PLANTING. 



363 



roots takes place solely by the extremity of each 

 radicle fibril, or, which is to say the same thing, 

 by the spongioles which terminate each of their 

 ramifications." Decandolle had some idea of 

 this when he remarked that young trees exhaust 

 the earth very near their trunks, while the old 

 ones with horizontal roots produce this exhaus- 

 tion at a distance from their trunks, the more 

 considerable in proportion as they are larger. 



Modern physiologists have confirmed this 

 opinion, in remarking the longitudinal direction 

 of the fibres, and the thickness of the cellular 

 envelop, which prevents the juices from reach- 

 ing them laterally. Sennebier has also shown 

 this by very conclusive experiments. " It is 

 certain, then," he says, " that the absorption of 

 roots only takes place by their extremities : we 

 may here mention that it is, then, at the extre- 

 mities of the roots, and not at the base of the 

 trunk, that we ought to apply water, manures, 

 and, in general, all the substances which we wish 

 plants to absorb." 



If preserving uninjured the spongioles, and 

 consequently the roots of trees, even to their 

 very extremities, be of the importance stated by 

 the authorities above, then it would appear that, 

 in removing a plant or tree, far less of the suc- 

 cess depends on the compactness and size of the 

 ball, providing every root is not contained with- 

 in it, than on the preservation of the roots, 

 which can only be preserved to a very limited 

 extent, as all beyond the ball must of necessity 

 be cut off. As trees increase in age and size, so 

 do their roots diverge from their stem— no doubt 

 in search of food, and also to enable them to 

 maintain their natural upright position ; and it 

 is no uncommon thing for shallow-rooting trees 

 — the Abies tribe, for example — to extend their 

 roots horizontally to the extent of 40 or 50 feet, 

 that is, giving a diameter to the field they 

 occupy of from 80 to 100 feet. Now, according 

 to the doctrine maintained by the advocates for 

 the spongiolet system, the whole of the food- 

 absorbing portions of the roots must occupy 

 a zone forming the circumference of a circle 

 whose diameter is equal to that given above* 

 For Decandolle, if we mistake not, stated the 

 theory, and almost every physiological writer 

 of eminence since his time has confirmed his 

 views, that the absorption of the food takes 

 place solely at the extremity of each radicle 

 fibre, by the spongiolets which terminate each 

 of the ramifications. If these opinions be cor- 

 rect — and they have not been as yet contro- 

 verted — it would follow that it were better to 

 dispense with a ball altogether, and direct our 

 whole attention to the preservation of the roots, 

 even to their most minute points ; and hence 

 we apprehend that washing the soil entirely 

 from the roots, tying them up in bundles, enve- 

 loping them in moss, and using every other 

 possible means for preserving them uninjured 

 to their full extent, will yet be considered the 

 most likely means to insure the successful re- 

 moval of very large trees. 



The ball system of removal, however long 

 sanctioned by practice, must be defective in 

 every case in which the ball does not include 

 within it every rootlet and spongiolet ; and this 



can only be in the case of very small and young 

 plants, whose roots have not extended beyond 

 a radius of 4 or 5 feet from the trunk; and 

 although the rule is not without exceptions, it 

 may be set down as pretty near the average, 

 that the spread of the tree may be taken as 

 nearly that of the horizontal extent of the roots. 

 " Roots, in their lateral extension, bear usually 

 a relation to the horizontal spreading of the 

 branches, so as to fix the plant firmly, and to 

 allow fluid nutritive substances to reach the 

 spongiolets more easily." — Balfour in Manual 

 of Botany, p. 66. 



The prevention of excessive evaporation at and 

 after the process of transplanting. — " Evaporation 

 takes place in plants to an inconceivable degree 

 in certain circumstances. In damp or wet 

 weather this evaporation is least ; in hot dry 

 weather it is greatest. This loss has all to be 

 supplied by the moisture introduced into the 

 system by the spongioles ; and hence, if the 

 spongioles are destroyed, and evaporation takes 

 place before they can be replaced, a plant must 

 necessarily die. This is the reason why decidu- 

 ous trees cannot be transplanted while in leaf : 

 it is impossible to remove them without injur- 

 ing their spongioles, and it is equally impossible 

 to hinder the evaporation by their leaves ; but 

 if they are kept in pots, it matters not at what 

 season their removal takes place, because, as 

 their spongioles are then uninjured, even exces- 

 sive evaporation would be made good by their 

 action. It is well known that certain evergreens 

 can be transplanted in almost all months ; this 

 arises from their perspiration being much less 

 copious than in deciduous trees, wherefore the 

 spongioles have less difficulty in supplying the 

 loss occasioned by it ; yet even evergreens can- 

 not be removed in the hottest months of the 

 year, because then the action of such spongioles 

 as may be saved in the operation would not be 

 sufficient to supply the waste by evaporation. 

 Plants first beginning to grow in the spring, 

 with their leaves just turning green, are 

 in a most unfit state to remove ; for, when 

 transplanted, their roots will not have time to 

 form a sufficient number of new spongioles to 

 supply the loss to which the rapid perspiration 

 by the leaves at that season will give rise." — 

 George Lindley. In these views Mr Lindley is 

 supported by Dr Hales, Guettard, Knight, and 

 others. 



Excessive evaporation may be greatly coun- 

 teracted by shading, and copious applications of 

 water thrown over the foliage and branches by 

 a fine syringe or garden engine. We say a fine 

 syringe, because the water so applied should be 

 as much in the form of dew as possible, and 

 applied night and morning until the roots have 

 made sufficient progress to be able to supply the 

 trees by natural means. 



Preparing the places for transplanted trees. — 

 Digging pits is the usual term applied to this 

 operation, and in too many cases the term is 

 not misapplied ; for thousands of trees annually 

 have their roots thrust into pits from which few 

 of them ever escape. He who prepares a space 

 sufficiently large, so that the roots maybe spread 

 out to their fullest extent in all directions, 



