764 



THE GARDENERS' CHRONICLE. 



[Nov. 16 



natural advantages. Now, if the circumstance of being 

 situated partly on the northern brow, and partly on the 

 summit of a bleak high mountain, where the soil consists 

 of from 2k to 3 inches of black bog or peat, constitutes 

 natural advantages, certainly the woods at Nerquis pos- 

 sess such advantages in no ordinary degree ; perhaps the 

 diminutive and ill-thrhing plantations which join them 

 in many parts ought to be regarded as a further proof of 

 the natural advant es which they posses-. If their 

 vigour of growth be not chiefly owing to the training 

 which they have had, I confess I see no other rational 

 way of accounting for it. There being no plantations 

 anywhere near Dr. T.'s managed after the method 

 advocated by Mr. B., I cannot speak to its effects id 

 a comparative point of view ; yet, from what is known 

 of its tendencies, I feel warranted in raying, that if it had 

 been adopted at Nerquis, the results would not have 

 been quite so satisfactory. g 



Notwithstanding Mr. B.'s " protest against the non- 

 pruning advocates," be agrees with them in first prin- 

 ciples ; and, indeed, most of his arguments go to support 

 their views. Both parties seem to think that trees 

 arc supported chiefly from the atmosphere, through 

 the agency of the leave nd branches, and that the vigour 

 and growth of a tree U in proportion to the number of its 

 side branches, and amount of its foliage. That foliage is 

 essential to the healthy exercise of the vegetable functions, 

 there cannot be a doubt ; and care should be taken to 

 preserve as much of it as is consistent with the purposes 

 of artificial training ; but it is opposed to all experience 

 to maintain that the increase of timber in the trunk is 

 best promoted by having a tree loaded with side-branches, 

 or, as Mr. B. seems to think preferable, studded 

 with spurs. One of the arguments used by Mr. B. in 

 advocaring such doctrines is, "that if you cut down a 

 tree having numerous branches on one side, it will be 

 seen that the concentric annual rings are much wider on 

 the side having the numerous branches than on the 

 Other." Supposing inch to be the case, it by no means 

 follows that the side having the branches contains the 

 greatest quantity of useful timber ; for in such cases the 

 apparent increase of timber is just the effect of the inter- 

 ruption of the continuity of the vegetable circulation, 

 caused by the side-branches, and proves most effectually 

 the error of Mr. B.'s system ; for be it observed, that 

 what he would pass off for good timber is just the ends 

 of the branches, their twisted fibres forming, as it were, 

 knots, or distinct masses of wood within the body of the 

 trunk, and rendering it unfit for many purposes of car- 

 pentry. I think, then, there can be no advantage in any 

 enlargement of the concentric annual layers, when pro- 

 duced by such means a- I have described ; and I feel 

 pretty confident that those who have had most expe- 

 rience in converting timber will be «r me out when I say 

 that. ; .\ nine cases out of ten, that side of the tree on 

 ■which there has been fewest branches will be found to 

 contain most good timber. In the artificial culture of 

 wood the mere Increase of timber i.s not the end in view. 

 Fineness of quality is incompnrible with great rapidity of 

 growth ; indeed, everybody knows that rapid growth 

 produces coarseness of texture, and vice versa. There- 

 fore, in judging of the merits of a particular method of 

 training young plantations, by an inspection of results, 

 our ojinious must not be founded altogether on the 

 actual quantity of timber in the trees ; while keeping in 

 view vigour of growth, we must be satisfied that the 

 means employed have been such as to produce that form 

 of trunk which will, when it reaches maturity, yield the 

 greatest return in the shape of clean sound timber of 

 firm texture. 



