Bri)S 33 



may lonj; remain latent, and at length upon a favorable occasion start 

 into growUi. so formnjg lu-anelies apparently ont of place as tlie\' are 

 ont of time. The new shoots seen springing directly out of large 

 stems may sometimes originate from such latent buds, which have 

 preserved their life for years. But commonly these arise from 



40. Adventitious buds. — These are buds which certain shrubs and 

 trees produce anywhere on the surface of the stem, especially where 

 it has been injured. They give ris(; to the slender twigs which often 

 leather the sides of great branchi's of our Aniei-ican Elm. They 

 sometmies forni on llie rnut, which natui'ally is destitute of bud.s; 

 they are found e\'en upon some Iraves; and lliey are sure to appear 

 on the trunks and roots nf Willows, f'oplars, and Chestnuts, when 

 these are wounded or nnitilaled. 



41. Definite annual growth from winter buds is marked in most 

 of the shoots from sti'oiig luids, such as those of the Horse-chestnut 

 and Hickory. Such a )uid generally contains, already formed in 

 miniature, all or a great part of the leaves and joints of stem it is to 

 produce, makes its whole growth in length in the course of a few 

 weeks, or sonietinie.s even in a few days, and then forms and ripens 

 its inids for the next year's similar growth. 



42. Indefinite annual growth, on the other hand, is well marked 

 111 such trees or shrubs as the Sunuic, and in sterile shoots of the Rose, 

 Blackberry, and Rasplierry. That is, these shoots are apt to grow all 

 summer long, until stopped by the frosts of autumn or some other 

 cause. Such stems commonly die back from the top in winter, and 

 the growth of the succeeding year takes place mainly from the lower 

 axillary buds. 



43. Forms of trees determined by the development of the buds. — 

 Tlie muiu stem of l-'irs and .Spruces, mdess destroyed by some injury, 

 is carried on in a direct line thriuigli(jut the whole growth of tlie tree, 

 by tlie develoiuneiit year after yi'ar of a terminal bud : this forms a 

 single, rminterru[ited shaft, — an c.iciirrcnt trunk, which cannot be 

 confounded with the branches that piroceed from it. Of sucli xpiri/ or 

 spim-stiapeil trees, the I'irs or Spruces are characteristic and familiar 

 examples. 



44. On the other hand, when Ihc terminal bud fails to take the 

 lead regularly, there is no singli' main stinn, but the trunk is soon lost 

 in its branches, 'i'l'ees so formed (■(.)niinonly have rounded or spread- 

 ing tops. Till' Anierican Kim is a good illustration of this type, m 

 which the stem is said to be ileliijiicxceiU. 



Supplementary Work. Ecology of Buds 



The following outline is meant te suggest some lines of iiulividual research 

 that may be tolloweil llireii^iiotit tlie year in anyplace where plants grow. 

 Notes made Ironi natnre will not, of course, follow this scheme; for such a 



