130 EXPERIMENT STATION RECORD. [Vol.36 



The mechanism of movement in Dionsea leaves sliows many points of apparent 

 similarity to that of geotropic curvatures. At 21° C, two mechanical stimuli 

 are usually necessary to produce closure, an increase in the time interval re- 

 quiring increase in the repetitions of the stimuli. 



Sexual variations of the inflorescences and flowers in cultivated Codiseum, 

 J. Chifflot (Compt. Rend. Acad. Sci. [Paris'\, 162 (1916), No. U, pp. 508- 

 511). — Summing up the results of his observations, the author cites that 

 Codiseum, which is normally monoecious under cultivation, has shown the 

 formation of female flowers from the second generation on male inflorescences, 

 the formation of male flowers from the second generation on female inflores- 

 cences, and the formation of inflorescences which were bisexual from the first 

 and of flowers which were hermaphrodite from the first. 



Hybridization between a wild crucifer and a cultivated crucifer with 

 tuberous roots, Mlle. Trouabd-Riolle (Compt. Rend. Acad. Sci. [Paris], 162 

 (1916), No. H, pp. 511-513). — It is stated that crossing the wild plant, Raphanus 

 raphanistrum, with the cultivated species, R. sativiis, gave in the first and in 

 the second generation the same product which was obtained from the reciprocal 

 cross. The plants of the first generation were more or less intermediate be- 

 tween the parents. Those of the second generation segregated, about two- 

 thirds or more being tuberous-rooted, while some reverted to the wild type and 

 some showed a mixture of characters. In some cases seeds of the same pod 

 differed greatly. Crossing the wild plant with a hybrid obtained from varieties 

 of cultivated plants gave in the second generation the wild parent, the original 

 hybrid, and intermediate forms suggesting the ancestry of the hybrid parent. 



It is thought that hybridization may prove to be an excellent means of ac- 

 complishing the tuberization of the wild forms. 



Eiccolonization of cultivated land allowed to revert to natural conditions, 

 Winifred E. Brenchley and Helen Adam (Jour. Ecology, 3 (1915), No. Jf, pp. 

 193-210, ^figs. 2). — This is a study carried on for several years of two wilder- 

 ness areas left in 1882 with a standing wheat crop, which was permitted to 

 seed itself but which had almost completely died out after four years. The 

 changes which took place during each year and during successive years are dis- 

 cussed in connection with drainage and other factors. 



A text-book of general bacteriology, E. O. Jordan (Philadelphia and Lon- 

 don: ^y. B. Saunders Co., 1916, 5. ed., rev., pp. 669, pi. 1, figs. i77).— This is the 

 fifth edition of the general text-book by this author, previous editions of which 

 have been noted (E. S. R., 32, p. 371). The present edition has been revised 

 and considerable additions made to certain chapters, particularly those relating 

 to disinfection and the testing of disinfectants, and a new chapter on typhus 

 fever has been inserted. 



Aspergillus niger group, C. Thom and J. N. Currie (U. S. Dcpt. Agr., Jour. 

 Agr. Research, 7 (1916), No. 1, pp. 1-15). — The recent discovery by the writers 

 that certain species of Penicillium are able to form oxalic acid led to a study 

 of the black form species of Aspergillus. About 20 strains or species were ex- 

 amined, and all were found to possess in some degree the ability to form oxalic 

 acid when grown in Czapek's solution. Culture experiments with 10 strains 

 led the authors to the conclusion that there are many strains or varieties of 

 black Aspergillus which differ markedly in the production of oxalic acid. 

 Comparative studies of the colonics did not correlate the differences in acid 

 production with the morphology of the organisms. The members of this group 

 were found to grow under a wide range of cultural conditions and to exhibit 

 distinct differences, this fact being considered to harmonize with the conclu- 

 sion of Schiemann that A. niger is an unstable or mutating group comparable 

 with (Enothera (E. S. R., 28, p. 430). 



Il 



