PROCEEDINGS 11 I5X | NH OF THE Iowa Academy of FOR 1917 VOLUME XXIV Thirty-first Annual Session, Held April 27 and 28, 1917 Published By THE STATE OF IOWA Des Moines Science in Grinnell, t i , PROCEEDINGS OF THE Iowa Academy of Science VOLUME XXIV Thirty-first Annual Session, Held in Grinnell, April 27 and 28, 1917 Published By THE STATE OF IOWA Des Moines IOWA ACADEMY OF SCIENCE Officers of the Academy 1916- 1917. President — Professor G. W. Stewart, State University. First Vice-President — Professor L. S. Ross, Drake University. Second Vice-President — Miss Alt so a E. Aitchison, State Teachers College. Secretary — James H. Lees, Iowa Geological Survey. Treasurer — Professor A. O. Thomas, State University. executive committee. Ex-officio — G. W. Stewart, L. S. Ross, Miss Aitchison, James H. Lees, A. O. Thomas. Elective — S. W. Beyer, Iowa State College; E. A. Jenner, Simpson College; D. W. Morehouse, Drake University. 1917- 1918. President — Professor L. S. Ross, Drake University. First Vice-President — Professor S. W. Beyer, State College. Second Vice-President — Professor C. E. Seashore, State Uni- versity. Secretary — James H. Lees, Iowa Geological Survey. Treasurer — Professor A. 0. Thomas, State University. EXECUTIVE \ COM MITTE E . Ex-officio — L. S. Ross, S. W. Beyer, C. E. Seashore, James H. Lees, A. O. Thomas. Elective — Professor Nicholas Knight, Cornell College; Professor H. E. Jaques, Parsons College; Mr. R. I. Cratty, Armstrong. PAST PRESIDENTS Osborn, Herbert 1887-1888 Todd, J. E. 1888-1889 Witter, F. M 1889-1890 Nutting, C. C. (2 terms) 1890-1892 Pammel, L. H 1892-1893 Andrews, L. W 1893-1894 Norris, H. W. (1 term) 1894-1896 Hall, T. P. 1896 Franklin, W. S 1896-1897 Macbride, T. H 1897-1898 Hendrixson, W. S 1898-1899 Norton, W. H 1899-1900 Vkblen, A. A 1900-1901 Summers, H. E 1901-1902 Fink, Bruce 1902-1904 Shimek, B 1904-1905 Arey, M. F 1905-1906 Bates, C. 0 1906-1907 Tilton, John L 1907-1908 Calvin, Samuel 1908-1909 4 IOWA ACADEMY OF SCIENCE Vol. XXIV, 1917 past presidents — Continued Almy, Frank F 1909-1910 Houser, Gilbert L 1910-1911 Begeman, L 1911-1912 Bennett, A. A 1912-1913 Kinney, C. N 1913-1914 Conard, Henry S 1914-1915 Kelly, Harry M 1915-1916 Stewart, George W 1916-1917 MEMBERS OF THE IOWA ACADEMY OF SCIENCE LIFE FELLOWS Beyer, S. W Ames Clarke, J. Fred Fairfield Conard, Henry S Grinnell Erwin, A. T Ames Fitzpatrick, T. J Sta. A, Lincoln, Nebr. Greene, Wesley Des Moines Houser, G. L Iowa City Kay, George F Iowa City Kuntz, Albert, St. Louis Univ., St. Louis, Mo. Lees, Jas. H Des Moines Norton, W. H Mt. Vernon Pellett, Frank C Atlantic Ricker, Maurice Des Moines Ross, L. S Des Moines Seashore, C. E Iowa City Shimek, B Iowa City Summers, H. E Ames Sylvester, R. H Iowa City Thomas, A. O. Iowa City Tilton, J. L 'Indianola Williams, Miss Mabel C Iowa City Wylie, R. B ...Iowa City FELLOWS. Aitchison, Miss A. E.. Cedar Falls Albert, Henry . . . ..... Iowa City Almy, F. F Grinnell Anderson, J. P. . . . . Sitka, Alaska Arey, Melvin F. . . . . . Cedar Falls Baker, J. A . . . . . .Indianola Baker, R. P Iowa City Bakke, A. L Bates, C. 0 . . Cedar Rapids Begeman, Louis . . . , . . . Cedar Falls Bond, P. A . . . Cedar Falls BROWN, F. C Iowa City Brown, P. E Ames Brumfiel, D. M. . Buchanan, R. E. Ames Burnett, L. C. Ames Cable, E. J . . . . Cedar Falls Carter, Chas. . . . Fairfield Chaney, Geo. A. .Ames Condit, Ira S. ... Cratty, R. I Armstrong Davis, W. H Dodge, H. L Iowa City Doty, H. S **Dox, A. W Ames Eward, J. M Ames Ewing, H. E. Ames Faris, Ellsworth Iowa City Fay, Oliver J Des Moines Finch, Grant E Dillon, Mont. Fordyce, Emma J. . . Cedar Rapids Getchell, R. W Cedar Falls Goodell, F. E Iowa City Guthrie, Jos. E Ames Hadden, David E Alta Hance, Ja-s. H Iowa City Hayden, Ada Ames Hendrixson, W. S Grinnell Hersey, S. F Cedar Falls Hinman, J. J. Jr Iowa City Hixson, A. W Iowa City Jaques, H. E Mt. Pleasant Jenner, E. A Indianola Jewell, Susan G Tabor Kelly, H. M. Mt. Vernon Keyes, Chas. R Des Moines King, Charlotte M Ames Kinney, C. N. ........ Des Moines Knight, Nicholas . . . .Mt. Vernon Knupp, N. D. . . Santa Monica, Cal. Kunerth, Wm Ames Lazell, Fred J Cedar Rapids ACADEMY OF SCIENCE MEMBERS 5 fellows — Continued Learn, C. D Stillwater, Okla. Leighton, M. M Univ. Washington, Seattle, Wn. Macbride, Tiios. H Pacific Grove, Cal. McClintock, J. T Iowa City McDonald, G. B Ames McKenzie, R. Monroe. . .Fairfield Martin, Jno. N Ames Melilus, I. E Ames Miller, A. A Davenport Morehouse, D. W Des Moines Mueller, H. A St. Charles Norris, H. W Grinnell Nutting, C. C Iowa City Oleson, 0. M Ft. Dodge Orr, Ellison Waukon Pammel, L. H Ames Pearce, J. N Iowa City * Pearson, R. A Ames Peck, Morton E Salem, Ore. Pew, W. H Ames Plagge, H. J Ames Reilly, Jno. F Iowa City Rockwood, E. W Iowa City Sanders, W. E Des Moines Sieg, L. P Iowa City Smith, Geo. L Shenandoah Smith, Orrin H Mt. Vernon Spinney, L. B Ames Stange, C. H Ames Stanley, Forrester C.. . Oskaloosa Stanton, E. W Ames Stephens, T. C Sioux City Stevenson, W. H Ames ♦Stewart, G. W Iowa City Stookey, S. W Cedar Rapids Stromsten, F. A Iowa City ♦Trowbridge, A. C Iowa City Van Hyning, T. . . Gainesville, Fla. Van Tuyl, F. M Golden, Colo. Walters, G. W .Cedar Falls Watson, E. E Fairfield Webster, R. L Ames Weld, L. D Cedar Rapids ♦♦Wentworth, E. N Manhattan, Kansas Wickham, H. F. ...... .Iowa City Wifvat, Samuel Des Moines Wolden, B. O Wallingford Woodward, S. M Iowa City associates. ♦'♦Baker, Norval E. .. .Burlington Barnhart, Frances .E Omaha, Nebr. Belanski, C. H Nora Springs ♦♦Bennett, Walter W Wilder, Minn. Bern ingh ausen, F. W .New Hartford Berry, E. M Iowa City Betts, Geo. H Mt. Vernon Bleasdale, B. T Des Moines Boot, D. H .Flagstaff, Ariz. Boyd, Mark F. ... Galveston, Tex. Breitbacil, Jno. J Dubuque Briggs, Leo Indianola Brook, Rev. A. H. . Boone Buchanan, L. L Towa City Butterfield. E. J... Dallas Center Carter, Edna M Fayette Case, Rev. Ciiauncey Ellsworth Station, O. C'avanagil, Jno. A. ...Des Moines Cavanagil, Lucy M Iowa City Coffin, Chas. L Oskaloosa Conklin, R. E Des Moines Corson, Geo. E Cedar Falls Gotten, Ruth H Iowa City Cross, H. A., Jr Grinnell Curran, Dr. E Cedar Rapids Davis, Elmer Dallas Center Dersfiem, Elmer Urbana, 111. Dewey, A. H Iowa City Dieterich, E. 0 Minneapolis, Minn. Diehl, Wm Ames Dill, Homer R Iowa City Dodd, L. E Iowa City Dobson, R. B Iowa City Dole, J. Wilbur Fairfield Durrell, L. W Ames Eckerson, Rev. Ray . . .• . Humeston Edmundson, Sophia. . .Des Moines Eillis, S. F.. Des Moines Eixyson, C. W Alta Emery, Geo. V Ames Fakkenberg, Rev. H. G Davenport FEes, L. V Billings, Mont. Flint, 0. W Mt. Vernon Foft, S. F. Waukee Fortscit, Arthur R Iowa City Foster, C. L Shanghai, China Fraser, Chas. M... Nanaimo, B. C. Frazier, Zoe R Oskaloosa ♦Engaged in defense work for the Federal Government. ♦♦Enlisted in the U. S. Army. 6 IOWA ACADEMY OF SCIENCE Vol. XXIV, 1917 associates — Continued French, It. A Des Moines Fulcher, J. E Des Moines Gabrielson, Ira N Washington, D. C. Gaessler, Wm. G Ames Galfin, Sidney D Ames Gidbings, L. A. Gi.omset, D. J Des Moines Gose, Bert Indianola Goss, C. A Des Moines **Grissel, Earl Iowa City Grubb, Aubrey C. . .Lafayette, Ind. Hadley, S. M Oskaloosa Hagan* Wayne .Clinton Hart, Irving H Cedar Falls Hastings, Jessie P Iowa City Hawk, Grover C Oskaloosa HayeR, Walter E... Garden Grove Hayward, W. J Sioux City Heitkam^, G. W. ...Dubuque Helmiok, Paul S Iowa City Higbee, F. G Iowa City Himmel, W. J. Iowa Falls **Hoerscii, V. A Iowa City Horsfall, Jno.. L Dubuque Howell, Jesse V Tulsa, Okla. Hughes, Sally P Grinnell Hughes, U. B Fulton, Kv. Jeffs, Royal E Norman, Okla. * Jessup, W. A Iowa City Job, Thfstle T Iowa City ** J ordan, R. L Burlington Julian, A. E Burlington Kenoyer. L. A. . .Allahabad, India King, Inez Naomi.. .Langdon, N. D. Kirby, R. S Ames Knoll, Wm. V... Iowa City Krall, J. A Ames Kuzirian, S. B . .Ames Lamb, A. R Ames Larson, G. A Des Moines Lindsey, Arthur. W. . . . Sioux City Lorenc. F. A Loma, Nebr. Lloyd-.Tones. Orren dnnes McGaw, F. W Mt. Vernon Maxwell, H. L Mt. Vernon Merrill, D. E State College, N. Mex. Miller. Rev. J. C Dubuque Moon. Helen Iowa City Morbeck, Geo. C Ames Mortimer, F. S Oskaloosa Muilenburg, G. A Rolla, Mo. Noll, W. C Toledo Nollen, Sarah M Des Moines Oncley, L Fayette Overiiolt, Sigel . ■ Kirkman OVERN, O. B Paige, F. W