WINTER STUDY OF TREES 31 



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. Each 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. 



BUD-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 j 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 burst- 



