PROPAGATION BYSUCKERS, SLIPS, ETC. 



279 



to the ascending sap by the acute angle formed by the bend, after which all 

 the other branches of the plant may be cut off close to the stem-sucker. 



Cuttings of the side branches of Cun- 

 ninghamia lanceolata have by this 

 treatment made as good plants as seed- 

 lings ; and we believe it has also been 

 successful with Araucaria exc&sa. 



634. Offsets. An offset is a term 

 for the most part confined to the small 

 bulbs, corms, tubers, or underground 

 stems, which are formed at the side of 

 the base of large ones, and by which the 

 plant producing them may be propa- 

 Fig.i9i. Thebranches of a coniferous piantpegged,^ They are very readily observed 



down to force it to throw up a stem-sucker as 6 <f J I* 



a leader. in the hyacinth, tulip, and crocus, in 



which they afford the only means of propagation, excepting by seed. All offsets 

 have a natural tendency to separate from the parent bulb, excepting when they 

 are very small and young; in which case they are left adhering to the parent 

 bulb or tuber for another growing season. When offsets are to be separated, 

 the bulb, when it is in a dormant state, is taken up, and the offsets are 

 removed and planted by themselves, at various depths, according to the size 

 and nature of the offset ; and bearing in mind that all bulbs are buds, and 

 consequently that they would all grow if placed on 

 the surface of moist soil, and pressed firmly against 

 it, without any covering of soil. Offsets may be 

 produced from bulbs, by searing or otherwise destroy- 

 ing their central bud by mutilation, or by cutting 

 them over a little above the plate, from which 

 proceed the scales, as in the hyacinth, and the con- 

 centric coats, or rudiments of tubular leaves, as in 

 the onion; the buds in both cases being in the axils 

 of the members. Sometimes the frost destroying the 

 outer scales of a bulb will stimulate the buds in their 

 axils to develop themselves (fig. 192) ; and some- 

 ib times, when the scales are very closely compressed 



conse uence o tn'u ^ *P' ^ G ^uds ^ t ^ le " r aX ^ S W ^ ^6 developed, and 



riet sustained by the scales will protrude below (fig. 193). A bulb of Crinum 

 from frost. canaliculatum, cut over a little above the plate, was 



found by M. Syringe to throw out no fewer than forty offsets. Practices of 



this kind are rendered unnecessary with tubers, or 



underground stems, which containing numerous 



buds distributed over them, as in the potato, the 



anemone, &c., are propagated by division; but 



those roots which are commonly called tubers, as 



the ranunculus and the dahlia, are naturally in- 

 creased by offsets, and the production of these can 



in general be forwarded by destroying the central 



bud, by which several latent ones are developed. 

 635. Runners or stolones are long slender shoots, 



with joints at distant intervals, which are protruded 



from the collar of perennial herbaceous or sub-her- Fig. 193. Buds developed beic 



baceousplants,suchasthestrawberry,manygrasses, conse( i uence f the cal 



* closely compressed at top. 



Fig. 192. The buds in the 