Palmer, E. L . . Cedar Falls Perry, Winifred . . . Pieterpol, Henry W. Pella Pomeroy, J. C Quigley, T. H .Fargo, N. D. Read, 0. B . . Cedar Falls Ressler, I. L Ames Reynolds, 0. E Riggs, L. K Toledo Roberts, T Robinson, C. L Rogers, W. E New Wilmington, Pa. Roilret, Marguerite B. . .Iowa City Rowe, Paul Rusk, W. J Salters, R. C Sargent, Louise Grinnell Sayre, A. Raymond. . . . .Indianola Schell, E. A Mt. Pleasant Schoewe, W. H Iowa City Schriever, Wm Iowa City Scoit, Helen Grinnell Scullen, H. A Ames Shimek, Ella Grand Junction, Col. Silane, Adolph ......Des Moines Silipton, W. D St. Louis, Mo. Smith, Donald M Zearing Somes, M. P St. Paul, Minn. Spencer, Clementina S ....." Cedar Rapids Springer, Elizabeth W apello Spurrell, J. A Wall Lake Stainbrook, M. A Brandon Starin, L. M. Ames Stiles, Harold Ames Stoner, Dayton Iowa City Swenson, L. G Lamom Taylor, Beryl Cedar Rapids Tenney, Glenn I Des Moines Thomas, E. H Tabor Thomas, Wilbur A Grinnell Thompson, Geo. E Amc Thompson, L. D Mt. Pleasant Thone, F. E. A La Jolla, Cal. Tisdale, Wilbur E Iowa City Treganza, J, A. . Britt Tuttle, Mrs. F. May Osage Uttley, Marguerite. . .Cedar Falls Walter, Otto Dubuque Webster, 0. L Charles City Weigle, O. M Fulton, Mo. Weir, Samuel Indianola Werner, Herbert L Ames Wilcox, A. 0 Mt. Vernon ACADEMY OF SCIENCE MEMBERS 7 associates — Continued Williams, A. J. .. . .Norman, Okla. Yotiiers, J. F Toledo Wilscn, Ben H Mt. Pleasant Young, V. H Iowa City Yocum, L. Edwin Ames Zuker, W. B Des Moines CORRESPONDING fellows. V -Vndrews, L. W 6643 Stewart Ave., Chicago, 111. Arthur, J. C Purdue University, Lafayette, Ind. Bain, H. F London, England Ball, C. R Department of Agriculture, Washington, D. C. Ball, E. D State Entomologist, Madison, Wis. Barbour, E. H State University, Lincoln, Nebr. Bartsch, Paul Smithsonian Institution, Washington, D. C. Bruner, H. L Irvington, Ind. Carver G. W Tuskegee, Ala. Cook, A. N University of South Dakota, Vermillion, S. Dak. Drew, Gilman C Orono, Maine Eckles, C. W ....University of Missouri, Columbia, Mo. FInk, Bruce . . . ; Oxford, Ohio Franlin, W. S Massachusetts Institute of Technology, Boston Frye, T. C .State University, Seattle, Wash. Gillette, C. P. Agricultural College, Fort Collins, Colo. Gossard, H. A ...Wooster, Ohio Halsted, B. D New Brunswick, N. J. Hansen, N. E .'.Agricultural College, Brookings, S. D. Haworth, Erasmus State University, Lawrence, Kan. Hitchcock, A. S Department of Agriculture, Washington, D. C. Hume, N. H Glen St. Mary, Fla. Leonard, A. G Grand Forks, N. Dak. Leverett, Frank 1724 University Ave., Ann Arbor, Mich. Miller, B. L Lehigh University, South Bethlehem, Pa. Newell, Wilmon State Plant Board, Gainesville, Fla. Osborn, Herbert State University, Columbus, Ohio Price, H. C Evergreen Farm, Newark, Ohio Reed, Ciias. C Weather Bureau, New York City Savage, T. E . Urbana, 111. Sirrine, Emma Dysart, Iowa Sirrine, F. A. ...79 Sound Ave., Riverhead, Newr York Todd, J. E ....’..Lawrence, Kan. Trelease, William University of Illinois, Urbana, 111. Udden, J. A. University of Texas, Austin, Texas TITLES OF PAPERS RECEIVED The number follounng a title indicates the page of the Proceedings on which it may be found. Page The Address of the President Geo. W. Stewart 29 Geology and Allied Subjects. Wave Action and Results of Ice Action as Seen Near the Macbride Lakeside Laboratory, Summer of 1916 John L. Tilton Second Record of Oscillations in Lake Level, and Records of Lake Temperatures and Meteorology, at the Macbride Lakeside Laboratory, July, 1916 John L. Tilton 33 A Notable Mound Group Near the Proposed Government Park at McGregor Ellison Orr 43 High-level Terraces of Okanogan Valley, Washington Charles Keyes, 47 Continental Perspective of American Pre-Cambrian Strati- graphy Charles Keyes 53 Extent and Age of Cap-au-Gres Fault Charles Keyes 61 A Bibliography of the Driftless Area W. D. Shipton 67 Post-Kansan Erosion M. M. Leighton 83 The Buchanan Gravels of Calvin and the Iowan Outwash. .... M. M. Leighton 86 The Iowan Glaciation and the So-called Iowan Loess Deposits M. M. Leighton 87 The Loess and the Antiquity of Man B. Shirnek 93 History of the Pleistocene in Iowa Emmet J. Cable Pleistocene Deposits Between Manilla in Crawford County and Coon Rapids in Carroll County, Iowa George F. Kay 99 Ocheyedan Mound, Osceola County, Iowa George F. Kay 101 A Note Regarding a Slight Earthquake at Iowa City on April 9, 1917 George F. Kay 103 A Large Colony of Fossil Coral, A. O. Thomas. 105 A Supposed Fruit or Nut from the Tertiary of Alaska A. O. Thomas 113 Notes on a Decapod Crustacean from the Kinderhook Shale near Burlington ... Otto Walter 119 Some Observations on the History of Yangtse River, China.. C. L. Foster 127 Some Geologic Aspects of Conservation James H. Lees 133 Some Fundamental Concepts of Earth History. .James PI. Lees 155 The Origin of the St. Peter Sandstone A. C. Trowbridge 171 The Prairie du Chien-St. Peter Unconformity in Iowa A. C. Trowbridge 177 Some Conclusions Concerning the Erosional History of the Driftless Area A. C. Trowbridge Home Economics. An Improved Method for Home Canning C. N. Kinney and Maurice Ricker TITLES OF PAPERS RECEIVED 9 Physics. Page Certain Features of Rheostat Design H. L. Dodge 183 An Interesting case of Resonance in an Alternating Current Circuit H. L. Dodge 189 The X-Ray K-Radiation of Tungsten.. Elmer Dershem 201 The Absence of Relationship Between Electro-mechanical Properties of Selenium Crystals and Their Photo-Electric Emission by Ultra-Violet Light F. C. Brown and F. S. Yetter The Influence of Intensity Ratio in Binaural Sound Localiza- tion E. M. Berry and C. C. Bunch 203 A Peculiar Electrically Conducting Layer on the Surface of Mica G. W. Stewart On the Torsional Elasticity of Drawn Tungsten Wires L. P. Sieg 207 The Thermal Conductivity of Tellurium. . . .Arthur R. Fortsch. .... .213 Electrical Capacity of Similar, Non-parallel Plane Plates and Its Application Where the Plates are Non-rectangular . . . . L. E. Dodd 217 The Stroboscopic Effect L. E. Dodd 221 Precontract Conduction Currents L. E. Dodd 231 Effect of Drawing on the Density and Specific Resistance of Tungsten Wm. Schriever 235 Effect of Gases on Unilateral Conductivety. .Robert B. Dodson 241 Zoology and Allied Subjects. Birds of the Past Winter, 1916-1917, in Northwestern Iowa. . T. C. Stephens 245 A List of the Birds Observed in Clay and O’Brien Counties, l'owa Ira N. Gabrielson. 259 An Annotated List of the Mammals of Sac County, Iowa J. A. Spurrell 273 Notes on Bell’s Vireo Walter Bennett 285 An Analysis of the Cranial Ganglia of the Dogfish Sally P. Hughes 295 The Eyeball and Associated Structures in the Blindworms.. H. W. Norris 299 Bermuda as a Type Collecting Ground for Invertebrates H. A. Cross, Jr 301 White Grub Outbreaks in Northeastern Iowa..R. L. Webster The Influence of the Male on Litter Size Edward N. Wentworth 305 A List of Entomostraca from Lake Okoboji Frank A. Stromsten 309 The Development of the Musk Gland in the Loggerhead Turtle Frank A. Stromsten 311 Some New Endoparasites of the Snake Thestle T. Job 315 Further notes on the Venous Connection of the Lymphatic System in the Common Rat. Thestle T. Job., 319 Mites Affecting the Poison Oak H. E. Ewing 323 The Odonata of Iowa Lloyd Wells 327 Observations on the Protozoa, With Descriptions and Draw- ings of Some Probable New Species Clementina S. Spencer 335 10 IOWA ACADEMY OP SCIENCE Vol. XXIV, 1917 Page Notes on Some Iowa Rodents Dayton Stoner 353 Botany. The Sand-flora of Iowa.. B. Shimek Some Additional Notes on the Pollination of Red Clover L. H. Pammel and L. A. Kenoyei .