Michigan wants woolen and cotton, and various other factories to provide employment for the over-crowded population of her cities and villages, and to open a market for all her produce. The farmers of Great Britain and Ireland could not pay the high rents and taxes which are imposed on them, were it not for their proximity to the great manufacturing cities of England. The cotton factories of Manchester, the woolen factories of Leeds and Huddersfield, the hardware works of Birmingham and Sheffield, and the potteries of Staffordshire, employ hundreds of thousands of men, women, and children, who consume the fruits of the soil, and create a steady demand for the farmer's stock and grain. All these manufactures were fostered by protective laws until they had attained a magnitude and importance which enabled them to protect themselves by the wealth of their proprietors and the excellence of their products. Large cities always afford a market for farm produce, and on this account exert a very beneficial influence on agriculture. The population of London is about two and a half millions, and they are possessed of so much wealth, and are so fastidious in their requirements, that almost every part of the world contributes to supply them with the necessaries or luxuries of life. The rapid growth of the cities of Michigan afford a home market for the fruits of the soil. A great deal of land in the old settlements of this State has been exhausted by a too frequent repetition of the wheat crop, and is now being employed as pasture for sheep and cattle. After remaining in grass for a few years, this land will be in excellent condition for producing wheat, especially when fertilized with that plentiful supply of barn-yard dung which the raising of stock always produces. There are some varieties of wheat which are much better suited to the climate and soil of Michigan than others, as they are in a great measure able to withstand the combined attacks of wheat insects and the various diseases to which the plant is liable. These are now fast supplanting the worn out grain, and as every malady has its cure or preventive, it is probable that the introduction of the best kind of seeds, the alternation between grass and tillage, and the supply of rich manure which the raising of stock creates will have a very great tendency to improve the wheat crop of this State. It is remarkable fact although the wheat crop has rather declined in the majority of States, the corn crop has steadily increased in all of them. Thus in 1840, the entire corn crop of the United States amounted to 400,000,000 of bushels; in 1850 it was nearly 600,000,000, of bushels. The crop of 1855 was between 7 and 800,000,000 and that of 1858 was fully 800,000,000 of bushels. Taking into consideration the large breath of land planted in 1859 and the damage by frost, we might with safety set down the crop as amounting to 800,000,000 bushels.