The method of pruning by the fore-shortening of the 

 lateral branches cannot, with any degree of propriety, be 

 applied to the more valuable kinds of hard wood ; for, 

 in wood of this description, the natural tendency of fore- 

 shortening is to give to the branch or limb so treated 

 the character and disposition of the parent stem, and 

 consequently a capacity for forming what is termed 

 heart-wood ; and it is well known that the twisting of 

 the fibres produced by the side-branche3 is much greater 

 in the case of branches containing" heart-wood than in 

 the case of those that have not reached to such an ad- 

 vanced stage of growth. Another circumstance worthy 

 of notice is, that this twisting of the fibres, so injurious to 

 the texture of the timber, begins where the branch origi- 

 nated, and not at its surface. How improper, then, to 

 follow a method of uniformly fore-shortening branches 

 intended to be eventually taken off close to the trunk, 

 and how necessary to remove superfluous shoots at an 

 early stage of their growth ! 



Th^ main object in pruning a tree is to give a proper 

 direction to its growth ; and as the greater part of the 

 useful timber is contained in the body of the tree, we 

 ought to endeavour to produce "as great a length of 

 trunk, in proportion to the branched top, as the habits 

 of the tree will admit of. In short, to give to the tree 

 that form which is most conducive to utility. That this 

 may be effected by a judicious method of training, 

 the results at Nerquis most distinctly prove. 

 Mr. B.'s report would induce a belief that Dr. T.'s 

 woods have been mutilated by excessive pruning ; 

 but I would mention, and can be borne out in the state- 

 ment, that there is not the slightest appearance of any- 

 thing having been overdone, and there is good reason to 

 believe that the whole operations have been conducted 

 with much caution, much care, and perhaps some 

 niggardly-minded persons might be inclned to say, with 

 no Utile cost. It has sometimes occurred to me that the 

 Tery great nicety of method which characterises every 

 department of the management at Nerquis gives rise to 

 the opinion which we sometimes hear expressed (by such 



as have been accustomed to range slovenly and much 

 neglected plantations) as to things being overdone. 



There is one other point in Mr. B.'s report which 

 deserves notice. Mr. B. appears to imagine that the 

 trees at Nerquis have suffered greatly from the want 

 of proper thinning. To form a correct opinion as to the 

 extent to which this operation ought to be carried, 

 reference must be had to the situation of the woods. 

 Although Dr. T.'s woods are much more open and 

 airy than any others in the same part of the country, 

 yet to a person who has had but limited means of obser- 

 vation, or at least whose experience has been confined 

 to the rearing of timber on fertile plains and sheltered 

 valleys, they may appear to be too thick. On the other 

 hand, those who have experienced the mischief done by 

 the autumnal winds, where the soil is light and the 

 plantations much exposed, might think that the woods 

 at Nerquis have been thinned out to a greater extent 

 than their exposed situation seems to warrant. My 

 own opinion is, that Dr. T. has nothing to regret on 

 this head. 



Mr. B. refers to a plantation belonging to W. O. 

 Gore, Esq., M.P., in which it seems there is a noble 

 Larch girthing at 4 feet from the ground Gl inches. 

 We are told it was planted about 40 years ago, that •• it 

 has had no pruning, but never was crowded." To meet 

 this fact, which Mr. B. holds to be quite sufficient to 

 show what might be accomplished by " proper manage- 

 ment" — in a plantation at Craiglelo, near Ruthin, 

 planted by Dr. T., and pruned according to the system 

 practised at Nerquis, there are several such noble 

 Larches ; and although planted only 38 years ago, some 

 of them girth at 4 feet from the ground Go incites, and 

 are from G5 to 70 feet in height. How justly might I too 

 say, " This shows what may be done by proper manage- 

 ment!"— T, S, G., Flintshire. 





■ 



• 



DISEASES OF PLANTS.— No. VI. 



- , [Fungi.] 