-357 The Germination and Juvenile Forms of Some Oaks .L. H. Pammel and Charlotte M. King 367 Plant Studies in Lyon County, Iowa D. H. Boot 393 Notes on Melilotus alba Walter E. Rogers 415 The Cleistogamy of Heteranthera dubia R. B. Wylie The Morphology of the Thallus and Cupules of Blasia pusilla ...Marguerite B. Rohret 429 The Influence of Soil Management on the Formation and De- velopment of Fruit Buds R. S. Kirby 447 The White Waterlily of Clear Lake, Iowa H. S. Conard 449 Tree Growth in the Vicinity of Grinnell, Iowa. < .H. S. Conard A Picea from the Glacial Drift Wilbur H. Thomas 455 Pioneer Plants on a New Levee, III Frank E. A. Thone 457 Chlorotic Corn W. H. Davis 459 The Aecial Stage of Alsike Clover Rust.. .W. H. Davis 461 The Use of Ferric and Ferrous Phosphate in Nutrient Solu- tions. George E. Corson and Arthur L. Bakke 477 The Cutinization of Apple Skins in Relation to Their Keeping Qualities and their Environment Winifred Perry 483 Chemistry. Some Natural Waters of Central New York Nicholas Knight and Vernon C. Shippee 485 Diffusion Phenomena of Double Salts Harold L. Maxwell and Nicholas Knight 489 Water Works Laboratories Jack J. Hinman, Jr 501 The Free Energy of Dilution of Lithium Chloride in Aqueous and Alcoholic Solutions by the Electromotive Force Method F. S. Mortimer and J. N. Pearce 507 The Electrical Conductivity and Viscosity of Solutions of Silver Nitrate in Pyridine. . .H. L. Dunlap and J. N. Pearce A Study of the Relation between Solubility, the Heat of Solu- tion and the Properties of the Solvent H. E. Fowler and J. N. Pearce 523 The Partial Analysis of Some Iowa Clays (Preliminary Re- port) J. N. Pearce The Protein Content and Microchemical Tests of the Seeds of Some Common Iowa Weeds. .L. H. Pammel and A. W. Dox. .... .527 Synthesis of a Naphthotetrazine from Diethyl Succinylosuc- cinate and Dicyandiamide Arthur W. Dox 533 The Behavior of Benzidine Toward Selenic and Telluric Acids Arthur W. Dox 537 Amino Acids and Micro-organisms .Arthur W. Dox 5&9 The Separation and Gravimetric Estimation of Potassium... S. B. Kuzirian. . . . . ,547 The Action of the Amino Group on Amylolitic Enzymes. E. W. Rockwood 551 Some of the Factors that Influence the Extraction of Gold from Ores by the Cyanide Process A. W. Hixson PROCEEDINGS OF THE THIRTY-FIRST ANNUAL SESSION Held in Grinnell, April 27 and 28, 1917 The Iowa Academy of Science held its meeting at Grinnell College, with Alnmni Recitation Hall as headquarters. The first meeting was opened at 1:30 on Friday afternoon, the 27th, with President Stewart in the chair. After the business session a general literary session was held, following which the Academy divided into three sections as follows for the reading of papers of special interest: (1) Geology, (2) Biology and Botany, (3) Mathematics, Physics and Chemistry. In the evening at 8 o’clock Professor S. M. Woodward of the State • University of Iowa gave his illustrated lecture on the Flood Protection Plans for the Miami Valley, Ohio. This address is published substantially as given, in the Pro- ceedings of the Ohio Engineering Society — Thirty-eighth Annual Meeting, 1917. On Saturday morning the sections resumed their meetings and at 11 o’clock the Academy met for its final business meeting, at which new members were elected and officers for the ensuing year were chosen. The Iowa and Ames sections of the American Chemical So- ciety, and the Iowa section of the Mathematical Association of America held their meetings in connection with the Academy. REPORT OF THE SECRETARY. Members of the Iowa Academy of Science: The past year has been an active and prosperous one for the Academy, one of the best years, indeed, in its recent history. A number of scientists and friends of science have united with the Academy during the year. The President of the Academy has prosecuted a vigorous campaign for recruits to our ranks, and as a result of this effort coupled with the activity of other members, the names of over sixty candidates are to be presented to the Academy for election to membership. The Executive Committee has made a canvass of the membership roll and has recommended a 'large number of Associates to promotion as Fel- 12 IOWA ACADEMY OF SCIENCE Vol. XXIV, 1917 lows. Many of the Associates have availed themselves of this privilege and their names will be presented at the business ses- sion. The Treasurer and the Secretary have continued their hurry-up campaign among those members who from one cause or another have grown lax in their interest in the Academy, The program which you have received will show that the members of the Academy have been busily engaged in their chosen lines of research, and that their work has been far from fruitless or pur- poseless. It may be of interest to recall that when the Academy met with Drake in 1907 twenty-three papers were presented. When the Academy returned to Drake last year eighty-five titles were on the program. When we met with Grinnell in 1910 thirty papers was the maximum. Today there are already eighty- five titles printed on the program and others will be presented at this meeting. No doubt this increase represents in a very ac- curate way both the growth of scientific work in the state and the enlarged interest in the Iowa Academy of Science and apprecia- tion of the important place it fills in the scientific world. A large part of the work of the Secretary is editorial and much of his attention and effort must of necessity be directed in editorial channels. Upon liis shoulders rests the responsibility for the creditable appearance of the published Proceedings arid upon his shoulders, likewise, will fall the whip of censure for whatever shortcomings may be evident. One who has had no experience in the process of editing and publishing such a book as our Proceedings can not realize the amount of work neces- sary nor the details to which attention must be given. It is in the power of every contributor to the Proceedings, however, to assist in the work by seeing to it that his paper is correct in all its details. Such a paper is a joy to the editor, and to the printer as well. Experience has led me to feel confident that there is in this Academy a host of productive workers whose published contributions would have real literary value if they were pre- pared with the care that the merit of the subject would justify. We all realize that a subject of considerable worth may be so abused by the literary mistreatment which it receives in its in- troduction to the reading public that no one recognizes its true value and no one appreciates the ability of its progenitor. And yet in the face of this situation, to what extent does every author live up to his realization of his obligation to his subject, to the Academy and to the scientific world? This is a question to which PROCEEDINGS OF THE THIRTY-FIRST ANNUAL SESSION 13 each member of the Academy may well give serious considera- tion. Your attention is called to a change in the last volume of the Proceedings. Instead of being printed on soft paper, with the illustrations printed on calendared paper and tipped in, as has been the case with former volumes, the text and illustrations of this volume are printed together on a thinner, finished book paper. This effects an economy in paper and binding and gives a smaller, less bulky volume. In this connection may I suggest the advisability of keeping papers for the Proceedings within reasonable limits as to size. While there is no legal limit on the number of pages in our Proceedings it would be well to have the papers short enough so that the volume will not attain undue dimensions. There is a feeling that sixty pages, for example, a number which was reached by three papers in the last volume, is too much for one member to demand in a publication such as ours. I commend this suggestion also to your consideration. This is the day of preparedness. Every people in the forefront of civilization is issuing the call to its citizenship to prepare, whether it be to advance to the attack against the high cost of living — or the cost of high living, as the case may be — or to ward off the encroachments of a foreign foe. In such a time of stress the men and women of science must not and will not be found wanting. Whether the call comes to us to serve in the laboratory or on some more strenuous field it is for us each one to do our bit — to appropriate a popular phrase — to advance the cause of democracy and of the ideal social order in every way that lies within our power. The world is making demands upon science on a scale which is entirely unprecedented in history. Undoubt- edly as strenuous demands will be made for the amelioration and the improving of the conditions of human existence as are now being made for the aid of science in destroying human life. Here, too, the devotees of research must not be found wanting. This call too must find us proven men and women of action, pre- pared still to measure up to the need and to the responsibility which our opportunities have put upon us! You who now are and who are to be the leaders in intellectual and social progress will not shirk the duty which your country expects you to fulfill. Respectfully submitted, James H. Lees, Secretary. 