No. 2, September, 1920] GENETICS 215 



of van dicr Wor.K, "Onderzoek ingen obcr blijvende modification en bun betrekking tot muta- 

 ties" [Researches on persistent modifications and their relation 1<> mutations]. Cultura 1919. 

 K. V. Ossian Dahlgren. 



1624. S., W. [Re\ . <>f : RlGNANO, Euqenio. Upon the inheritance of acquired characters: 

 A hypothesis of heredity, development, and assimilation. 418 p. Open Courl Publishing Co. : 

 Chicago, 1911.] Science Progress 14: 514-515. Jan., 1920. 



1625. Salisbury, E. J. Variation in Anemone apennina, L., and Clematis vitalba, L., 

 with special reference to trimery and abortion. Ann. Botany 34: 107-116. 9 fig. Jan., 1920. 

 — Author presents further data on his views relative to essential trimery of Ranunculaceae. 

 In A. apeimina perianth segments ranged from 9 to 21 with 34 per cent of the flowers departing 

 from trimerous condition in perianth. Distribution of variations tends to be symmetrical 

 about mode in contrast to condition in A. nemorosa where skewness was associated with lower 

 modal value. Stamen number in A. apennina ranged from 48 to 111 (multiples of 3). Curve 

 was multimodal with succession of trimerous modes, greatest frequency being at 72, 81 and 87; 

 in 55.3 per cent of flowers staminal number was multiple of three; departure from modes 

 explainable on basis of fission or fusion. In 57 3 per cent of flowers carpel number was multiple 

 of 3, largest modes being at 60, 63, 51, and 57 with limits of range 27 and 87. One instance 

 of a carpel with two stigmas suggested fission as cause of departure from trimery. — In Clem- 

 atis vitalba the gynaecium of 1202 specimens furnished again a many-peaked curve with 

 modes at multiples of three. There was a tendency for number of abortive carpels to increase 

 as total carpel number increased. Abortion seemed to depend on conditions of nutrition and 

 development and not on idiosyncrasies of pollinating agent. — James P. Kelly. 



1626. Schaffner, John H. A remarkable bud sport of Pandanus. Jour. Heredity 10: 

 376-378. 1 fig. Nov., 1919. 



1627. Schaffner, J. H. The expression of sexual dimorphism in heterosporous sporo- 

 phytes. Ohio Jour. Sci. 18: 101-125. 25 fig. 1918 — "The sexual condition is simply a state 

 of the living substance which may continue for a greater or less length of time before a neu- 

 tral state or the opposite sex condition is set up." Author maintains inadequacy of sex- 

 chromosome mechanism for most plants, even suggesting that Allen's work on Sphaerocarpus 

 is not conclusive. Body of paper involves examples of various stages in development of dioe- 

 cious condition. No original monosporangiate flowers exist ; few seeming examples show di- 

 rect relationship to groups with opposite structures present. Usually dioecious condition 

 comes directly from bisporangiate ; sometimes monoecism is intermediate. Carpellate flowers 

 more likely to retain vestiges of stamen structures, than are staminate to retain carpel parts. 

 Zizania aquatica has staminate spikelets awnless, carpellate long-awned, bisporangiate 

 short-awned; latency of awn factor caused by presence of male condition. Cannabis sativa 

 normally an extreme example of dioecism, but plants grown under unusual conditions may 

 show reversal of certain parts to opposite sex. Discusses genera (Acer, Rumex, Fraxinus) 

 and larger groups which themselves show many gradations in the development of dioecism. 

 Suggests inadequacy of sex-chromosome idea even in animal kingdom, though in some cases 

 "hereditary factors may arise in a special chromosome which may assist in retaining and 

 intensifying a male or female state already established. " Sex-linked transmission can be read- 

 ily explained without sex chromosomes. With assumption of sex chromosomes greater part 

 of sexual phenomena becomes unexplainable and contradictory. Adds list of 41 plant species 

 which are promising for investigation, describing general sexual condition of each. — Merle 

 C. Coulter. 



1628. Schaxel, Julius. Uber die Darstellung allgemeiner Biologie. [On the presenta- 

 tion of general biology.] Abhandl. Theoret. Biol. 62 p. 1919.— See Bot. Absts. 5, Entry 1426. 



1629. Schaxel, J. Grundziige der Theorienbildung in der Biologie. [Principles of theory 

 formation in biology.] 221 p. G. Fischer: Jena, 1919. — See Bot. Absts. 5, Entry 1426. 



BOTANICAL ABSTRACTS, VOL. T, NO. 2 



