﻿i 9 i6] CURRENT LITERATURE 449 



investigation he has attempted to show quantitatively the influence of nutri- 

 tion. In the two ferns investigated, he found that the development of the two 

 sex organs could be controlled by certain concentrations of Knop's solution. 

 In general, the number of antheridia decreases as the concentration decreases. 

 In both species archegonia are formed only above 0. 175 per cent Knop's solu- 



was the optimum for Osmunda. In many of the prothallia of As planum the 

 two sex organs appeared only successively. The prothallia of Osmunda 

 remained almost completely sterile when grown in solutions lacking calcium 



varying results, and the evidence all indicated that the production of sex organs 

 is a response to factors in the environment— J. M. C. 



Indiana Academy. — The Proceedings of the Indiana Academy of Sciences 

 for 1914 contains the following contributions of interest to botanists: An 

 apparatus for aerating culture solutions, by Paul Weatherwax; Antagonism 

 of B. fiuorescens and B. typhosus in culture, by P. A. Texrault; Notes upon 

 the distribution of forest trees in Indiana, by Stanley Coulter; Mosses of 

 Monroe County, Indiana, by Mildred Nothnagel and F. L. Pickett; A 

 new enemy of the black locust, by Glenn Culbertson; A new leaf spot of 

 Viola cucullata, by H. W. Anderson; Oat smut in Indiana, by F. J. Pipel; 

 Plants new or rare to Indiana, by C. C. Dean; Some peculiarities in Spirogyra 

 dubia, by Paul Weatherwax; Report on corn pollination, by M. L. Fisher; 

 Stomata of Trillium nivale, by F. M. Andrews; The primrose-leaved violet 

 in White County, by L. M. Heimlich; Continuous rust propagation without 

 sexual reproduction, by C. A. Ludwig; Correlation of certain long-cycled and 

 short-cycled rusts, by H. C. Travelbee; Some species of Nummularia com- 

 mon in Indiana, by C. E. O'Neal; The genus Rosellinia in Indiana, by G. B. 

 Ramsey; Some large botanical problems, by J. C. Arthur— J. M. C. 



A new genus of Bennettitales— Thomas^ 1 has described a new genus of 

 Bennettitales (Williamsoniella) based upon material obtained from mesozoic 

 beds in Yorkshire. It is represented by buds, mature strobili ("flowers"), 

 microsporophylls, and the ovulate portions of the strobili. The strobilus is 

 bisporangiate and very small, with no ensheathing sterile bracts; 12-16 wedge- 

 shaped microsporophylls, each bearing 4-6 synangia; sessile ovules, "very 

 similar in external appearance to the interseminal scales"; and the sterile 

 tip of the strobilus axis terminating in "a characteristic corona-like structure" 

 (which suggested the specific name, W. coronata). In all probability these 

 strobili were borne in the forks of dichotomously branching stems, whose 



belong to the same genus, is named W. roseberriensis. The marked features 



» Thomas , H. H. , On Williamsoniella , a new type of Bennettitalean flower. Phil . 

 Trans. Roy. Soc. London B 207:113-148- ph. 12-14. 1915- 



