The New York market, says the American Agriculturist, has been unusually well supplied with excellent grapes during the present season. The number of persons in the vicinity of the city who have a few vines about the homestead yielding a smaller or larger suplus of this fruit for sale, has wonderfully multiplied dur-a year or two past. A gentleman residing in Brooklyn, stated to us the other day that, although living upon a lot 32 by 100 feet, his two children have cultivated a few vines, from which they gather and sell grapes enough to supply themselves with books, pocket money, and most of their clothing. We do not remember any former season when this fruit has been so abundantly offered for sale everywhere throughout the city, not only in the markets and at the confectioners, fruit stores and groceries, but also on every street corner. We introduced them into the regular weekly Prices Current during the past month where the wholesale prices has been quoted at 3c. to 4c. per ft)., for ordinary; 5 c to 8c. for medium, and 9c. to 12c. for superior.

But these prices have uot referred to those now so well known in this market as " Dr. Underbill's Grapes," for these have been wholesaled readily at 15 cents per lb. Judging from the immense number we have noticed selling every where throughout the city, and from the constant crowd of purchasers at the sales depot, (293 Broadway) we think the Doctor is reaping a golden harvest in return for his patient and long continued experimental efforts to bring the cultivation of this delicious fruit to perfection, at his Croton Point vineyards.