No. 1, February, 1921] GENETICS 23 



161. Becker, J. BeitrSge zur Ziichtung der Kohlgewachse. [Contribution to the breeding 

 of the Brassicas.] Zeitschr. Pflanzenziicht. 7:91-99. Dec, 1919. — Discusses the necessity 

 of seed selection. Outlines a method whereby the four best plants are selected from a good 

 variety. These four plants are over-wintered and planted together the following year. 

 Pods from each plant are harvested separately, and each pod is handled as a unit. Seeds of 

 each are sown the following spring, and each individual seedling is grown in a pot and trans- 

 planted to the field. Undesirable lines and plants are eliminated after taking careful data 

 on plant characters, production, and food value. The ten best plants are selected, and 

 the following year the four best are again grown in an isolation plot. A second selection 

 of plants is made in the fall and carefully over-wintered. These produce seed for the main 

 crop. A single Brassica plant produces 2100 to 15,000 seeds — sometimes as high as 36,000. — 

 The writer favors the use of plants for seed production which themselves have produced 

 well-developed heads. States that different sorts should be 400 to 500 meters apart in the field 

 to prevent cross-pollination. — H. K. Hayes. 



162. Becker, J. Serologische Untersuchungen auf dem Gebiete von Pflanzenbau und 

 Pflanzenzucht. [Serological investigations in the realms of plant culture and plant breeding.] 

 Landwirtsch. Jahrb. 53:245-276. 1919.— By the use of serums prepared by injecting plant 

 extracts into animals it is possible to distinguish between seeds which are so nearly alike 

 that by examination it is difficult to classify them; for example, seeds of Brassica napus and 

 B. rapa. It is also believed that it will be possible to determine genetical differences, by 

 this means, where no morphological differences can be made out, in closely related individuals. 

 — D. F. Jones. 



163. Blakeslee, a. F. Unlike reaction of different individuals to fragrance in Verbena 

 flowers. Science 48:298-299. Sept. 20, 1918.— On the basis of susceptibility to the fra- 

 grance of two varieties of Verbena, A and B, 48 persons could be classified into two groups. 

 The one group, of 32 persons, was susceptible to fragrance in variety A but not to any in 

 B; for the other group or 16 persons the reverse was true. — Edgar Altenburg. 



164. Blaringhem, L. Couleur et sexe des fleurs. [Color and sex of flowers.] Compt. 

 Rend. Soc. Biol. 83:892-893. June, 1920.— Many horticultural varieties of Sweet William, 

 Dianthus barbatus, are hybrids, and sometimes show hybrid origin by a mosaic splitting, which 

 appears only on a few shoots and only on old plants. One remarkable plant showed, during 

 two seasons, color changes in the petals which ran parallel with the sexual development of 

 each flower. D. barbatus is hermaphroditic and protandrous. During 5-8 days while an- 

 thers are shedding petals are white. Within subsequent 24-48 hours stigmas become func- 

 tional, and petals turn bright red. This abrupt change should furnish a convenient index 

 in a study of the inheritance of those physiological conditions which are associated with the 

 sexes. — Merle C. Coulter. 



165. Blaringhem, L. Heredite et nature de la pelorie de Digitalis purpurea L. [Heredity 

 and nature of the peloria of Digitalis purpurea L.] Compt. Rend. Acad. Sci. 171: 252-254. 

 July, 1920. 



166. Blaringhem, L. Variations de la sexualite chez les composees. [Variations in sexu- 

 ality in the Compositae.] Compt. Rend. Soc. Biol. 83 : 1060-1062. July, 1920.— Author 

 recalls supposition of Hildebrand and van Uexkull-Gtllenband to effect that common 

 composites are in state of evolution away from hermaphroditism. This opinion was based 

 on existence of florets in intermediate conditions. Author says his observations on Cen- 

 taureas of jacea group do not support such an hypothesis. Plants from four stations gave 

 evidences of having resulted from hybridization of C. jacea and C. nigra. In the sterile 

 (peripheral) flowers there was pollen sterility and variation in degree of ciliation of a cer- 

 tain part of the achene; and there were appendages, such as free stamens or deformed styles. 

 ~J. P. Kelly. 



