14:0 SELECT PLANTS FOR INDUSTRIAL CULTURE 



which produces only a single trunk. F. rubiginosa also sends air- 

 roots to the ground to form additional trunks (Dr. G. Bennett). 

 The allied Fig-trees of continental East Australia have great but- 

 tresses, but only now and then a pendulous root, approaching in 

 similarity the stems of Ficus columnaris. The Lord Howe's Island 

 Fig-tree is more like F. macrophylla than F. rubiginosa, but F. 

 columnaris is more rufous than either. In humid, warm, sheltered 

 tracts this grand vegetable living structure may be raised as an 

 enormous bower for shade and for scenic ornament. The nature of 

 the sap, whether available for caoutchouc or other industrial mate- 

 rial, requires yet to be tested. A substance almost identical with 

 gutta-percha, but not like India-rubber, has been obtained by 

 exsiccation of the sap of F. columnaris (Fitzgerald). The hardened 

 sap of this species resembles in many respects that of F. subracemosa 

 and F. variegata, called Getah Lahoe, but differs apparently by its 

 greater solubility in cold alcohol, and by the portion insoluble in 

 alcohol being of a pulverulent instead of a viscid character. The 

 mode of exsiccation affects much the properties of the product. 



Ficus Cunninghami, Miquel. 



Queensland, in the eastern dense forest regions. Mr. O'Shanesy 

 designates this as a tree of sometimes monstrous growth, the large 

 spreading branches sending down roots which take firm hold of the 

 ground. One tree measured was 38 feet in circumference at 2 feet 

 from the ground, the roots [forming wall-like abutments, some of 

 which extended 20 feet from the tree. Several persons could con- 

 ceal themselves in the large crevices of the trunk, while the main 

 branches stretched across a space of about 100 feet. A kind of 

 caoutchouc can be obtained from this tree. A still more gi- 

 gantic Fig-tree of Queensland is F. colossea (F. v. M.), but it 

 may not be equally hardy, not advancing naturally to extra-tropi- 

 cal latitudes. This reminds of the great Council-tree, F. altissima. 

 F. engenioides, F. v. M., from North-east Australia, attains a height 

 of 100 feet, and produces also columnar air-roots. It is compara- 

 tively hardy, reaching extra-tropic latitudes. 



Ficus elastica, Roxburgh.* 



Upper India, to the Chinese boundary known as far as 28 30' north 

 latitude. A large tree, yielding its milk-sap copiously for caoutchouc, 

 i.e., the kind called Assam Rubber. Roxburgh ascertained sixty 

 years ago that India-rubber could be dissolved in cajaput oil (so 

 similar to eucalyptus oil), and that the sap yielded about one-third 

 of its weight caoutchouc. This tree is not of quick growth in the 

 changeable and often dry clime of Melbourne, but there is eveiy 

 prospect that it would advance rather rapidly in any unutilised 

 humid forest gullies, and that copious plantations of it there would 