14 IOWA ACADEMY OF SCIENCE Vol. XXIV, 1917 REPORT OF THE TREASURER, 1916-1917. RECEIPTS Cash on hand, April 25, 1916 . $ 5.62 Dues from members 175.05 Initiation fees, fellows 3.00 Initiation fees, associates 33.10 Transfer fees, associate to fellows 6.00 Life membership fees 14.00 From sale of proceedings 5.68 Total $ 242.45 DISBURSEMENTS Honorarium and expenses of speaker, 30t.h meeting. .$ 25.58 Supplies and postage for the secretary 21.52 To Miss Newman, wrapping and tying volume XXII. 10.00 Independent Printing Co., envelopes and blank re- ceipts 4.50 Postage and supplies for treasurer 9.00 To Miss Rosenberger, clerical work for treasurer... 5.00 Refund to Frofessor Kay, excess payment 1.00 Honorarium to secretary 25.00 American Lithographing Co., 400 programs 9.00 State binder, binding volume XXI and separates. . . . 68.50 State printer, excess pages Vol. XXI 25.00 Total $ 204.10 Balance on hand April, 25, 1917 $ 38.35 A. O. Thomas, Treasurer. REPORT OF PROFESSOR CONARD. Mr. President , and Fellow Members of the Academy: In thanking you for the honor of representing you at the tenth anniversary of the Illinois Academy of Science, I can report that I attended all of the sessions of that body at their recent meeting at Galesburg, Illinois, February 23 and 24. The welcome given the Academy by Knox and Lombard Colleges and by the Citi- zens of Galesburg was most cordial, and only equalled by the generous hospitality offered to the visiting delegates. The Acad- emy had two sessions for the general public. One of these was a symposium on Public Health. Both were largely attended. Sectional meetings and a business meeting closed the sessions. On Friday evening an anniversary banquet was held, on which occasion I had opportunity to convey the greetings of this Academy. ELECTION OF NEW MEMBERS. The Secretary submitted the following names for election in behalf of the membership committee: The persons named were declared elected. ELECTION OF MEMBERS 15 Elected as Fellows — Edwards, J. W., Wesleyan College, Mount Pleasant; Faris, Ellsworth, S. U. I., Iowa City; Winter, C. L., Western Union College, Le Mars. Transferred from Associate Member to Fellow — Boyd, Dr. Mark F., Iowa City; Brown, Percy E., Ames; Brumfiel, D. M., Iowa City; Carter, Chas., Fairfield; Coffin, Chas. L., Oskaloosa ; Davis, W. H., Cedar Falls; Doty, H. S., Ames; Ewing, H. E., Ames; Fordyce, Emma J., Cedar Rapids; Goodell, F. E., Iowa City; Higbee, F. G., Iowa City; Hinman, Jack J., Jr., Iowa City; Jaques, H. E., Mount Pleasant; Jewell, Susan G., Tabor; Lazell, Fred J., Cedar Rapids; MacDonald, G. B., Ames; McKenzie, R. Monroe, Fairfield; Oleson, 0. M., Fort Dodge; Oncley, Law- rence, Fayette; Overn, 0. B., Decorah; Plagge, Herbert J., Ames; Pomeroy, J. C., Ames; Reilly, John F., Iowa City; Scullen, H. A., Ames; Smith, George L., Shenandoah; Smith, Dr. 0. H., Mount Vernon; Stoner, Dayton, Iowa City; Watson, E. E., Fairfield; Weld, Leroy D., Cedar Rapids; Wifvat, S. J. A., Des Moines; Wolden, B. 0., Wallingford. Elected as Associates — Baker, N. E., Iowa City; Ballew, How- ard, Mount Pleasant; Barnhart, Frances, Iowa City; Berry, E. M., Iowa City; Betts, Prof. G. H., Mount Vernon; Breitbaeh, Dean J. J., Dubuque College, Dubuque ; Briggs, Leo, Indianola ; Buchanan. L. L., Iowa City; Campbell, J. W., Indianola; Carter, Edna M., Fayette • Carson, Russell, 2923 Rutland ave., Des Moines; Cross, Harry A., Jr., Grinnell ; Dewey, A. H., Iowa City • Dodson, R. B., Iowa City; Emmons, C. W., Indianola; Flint, President Chas. W., Mount Vernon; Foster, C. L., Iowa City; Fortsch, A. R., Iowa City; Galloway, J. Earle, Highland Park College, Des Moines; Godfrey, Geo. H., Ames; Grubb, Aubrey C., Cedar Falls; Hadley, S. M., Oskaloosa; Hart, Irving H., Cedar Falls ; Hawk, G. C., Oskaloosa ; Heitkamp, G. W., Du- buque ; Henderson, R. W., Iowa City; Hilleboe, H. S., Decorah; Himmel, W. J., Sioux City; Hughes, Miss Sally P., Grinnell; Jordan, R. II,, Iowa City; Julian, Arthur, Burlington; Kagy, Elbert 0., Des Moines; Kirby, R. S., Ames; Knoll, Wm. V., Iowa City; Krall, John A., Ames; Kuzirian, S. B., Ames; Lind- sey, Arthur W., Sioux City; Lockhart, W. 0., Cedar Falls; McGaw, Frederick M., Mount Vernon; Maxwell, Harold L., Mount Vernon; Miller, Rev. J. C., Dubuque College, Dubuque; Mock, President Charles A., Western Union College, LeMars; Mortimer, F. S., Iowa City; Rohret, Marguerite B.% Iowa City; 16 IOWA ACADEMY OF SCIENCE Vol. XXIV, 1917 Rowe, Paul, Glen wood ; Savre, B. K., Decor all ; Sayre, A. Ray- mond, Indianola; Schell, President Edwin A., Iowa Wesleyan College, Mount Pleasant; Schoewe, W. H., Iowa City; Schriever, Wm., Iowa City; Scott, Helen, Grinnell ; Smith, Donald M., Zearing; Springer, Elizabeth, Iowa City; Spur r ell, Jno. A., Wall Lake; Stainbrook, Merrill A., Brandon; Thomas, E. H., Tabor; Thomas, Wilbur A., Grinnell; Thompson, Geo. E., Ames; Thomp- son, L. D., -Mount Pleasant; Uttley, Marguerite, Cedar Falls; Walter, Otto, Iowa City; Weir, Samuel, Indianola; Wilcox, Al- fred C., Mount Vernon; Wilson, Ben IT., Mount Pleasant; Woodruff, H. B., Drake University, Des Moines; Yocum, L. E., Ames; Young, V. PI., Iowa City; Zuker, W. B., 3127 Fourth street, Des Moines ; Jessup, President W. A., Iowa City; Galpin, Sidney L., Ames; Perry, Winifred, Boone. RESOLUTIONS ADOPTED. The Committee on Resolutions submitted the following report and it was adopted by the Academy. Your committee on resolutions present the following report : lie solved, First — That we express to the Faculty of Grinnell College our appreciation of the excellent local arrangements for this our Thirty-first Annual Meeting, and to the . ladies especially who have provided so splendidly for the general luncheon with its pleasing associations. Second — That we express to Professor S. M. Woodward our ap- preciation of the very instructive and entertaining lecture which he has so kindly consented to give. Third — That we instruct the Secretary of the Academy to telegraph to the President of the United States that the Fellows and Members of the Iowa Academy of Science appreciate his stand in these trying times, and pledge to a man their support in this war till the spirit of democracy shall prevail, and all the leading nations of the earth shall have government of the people, for the people, and by the people. Fourth — That we endorse the recent action of the legislature in passing laws to protect quail and prairie chicken for a period of five years, and in providing for the establishment of a Board of Conservation to determine upon regions of scenic beauty that shall be preserved for the benefit of future generations. That we commend the energy and farsightedness of the mem- bers of the legislature who fathered these acts and secured their passage. John L. Tilton, Nicholas Knight, R. L. Webster, Committee. 7 2 IN MEMORIAM ARTHUR G. SMITH. Arthur Gr. Smith, Professor of Mathematics in the State Uni- versity of Iowa, a Fellow of this Academy and of the American Association for the Advancement of Science, died on November 7, 1916. Born November 27, 1868, Professor Smith took his B. Ph. at the State University in 1891. He became a member of the staff in 1893, proceeding to the Master’s degree in 1894. His Iowa training was supplemented by extended residence at Gottingen where he was a pupil of Klein and Schoenflies and at Cam- bridge (England) where he studied with G. H. Darwin. For twenty-three years he served the State of Iowa with en- thusiastic and far sighted activity at the University. He was known far and wide as a genial and broad minded scientific worker and in his devotion to the athletic interests of the Uni- versity has left a record of work done under many difficulties which is an enduring monument of energy, wisdom and single hearted devotion to the best interests of the youth of Iowa. The fact that he was largely responsible for the introduction of a rational college marking system in the University takes on a peculiar light in view of the fact that his own early training was on a system devoid of marks, credits and rewards. The breadth of scientific range which characterized him may be judged by the following bibliography : Empirical Formulae and Constants: Transit, Yol. 9, 33-67, 1903. Measurements upon the Okoboji Indian Skulls : Iowa Journal of History and Politics, Yol. 3, 435-444, 1905. College Spirit : Iowa Athletic Journal. Evaporation from Free Water Surfaces : Iowa Academy of Science, Proceedings, Yol. XYI, 185-188, 1909. Intercollegiate Relations: Iowa Alumnus, Yol. 6, 140- 145, 1909. 