The subject of Galls belongs to Entomology, and a great 

 variety have been figured in this Paper and traced home 

 to their actual causes. It is mentioned here also because 

 the forms, in many instances, have so close a resemblance 

 to Fungi, and have been referred to them even by good 

 botanists on a hasty and superficial inspection. For 

 here, as in other branches of the creation, we observe 

 somewhat of that wonderful analogy by which, in each 

 distinct class or even division of natural productions, the 

 same or extremely similar forms are repeated though 

 accompanied by an organisation totally different; and it 

 is this amongst other circumstances which makes it so 

 absolutely necessary to examine into the intimate struc- 

 ture of the works of the creation, before venturing to 

 pronounce upon their proper place in the system. In 

 the case of Galls it is but a superficial examination which 

 can possibly deceive, for even where the little grub 

 which produced them has vanished, the total absence of 

 all parts of fructification will at once decide the point. If, 

 for instance, the cup- shaped Gal!, which is so common 

 on Oak leaves, be the object in question, any one who 

 has once examined the hymenium of a Peziza, and ob- 

 served the fructifying cells arranged vertically like the 

 pile of velvet, with their row of eight mostly elliptic 

 sporidia, cannot for a moment be deceived. One of the 

 most puzzling Galls I have ever seen was sent by Mr. 

 Macleay, from Cuba, on the leaf of some plant of the 

 natural order Ochnacess, and has been figured in 



the M Transactions 

 of the Linnean 

 Society." In this 

 case there is not 

 merely an extra- 

 ordinary develop- 

 ment of the exter- 

 nal cellular tissue, 

 but the Gall is 

 formed within the 

 substance of the 

 leaf, and after a 

 time bursts through 

 the cuticle and pre- 

 sents a little ovate 

 body with a crenate 

 border, and within 

 this an operculum 

 Orhich is perfora- 

 ted, or at least 

 apparently perfora- 

 ted in the centre, 

 so as to present a 

 very close resem- 

 blance to some 

 strange parasite. 

 And, as if to make 

 the resemblance to 

 some Fungus more 

 close, the Gall ap- 

 pears to make an 

 abortive attempt to 

 penetrate the op- 

 posite surface of 

 the leaf, almost 

 exactly in the way which is observable in the curious 

 production which is sometimes so injurious to Pear- 

 trees. But even in this case, where there is no trace 

 of the inclosed grub or pupa, the texture of the walls 

 of the Gall is so different from that of Fungi that 

 it can scarcely deceive, on any moderately accurate ex- 

 amination. 



There is a class of productions which, though not ac- 



tually Galls, require a moment's notice here. They are 

 indeed very nearly of the same nature with those men- 

 tioned in the foregoing article. I meau the curled spots 

 which are so common on plants when attacked by the 

 smother-fly ; as, for instance, in the Red Currant and 

 the Peach. It is probable, indeed, that all of these are 

 not caused by the presence of the insect, but that the 

 insect is attracted to them especially by the greater tender- 

 ness and juiciness of the tissue in these parts. Certain 

 it is, that in the Peach the curled leaves, abounding i Q 

 juice from the extreme development of the cellular tissue 

 exist in immense numbers on certain trees, before the' 

 slightest trace of the aphis is visible. This is a subject 

 of much interest, and would amply repay an extended 

 series of accurate observations. Of a somewhat similar 

 nature are the rough spots which are so common on 

 Pear-leaves, on the Mountain Ash, &c, and which some- 

 times appear on the Vine. I have never, however, ex- 

 amined leaves so affected, without finding some minute 

 species of Acarus in their company. 



There is yet another production, referred to Fungi by 

 Bernhardi, and after him by Fries and others, which 

 however, is probably to be regarded neither as a disease 

 nor parasite. I allude to the tuberous bodies so common 

 on the roots of leguminous plants. Their exact nature 

 and use at present is not known ; but a Memoir on them 

 h*s been prepared some time by M. Deioeaziere*. They 

 appear a very few days after the germination of the seeds, 

 and are accompanied by a little bed of vessels, in which 

 they are nestled. At an early stage of growth, I con- 

 tents of their cells become blue, when treated by iodine, 

 which is not the case when their pulpy contents have ac- 

 quired a salmon-coloured hu°, when in some cases 

 the granules are simple and oblong, in others forked. 

