RAMIFICATION. 



99 



seems to divide into three, or itself give rise to a lateral bud on 

 each side. On some shoots of the Tartarean Honeysuckle (Fig. 

 160) from three to six buds appear in 

 each axil, one above another, the lower 

 being successively the stronger and earher 

 produced, and the one immediately in the 

 axil, therefore, grows in preference : oc- 

 casionally two or more of them grow, and 

 superposed accessory branches result. It 

 is much the same in Aristolochia Sipho, 

 except that the uppermost bud is there 

 strongest. So it is in the Butternut (Fig. 

 159), where the true axillary bud is mi- 

 nute and usually remains latent, while the 

 accessory ones are considerably remote, 

 and the uppermost, which is much the 

 strongest, is far out of the axil ; this 

 usually develops, and gives rise to an 

 extra-axillary branch. 



170. Exciirrcnt and Deliquescent Stems. 



Sometimes the primary axis is prolonged 

 without interruption, by the continued 

 evolution of a terminal bud, even through 

 the whole life of a tree (unless acciden- 

 tally destroyed), forming an undivided '^* '^' 

 main trunk, from which lateral branches proceed ; as in most Fir- 

 trees. Such a trunk is said to be excurrent. In other cases the 



main stem is arrested, sooner or 

 later, either by flowering, by the 

 failure of the terminal bud, or by 

 the more vigorous development 

 of some of the lateral buds ; and 

 thus the trunk is dissolved into 

 branches, or is deliquescent, as in 

 the "Wliite Elm and in most of 

 our deciduous-leaved trees. The first naturally gives rise to conical 



FIG. 158. Branch of Red Maple, with triple axillary buds, placed side by side. 



FIG. 159. Piece of a branch of the Butternut, with accessory buds placed one above 

 another : a, the leaf-scar : 6, proper axillary bud : c, rf, accessory buds. 



FIG 160. Part of a branch of Tartarean Honeysuckle, with crowded accessory buds in 

 each axil. 



