=1.= Hogg _Fruit Man._ 684. 1884. =2.= _Ont. Fr. Gr. Assoc. Rpt._ 35. 1891. =3.= _U. S. D. A. Pom. Rpt._ 45. 1895. =4.= _W. N. Y. Hort. Soc. Rpt._ =42=:83. 1897. =5.= _Cornell Sta. Bul._ =131=:182. 1897. =6.= _Mich. Sta. Bul._ =169=:241, 242. 1899. =7.= _Ibid._ =187=:77, 78. 1901. =8.= _Waugh Plum Cult._ 95. 1901. =9.= _Thompson Gard. Ass’t_ =4=:156 1901. =10.= _Ohio Sta. Bul._ =162=:242, 243 fig., 254, 255. 1905. _Late Diamond_ 1. Arch Duke ought to become one of the leading plums for the market in New York. The qualities which fit it for a high place among commercial varieties are: large size, handsome color—a rich, dark purple with thick bloom—and firmness of flesh and skin so that it both keeps and ships well. The accompanying color-plate does not do the variety justice, either in beauty, color or size of fruit. Arch Duke compared with Grand Duke, known by all plum-growers, is nearly as large, neck thicker, the same color, bloom heavier, quality higher, flesh firmer, stone free and ripens earlier. The tree-characters, like the fruit-characters, are all good. While this variety is suitable for both home and market use it appears after a thorough test in many parts of the State for nearly twenty years to be especially well adapted for a market fruit. Arch Duke was raised by Thomas Rivers, Sawbridgeworth, England, from seed of De Montfort, and was sent out in 1883. It was first noted in America by the Ontario Fruit Growers’ Association in 1891 and was imported into the United States by S. D. Willard[205] of Geneva, New York, about 1892. Tree of medium size, upright-spreading, hardy in New York except in exposed locations, very productive; branches smooth, dark ash-gray, with small, raised lenticels; branchlets of medium thickness and length, with long internodes, greenish-red changing to brownish-red, glossy, covered thinly with bloom and with sparse pubescence; lenticels numerous, very small, obscure; leaf-buds large, long, pointed, free; leaf-scars swollen. Leaves folded upward, oval or obovate, one and five-eighths inches wide, three and five-eighths inches long, thickish, stiff; upper surface dark green, glossy, glabrous, with grooved midrib; lower surface silvery-green, sparingly pubescent; apex and base acute, margin doubly serrate, with small, dark glands; petiole three-quarters inch long, pubescent along one side, tinged red, usually with two large, globose, greenish-yellow glands on the stalk or on the base of the leaf.