Naturalisation in Extra- Tropical Countries. 435 



its rigidity and remaining straight till ripening, is particularly 

 eligible for regions subject to severe storms. Mr. B. McDougall 

 recommends the " Fiji grey " variety, particularly for Queensland, 

 the canes growing quickly and being remarkably weighty. Many 

 other varieties are known. The sugar-cane is one of the best of all 

 plants of economic value, to keep cleared ground in tropical forests 

 free from weeds or the invasion of other plants. Excessive rains 

 produce a rank luxuriance of the canes at the expense of the 

 saccharine principle. Rich manuring is necessary to obtain good 

 crops, unless in the best of virgin soil. The lower leaves of the 

 stem must successiyely be removed, also superabundant suckers, to 

 promote the growth upwards, and to provide ventilation and light. 

 Out of the remnants of sugar-cane either molasses or rum or taffia 

 can be prepared, The average-yield of sugar varies from 1 ton 6 

 cwt. to 3 tons for the acre ; but exceptionally as much as 6 tons 

 per acre have even been obtained in the hardly tropical Hawaian 

 Islands. The world's production of cane-sugar in 1875 amounted 

 2,140,000 tons [Boucheraux], in 1886 to 2,583,000 tons [F. 0. 

 Licht]. Among some other works for fuller information the 

 valuable volume of Mr. A. Mackay, " The Sugar-Cane in Austra- 

 lia," should be consulted, particularly in the far southern colonies. 

 For the conditions and prospects of the cane-sugar industry in the 

 Southern United States see the special report of the Hon. General 

 Le Due, Washington, 1877 ; also the " Sugar Industries of the 

 United States,"by H. W. Wiley, 1885. The stately S. spontaneum 

 (Linne), which extends from India to Egypt and New Guinea, is 

 available for scenic culture. It attains a height of 15 feet, and 

 ascends in Java, according to Dr. Junghuhn's observations, to a 

 height of 17,000 feet. Other tall kinds of Saccharum occur in 

 South-Asia. 



Sag-ittaria lancifolia, Linne. 



From Virginia to the Antilles. This very handsome aquatic 

 plant can doubtless be utilised like the following species. It 

 attains a height of five feet. 



Sag-ittaria obtusa, Muehlenberg. (8. latifolia, Willdenow.) 



North- America, where it replaces the closely allied S. sagittifqlia. 

 A few other conspicuous species are worthy of introduction. The 

 Tule- or Wapatoo-root of California is derived from S. variabilis 

 (Engelmann). 



Sagittaria sagittifolia, Linne. 



Europe, Northern and Middle Asia, east to Japan. One of the 

 most showy of all hardy water-plants ; still not alone on that 

 account deserving naturalisation, but also because its root is edible. 

 If once established, this plant maintains its ground well, and might 

 occupy submerged spots not otherwise utilised For a full account 

 . of this plant refer to Bulletin de la Soc. d'Acclimat. 1888, p. 1102- 

 1106. 



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