WINTER STUDY OF TREES 3] 
the axil. This axillary bud may grow during the time 
the leaf remains on the tree, and afterward the growth 
of the strongest one of the others may give the tree two 
branches almost together. 
Some plants form extra buds especially when they are 
bruised or injured; those which have the greatest ten- 
dency to do so are the Willows, Poplars, and Elms. Such 
buds and growths are called adventitious. By cutting 
off the tops or pollarding such trees, a very great number 
of adventitious branches can be made to grow. In this 
way the Willow-twigs used for baskets are formed. Ad- 
ventitious buds form the clusters of curious thorns on the 
Honey-locust and the tufts of whip-like branches on the 
trunks and large limbs of the Elms. 
In trees the terminal bud and certain axillary ones, 
differing according to the species or variety of tree, are, 
during the winter, much larger than the rest. These are 
the ones which naturally form the new growth, and upon 
their arrangement the character of branching and thus 
the form of the tree depend. Hach species has some pe- 
culiarity in this regard, and thus there are differences 
in the branching of all trees. In opposite-leaved plants 
the terminal bud may be small and weak, while the two 
buds at its side may be strong and apt to grow. This 
causes a forking of the branches each year. This plan is 
not rare among shrubs, the Lilac being a good example. 
Bup-ScaLes.— The coverings of buds are exceedingly 
varied, and are well worthy of study and investigation. 
The large terminal buds of the Horse-chestnut, with their 
numerous scales, gummy on the outside to keep out the 
dampness, and hairy within to protect them from sudden 
changes of temperature, represent one extreme of a long 
line; while the small, naked, and partly buried buds of 
the Honey-locust or the Sumac represent the other end. 
The scales of many buds are merely extra parts formed 
for their protection, and fall immediately after the burs 