20 IOWA ACADEMY OF SCIENCE Vol. XXIV, 1917 Conference Control and Direction of Athletics in the Middle West: American Physical Educational Re- view, Yol. 16, 95-101, 1911. A Rational College Marking System : Journal of Edu- cational Psychology, Vol. 2, 383-393, 1911. The Teaching of Arithmetic : School Science and Mathe- matics, Yol. 12, 457-460, 1912. His scientific interest was displayed in a long series of papers read before the Baconian Club of the University. Among the subjects most often appearing are Meteorology (he was for many years the U. S. observer at Iowa, City), The Application of Sta- tistical Methods to Biological and Sociological Problems, Aero- nautics ; Projectiles, Gfeodesy and Acoustics. He was also an enthusiastic and successful photographer. Those who were so fortunate as to know him will long remem- ber him as a man of genial wisdom and unsurpassed courage. This courage he proved in expeditions for .zoological purposes with C. C. Nutting and F. Russell, in his fight for purity in athletics and in the perfect serenity of his bearing in the face of the incurable disease which carried him away too soon. R. P. Baker. . ■ V . : DR. BERT HEALD BAILEY IN MEMORIAM BERT H. BAILEY. Dr. Bert Heald Bailey, Professor of Zoology in Coe College, passed from life on June 22, 1917. He had not been in good health for some weeks preceding -his death, but not until a few hours before the end came was it believed by his physicians that he would not recover. Doctor Bailey was born at Parley, Iowa, May 2, 1875. His early childhood was spent at Carroll, Iowa, where his father was pastor of the Presbyterian church. He early showed a love for the outdoor world. Birds especially attracted him and he began to accumulate that knowledge of the habits of wild life which later distinguished him. It was a passion with him to examine everything and the collecting habit was early cultivated. In 1877 the family moved to Cedar Rapids, Iowa. Here the lad attended the public schools and later Coe Academy. He naturally came to know the professors in the Natural Science departments of the College and formed friendships with Dr. Seth E. Meek, Dr. C. 0. Bates, and later with the writer that were deep and lifelong. His habit of wandering in the woods was continued, sometimes to the detriment of the interests of Latin and Greek, but with ever increasing promise for his fu- ture as a naturalist. During those years he cultivated the acquaintance of many of the local sportsmen, who often were glad to take him with them on their expeditions. Through these men he increased his knowledge of nature and his collection of birds. From one of these men he received his first important lessons in taxi- dermy, an art which he thereafter assiduously cultivated. From 1898 to 1897 Doctor Bailey was in college. Three of these years were spent in Coe College from which he received his degree. His junior year was spent at the State University of Iowa. In September, 1897, he entered Rush Medical College, from which he graduated in 1900, intending to become a medical missionary. To his great disappointment he then found that 24 IOWA ACADEMY OF SCIENCE Vol. XXIV, 1917 a heart lesion would prevent his carrying out his cherished plan. He therefore accepted the Chair of Zoology in his Alma Mater and began his work there in the autumn of 1900, con- tinuing it until his death. Doctor Bailey was married December 26, 1900, to Miss Anna W. Condit, of Des Moines, Iowa, who with their three daugh- ters, Helen, Jean and Elizabeth, survives him. Doctor Bailey was a member of the Iowa Academy of Science, the American Geographic Society, the American Association of Museums, the American Association for the Advancement of Science, the American Ornithologists’ Union, the Wilson Or- nithological Club ; also of Sigma Xi, the Baconian Society (S. U. I.), the Zoology Club (S. U. I.), the Triangle Club (S. U. I. Faculty), the Iowa Forestry and Conservation Association, the Alumni Association of Rush Medical College, and the Masonic Order. Undoubtedly, Doctor Bailey’s greatest service grew out of his remarkable personal influence upon the many students who came under his instruction. All who knew him were impressed with the charm of his personality and the winning power of his character ; and these qualities, added to his enthusiasm for scientific study, made him a truly great teacher. It is of in- terest that one of his students, Miss Clementina Spencer, was selected to continue his work at Coe. It is marvelous that he found time outside of the heavy duties of his teaching to do so much constructive work. He managed, under heavy handicaps, to build up a remarkable museum at Coe College which the trustees have named the Bert H. Bailey Museum. He came into friendly relations with the leading museum men of the country. He collected much ma- terial himself and was on the alert constantly to secure speci- mens from other sources. He spent some time in 1905 in British Honduras, bringing back the third largest collection of birds from that region in this country. He had been collecting data for some time for a report on the small mammals of Iowa which was to be published by the Iowa Geological Survey. In order to complete this work he was granted leave of absence for the year 1916-17 by the trustees of Coe College. He entered the Graduate School of the State University of Iowa, intending to present his Doctor's thesis in June. His illness put an end to a work that prom- ised much of scientific value. DR. BERT H. BAILEY 25 In the passing of Doctor Bailey the state has lost a leader in educational, scientific, religious, and philanthropic activities, and his many personal friends will miss his genial presence. Doctor Bailey published the following papers : Notes on Krieder’s Hawk in Alaska: Auk, July, 1916. A New Subspecies of the Broad Winged Hawk : J^uk, Jan., 1917. The Western Goshawk in Iowa: Auk, July, 1917. Notes on the Raptorial Birds of Iowa: Annual meeting of the Wilson Club, 1915. Notes on the Red Tailed Hawk : Annual meeting of the Wilson Club, 1916. Science in the High School, read before the N. E. I. T. A. Published in College Eyte, Cedar Falls, May 3, 1916. The Duck Hawk in Iowa : Proc. Iowa Acad. Sci., Yol. X. Successful Mink Farming in Iowa: Proc. Iowa Acad. Sci., Yol. XXIII. Notes on the Distribution of the Prairie Spotted Skunk in Iowa: Proc. Iowa Acad. Sci., Yol. XXII. The Building and Function of a College Museum : Proc. Iowa Acad. Sci., Yol. XXII. The Occurrence of Melanism in the Broad Winged Hawk: Proc. Iowa Acad. Sci., Yol. XIX. A Remarkable Flight of Broad Winged Hawks. Proc. Iowa Acad. Sci., Yol. XIX. Notes on the Food of the Black Crowned Night Heron in Captivity: Proc. Iowa Acad. Sci., Yol. XIX. Birds of Iowa : Iowa Arbor and Bird Day Book, April 1913. Additional Notes on the Little Spotted Skunk: Proc. Iowa Acad. Sci., Yol. XXIII. Another Case of Melanism in the Broad Winged Hawk. AVhy the Quail Should be Protected : Des Moines Reg- ister, March 28, 1917. The Mississippi Kite in Nebraska : The Wilson Bulletin, Oberlin College, 1915. Two Hundred Wild Birds of Iowa. Published in book form. S. AY. Stookey. Papers Presented at the Thirty-First Meeting of the Academy / THE ADDRESS OF THE PRESIDENT. GEO. W. STEWART. As President of the Academy I now haye the honor to present an address, thus reestablishing a former custom, but with ap- propriate regard for the necessity of brevity. Within the time of twelve minutes I propose to glance at recent progress in physics and also to discuss the function and responsibility of this Academy, The notable achievements in that science within the past few years cannot all receive mention hence it is essential that there be pointed out but a few typical cases of progress. One of the most