 There csn be little doubt that they are of some importance 

 to the plant, though they are not, like common tubers, des- 

 tined for the reproduction of the species, as they pass 

 through the phases of vegetation in a short time, and soon 

 become ruptured and discharge their contents. No insect 

 has ever been observed in them, nor indeed does it at 

 all appear that they are of the nature of Galls. It is 

 probable that in very dry situations, and in time of 

 drought, the nutriment collected in them is serviceable to 

 the plant ; but this is very doubtful. — M, J. B. 



* ENTOMOLOGY. 



Bibio Marci (St, Mark's Fly.)— The larva? of this, 

 and of many other allied species of rlies, are so fre- 

 quently transmitted to us as mischievous inhabitants of 

 the garden, that I am induced to believe their history 

 will not be unacceptable. These larva? are generally gre- 

 garious, living in large groups of a hundred or more, in 

 Strawberry-beds, Vine borders, flower-pots and similar 

 uudisturbed spots, feeding upon the roots and sometime s 

 destroying the entire plant. Bouche' says they com- 

 pletely demolished his bed of Ranunculuses for several 

 successive years, by eating up the tubers. The larva 

 (fig. 1) was found, with others, in a Strawberry-bed in 

 October ; it is of a dark-brown colour, somewhat cylin- 

 drical, the belly flattened, moderately broad, and nearly 

 linear ; the head is comparatively small, deep brown, 

 sometimes of a chesnut colour and very shining ; the 

 segments are divided into three narrow fillets, the 

 second of which bears a transverse row of short ochreous 

 spines, with a longer curved one on each side near the 

 spiracles ; the two last segments are sometimes cull 

 ochreous, the penultimate one being armed with si* 

 longish curved spines, and the apical one with four 

 equally long, and a large spiracle on either side. It has 

 no feet; the mouth is furnished witu tridentate jaws, 

 articulated palpi, lips, and maxilla. 



It is in rotten dung, especially of cows that these 

 larva seem to delight, and they perforate the earth in 

 everv direction, their burrows making a honey-comb of 

 the soil. When they are full fed, and about three quar- 

 ters of an inch long, they change to pup*, generally 

 towards the end of March; these are of a pale ochreous 

 Sou ! the head being brighter; the face is heart shaped, 

 and the short brown curved antenna are very distil ctly 

 seen, and look like eyes ; the thorax is very gibbose ; he 

 abdomen is cvlindrical, with a conical apex terminated 

 J two Uttle'spine. (fig. 2). In this state they remain 

 Vom three to five weeks, the males making their appear- 

 anc" firsTtowards the end of April, and the females the 



b the ' sixes rf^he ny, which I will now describe, are 

 verisimilar, as the/ are throughout the genus B, too. 

 not merely in size, but the head of the males is ^tota ly 

 different in form as well as being very much larger the 

 wings are always very much lighter and smaHe than 

 that* of the female, as well as the abdomen. Ihe spe 

 cles before u was named Tipula Marci by Linnreus but 

 i now better known as the Bibio Marci : the male s 

 black shining, and clothed with long sole hairs ; bed anu 

 e e%ge?the latter very hairy, and covering the head, 

 with thr°ee little ocelli on an eminence near the ba. , 

 antennas short, drooping, and exposed of nine 

 mints'* thorax globose; icntel semi-orbicular , a WO- 

 Cn long not stouter than the thorax, tapering, the 

 we* obtnse and armed with forceps ; legs long, espe- 

 cfa.fy the hinder; anterior tibia, very short, mueron, ted 

 externally with a minute spine on the inside, the other 

 sirred-; intermediate slender; hinder long, as wed as 

 the thighs, broad and compressed ; anterior tarsi I e tr 



on* afl 5 , -jointed, and terminated by minnte daw- and 

 nulvilli ; wings incumbent in repose, very white and 



ransparent, but iridescent ; costal margin brown; tu 

 stigma and surrounding nervures brown also, the otner 

 ~~* for dissections, see Curtis'* Brit. Ent. pL M> and for ta 

 species the Guide, Genus 1179- 



