62 PROPAGATION 



trees, may sometimes be used as a means of propagation. When 

 these reach the ground they at once fix themselves in the soil, and 

 in a short time form stout independent columns or trunks. The 

 latter will afford support to the parent tree and thus prolong its 

 life, or they may be severed, and thus become independent trees. 

 Where "Gutta Rambong " (Ficus, elastica) is systematically culti- 

 vated for rubber, these root-stems are regularly tapped for their 

 latex. The method adopted in Peracleniya Gardens for enabling 

 the aerial roots of Ficus trees to reach the ground and strike root is 

 as follows : Long bamboo stems (preferably the Giant-bamboo) 

 are split into two, the transverse divisions being cut out ; the two 

 halves are placed together round the aerial root, or at least the 

 portion of it nearest the ground. The bamboo sections are then 

 tied together, the lower ends securely fixed in the ground, and the 

 top filled in tightly with moss to prevent the ingress of rats or 

 squirrels, which feed on the delicate young roots. 



Division of Root-stock. By this method plants which grow 

 in clumps, or have a fibrous or tuberous root-stock, as herbaceous 

 perennials, are easily multiplied. "Division" consists in separating 

 portions of the main plant, each portion bringing with it some 

 of the roots ; if planted under suitable conditions either in pots or 

 out in the field, these soon become established and form new clumps. 

 To many plants of this nature the process of lifting, dividing and 

 replanting each year is beneficial rather than otherwise, as if left 

 undisturbed for a long period the soil becomes impoverished and 

 the plant more or less exhausted. Orchids and herbaceous peren- 

 nials are generally multiplied by division. 



Propagation by Bulbs, Corms, and Tubers. Bulbs or tubers 

 may appear on plants either underground, or on the stem or 

 branches above the ground. In some Yams (Dioscorea) both 

 underground and aerial tubers are found on the same plant. A bulb 

 is composed of either modified leaves in the form of scales, as in 

 Lilium, or of the thickened bases of ordinary leaves folded round 

 each other, as in the onion and Crinum f'Tolobo," S). Bulbil is a 

 term applied to a small bulb, but more generally to aerial buds when 

 they assume the form of small bulbs, as in the case of some ferns, 

 Sisal-hemp and allied plants. Sometimes such bulbils are produced 

 in large numbers (e.g., Sisal-hemp), and take the place of seeds in 

 the function of reproduction, the seeds themselves being habitually 

 either abortive or infertile. These bulbils, if planted in a nursery 

 bed, will in due course grow into large plants. A conn is a short, 

 solid, conical tuber or a modified underground stem, from which 