interesting advances has been an extension of our. knowledge of crystal structure, this being made possible by X-ray analysis. Not only can the distance between planes be measured but, in the case of compounds like sodium chloride, the distribution of the constituent atoms can be ascertained. The significant result is that, in almost all crystals investigated, there is at each lattice point not a molecule but an atom. Thus in the crystal of sodium chloride, the sodium and chlorine atoms are each arranged according to a simple cubic lattice, but the two lattices are arranged so that each atom is surrounded by six equidistant atoms of the other kind. Thus at no point in the crystal of sodium chloride do we find what we have for- merly conceived to be a molecule of that substance. Similar re- sults are found with crystals of other compounds. It is yet too early to appreciate the full significance of these discoveries with crystals, but we can now at least opine that our conception of the molecule must meet with a very definite revision. The study of X-ray radiation has served another and perhaps more important function, for it has led us to see that the funda- mental characteristic of an element is not its atomic “'weight” but rather its atomic number which is approximately one-half of its atomic weight. This is very clearly proved by the re- lationships between the X-ray radiations which are characteristic of the various elements and constitutes one of the most important recent advances made in our knowledge of atomic structure. But what is the present conception of the physicist concern- ing the constitution of the atom? For many years the spectra 30 IOWA ACADEMY OF SCIENCE Vol. XXIV, 1917 of the elements have informed us that atoms must be .complex. But only after the discovery of X-rays and radioactivity did detailed truth begin to appear. Today we find ourselves at a time when the most conservative will admit the necessity for an atom consisting of a very small nucleus, less than one ten- thousandth the atomic radius, surrounded by electrons, pre- sumably in orbital motion. The conception of the atom as a solid elastic sphere has now completely disappeared, save in so far as it is useful in theories yet in a crude and approximate state, .such as the kinetic theory of gases. In fact there is con- siderable evidence that the atom is not symmetrical in shape. The collision .between atoms does not now find its analogy in the clash of billiard balls, but in the orbital hyperbolic motions in the solar system. Collision involves not contact but an electrical re- pulsion occurring upon the close approach of the positively charged nuclei. Cohesion is occasioned by an electrical . attrac- tion. Time was when we sought a mechanical explanation of electrical phenomena. Now we attempt to explain all in terms of electricity, in terms of that which once was thought to be a superficial effect obtained by rubbing two bodies together. Surely, we have come upon a day when the scientific men meet eye to eye with the philosophers, the former seeing a new vision and the latter adopting the new revelations in matter with a zeal which portends a new era in philosophy. One of the most notable recent achievements in our own coun- try is that which must be credited to him who was to give our annual address. Professor Millikan has succeeded in demon- strating and measuring with a satisfactory degree of accuracy the unit of electricity. Numerous physicists contributed in a more or less direct way to the final successful measurement, and among these should here be mentioned our own Professor Bege- man. Evidence of the inadequacy of any theory of light requiring a continuous wave front, is accumulating. The quantum con- ception of light is receiving each year additional confirmation. The recent notable contribution in this field is the establishment of this quantum relationship in photo-electric effect and in the emission of characteristic X-rays. It would seem that, while the intensity of radiation does diminish with distance from a point source in accord with the inverse square law, yet the THE ADDRESS OF THE PRESIDENT 31 energy is transmitted in quanta which do not change with dis- tance. We may anticipate in the years to come a vigorous and continuous attempt to establish an adequate theory of radiation. All of the phases of progress which I have mentioned deal with radiation and atomic structure, excepting the fairly exact measurement of the unit of electricity or the charge carried by the ubiquitous electron. This leads me to make two statements. The first is indicated by my selection of material, namely that the most important physics problem of the time and perhaps of all time, is the structure and behavior of the atom. The second is that although the present really great work in physics does require accurate thinking it does not demand measurements of the highest precision. Yet, peculiarly enough, in the most notable contributions in physics from America during the last twenty years, reports of precision measurements predominate. Our country is not, greatly to our regret, a leader in physics thought today. That it can so become is certain. But to attain that goal we must lay continually greater stress upon theoretical physics and less upon accurate measurements. This suggestion applies to teaching in high schools and colleges, and to the thinking of those among us who are devoting their lives to physics. I doubt not but that you may make similar comments upon the need of the change of emphasis in some of the other sciences. Yet we must appreciate that in astronomy and geology and perhaps in other sciences represented here today America is a leader. It has been and now is the custom of the Secretary to make specific recommendations to the Academy. Therefore in a few comments I shall confine myself to a general statement concern- ing the function of the Academy and our responsibility thereto. Consider first certain significant facts concerning the location of this Academy. Iowa is favorably situated as to climate, hav- ing neither the severe winters nor the depressing summers of many of our states. Iowa is not overwhelmed with the commer- cial spirit but is a state of farms, of small cities, of comfortable homes. And what kind of a location does the desirable growth of science need? The development of science demands strong physiques, keen, logical and broad- visioned minds, and oppor- tunities for contemplation free from distractions. Our conclu- sion is that the State of Iowa is distinctly favorable to the devel- opment of science. Out of these two million people, approxi- 32 IOWA ACADEMY OF SCIENCE Vol. XXIV, 1917 mately one-fiftieth of the entire population of our nation, there should arise real leaders in scientific thought. Our responsibility is not the remodeling of our educational systems in order to catch these leaders, but is the creation of a cordial attitude to- ward and interest in science that shall make the awakening of these young minds possible. We should be conscious not only of the obvious functions of the Academy in contributing to scien- tific knowledge, but also of the equally important activity in creating an atmosphere in all our institutions of learning that will foster the development of scientific leadership. We can go forward in our labors with peculiar confidence for there is no branch of learning that more certainly contributes to the knowledge of truth, that more definitely points out, by its own methods, the way in which the progress in civilization must be made if we the most rapidly attain happiness, justice and free- dom. Our Academy exists not merely for Iowa but for the world, serving as a means of assisting Iowa to make generous contributions to the welfare of this nation and of the entire world. Department of Physics, State University. SECOND RECORD OF OSCILLATIONS IN LAKE LEVEL, WITH RECORD OF LAKE TEMPERATURE AND OF METEOROLOGY, SECURED AT THE MACBRIDE LAKESIDE LABORATORY, LAKE OKOBOJI, IOWA, JULY, 1916. JOHN L. TILTON. In the “Proceedings of the Iowa Academy of Science’ ’ for 1916 may be found a somewhat similar title for a paper in which data obtained in July, 1915, were discussed. It is the purpose of the present paper to present the records of a second