THE SILK-WORM AND OTHER MOTHS. 249 



rest, exterminate his cattle, devour the fruits of his fields and 

 orchards, ransack his chests and wardrobes, feast on his 

 provisions, and plague and worry him wherever they can — it is 

 but justice to mention their services. 



Among the insects which are of direct use to us, the silk- worm 

 {Bomhyx Tnori) is by far the most important. Originally a 

 native of tropical or sub-tropical China, where the art of 

 making use of its filaments seems to have been discovered at a 

 very early period, it is now reared in countless numbers far and 

 wide over the western world, so as to form a most important 

 feature in the industrial resources of Europe. Thousands of 

 skilful workmen are employed in spinning and weaving its 

 lustrous threads, and thousands upon thousands, enjoying the 

 fruits of their labours, now clothe themselves, at a moderate 

 price, in silken tissues which but a few centuries back were the 

 exclusive luxury of the richest and noblest of the land. 



Besides the silk-worm, we find many other moths in the 

 tropical zone whose cocoons might advantageously be spun, and 

 only require to be better known to become considerable articles 

 of commerce. The tusseh-worm (Bomhyx mylitta) of Hin- 

 dostan, which lives upon the leaves of the Ehamnus jujuba 

 furnishes a dark-coloured, coarse, but durable silk ; while the 

 Arandi {B. cynthia), which feeds upon the foliage of the 

 castor- oil plant {Ricinus communis), spins remarkably soft 

 threads, which serve the Hindoos to weave tissues of uncommon 

 strength. 



In America, there are also many indigenous moths whose 

 filaments might be rendered serviceable to man, and which 

 seem destined to great future importance, when trade, quitting 

 her usual routine, shall have learnt to pry more closely into the 

 resources of Nature. 



While the Cocci, or plant bugs, are in our country deservedly 

 detested as a nuisance, destroying the beauty of many of our 

 garden plants by their blighting presence, two tropical members 

 of the family, as if to make up for the misdeeds of their 

 relations, furnish us — the one with the most splendid of all 

 scarlet dyes, and the other with gumlac, a substance of hardly 

 inferior value. 



The English gardener spares no trouble to protect his hot- and 

 greenhouse plants from the invasion of tlie Coccus hespeHdum, ; 



I 



