

IN EXTRA-TROPICAL COUNTRIES. 299 



sugar-fields in Mauritius. The Bourbon variety is praised as one 

 of the richest for sugar; the Batavian variety, S. violaceum (Tussac), 

 is content with less fertile soil. Many other varieties are known. 

 Excessive rains produce a rank luxuriance of the canes at the ex- 

 pense of the saccharine principle. Rich manuring is necessary to 

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

 leaves of the stem must successively be removed, also superabundant 

 suckers, to promote the growth upwards, and to provide ventilation 

 and light. Out of the remnants of sugar-cane molasses, rum and 

 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 been obtained in the Hawaian Islands. The 

 world's production of cane-sugar in 1875 amounted to 2,140,000 

 tons (Boucheraux). For fuller information the valuable local work 

 of Mr. A. McKay, "The Sugar-cane in Australia," should be con- 

 sulted. The stately S. spontaneum (L.), which extends from India 

 to Egypt, is available for scenic culture. It attains a height of 15 

 feet. Other tall kinds of Saccharum occur in South Asia. 



Sagittaria lancifolia, Linne. 



From Virginia to the Antilles. This very handsome acquatic plant 

 can doubtless be utilised like the following species. It attains a 

 height of 5 feet. 



Sagittaria obtusa, Muehlenberg. (S. latifolia, Willdenow.) 



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

 A few other conspicuous species are worthy of introdiiction. The 

 Tule or "Wapatoo root of California is derived from a species of 

 Sagittaria. 



Sagittaria sagittifolia, Linn6. 



Europe, North 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 

 spots neither arable nor otherwise utilised. 



Salix alba, Linne.* 



The Huntingdon or Silky "Willow of Europe, originally probably 

 from Middle Asia. Available for wet places not otherwise utilised. 

 Height 80 feet ? circumference of stem 20 feet ; of rapid growth. 

 Foliage silvery pubescent. Wood smooth, soft, and tough, bearing 

 pounding and knocking better than that of any other British tree ; 

 eligible where lightness, pliancy, elasticity, and toughness are 

 required ; hence in request for wheel-floats and shrouding of water- 

 wheels, as it is not subject to splinter ; for the sides and bottoms of 

 carts and barrows, for breakblocks of trucks ; also used for turnery 



