1906] WIEGAND—BUDS AND TWIGS IN WINTER 375 
all but the outermost scales are living and contain a large amount 
of water throughout the winter. The inner scales are frequently 
almost destitute of epidermal thickenings and are quite green and 
fresh. Because of the much larger size of the cells in the scales, 
and much larger vacuoles, there is much more water present in these 
structures than in the young shoot whose cells are small and nearly 
filled with protoplasm. This it will be seen is an important con- 
sideration when the buds freeze during the winter. The abso- 
lute amount of water in the whole bud is however very nearly the 
same as that in the young bark, being about 51 to 55% for the 
fruit buds examined; and, as in the bark, this amount is remarkably 
constant for the species. 
The proportion of space occupied by the young shoot varies with 
the species and nature of the bud. In flower buds this proportion 
is usually greater than in leaf buds. In many cases only a very 
small fraction of the total volume is shoot-tissue, all the rest being 
composed of scales; but in other cases, as for instance the flower 
buds of pine, almost the whole volume is made up of cones, leaves, 
and stem; while the scales are very thin, dry, and firmly ‘cemented 
together. In this case of course nearly all the water is located 
within the young shoot. The spaces between the various organs 
and scales usually contain air alone; but in some cases, as for example 
in apple and horsechestnut, there is also a large amount of wool 
present in which the organs are seemingly imbedded. In Populus 
and some other trees the spaces are more or less completely filled 
with resin. 
Buds of most indefinite growers differ from those of the majority 
of definite growing trees in two essential ways: in the slight develop- 
ment of the fundament, and in the usual absence of scales. The 
young shoot is most frequently represented merely by a growing 
ihrer Entwickelung. Nova Act. Leop. Carol. Ak. Naturf. 2: 303-344, 1887, Ref. Bot. 
Centralb. 36:43. 1888; ScHUMANN, C. R. G., Anatomische Studien iiber die Knos- 
Penschuppen von Coniferen und dicotylen Holzgewachsen. Biblioth. Botan. 15:32. 
Cassel, 1889, Ref. Bot. Centralb. 42:275. 1890; Griss, J., saat zur Biologie 
der Knospen. Jahrb. Wiss. Bot. 23:637. 1892; Lussock, J., On buds and stipules. 
Jour. Linn. Soc. 30: 463-532. 1895; 33:202-269. 1897; CapuRA, R., Physiologische 
Anatomie der Knospendecken dicotyler Laubbaiume. Breslau, 1887, pp. 42; Mrkosca, 
K., Beitrige zur Anatomie und Morphologie der Knospendecken dicotyler Holzge- 
Wichse, Sitz. Konig. Akad. Wiss. Wien Math. Wiss. Kl. 74':723-755- 1877- 
