150 HORTICULTURE [BoT. Absts., Vol. VII, 



cation of nitrate of soda held their leaves much later in the fall than similar trees which 

 had received no nitrate. When excised spurs with fruit were immersed in water, abscission 

 did not occur.— The author concludes as follows : "The facts here presented and those recorded 

 in the literature are not sufficient to afford an entirely satisfactory explanation of the behavior 

 of the cells in the abscission zone. Undoubtedly, the causes that stimulate or excite the 

 peculiar changes in this region are associated with variations in nutrition and water supply. 

 If the tissues above the plane in which separation may occur is abundantly supplied with 

 water and other substances that counteract maturity or favor translocation or utilization of 

 assimilated material, conditions apparently are not favorable for manifestation of the meris- 

 tematic nature of cells in the potential abscission zone. In many fruits effective fertilization 

 helps to bring about these desirable conditions, but it should be remembered that develop- 

 ment of seeds is only one of several possible means of causing a set. Self fruitfulness may be 

 associated with the fact that the cells at the base of the pedicels of flowers on such varieties 

 are not as easily stimulated into abscission activity as similar cells of self-barren trees." — 

 E. C. Auchter. 



978. HiGGiNS, J. E. The litchi— Litchi chinensis. Proc. Amer. Pomol. Soc. 1917: 59-66. 

 1918. — This paper gives a general discussion concerning our present knowledge of the litchi. 

 A brief history of its origin and present distribution is included. Its cultural and fertilizer 

 requirements are stated, and methods of propagation are discussed. In general, the trees 

 do best on a deep, moist, alluvial soil and respond well to heavy applications of various 

 manures. Air-layering is generally used as a means of propagation. A few trees are now 

 growing in California and Florida, but the bulk of the crop is produced in southern China, 

 India, Ceylon, and other parts of the Orient. Trees of the litchi are also found in Japan, 

 Formosa, Australia, Hawaii, Mauritius, Brazil, and the West Indies. The fresh fruit is eaten 

 in these countries, where the trees grow, but the dried litchi nut is the product generally 

 found in our markets. — E. C. Auchter. 



979. Hoy, B. Report of district horticulturist and inspector of fruit pests, Okanagan 

 Valley, British Columbia 14th Ann. Rept. Dept. Agric. 1919: 20-24. 1920. 



980. Hunter, W. T. Report of district field inspector, southern Okanagan, Similkameen 

 and boundary districts. British Columbia 14th Ann. Rept. Dept. Agric. 1919: 22-24. 1920. 



981. HusMANN, George C. Growing currant grapes.— A promising new industry for this 

 country. Proc. Amer. Pomol. Soc. 1917:66-69. 4 pL, 5 fig. 1918.— Currant grapes were 

 grown extensively in France until the Phylloxera destroyed the vineyards. At this time 

 the plantings were greatly increased in Greece and were very profitable until the re-establish 

 ment of the French vineyards on Phylloxera-resistant grape stocks introduced from the 

 United States.— The U. S. Department of Agriculture has demonstrated that these currant 

 grapes can be profitably grown in this country. These grapes are among the earliest to 

 ripen, and the crop can be dried and put away before the earliest rains occur in districts 

 where other raisin varieties are too late in ripening. — Currant grapes were introduced into 

 California in 1861. In 1901, David Fairchild introduced the Panariti variety from Greece. 

 This proved to be greatly superior to the other varieties. When grafted on Phylloxera- 

 resistant stock and stock suited to the soil and climate under which it is grown, it has proven 

 extremely fruitful and profitable in California, Arizona, and southern Nevada. The author 

 states, "It has been ascertained that to make the blossoms set and secure a full crop of fruit, 

 the vines must be incised." This should be done while the vines are in blossom. When vines 

 are planted eight by eight feet apart, they will yield an average of 10| tons, or conserva- 

 tively from two to five tons, of dried currents to the acre. — E. C. Auchter. 



982. Kains, M. G. Home fruits as educators of public taste. Proc. Amer. Pomol. Soc. 

 1917:94-98. 1918.— Attention is drawn to the fact that in many of our large commercial 

 orchards, varieties of fruit, often with only fair or even poor quality, are planted. It is shown 

 that in the older home orchards or small fruit plantations, only fruits of the highest quali- 



