THE SILK-WORM-THE COCHINEAL INSECT. 591 



threads, and thousands upon thousands, enjoying the fruits of their labors, 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 con- 

 siderable articles of commerce. The tusseh-worm {Bomhyx mylitta) of Hindostau, 

 which lives upon the leaves of the Rhamnus jujuba, furnishes a dark-colored, coarse^ 

 but durable silk ; while the Arandi {B. cyntkia), 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; while, in 1843, the 

 Coccus of the orange trees proved so destructive in the Azores that the island of 

 Fayal, which annually exported 12,000 chests of fruit, lost its entire produce from 

 this cause alone, two tropical members of the family, as if to make up for the mis- 

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

 dyes, and the other with gum-lac, a substance of hardly inferior value. 



Our gardeners spare no trouble to protect their hot and greenhouse plants from the 

 invasion of the Coccus hesperidum ; but the Mexican haciendero purposely lays out 

 his Nopal plantations that they may be preyed upon by the Coccus cacti, and rejoices 

 when he sees the leaves of his opuntias thickly strewn with this valuable parasite. 

 The female, who from her form and habits might not unaptly be called the tortoise of 

 the insect world, is much larger than the winged male, and of a dark-brown color, 

 with two light spots on the back, covered with white powder. She uses her little legs 

 only during her first youth, but soon she sucks herself fast, and henceforward remains 

 immovably attached to the spot she has chosen, while her mate continues to lead a wan- 

 dering life. While thus fixed like an oyster, she swells or grows to such a size that 

 she looks more like a seed or berry than an insect ; and her legs, antennae, and pro- 

 boscis, concealed by the expanding body, can hardly be distinguished by the naked 

 eye. Great care is taken to kill the insects before the young escape from the eggs, as 

 they have then the greatest weight, and are most impregnated with coloring matter. 

 They are detached by a blunt knife dipped in boiling water to kill them, and then 

 dried in the sun, when they have the appearance of small, dry, shriveled berries, of a 

 deep-brown purple or mulberry color, with a white matter between the wrinkles. The 

 collecting takes place three times a year in the plantations, where the insect, improved 

 by human care, is nearly twice as large as the wild coccus, which in Mexico is gath- 

 ered six times in the same period. Although the collecting of the cochineal is exceed- 

 ingly tedious — about 70,000 insects going to a single pound — yet, considering the 

 high price of the article, its rearing would be very lucrative, if both the insect and the 

 plant it feeds upon were not liable to the ravages of many diseases, and the attacks of 

 numerous enemies. The conquest of Mexico by Cortez first made the Spaniards ac- 

 quainted with cochineal. They soon learnt to value it as one of the most important 

 products of their new empire; and in order to secure its monopoly, prohibited, under 



