No. 1, August, 1920] GENETICS 67 



498. Webber, Herbert John. Selection of stocks in citrus propagation. California 

 Agric. Exp. Sta. [Berkeley] Bull. 317: 2G7-301. /, tables, 14 fig. Jan., 1920.— The individual 

 trees in citrus orchards are always markedly variable in yield, doubtless partly because of 

 variation in the stocks used in budding. Sweet orange and sour orange are principal citrus 

 stocks in California. Seeds of each species have usually been collected indiscriminately; 

 seedlings are always highly variable, yet few are usually discarded in nursery. — Tests at Citrus 

 Experiment Station showed that large, intermediate and small nursery trees of three standard 

 Citrus varieties retained their original size rank after two years in orchard, though selected 

 in nursery budded from "performance-record" trees, where many of smaller stocks had been 

 discarded at transplanting and some also at budding. Sweet-orange and sour-orange seed- 

 lings selected in nursery rows for variation in leaf form, habit, etc., and budded on sour-orange 

 stocks in duplicate, indicate presence of numerous genetic types, some undesirable, among 

 ordinary nursery stocks. Measurements in nursery of sour-orange stocks sorted at trans- 

 planting showed great variation, with much greater average size from the seedlings originally 

 larger. — Possible factors in stock variation discussed. Probably seedlings small because of 

 small embryos in polyembryonic seeds, crowding in seed bed, etc., as well as those genetically 

 weak, are undesirable as stocks. Recommendations include: (1) planting of seeds from 

 trees budded to selected good stock varieties, (2) rigorous elimination of small seedlings at 

 transplanting and budding, and of small budded trees when ready for orchard planting. — 

 IF. B. Frost. 



499. Weibull, C. G. Weibullsholm 1870-1920, en aterblick. [Weibullsholm 1870-1920, 

 a retrospective review.] 18 p., 11 fig. W. Weibulls Illustrerade Arsbok (Landskrona) 15 

 (1920). 1919. — Account of the evolution and working methods of Weibull's station for plant 

 improvement. — K. V. Ossian Dahlgren. 



500. Weingart, W. Kunstliche Befruchtung von Kakteen. [Artificial fertilization of 

 cacti.] Monatsschr. Kakteenkunde 29: 106-107. 1919. — The author gives the results of self 

 and cross pollination of several cactuses, mostly species of Cereus. — A. S. Hitchcock. 



501. Wolff, Friedrich. Ein Fall dominanter Vererbung von Syndaktylie. [A case of 

 dominant inheritance of syndactyly.] Arch. Rassen u. Gesellschaftsbiol. 13: 74-75. 191S. — 

 One man in a family of five was syndactyl. Both of his parents, his sister and his three 

 brothers were normal, and there seems to have been no previous history of syndactyly in this 

 family. Married to a normal woman, he had seven children, all syndactyl. Each of these 

 has married a normal individual and the combined number of grandchildren is now eighteen, 

 of whom eight are syndactyl. In this family the syndactyly is somewhat more marked in 

 males. — C. H. Danforth. 



502. Yampolsky, Cecil. The occurrence and inheritance of sex intergradation in plants. 

 Amer. Jour. Bot. 7: 21-38. Jan., 1920. — A general discussion of sex intergrades based on the 

 author's studies of Mercurialis annua, on various other studies of sex-intergrades and sex 

 polymorphism in plants and in animals, and on a survey of data on sex forms in orders of seed 

 plants as given in Engler and Gilg's "Syllabus der Pflanzenfamilien." — In the monocots, 10 

 out of 11 orders representing 22 families have hermaphroditic, monoecious, dioecious and 

 polygamous individuals, and in dicots 31 of the 40 orders including 90 families have certain 

 representatives with two or more of the various types of sex. This distribution, shown in 

 tables for orders and families (not for species) reveals that "practically every order has fam- 

 ilies which contain forms that show more than one kind of distribution of sex elements." The 

 various terms used in describing sex conditions in plants are defined and species illustrating 

 them are cited. It is pointed out that the obvious facts of sex distribution in plants, together 

 with the results of experimental studies of heredity in polygamous or intersexual forms sup- 

 port the doctrine of varying sex potencies in germ cells rather than a sex-determination based 

 on segregation of fixed unit factors. — A. B. Stout. 



