OBGANS OF NTJTEITION. 



99 



'a number of nodules meeting together on the surface form an 

 excrescence. That such nodules are analogous to buds is further 

 proved by the fact of their sometimes producing a short branch 

 ■from their summits, as in the Cedar of Lebanon and in the 

 •Olive. Those of the latter plant, under the name of Uovili, 

 are really employed for its propagation. The peculiar appear- 

 ance of the Bird's-eye Maple is said to be caused by the presence 

 in it of these nodules. 



3. Accessory Buds. — The third cause of irregularity in the dis- 

 tribution and appearance of branches arises from the multipli- 

 cation of buds in the axils of leaves. Thus, instead of one bud, 

 we have in rare cases two, three, or more thus situated {figs. 

 192-194) ; such are called accessory buds. These buds may be 

 either placed one above the other, or side by side. Thus, in 

 certain Willows, Poplars, and in Maples, we have three buds 

 placed side by side (fig. 192, a), which frequently give rise to a 

 corresponding number of branches. In some Aristolochias, in 

 Walnuts {fig. 193,5), in the Tartarian Honeysuckle {fig. 194, h\ 

 •and other plants, the accessory buds are arranged one above 

 the other. Sometimes the uppermost bud alone developes, as in 

 the Walnut, and thus the branch which is formed arises above 

 the axil of the leaf, in which case it is said to be extra-axUlary, 

 In the Tartarian Honeysuckle the axillary or lowest bud is that 



Fig, 192. 



Fig. 194. 



Fig. 192. Branch of a species of Maple with three buds, a, 



placed by the side of one another. Fig. 19.3. A piece of 



the branch of the Walnut-tree. p. The petiole having in 

 Its axil a number of buds, b, placed one above the other, 



the uppermost most developed. Fig. 194. A piece of the 



branch of the Tartarian Honeysuckk- (ionirera tartarica), 

 bearing a leaf, /.with numerous buds,6, inits axil, placed 

 above one another, the lowermost being the most de- 

 veloped. 



which forms the strongest branch, over which a number of 

 smaller branches are placed, arising from the development of the 



