481 
acids in the soil prevents free absorption : thus we find that among 
cultivated plants in this country, ‘Rambong’ ( Ficus elasticci) — - 
whose leaves are protected against excessive transpiration by having 
an epidermis consisting of three layers — is better adapted to this 
class of soil than any other cultivated plant. 
Plants inhabiting regions which have a w T ell defined wet and dry 
season, as in parts of California ar d South Africa, and the shores 
of the Mediterranean, are known as tropophytes, and at the com- 
mencement of the dry season shed their leaves and thus protect 
themselves against excessive transpiration. In these countries a large 
number of plants develope bulbs or tubers which act as reservoirs ; 
so that they may become completely dried up and experience ex- 
treme drought without injury, passing through the dry season in a 
dormant state, and bursting out into fresh growth when the condi- 
tions become favourable. Such plants include Yams, Lilies, Etc. 
We see therefore, how perfectly plants have accommodated them- 
selves to every physical environment, and how necessary it becomes 
to study in detail the conditions under which plants occur in nature, 
in order to cultivate them to the .best advantage. As illustrating this, 
the Mexican rubber tree ( Castilloa spp .) may be cited : this tree has 
its branches arranged in whorls, its leaves densely covered with 
hairs, and in many respects exhibits the peculiarities of a true 
xerophyte, and, as has been proved by experience, is totally unsuited 
to the hot moist conditions obtaining in the Malay Peninsula. On 
the other hand, the ‘ Para ’ rubber tree ( Hevea hrasiliensis) is almost 
a typical hygrophyte, having a large spreading crown, with an 
abundance of large thin leaves which favour rapid transpiration, and 
although likewise an alien has proved itself to be admirably adapted 
to the conditions obtaining in*this country, 
( To be continued . ) 
STANLEY ARDEN, 
Superintendent , Experimental Plantations, F M,S. 
ANON A PALUSTRIS. 
The Alligator apple is one of the Anonas which occurs on muddy 
river-banks and such places in the West Indies and Brazil. It has 
long been cultivated in the Singapore Botanic Gardens but has 
never fruited. Mr. ARDEN sends a ripe fruit growt> in the Batu 
Tiga gardens. Like the other anonas it is a large shrub or small 
tree with ovate rather stiff leaves. The fruit is 5 inches long and 4 
inches through, oval in outline with low marked reticulations much 
like the bullock’s heart [A. squamosa). The skin of the fruit yel- 
lowish green, the pulp very soft yellow -acid and with a decidedly 
unpleasant flavour. The fruit seems to be hardly ever eaten even 
in its native country and indeed is said by some persons to be 
narcotic and dangerous so that it is mere of a curiosity than an 
addition to our dessert. 