year. These records were- obtained in part for personal information, and in part for reference by students at the laboratory. It is believed that the records (and also those of last year) are suffi- ciently accurate for use by those studying the limnology of the lake and possibly by those who may work on the heat budget. The 'computations of volume, given in the last paper, are here omitted. Unfortunately it was not convenient to obtain records the fifteenth of August, nor near that date, the time preferred for such records. Since from data previously obtained it was evident tidal ef- fects and changes in level due to changes in barometric pres- sure were not appreciable near the laboratory, all discussion of such data is omitted from the present paper. Only a part of the record of meteorology is here given, and that part is largely presented by diagrams. Wind direction and general velocity were noted, and data used in connection with oscillations in lake level, but they are not given separately in this report. APPARATUS. To ascertain the temperature at different levels in the lake a Leeds and Northrup “Electrical Resistance Thermometer” was at first used (see records of lake temperatures for June 28 and July 18) with excellent results; but on July 25 the lead cable sprang a leak, preventing further determinations by means of that instrument. Recourse was then had to a minimum ther- mometer held in a horizontal position, as extemporized the pre- vious year. To determine whether the pressure of water in the 3 34 IOWA ACADEMY OF SCIENCE Vol. XXIV, 1917 lake affected the minimum thermometer the thermometer was later placed in a water gauge and subjected to various pressures of air up to fifty pounds per square inch. Under the conditions of the experiment the effect on the thermometer varied from the tenth of a degree for fifty pounds to a degree for fifty pounds, with an average rise of thirty-five hundredths of a degree for the five best determinations. This would give a correction of forty- three hundredths of a degree to be subtracted from the reading of fifty-six degrees Fahrenheit obtained for the deepest place in the lake, 135 • feet, as recorded a year ago. In the present records of lake temperature this correction is not included. (It applies only to those of the twenty-sixth of July.) The maximum and minimum temperatures on the porch were obtained by the use of the ordinary maximum and minimum ther- mometers such as are used by the Weather Bureau. The mini- mum thermometer is subject to an additive correction of half a degree, which is here included in the data used. The maximum thermometer requires no correction. To record fluctuations in the level of the lake the same ap- paratus was used as last year, consisting of a cylindrical float in a larger cylinder pierced with a few nail holes. On the upper end of the float was a pen that traced a line on a revolving cylinder. GENERAL CONDITIONS. For study of the effect of wind pressure upon the general movement of water in the lake the opportunity for observation in July, 1916, was not as good as in July, 1915, when the wind was more variable and at times stronger than in 1916. The data on temperature are in some respects better than those ob- tained in 1915. Records were obtained in three different places with a view to comparing temperatures obtained north and south of the center of oscillation. The inflow from Spirit Lake seemed by inspection to be about equal to the outflow from Lower Gar Lake, as last year ; but the lake was four inches higher this year than last. FLUCTUATIONS UN LAKE LEVEL AT THE LABORATORY. The graph, not here reproduced, reveals a uniform fall in the surface due to evaporation, interrupted by occasional precipita- tion, the two about compensating each other the first and third SECOND RECORD OF OSCILLATIONS IN LAKE LEVEL 35 weeks of the session (June 26-July 2 and July 10-16). Four rainfalls caused marked elevations in the surface of the lake. One occurred in the night of June 28-29, when a heavy rain raised the surface 1.75 inches. On July 2 the surface was raised .4 inch, on July 19 it was raised .5 inch and on July 24, .6 inch. In each case the graph shows the presence of large storm waves. Slight fluctuations that seem due to oscillations in the level of the lake at the point of observation are noted in the graph for June 30 and for July 2, each amounting to .06 inch, when waves were small, each oscillation varying through a period of ten hours. On July 19 there was a rise in the level of the lake of about .06 inch for about six hours at the point of ob- servation, and then a return to the former level without a corre- sponding depression. This was accompanied by high waves, when a strong wind shifted from southeast to northwest. In a similar manner on the night of July 23-24 there was an oscilla- tion when there were large waves preceding a thunderstorm. The wind had been in the southwest the day preceding the storm. Of changes in direction during the storm there is no record. During the night of July 23-24 the wind gauge recorded an average velocity of 9.1 miles per hour. This was the only in- stance during the time that the wind gauge was used that there was any relation to be detected between wind velocity and the oscillations in the lake. During that time the wind was almost constantly from the southwest. Generally when the wind gauge near the laboratory (and about sixty feet above the lake) re- corded a velocity of about four miles per hour the wind out in the center of the lake was strong enough to raise large waves on which white caps were nearly ready to appear. CIRCULATION IN THE LAKE, AND THE TEMPERATURE. Changes in the circulation of water at the end of the pier were noticeable, and these followed tl^e direction and velocity of the wind. They were of two types: When the wind blew strongly toward the laboratory from the lake not only were floating ob- jects tossed up on the beach but the warm water at the surface was pushed in and down, SO' that often when the wind was pro- longed the water at the bottom was at the same temperature as that at the surface at the end of the pier where the water was 36 IOWA ACADEMY OF SCIENCE Vol. XXIV, 1917 seven feet deep. When the wind blew in the opposite direction, away from the pier, there was an upward and outward move- ment resulting in a lower temperature at the bottom at the end of the pier. During the latter part of June and the early part of July the water from beneath the surface mingling with that at the surface (combined with effects due to radiation, evapora- tion and contact with air of different temperature) caused a drop in the surface temperature of one and even two degrees, and on one occasion (June 21), assisted by the low temperature half way between the end of the spit and the laboratory pier in Miller’s Bay. of a cool day, caused a lower temperature at the evening ob- servation than at the morning observation, the temperature at the surface and at the bottom being the same (62.5° Fahr.), the latter without the immediate influence of evaporation and of the temperature of the air. On quiet sunny days the tempera- ture of the surface water rose even as much as six degrees (July 29). SECOND RECORD OF OSCILLATIONS IN LAKE LEVEL 37 Circulation that was pronouncedly horizontal was commonly noticeable at the end of the laboratory pier. Sometimes it was seen in the slow movement of a thin surface film even an eighth of an inch in depth moved by gentle winds. Often when the wind was strong there was a general movement of the water as seen at the pier. Up to the last two days of the observations this drift seemed to follow the direction of the wind when the wind was northwest, southwest, south and even southeast. Apparently the drift to the north when the wind was southeast was dne to a double eddy within the bay, a second eddy forming west of the spit opposite the laboratory. On the last two days (July 26 and 27) it was noticed that even with a southwest wind the circulation at the pier was toward the south, as if the effect of the strong southeast wind of July 25 still persisted. Fig. lb: The heavy upper line -gives the temperature of the surface water at the end of the laboratory pier during the session of 1916, June 18-July 26. The light