247 



Our conceptions of the rate of growth in the tropics have 

 been formed from observations made in tropical lowlands on 

 such manifestly rapid-growing plants as the banana, the bamboo, 

 Dendrocalamus, Amherstia nobilis and some other trees ;* such high 

 rates as 231 mm. per day having been observed in stems of 

 Dendrocalamus, and 107 mm. per day in leaves of the banana. 



Owing to the slowness of the elongation of shoots the follow- 

 ing observations have been made only upon growth of leaves. 

 The individual plants upon which measurements were made were 

 all located near Morce's Gap at 1525 m. altitude on the windward 

 slope of the Blue Mountains. Plants were selected with a view 

 to securing such as were growing under average light conditions 

 for the species, and the leaves selected were those unfolding at 

 the ends of shoots which were neither the most nor the least 

 advantageously situated upon the plant. 



Bochmcria caudata Sw. (Urticaceae). This is a large shrub or 

 a small tree with leaves of thin texture, 20 to 30 cm. long by 10 

 to 20 cm. wide and opposite in insertion. Boehmeria grows 

 continuously through the year, and its leaves fall continuously, 

 being from five to seven months old at fall. The following 

 figures give in millimetres the length and width of the laminas of 

 two paired leaves, and the rate of growth in length per day. 

 Date. A. Size. Rate. B. Size. Rate. 



Alchornea latifolia, Sw. (Euphorbiaceae.) This is a common 

 forest tree with rather xerophilous leaves 15 to 20 cm. long by 6 

 to 8 cm. wide in shade leaves, or much smaller in sun leaves. 

 Alchornea grows throughout the year and leaf-fall is continuous. 

 The following figures give the lengths of the laminas of five 

 consecutive leaves on the same shoot. 



For the literature of this subject the reader is referred to Schimper, Plant 

 Geography, Oxford Ed. pp. 218 ff., and to a more recent paper of Lock, R.H., on 

 the Growth of Giant Bamboos. Ann. Royal Bot. Gard. Peradeniya, Vol. II. Pt. 2, 

 Aug. 1904. 



