48 1 



acids in the soil prevents free absorption : thus we find that among 

 cultivated plants m this country, ' Rambong ' (Ficm elastica)-- 

 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 well defined wet and dry 

 season, as in parts of California and 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 again >t 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 brasiliensis) 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. 



ANONA 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 grown 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 more of a curiosity than an 

 addition to our dessert. 



