OCTOBEK 25, 1912] 



SCIENCE 



569 



Behavior of Pollen Tubes in BicTiardia Africana: 



James Ellis Gow. 

 An Anomalous Ovary: James Ellis Gow. 

 The Late Blight of Barley — Helminthosporium 



teres Sa-cc: A. L. Bakke. 

 Some Points on the Floral Development of Bed 



Clover (Trifolium pratense) : J. N. Martin. 



Introduced by L. H. Pammel. 

 Native Dye-plants and Tan-plants of Iowa with 



Notes on a Few Other Species: Harrietts S. 



Kellogg. 

 The Genus Lycoperdon as Represented in the 



Herbarium of the State University of Iowa: 



N. D. Knupp. 

 Notes on Heteranthera duhia: R. B. Wylie. 

 Notes on Some Parasitic Fungi Chiefly from the 



Bitter Boot Mountains: L. H. Pammel and 



Ella Grace Harvey. 

 The Effect of Continued Grinding on the Water 



of Crystallisation (second paper) : Nicholas 



Knight. 

 The Dynamics of the Beaction tetween Ethyl 



Iodide and Silver Nitrate in Ethyl and Methyl 



Alcohol and in Mixtures of these Solvents: 



O. M. Weigle and J. N. Pearee. 

 The Solubility of Lead Sulphate in Aqueous Solu- 

 tions of Sulphuric Acid: P. A. Jans and J. N. 



Pearee. 



The First Beported American Lepidostrobus is 

 from Warren County, Iowa: John L. Tilton. 

 The paper records the discovery of the specimen, 

 the conditions under which it had been preserved 

 and evidences that in other places may lead to the 

 discovery of specimens of equal interest. It was 

 illustrated by the specimen itself and by lantern 

 slides of prepared sections. 



Nether Delimitation of our Carbonic BocJcs: 



Charles E. Keyes. 



Singularly enough the base of the Carbonic 

 rocks in Iowa has never been definitely recognized; 

 neither has the top of the Devonic sequence. The 

 present paper records the facts recently discov- 

 ered which go to show that there is a marked 

 unconformity between the two great formations. 

 This basal terrane of the Carbonic strata is the 

 Grassy black shale of Missouri, which has always 

 been regarded as of Devonic age. Its northern 

 continuation proves to be the Sweetland shale of 

 Muscatine County. 

 Arid Plateau Plains as Features of Folic Erosion : 



Charles E. Keyes. 



One of the great difficulties in the consideration 



of eolic erosion has been the securing of quantita- 

 tive data, and direct proofs that supposable ex- 

 amples are not possibly the results of stream- 

 corrasion. These proofs are believed to be found 

 in the lava-capped mesas of excessively dry re- 

 gions. 



Sundry Provincial and Local Phases of the Gen- 

 eral Geologic Section of Iowa: Charles E. 



Certain features of the stratigraphy of the 

 state are briefly discussed in the light of recent 

 advances in geologic classification. The present 

 need appears to be a careful revision of the no- 

 menclature of the geologic formations now recog- 

 nized and a detailed study of certain of the larger 

 groups with a view to properly subdividing them. 

 The Salem Limestone and its StratigrapMc Bela- 



tions in Southeastern Iowa: Francis M. Van 



Tuyl. 



Eecent stratigraphie studies have suggested that 

 a limestone member formerly regarded as the 

 basal portion of the St. Louis is distinctly forma- 

 tional in character and is of the horizon of the 

 Salem limestone of Illinois and Indiana. Uncon- 

 formities occur both at the base and at the top of 

 the formation. 

 The Origin of the Geodes of the KeoTcuJc Beds: 



Francis M. Van Tuyl. 



Previous theories of the origin of the geodes 

 are briefly discussed and evidence is presented to 

 show that these theories are untenable. The pres- 

 ence in the beds at some localities of calcareous 

 nodules grading into geodes suggests a method of 

 geodization not previously recognized. 

 A Study in the Cherts of the Osage Series of the 



Mississippian System: Francis M. Van Tuyl. 



Cherty nodules and bands are prominent fea- 

 tures of the Burlington and Keokuk limestone 

 members of this series. Excellent facilities for 

 studying the chert were recently afforded in the 

 power-plant excavation at Keokuk. In the discus- 

 sion of the origin of the material it is concluded 

 that it has resulted from the metasomatic replace- 

 ment of the limestone. 

 A Method of Teaching Elementary Mineralogy: 



G. F. Kay. 

 A Survey of the Water-bearing Gravels at Esther- 



ville, Emmet County, Iowa: G. G. Wheat. 

 Additional Evidence of Unconformity between the 



Cedar Valley and Lime Creels Stages of the 



Devonian of Iowa: A. O. Thomas. 



The type outcrop showing unconformity is de- 

 scribed; several similar outcrops are noted. A 



