[181] Jour. Agr. Research 1:147-177. 1913.

[182] U. S. D. A. Seeds and Plants Imported Invent. 13:173. 1908.

[183] Trans. Hort. Soc. Lond. 3:380-387. 1820.

[184] Ibid. 5:525-560. 1824.

[185] For a brief history of the life and pomological work of Gilbert Onderdonk, the reader is referred to The Plums of New York, page 392.

[186] U. S. D. A. Rpt. 648-651. 1887.

[187] Tex. Sta. Bul. 39:826-832. 1896.

[188] Am. Pom. Soc. Rpt. 110. 1887.

[189] Waugh, F. A. Systematic Pomology, 178. 1903.

[190] Hume H. Harold Fla. Sta. Bul. 62: 1902.