(28) 



and laid flat. The lines represent the vascular bundles, which enter the 

 bud at the numbered points. In Fig. 19 we see that the fibres of two- 

 fifths of the vascular ring enter into one leaf. If we segregate the meri- 

 thalls and put the buds at the same level, we have a whorl of 5, 8 and 13, 

 and the whole number of buds represents a whorl pulled out into a spire. 



There are sometimes supernumerary buds in some species of Juglans, 

 Carya, Gymnocladus, Amorpha, Gleditschia ; two to even four buds ap- 

 pearing one above the other. The uppermost develops, or it forms an 

 abortive twig, a spine (Gleditschia) ; then the next lower develops, the lowest 

 remaining dormant. In Crataegus the axillary bud is often transformed into 

 a spine, when an accessory bud appears on both sides. 



The species with opposite buds have a true terminal bud. This is 

 sometimes abortive and wanting in Euonymits and Stapliyleo, or the shoot 

 had an indefinite growth and withered in fall at the upper end, as in Sam- 

 bucus, Tecoma, Catalpa, Cephalanthus. Then of course there is no ter- 

 minal bud. 



SIZE AND FORM OF THE BUD. 



The buds of our woody plants are formed in summer, and are visible 

 during winter. Only GleditscJiia and Rohinia show no buds in winter ; 

 these are hidden in the bark and break forth only in spring. Others show 

 only a little knob (Ptelea^ Cqyhalanthm). There are a number of trees 

 which have very large buds, at least at the upper end of the shoot (^Aescu- 

 lus^, Fraximis, Juglans, Carya ^ Fopidm), others very small ones {Cercis, 

 Celastrus). The buds are either leaf-buds or flower-buds or mixed, con- 

 taining leaves and flowers at once. The latter are quite similar to the leaf- 

 buds ; the flower-buds are mostly more roundish and swollen, and placed at 

 the lower part of the shoot (Fraximis^, but some flower-buds are cylindrical 

 and appear (in Ehus aromatica) at the upper end of the shoot. 



The true terminal bud of the species with decussate buds and the 

 pseudo-terminal bud of the species with alternate buds, are often much 

 larger than the axillary buds ; and, as these are often the only ones that pro- 

 duce new shoots, these trees show in winter a limited number of long 

 branches. When we examine such branches, we find sometimes a row of 

 shoots, each with a few approximated leaf-scars, and below these a ring of 

 narrow scars of the bud scales, fixing the limit of each shoot, and then a 

 long shoot with remote buds. (Faguf, Fig. 16 on PL II, and Cornus al- 

 ternifoliu!^ Fig. 9 on PI. 111. ) By counting these shoots we can determine 

 the age of the branch. 



The bud is fusiform, often very slender [Amelanchier, Cormi!<, Virbur- 

 num lentayo); or ovate, more or less pointed (^Aesculus), or oval and ob- 

 tuse {Diosp)yrof, Ulmus fulvo), or globular {Crataegus), or compressed 

 (^Asinima, Liriodendron, Haniamelis). 



DIRECTION OF THE BUDS. 



The axis of the bud stands mostly at an angle of 15 to 45 degrees to 



