18. The two Australian Black Swans {Chenopis atrata) and the Peking 
Ducks placed on the Lake have been responsible for the depletion of the 
Nymphaea and other aquatic plants. To prevent the complete disappearance 
of water plants, the northern end of the Lake has been fenced off to exclude 
the birds from this end where water lilies and other plants still flourish. An 
attempt to increase the number of the Black Swans was unsuccessful. Five 
eggs received from the Director, Royal Botanic Gardens, Kew, were sent for 
incubating at the Sembawang Research Station. Only one developed, but this 
too did not hatch. 
19. The Lawns were well maintained and regular mowing was carried 
out. The extra labourers sent by P.W.D. for training in the Gardens permitted 
weeding of lawns of Elephantopus scaber which had tended to spoil the 
appearance of the turf. A large number of lawn plantings were made, princi- 
pally to Lawns H, O and W. A feature of this has been the establishment of 
plantings of Acalypha siamensis for topiary work. Several trees within the 
Gardens which were considered to be in a dangerous condition were removed. 
696 wooden labels were made or renewed, 3,698 aluminium tags were made 
and 21 signboards were prepared. A programme of checking all lawn plans 
and plant labels was begun with a view to bringing out a new Gardens Guide. 
20. Monkeys remained the major pest, and 47 were shot during the year, 
mainly in the period September/ October. The watchman-shooter became so 
well known to the monkeys that eventually he could not get near them, with 
or without a gun. Because of this, no shooting of monkeys could be carried out 
for some time. A new pest appeared in the form of a cochchafer, Holotrichia 
bidentata. Several lawns were affected with browning and dying turf caused by 
sporadic outbreaks of grubs of this species in the earlier part of the year. Out- 
breaks were reported also on at least one of the major golf courses of Singa- 
pore. Control was effected with an aqueous dressing of Chlordane and 
Heptachlor. These outbreaks were the first recorded of this species. 
VII. PLANT COLLECTING 
21. Three major collecting expeditions were undertaken, two for orchids 
and living plants for cultivation, in Kedah, Penang and north Perak, and the 
other for botanical material in Penang. Mr. Burkill made collections while on 
leave at Penang Hill and at points along the East Coast of the Peninsula, and 
four 1-day visits were made to the Gunong Panti area to collect tree seeds for 
the Tree Planting Campaign. Details of these and other collecting trips outside 
Singapore are listed in the Appendix. Many collecting trips were also made 
within Singapore. 
VIII. HERBARIUM MATERIALS 
22. The completion of the new wing in August relieved congestion in 
the herbarium. The mounters were able to undertake more work than routine 
mounting: repairs of damaged sheets holding old collections and indexing 
and registration of collections were undertaken. 16,654 specimens were indexed 
4 
