1020] HORTICULTURE. 439 



illustrated, to.Eretlier with illustrations of resultlns plants which show Ixitii 

 iuternu'diate and extreme ativistio types. 



Are our raspberries derived from AiiH-iicaii or Kiiropean species? 

 G. M. Dahuow {-Jour. Ilercdihi, <J iJUJO), ^'f). .',. pp. ITJ-IH.',, figs. //).— A con- 

 tribution from the Bureau of Plant Industry, V. S. Deiiartiiient of Agriculture, 

 in which the author presents some evidence to show that the Euroi)ean red 

 raspberry (Rubus idaus) has played a more important part in the development 

 of cultivated red raspberries in America than is commonly sui)posed to be the 

 case. 



Some results of flg breeding by the U. S. Department of Agriculture, 

 G. P. RixFORD (Fig and Olive ,/our., 4 (1920), No. 10, pp. 12, i.?).— Brief popu- 

 lar descriptions are given of several fig seedlings developed from the breeding 

 work of the Deiiartment. 



Some causes of the souring and splitting of figs, I. J. Condit (Fiy and 

 Olive Jour., 3 (1919), A'o. 9, pp. 13-16).— The theory that overcaprificution of 

 the Smyrna tig causes .splitting has not been sub.stantiated by investigations of 

 the author in various orchards. An account is given of a series of observations 

 to determine the relation between the number of fertile seeds in figs and their 

 tendency to split. The figures as tabulated show the split figs contain a larger 

 proportion of seeds than the others. Discussion is given of other possible 

 causes. The conclusion reached is that the .splitting of figs is probably due to 

 abnormal water relations in the fruit and leaves brought on by irregular 

 moisture in the soil or atmosphere. The splitting of the Smyrna fig due to 

 atmospheric conditions can hardly be remedied, urdess nonsDlitting types can be 

 developed. 



Souring of figs is also discussed in connection with such probable causes 

 as insects and variety. 



Statistics on olive production during tfte year 1919 (Estadistica dc la 

 Produccion Olivurera en le Ano 1919. Madrid: Govt., 1920, pp. 6). — A statistical 

 report on the olive acreage and the production of olives and olive oil in the 

 various regions and Provinces of Spain in 1919. 



Cooperative improvement of citrus varieties, A. D. Shamel (U. S. Dept. 

 Agr. Yearbook 1919, pp. 2.'i9-215, figs. 16). — A contribution from the Ofiice of 

 Horticultural and Pomological Investigations of the Bureau of Plant Industry 

 c<»mprising a popular resume of the author's investigations dealing with the 

 bud .selection in citrus fruits (E. S. R., 39, pp. 447, 448, 84.")). It includes a 

 description of the methods employed in keeping individual-tree records, and 

 an account of the cooperative work of the California Fruit Growers' Ex- 

 change in securing and distributing bud wood from superior parent trees. 



R«'sults of individual tree performance record studies with pruned and 

 unpruned Marsh grapefruit trees, A. D. Shamel (Cal. Citrogr., 5 (1920), 

 No. 8, pp. 21/8, 268, 269, figs. If). — In this paper the author presents some data 

 showing the behavior of pruned and unpruned Marsh grapefruit trees on the 

 same ranch and under similar concJitions to those existing in the case of the 

 Washington navel orange (E. S. R., 41, p. 241) and the Eureka lemon tree 

 Btudies (E. S. R., 43, p. 230). 



The grapefruit trees in this experiment were what is commonly termed of 

 fall hearing age, healthy, of a uniform strain, and producing desirable crops 

 of fruit. The comparative yield of the pruned trees has been consistently 

 less than that for the unpruned trees. During the course of the experiment, 

 the pruned trees produced on the average approximately 18 per cent less 

 fnilt than the unpruned trees. The most severely pruned trees have produced 

 the least fruit. What slight difference there was between the grades of fruit 

 7622°— 20 1 



