5 
[ 
Duplicate specimens were distributed as follows: — 
Botanic Gardens, Buitenzorg ... 
Bureau of Science, Manila ... .... 
Dr. E. D. Merrill, New York 
Royal Botanic Gardens Kew ... 
University of Amoy 
Royal Botanic Gardens, Calcutta 
Sun Yat-sen University, Canton 
Forest Research Institute, Kepong 
Imperial Forestry Institute, Oxford 
British Museum (Natural History) 
Government Botanist, Brisbane 
U. S. National Herbarium 
Dr. C. Christensen, Copenhagen 
The National Herbarium, Pretoria 
Arnold Arboretum, U. S. A. ... 
Mr. H. N. Dixon (mosses) ... 
Cambridge University 
Mr. C. E. Carr (orchids) 
Prof. W. A. Setchell (algae) ... 
Mr. R. Paulsen (lichens) 
Mr. W. E. Nicholson (liverworts) 
Mr. I. H. Burkill (Dioscorea) 
Prof. W. G. Craib (Siamese plants) 
Mr. Fr. Verdoorn (liverworts) 
Prof. U. Martelli (Pandanus) * 
Total 
623 
494 
4U 
407 
3M 
307 
272 
248 
213 
T 99 
144 
i37 
88 
74 
70 
65 
60 
46 
36 
32 
30 
26 
19 
11 
3 
••• 4,335 
Specimens have been received in exchange from the following: — 
Dr. E. D. Merrill, New York 
The Botanic Gardens, Buitenzorg 
The Arnold Arboretum 
Sun Yat-sen University, Canton 
The Bureau of Science, Manila 
Forest Research Institute, Kepong 
Prof. W. G. Craib, Aberdeen 
Prof. W. A. Setchell, California. 
The Director continued the cultivation of young plants of orchid 
hybrids, referred to in previous reports; a number of plants made good 
progress. Also the observations of periodicity of leaf fall of deciduous 
trees were continued; the results to date should be ready for publication in 
1931. The observations appear to indicate that a certain number of tree 
species renew their leaves annually, for the most part about February and 
March, though some change about August. A few species change their 
leaves at both these seasons. Individuals of a considerable number of 
species change their leaves at fairly regular intervals but without apparent 
reference to any season of the year. 
While on furlough the Director attended as an official delegate the 
International Horticultural and Botanical Congresses, held at London and 
Cambridge. The Horticultural Congress was also attended by Mr. G. A. 
Best. These Congresses gave the opportunity of meeting other horti¬ 
cultural and botanical workers from many parts of the world. Various 
excursions were also attended and plants seen noted for trial at Singapore 
