CH. IX.] THE COCHINEAL-IXSECT. 167 



They vary in figure, some being- globular, some 

 flattened, or slightly convex like the bottom of a 

 boat, or kidney-shaped. Some of these do not ex- 

 ceed in size a pepper-corn, others become as large as 

 a pea. 



These extraordinary creatures form the genus coc- 

 cus of Linnaeus, and are to be reckoned among the 

 insects which are directly useful to man. Formerly, 

 a species of these insects, the coccus Polonicus, 

 formed a considerable article of commerce in Poland. 

 The coccus cacti, or the cochineal-insect of South 

 America, however, has now, by the superiority of 

 the crimson dye it affords, superseded the other. In 

 1518, the Spaniards found it used by the Americans, 

 for the purposes of dyeing ; yet its true nature was 

 not discovered for nearly two centuries after, when 

 the observations of Hartsoeker, Leeuwenhoek, De la 

 Hire, and Geoffroy clearly proved it to be an insect, 

 and not, as was supposed, a grain, or seed. This in- 

 sect feeds on the nopal, which is a species of fig-tree 

 very common in New Spain, and in some parts of 

 India: the leaves are thick, and full of saccharine 

 juice. At the approach of the rainy season the cul- 

 tivators sweep from the leaves several little insects, 

 resembling a bug, which suck the green plant. They 

 preserve them in their own houses, and feed them 

 with the branches of the nopal. At the close of the 

 rainy season twelve or fourteen of these insects, by 



