LAY 



LEA 



The object of the gardener is to induce 

 the layer to emit roots into the earth at 

 the tongue. With this view he twists 

 the shoot half round, so as to injure 

 the wood-vessels ; lie heads it back, so 

 that only a hud or two appears above 

 ground, and when much nicety is re- 

 quisite, he places a handful of silver 

 sand round the tongued part; then 

 pressing the earth down with his foot, 

 so as to secure the layer, he leaves it 

 without farther care. The intention of 

 both tongueing and tAvisting is to pre- 

 vent the return of sap from the layer 

 into the main stein, while a small 

 quantity is allowed to rise out of the 

 latter into the former; the effect of this 

 being to compel the returning sap to 

 organize itself externally as roots, in- 

 stead of passing downwards below the 

 bark as wood. The bending back is to 

 assist in this object by preventing the 

 expenditure of sap in the formation or 

 rather completion of leaves, and the 

 silver sand is to secure the drainage so 

 necessary to cuttings. 



Tn most cases this is sufficient ; but 

 it must be obvious, that the exact man- 

 ner in which the layering is effected is 

 unimportant, and that it may be varied 

 according to circumstances. Thus, Mr. 

 Tames Mimro describes a successful 

 method of layering brittle - branched 

 plants by simply slitting the .shoot at 

 the bend, and inserting a stone at that 

 place ; ( Gardener's Magazine, ix. 3Q'2 ; ) 

 and Mr. Knight found that, in cases of 

 difficult rooting, the process is facili- 

 tated by ringing the shoot just below 

 tin' tongue about midsummer, when the 

 leaves upon the layers 

 nad acquired their full 

 growth; (Hort. Trans, i. 

 x>50 ;) by which means he 

 prevented the passage of 

 the returning sap further 

 downwards than the point 

 intended for the emission 

 of roots. It will sometimes 

 happen that a branch of a 

 plant cannot be conve- 

 niently bent downwards 

 into the earth ; in such 

 cases, the earth may be 

 elevated to the brand) by various con- 

 . as is commonly done by the 



Chinese. When this is done, no other 

 care is necessary than that required for 

 layers, except to keep the earth sur- 

 rounding the branch steadily moist. 

 See the figure below. 



XAYIXG-IN is a gardener's term for 

 training the branches of espaliers and 

 wall -trees. iMying-w-by^he-fi&ils is his 

 mode of describing a plant's having its 

 roots roughly buried in the soil for 

 some temporary purpose. 



LAZY-BEDS are beds dug for the 

 growth of potatoes, the sets being then 

 placed in rows on the surface, and 

 covered by the soil dug -out of narrow 

 deep alleys between the beds. 



LEADWOKT. Pluwba'yo. 



LEAF-MOULD. This is formed of 

 leaves kept moist and in a heap fre- 

 quently turned over, until completely 

 decayed, and reduced to a dark brown 

 moist powder. It usually takes two 

 years to complete this process. , s An 

 excess of water delays the decaying, 

 and either lime or gas ammoniacal 

 liquor, promotes it, but then few potted 

 plants are benefited by any such excess 

 of either of these additions. 



LEATHERWOOD. Di'rca. 



LEAVES are highly vascular organs, 

 in which are performed some of the 

 most important functions of a plant. 

 They are very general, but not abso- 

 lutely necessary organs, since the 

 branches sometimes perform their 

 offices. Such plants, however, as, na- 

 turally possess them, are destroyed or 

 greatly injured by being deprived of 

 them. 



Tlfie duration of a leaf is in general for 

 a year only, though in some plants they 

 survive for twice or thrice that period. 

 These organs are generally of a green 

 colour. Light seems to have a power- 

 ful influence in causing this, since if 

 kept in the dark they become of a pale 

 yellow, or even white hue, unless un- 

 combined hydrogen is present, in which 

 case they retain their verdure though 

 light be absent. Hence their blanching 

 would seem to arise from their being 

 unable to obtain this gas under ordinary 

 circumstances, except when light is 

 present. Now the only source from 

 which they can obtain hydrogen, Jw by 

 decomposing water ; and how light us 



