III. 
SUPERPOSED BUDS. 
Plate XII. 
BY A. F. FOERSTE. , 
Buds are usually produced singly in the axils of leaves. When 
more than one bud is found in the same axil, the additional buds are 
accessory and supernumerary . When they are placed at the side of 
the one immediately in the axil, the buds are collateral, when placed 
in a line vertically above the axillary bud, the additional buds are 
superposed. 
Accessory buds are not of the same age. In the case of collateral 
buds, the one immediately in the axil is the oldest. Among super- 
posed buds there are two methods of development. The axillary bud 
first produced becomes visible, grows, and may reach some size before 
any additional bud is apparent. After a time • another bud appears 
immediately above the one already produced. A third or fourth bud 
may appear above the one last formed. In the Tartarean honey- 
suckle ( 7 ) four or five buds are occasionally found arranged in such a 
series above the true axillary bud. This is called direct superposition 
and is of rare occurrence both among woody and herbaceous plants. 
Usually, however, the axillary bud first produced reaches a consid- 
erable size before a second bud appears. This second bud is inserted 
beneath the one first formed. If the second grows rapidly enough, a 
third bud may appear beneath the second, and a fourth beneath the 
third. This is inverted superposition and is very common indeed, both 
in ligneous and herbaceous plants. In several species of the Juglan- 
daceae and in Gyninocladus Canadensis (6) where the buds do not im- 
mediately follow one another but are arranged at short intervals along 
the internode, five or six buds are occasionally found superposed in 
this manner. The upper buds here betray their earlier origin by their 
greater size and development. 
