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organs of the worms, while on the contrary, if these were 
supplied with mature leaves of a firm texture, the worms' 
would not be able to consume a sufficient quantity without 
exhaustion, and thus induce disease and death from want 
of support. 
Another point to consider is the proper temperature the 
worms require, which is between 58° and 68°, and it has 
been found that they thrive better in a half-subdued light, 
or even comparatively dark room, the light being in the 
same manner injurious to the eggs, as it is known to be to 
seeds of plants. In its native country the insect lives and 
passes through its changes under the shade of plants, and 
even in the miserable huts of the peasants of India, where light 
scarcely ever penetrates. In the year 1850, Mrs. Whitby 
was most successful in her rearing ; the worms had no 
disease, and made their cocoons in 30 days, and the silk 
obtained was as strong, bright, and beautiful, as that which 
in 1844-5 was pronounced superior to the best Italian raw silk. 
During the last few years great attention has been paid 
to other species of Bombyx, whose silk is not only more 
abundant, but which is in general use by Eastern nations, 
with a view to its introduction into the manufactures of this 
country. Silk is easy to obtain in large quantities from 
China and other countries, but the introduction of a new raw 
material is not the object contemplated. It is the production 
at home of a material which shall obviate the importation of 
it from a foreign market, and thus increase the prosperity of 
our labouring population. To accomplish this two or three 
other species of moth have been introduced into Europe, as 
also into some of our foreign dependencies, for the cultivation 
of their silk. The French and Prussian Governments have 
considered the subject of national importance, and hence have 
promoted the cultivation of this new branch of commerce. 
The Scientific and other Associations have investigated the 
