CHAP, cxiir. coni'fer^. za^rix. 2385 



planted upon dry soil, were attacked by a small insect, resembling the wire- 

 worm, from i in. to Jin. in length. From 10 to 20 worms, and sometimes 

 more, have been observed at the root of one tree. (^Trans. Soc. Arts, vol. 

 xxxviii. p. 6.) 



Viingi. The European larch, and also the Russian variety, when old, or when 

 the trunk is beginning to decay, will produce the jBoletus laricis, which is called 

 by some authors Jgc'iricus pungens, and which is used in Russia, and some 

 other parts of the north of Europe, as an emetic in intermittent fevers. It is 

 also the agaric of the larch of the shops. The body of this fungus is sapona- 

 ceous ; and, Pallas informs us, is used by the women in some parts of Siberia 

 to wash themselves and their linen. The Tungouses dye the hair of their 

 reindeer with it and the roots of Galium verum, of a deep red colour. For 

 other Fungi growing on the larch, see the general article on the i^ungi of the 

 Jbietinae, p. 2146. 



The Rot in Larch Wood is a disease which has hitherto baffled every attempt 

 of physiologists and planters to ascertain its cause. It seems to have been 

 first observed about the beginning of the present century, when some larch 

 trees growing in fertile soils were cut down and sawn up for use. We are 

 not aware of any record of the disease earlier than that given in our Treatise 

 on Country Residences, published in 1806. In Sang's Plantei-'s Kalendar, the 

 first edition of which was published in 1812, several instances are given of 

 the rot having appeared in Fifeshire, apparently from the trees having been 

 planted in too rich a soil, and too warm a situation. Pontey does not notice 

 the rot in larch, though he does that of timber trees in general ; but Matthew 

 treats of it at some length. In the Gardener's Magazine, the subject is dis- 

 cussed by Mr. Gorrie and Mr. Munro ; and there are several articles on the 

 subject in the Quarterly Journal of Agriculture ; one of which, written in an- 

 swer to certain questions put by the editor of that journal to Professor De 

 CandoUe of Geneva, we have already quoted from. From all these sources, 

 and some other incidental ones, we are only able to give the following un- 

 satisfactory account : — 



The rot attacks trees at various ages, and in different soils and situations. 

 There are instances, in Scotland, of larch trees of 8 or 10 years' growth having 

 the interior of their stems tainted with the rot ; but, in general, both in Eng- 

 land and Scotland, it does not attack the trees till they are from 20 to 30 

 years of age. It generally commences at the root, and proceeds upwards, 

 rotting the heart of the trunk ; but, in some instances, it has been found to 

 commence at the top of the tree, and proceed downwards. In a majority of 

 cases, Matthew observes, the rot commences in the roots which have struck 

 down deepest into the earth ; especially those immediately under the trunk 

 of the tree. Thence, the corruption proceeds upwards in the centre of the 

 trunk ; which, when much diseased, swells considerably for a few feet above 

 the ground ; evidently, Mr. Matthew observes, from the new layers of sap wood 

 forming thicker there, to afford necessary space for the fluid to pass upwards 

 and downwards ; the matured wood, through which there is no circulation, 

 approaching, at the lower part of the trunk, to within one or two annual 

 layers of the bark. The disease can scarcely be detected by the external 

 appearance of the tree ; but, when it is cut down, the interior of the trunk is 

 found brown and rotten to a greater or less extent ; and, in trees which have 

 been subject to the disease for some years, the centre is so entirely rotten as 

 to have become hollow, like a pipe or wooden pump ; and hence, as before 

 observed, the name of pumping has been applied to this disease. Sections of 

 trees, of different ages and sizes, affected in this manner, have been sent to us 

 by Mr. Gorrie and Mr. Munro. (See Gard. Mag., vol. ix. p. 551. ; and vol. x. 

 p. 534.) Fig. 2266. a shows a section of a larger-sized tree, in which the pump- 

 ing has only just commenced, though the rot has extended itself so as to dis- 

 colour the whole of the heart wood ; and^g. 2266. b a section of a young tree 

 in which pumping has begun early, and extended very considerably, in pro- 

 portion to the diameter of the trunk. In some soils, the rot commences as 



7 p 2 



