Cochineal insects are very small, delicate creatures, remarkable for the great difference in the form of the male and female. The former has a slender body, long antennæ, and two large wings; the latter an oval body, without wings, and short antennæ. The mouth in both insects consists of a small conical bill and sucker, adapted for feeding on the juices of vegetables. At first, all the young brood, whether male or female, resemble tiny red tortoises, and are busily engaged in feeding on the stems and leaves of plants, which they pierce with their sharp beaks so as to do much injury. During this active period of their lives the insects continue to increase in size, but the period soon arrives when they undergo a transformation. All the insects fix themselves firmly to plants or stems, and the male soon appears in his new dress as a fly, while the female merely changes her skin, and remains fixed to the bark, which she gradually becomes so nearly like, that it is difficult to distinguish her. She now lays her eggs, which are very numerous, and which she accumulates beneath her body; but, at the same time, she gradually dwindles in size until her body becomes a mere pellicle or thin membrane enclosing the brood. The mother then dies, but her dried body remains as a sort of shell or cocoon for the protection of her young. When these are hatched, they soon make their way from beneath the scaly covering, and commence feeding vigorously on the juices of the plant. To the persevering exertions of a French gentleman, M. Thierry de Menonville, it was owing that the culture of the cochineal became known in the West India islands. This gentleman left Port au Prince, in St. Domingo, in January 1777, with the express object of procuring some living cochineal insects of the finest sort from Mexico, and bringing them for propagation in the French West India islands; an enterprise for the expense of which the French government had allotted the sum of four thousand livres. Owing to the jealousy of the Spanish government, there was great difficulty in penetrating as far as the cochineal districts, and M. Thierry pursued a plan to effect his object which cannot be considered justifiable, since it involved a departure from truth. At first he feigned ill health, and obtained permission to use the baths of the river Magdalena; but, instead of going thither, he proceeded as fast as possible in the direction of the desired district, where he was successful in getting some plants laden with cochineal, as a pretended remedy for gout. From his account of the expedition we gather the following particulars.