In a good year one pound of seed deposited upon the plant in October, will yield in December, twelve pounds of cochineal, leaving a sufficient quantity of seed behind for a second crop in May. The plantations of the cochineal cactus are confined to the district of the Misteca, in the state of Oajaca and in the valley of Oajaca at Ocotlan. Some of the Haciendas de Nopales contain from fifty to sixty thousand plants, arranged in lines like the aloes in the Maguey plantations already described, and cut down to a certain height, in order to enable the Nopaleros to clean them more easily. In the year 1758, a government registry-office was established in Oajaca, in consequence of the complaints of British merchants, who had received cargoes of adulterated cochineal. This bureau kept an accurate account of the production and value of the article, within its jurisdiction, and a tabular statement of the result has since been published in the Memoria Estadistica de Oajaca, &c. &c., of Don J. M. Murgnia y Galardi, who was a deputy to the Cortes from that province. By this document, and subsequent returns, it appears that from 1758 to 1832, inclusive,--or in 75 years,--44,195,750 pounds of cochineal were produced in the state of Oajaca alone, which were worth $106,170,671 at the market price. SILK. After the independence of Mexico was secured the Mexicans in the neighborhood of Zelaya, and in a few other places, attempted the cultivation of the mulberry tree, for the purpose of feeding silk worms. But this agricultural speculation failed. The planters did not possess the Chinese mulberry, which is universally adopted as the best in all silk producing countries. In 1841 an association under the style of the "Michoacan Company," was organized, in the capital of Michoacan, for the encouragement of silk culture. The members of this body labored diligently to introduce the Chinese tree, and spread it far and wide through the states of Vera Cruz, Puebla, Mexico, Queretaro, Jalisco, Aguascalientes, San Luis Potosi, Sonora and Michoacan. These labors were performed by thirty-six _Juntas de fomento_, or committees of encouragement, and although the trees have most generally grown well, it is to be feared that the enterprise resembled the wild speculations in that species of mulberry which, about the same period, both made and lost so many fortunes in the United States. The cultivation of silk has been warmly urged by Don Lucas Alaman, as exceedingly suitable for the state of Oajaca, where, in the course of time, it may replace the cochineal whose product it is said is beginning to fail in that district. FRUITS.