2i8 ZONES AND REGIONS [Pt. Ill, Sect. I 



The average daily increment during two montlis' observations was — 

 Culm No. I, in 58 days, 22-9 cm. per diem. 



„ ,, 2, „ 60 „ 19-0 „ 



„ ,, 3. >. 60 „ 19-9 „ 



The greatest increment in twenty-four hours was— 



Culm Xo. I, 57 cm. on 22nd December. 



„ „ 2, 42 „ „ 3rd Januarj'. 



„ .. 3. 45 „ .. 4th 



Very quick-growing plants are not at all rare in the tropics, at any rate 

 in rainy districts. I have made some measurements, at the Buitenzorg 

 botanic garden, on young shoots and leaves of woody plants whicl 

 appeared to be growing very rapidly : — 



On the 15th November I measured a still folded leaf of Aniherstia nobilis anc 

 found, rachis 6 cm., a leaflet 2-9 cm. On the 24th Nov. the same rachis and leafle 

 measured 31 cm. and 19-5 cm., showing an increased length of 5- and 7-fold respec 

 tivelj^ in 9 dajs, or a dailj' increment of 4-1 cm. and i-S cm. respectivelj'. Of a some 

 what older leaf of the same shoot the corresponding measurements on the 15th Nov 

 were lo-S cm. and 3-5 cm., on the 24th Nov. 36 cm. and 197 cm. In Brownea sp. 

 the length of a bud just opening on the 15th Nov. was 8 cm. ; on the 20th Nov. th' 

 young shoot, the leaves of which had not j-et unrolled, was i8-5 cm. long; on thi 

 24th Nov. with the leaves opened quite flat, the measurement was 29 cm. to the extrem 

 leaf-tip. The total length had therefore increased more than 3i-fold in 9 daj's, in fac 

 by 21 cm., and this gives a dailj^ increment of 2-6 cm. Other measurements of th 

 developing young shoots of Urostigma glabellum will be given subsequenth' i 

 connexion with the leaf-fall of trees. 



Haberlandt mentions several instances of rapid growth in Java : — 



'In 1874, at Willem Ill's school in Batavia, a plant of Eucalj'ptus alba, indigenou 

 in Timor, was planted ; after three years' growth it was alreadj- a tree, 15 meters i 

 height. In a plantation at Tjikomoh, near Buitenzorg, two-year-old mahogan}' plant 

 are 4^ meters high, and three-year-old plants of Swietenia macrophylla 5-6 metei 

 high. Albizzia moluccana— that admired shade-tree, the delicate pinnate foliage 

 which does not give one any impression of abundant vigour and activity— grows wit 

 fabulous rapidit}-. Fine j-earling plants actuallj' attain a height of 5-6 meters, si: 

 j'ear-old plants are already 25 meters high, with stems measuring 20-25 centimetei 

 in diameter at the height of a man \' 



In Honolulu Maxwell - undertook some investigations on the growth ( 

 banana leaves. The averages of his results he tabulates as follows : — 



' Haberlandt, op. cit., p. 115. • .Maxwell, op. cit., p. I. 



