HORTICULTURE. 441 



The introductory portion deals with the present status and prospects of the 

 industry. Information is given relative to varieties, top-working, location, site, 

 soil, fertilizers, planting operations, intercropping and cultivation, cover crops, 

 harvesting and marketing, pecan diseases, and insects. 



Citrus fruits, J. E. CJoiT {l^ew York: The Macmillan Company, 1915, pp. 

 XX-\-520, pi. 1, figs. 151). — ^An account of the citrus fruit industiy, with special 

 reference to requirements and practices in California and similar situations. 



The first two chapters deal with the history and development of the citrus 

 industry in the southwestern United States and the geography and climatology 

 of California. The succeeding chapters deal with the botany, gross structure, 

 and habits of growth of the citrus plants; varieties; the citrus nurseiy ; horti- 

 cultural inspection and quarantine service; improvement of citrus fruits by 

 breeding; judging citrus fruits; selection of site and preparation for planting; 

 planting the orchard; cultivation, fertilization, and cover crops; irrigation; 

 pruning and toivworking; frost and orchard heating; picking and packing 

 oranges; picking and packing lemons; blemishes of the fruit and their preven- 

 tion; by-products; marketing; profit and loss; diseases and tlieir control; citrus 

 insects and their control; insect control by fumigation; and various orchard 

 pests and their control. The concluding chapter is devoted to an extensive 

 bibliography dealing with citrus fruits, their culture, utilization of by-products, 

 etc., and including references to other bibliographies on the subject. 



A biometrical study in the variation of acidity and the ratio of total 

 solids to acidity of oranges, S. K. Mitra (Univ. Cal. Jour. Agr., 2 (1915), No. 

 7, pp. 245-247, figs. 3). — As a result of a study of 100 Washington navel oranges 

 of a well-known brand, the author found a wide variation among individual 

 oranges in the ratio of total solids to acidity. Hence it appears important that 

 inspectors' tests relative to the ratio of total solids to acid shajl be based on a 

 large number of oranges in each case. In another experiment conducted to 

 determine the differences in the quality of the juice in different parts of the 

 same orange a composite sample of juice taken from basic sections of ten oranges 

 showed a percentage of acidity of 0.98 as compared with 0.9 in a composite 

 sample taken from apex sections of ten oranges. The ratio of total solids to 

 acidity was 13.8 : 1 in the juice from the basic sections and 15.9 : 1 in the juice 

 from the apex sections. 



The pomerange, a natural hybrid between the orange and pomelo, L. S. 

 Perkins (Jour. Heredity, 6 {1915), No. 4, p. 192). — ^A short descriptive account 

 is given of a natural hybrid between the orange and pomelo which appeared in 

 an orange grove at Winter Garden, Fla., and has borne regularly for a number 

 of years. The fruit, although rather tart when it first ripens, develops a distinct 

 orange taste later. 



Reference is also made to another hybrid, probably a cross between the pomelo 

 and the lemon, which is of no special value. 



Notice to citrus growers (Porto Rico Bd. Agr. Expt. Sta. Giro. 4, pp. 2). — 

 The text is given of the resolution adopted by the Porto Rico Board of Commis- 

 sioners of Agriculture with reference to the control of citrus canker. The reso- 

 lution prohibits the entry into Porto Rico of all citrus stocks, buds, scions, seeds, 

 or fruits originating in Florida, Alabama, Mississippi, Louisiana, and Texas. 



Plant quarantine regulations (Porto Rico Bd. Agr. Expt. Sta. Circ. 5 (1915), 

 p. 1). — The text is given of regulations, effective in 1915, governing the entry 

 into Porto Rico of nursery stock and other living plant materials from the citrus- 

 growing States of the United States and of citrus nursery stock from foreign 

 countries. 



California garden flowers, shrubs, trees, and vines, E. J. Wickson (San 

 Francisco: Pacific Rural Press, 1915, pp. 262, pis. 12, figs. 14). — A popular 



