EUCALYPTUS TREES. 333 
this branch of industry has flourished ever since. In 
China, silk was reeled since 4500 years. This may 
demonstrate the permanency of an industry which 
we wish to establish here extensively under a similar 
sky. ‘One pound of silk is worth its weight in sil- 
ver, and this pound may be produced (so far as the 
food of the Bombyx is concerned) from 30 pounds of 
Mulberry-leaves, or from a single tree, which thus 
may be brought to yield annually the material for 16 
yards of Gros de Naples.’”? The White Mulberry-tree 
is of extremely easy growth from cuttings, also readi- 
ly raised from well-matured seeds. It is usually uni- 
sexual, and attains finally a large size. It can be 
grown in elimes where no longer Olives will thrive. 
Spots for Mulberry-culture must not be over-moist, 
when the leaves are to be utilized 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. 
Superior varieties of Mulberry can be grafted with 
ease on ordinary stock. M. Indica, L., M. macro- 
phylla, Morett., M. multicaulis, Perott., M. Moretti- 
ana, Jacq., M. Chinensis, Bertol., M. latifolia, Poir., 
M. Italica, Poir., M. Japonica, Nois., M. Byzantina, 
Sieb., M. nervosa, Del., M. pumila, Nois., M. tortuo- 
sa, Audib., as well as the Constantinople Mulberry, 
are merely forms of M. alba, to which probably also 
M. Tatarica, L., and M. pabularia, Jacquem., belong. 
The variety known as M. Indica produces black fruits. 
The planting of Mulberry-trees has recently assumed 
enormous dimensions in California, where, in 1870, 
