26 UTILIZATION OF MINUTE LIFE. 



Up to the present time almost all the silk pro- 

 duced in Europe, and the greater portion of that 

 manufactured in China, has been obtained from 

 the common silkworm (Bombyx mori). But new 

 varieties of Bombyx are beginning to be cultivated 

 in Europe, especially in France. 



For a very long time considerable quantities of 

 silk have been produced in India from other descrip- 

 tions of silkworms. Of these the most important 

 are the following : 



First, the Tussah and Armdy silkworms, whose 

 history has been given with detail by Dr. Roxburgh 

 (" Linnean Transactions/' vii. 33) . The tussali silk- 

 worm (Bombyx Pernyi) is a native of Bengal, and 

 feeds upon the leaves of the Jujube tree (Zizyplius 

 jujuba). Dumeril, the celebrated French naturalist, 

 cultivated it for some time, as an experiment, upon the 

 leaves of another tree, Jambosia pedonculata, and M. 

 Guerin Menneville has bred this tussali worm exclu- 

 sively upon oak leaves. Besides which, it is known 

 to live upon a plant called Terminalia alata glabra. 

 So that this grub has the advantage of being what 

 is termed Poly phytophagous, that is, it can be made 

 to feed upon different kinds of leaves. This fact 

 has been observed with some other species of 

 Bombyx. It is certainly a great advantage to those 

 who undertake to introduce it into Europe. 



The silk of the tussah worm is much coarser 



