Naturalisation in Extra- Tropical Countries. 283 



H. Kempe] . Spots for Mulberry-culture must not be over moist r 

 when the leaves are to be utilised for the Bombyx. In 1870, 

 according to the British Trade-Journal, the produce of cocoons 

 amounted in Europe to 16,588,000; in Asia to 28,112,000; in 

 Africa to 44,000; in the South-sea Islands to 24,000; in 

 America to 20,000 thus giving a general total of 44,788,000. 

 In 1875 the yield of raw silk in the district of Rajshahye (British 

 India) was estimated at 400,000, employing about 12,000 people, 

 the plantations extending approximately over 150 square miles 

 [Dr. S. Forbes Watson]. In that district alone a quarter of a 

 million people derive their support from the trade and other 

 branches of the silk-industries. Great Britain imported in 1884 

 4,519,000 Ibs. of raw silk, to a value of 3,341,000; of thrown 

 silk, husks and waste to the value of 907,000, irrespective of 

 manufactured silk-goods, the cost of which amounted to nearly 

 eleven million pounds sterling. In 1889 the imports came to 

 3,123,000 Ibs. of raw silk of a declared value of 2,192,000, 

 607,000 Ibs. of thrown silk worth 511,000, husks and waste to- 

 the amount of about 900,000, and manufactured to the value of 

 11,790,000. The French Government fostered in 1890 the silk- 

 production within its own territory by a subsidy of 140,000, 

 Superior varieties of mulberry can be grafted with ease on ordinary 

 stock. M. Indica, L., M. macrophylla, Moretti, M. Morettiana, 

 Jacq., M. Chinensis, Bertol., M. latifolia, Poir,. M. Italica, Poir., M. 

 Japonica, Nois., M. Byzantina, Sieb., M. nervosa, Del., M. pumila, 

 Nois, M. tortuosa, Audib., as well as M. Constantinopolitaiia, 

 Lamarck, which according to Professor C. Koch is identical with M. 

 multicaulis of Perrottet, are merely forms of M. alba, to which, 

 probably also M. Tatarica, L. and M. pabularia, Jacquin, belong. 

 The variety, known as M. Indica, produces black fruits. The 

 raising of Mulberry-trees has recently assumed enormous dimen- 

 sions in California, where between seven and eight millions were 

 planted since 1870. The process of rearing the silk-insect is- 

 simple, and involves no laborious exertions. The cocoons, after 

 they have been properly steamed, dried and pressed, readily find 

 purchasers in Europe, the price ranging according to quality from 

 3s. to 6s. per Ib. The eggs of the silk-moth sell at a price from 

 16s. to 2 per ounce ; in 1870, Japan had to provide two millions 

 of ounces of silk-ova for Europe, where the worms had extensively 

 fallen victims to disease. As an example of the profit to be 

 realised, a Californian fact may be cited, according to which 700 

 were the clear gain from the 3^ acres, the working, expenses having 

 been 93. The Commissioner of Agriculture of the United States 

 has estimated, that under ordinary circumstances an acre should 

 support from 700 to 1,000 mulberry-trees, producing, when four 

 years old, 5,000 Ibs. of leaves fit for food. On this quantity 

 of leaves can be reared 140,000 worms, from which ova at a net-profit, 

 ranging from 80 to 240 per acre, will be obtained by the work 

 of one person. Mr. C. Brady, of Sydney, thinks the probable pro- 

 ceeds of silk-culture to be from 60 to 150 for the acre. The 



