; the section is made at 

 about 1 ft. from the ground, and measures 1 ft. in diameter. 

 The soil is strong black loam, about 14 in. deep, on a bottom of 

 rotten whinstone or greenstone. The annular gi-owth of the first 

 four years from planting was 1 1 decimal parts of an inch each ; 

 in the year 1816, the annual layer of wood was increased to 26 

 decimal parts of an inch ; in 1 8 1 7, a wet, cold, and late season, 

 the annual deposit measured 3 decimal parts of an inch ; in 1818, 