lower line gives the temperature at the bottom (depth seven feet) at the end of the laboratory pier. In places the two lines coincide. Apparently the weeds were interfering with the circulation in the bay at the times of the last two observations of temperature (July 18 and 2.6), since the temperature at the bottom amid the weeds was higher than the temperature of the water above the weeds. In the last temperature observations taken out in the lake (July 25-26) after a strong southeast wind for two days, a stratum of water warmer than the water above it and also warmer than the water below it, was found at a depth of about eight meters (26 feet). When this was first noticed it was thought to be due to an error of observation, but the difference was detected in readings taken a mile and a half apart and on two successive days. It seems evident that this circulation involved horizontal sheets of considerable extent. The other variations seen in the curves for 38 IOWA ACADEMY OF SCIENCE Yol. XXIV, 1917 July 26 seem also to mark the presence of water with different temperatures, but not of the extent of that mentioned above. The graph gives a thickness of only five to seven meters for the epilimnion July 18, and a thickness of only two meters and of one meter for the thermocline. The graph for July 26 gives a thickness of seven and a half meters for the epilimnion and of three and a half for the thermocline. Doubtless these increased in the next three weeks. •Pig. lc. Graph of maximum and minimum temperature on the porch of the cottage at the Lakeside Laboratory during the session of 1916, June 18- July 26. SURFACE TEMPERATURE. The temperature of the surface at the pier rose steadily almost daily from 62.5° Fahr. on June 18 to 78.5° Fahr. on July 10, and then varied between 78.5° and 83.5° ; so that for bathing the wa- ter was generally above 78.5° Fahr. Fig. Id. Graph of the relative humidity on the porch of the cottage at the Lakeside Laboratory, June 18-July 26, 1916, from observations at 7 a. m., 12 m. and 7 p. m. METEOROLOGY. The maximum temperature of the air on the cottage porch ranged from 64° Fahr. (June 21) to 93.4° Fahr. (July 23), at which time it was ten degrees below the temperature reported SECOND RECORD OF OSCILLATIONS IN LAKE LEVEL 39 from cities away from the lake. The average maximum tem- perature from June 18 to July 27 was 83.8° Fahr. The relative humidity at noonday from June 17 to July 27, inclusive, aver- aged 67 per cent. From morning, noon and evening determina- tions it averaged 84.6 per cent for the same time. The general direction of the wind was southwest, and the sky averaged clear to partly cloudy. LAKE TEMPERATURE, JUNE 28, 1916. Meters Feet l 2 3 F.° c.° F.° c.° F.° c.° 0 0 66.0 18.9 68.0 20.0 67.2 19.6 1.5 5 64.5 18.1 65.8 18,8 66.3 19.1 3.0 10 64.5 18.1 65.5 18.7 66.2 19.0 4.6 15 64.5 18.1 65.5 18.7 6.1 20 64.5 18.1 64.0 17.8 7.6 25 64.0 17.8 64.8 18.2 9.1 30 64.0 17.8 65,0 18.3 10.7 • 35 64.0 17.8 64.6 18.1 12.2 40 64.0 17.8 63.1 17.3 13.7 45 63.3 17.4 64.0 17.8 15.2 50 62.6 17.0 61.7 16.5 16.8 55 61.6 16.4 18.3 60 61.8 16.6 19.8 65 61.9 16.6 21.3 70 61.0 16.1 22.9 75 61.0 16.1 24.4 80 60.4 15.8 25.9 85 58.4 14.7 27.4 90 57.3 14.1 1. Taken near the center of oscillation of the lake, southeast of “The Inn”. 2. Taken near the middle of the lake off Hayward’s Bay. 3. Taken half way between the spit and the laboratory pier, Mil- ler’s Bay. At the end of the laboratory pier on June 28th the tempera- ture at the surface was 20.6° C. and the temperature at the bottom 19.5° C. In the two following tables the numbers at the heads of the columns refer to the same locations. 40 IOWA ACADEMY OP SCIENCE Vol. XXIY, 1917 LAKE TEMPERATURES, JULY 18, 1916. Meters Feet l 2 3 F.° c.° F.° c.° F.° o.° 0 0 77.4 25.3 75.6 24.2 78,3 25 7 1 3.3 77.4 25.3 75.6 24.2 77.2 25.1 2 6.6 77.0 25.0 75.6 24.2 75.6 24.2 3 9.8 76.5 24.7 75.6 24.2 74.3 23.5 4 13,1 76.1 24.5 75.2 24.0 73.2 22.9 5 16.4 75.2 24.0' 74.5 23.6 71.2 21.8 6 19.7 74.7 23.7 74.1 23.4 59.9 15.5 7 23.0 71.4 21.9 64.9 18.3 60.8 16.0 8 26.3 68.4 20.2 63.9 17.7 9 29.5 68.4 20.2 63,3 17.4 10 32.8 64.0 17.8 62.8 17.1 11 36.1 63.3 17.4 61.9 16.6 12 39.4 62.2 16.8 61.0 16.1 13 42.7 61.5 16,4 60.6 15.9 14 45.9 61.0 16.1 60.6 15.9 15 49.2 60.8 16.0 60.3 15.7 16 52.5 60.6 15.9 60.1 15.6 17 55,8 60.3 15.7 59.4 15.2 18 59.1 59.9 15.5 59.2 15.1 19 62.3 59.5 15.3 58.9 14.9 20 65.6 59.0 15.0 58.8 14.9 21 68.9 58.6 14.8 58.6 14.8 22 72.2 57.6 14.2 58.8 14.9 23 75.5 57.6 14.2 58.8 14.9 24 78.7 57.7 14.3 25 82.0 57.2 14.0 26 85.3 55.9 13.3 27 88.6 55.9 13.3 28 91.9 55.8 13.2 29 95.1 55.4 13.0 30 98.4 55.4 13.0 31 101.7 55.9 13.3 32 105.0 55.6 13.1 SECOND RECORD OF OSCILLATIONS IN LAKE LEVEL 41 LAKE TEMPERATURES, JULY 26, 1916. Meters Feet l 2 3 F.° c.° F.° c.° F.° c.° 0 0 79.0 26.1 80.0 26.7 80.1 26.7 1 3.3 79.0 26.1 80.0 26.7 79.3 26.3 2 6.6 80.0 26.7 79.5 26.4 78.9 26.1 3 9.8 79.5 26.4 79.5 26.4 78.6 25.9 4 13.1 79.3 26,3 79.2 26,2 78.1 25.6 5 16.4 79.5 26.4 79.4 26.3 * G 19.7 78.8 26.0 79.3 26.3 7 23,0 79.5 26.4 78.7 25.9 8. 26.3 77.5 25.3 79.5 26.4 9 29.5 72.5 22.5 78.5 25.8 10 32.8 69.1 20.6 71.2 21.8 11 36.1 65.7 18.7 68.3 20.2 12 39.4 66.8 19.3 64.6 18.1 13 42.7 64.5 18.1 65,4 19.1 14 45.9 67.5 19.7 65.1 18.4 15 49.2 63.5 17.5 64.5 18.1 16 52.5 63,5 17.5 63,5 17.5 17 55.8 63.0 17.2 63.5 17.5 18 59.1 63.7 17,6 19 62.3 62.5 16.8 20 65.6 65.5 18.6 21 68.9 62.7 17.1 22 72.2 61.0 16.1 23 75.5 60.5 15.8 24 78.7 60.3 15.7 25 82.0 60.3 15.7 26 85.3 59.8 15.4 27 88,6 60.0 15.6 *Total depth 4.5 meters (14.8 ft.), temperature 78.5° F. (25.8° C. ) Department of Geology, Simpson College. NOTABLE MOUND GROUPS IN AND NEAR THE PRO- POSED GOVERNMENT PARK AT McGREGOR, IOWA. ELLISON ORR. Something over a year ago a move was started to ask Con- gress to set aside a tract of land lying along the Mississippi river south of McGregor in Clayton county of this state, and directly opposite the mouth of the Wisconsin river, as a National Forest Preserve or park. Among the reasons given were that it is a region of great natural beauty. The broad river with its channels, lakes and islands, hemmed in on either side by mountainous wooded bluffs, make scenery that in all seasons and all weathers is surpassing fair. It would preserve and make accessible to the people of the northern Mississippi River Valley a pleasure ground- differing from any other in the country and surpassed in restful beauty by none. It is a spot of great historical interest. Just across the river is Prairie Du Chien, settled by the French in 1737 and for years an outpost of civilization. It was the first land in Iowa seen by Father Marquette. The high point below the Pictured Rocks was recommended by Lieutenant Zebulon Pike in his report of his “Exploratory Expedition” as a suitable place for a fort. In connection with Joliet Wisconsin State Park it would make an ideal summer bird preserve for waterfowl and the shy wood- land birds. As considerable land now in cultivation would be included, there would be abundant opportunity for experimental forestry with a view to solving forestry problems peculiar to this section of the country. The numerous and fast disappearing aboriginal earthworks which are found along the bluff tops would be preserved from obliteration by cultivation which seems to be the fate awaiting them unless government or state aid is invoked for their pro- tection. 44 IOWA ACADEMY OF SCIENCE Vol. XXIV, 1917 It is these “Indian Mounds’7 in the proposed park area of 12,000 acres and on the bluff tops of the adjacent neighborhood that are to receive our attention in this brief paper. To begin with there are four types of earthworks, the work of the aborigines, found in Iowa. The most common type is the conical (so called) burial mound much like half an orange laid with the flat side down. They have an average diameter, measured at the base along the original surface of the ground, of twenty-five feet, and an average height of three to four feet. Some are found with a diameter of over sixty feet and a height of eight to ten feet. Others are not over fifteen feet in diameter with a height of about a foot. For the most part all are built up on the same plan. First an inner mound of hard dry clay, over that flat rocks laid irregu- larly, then another foot of earth closely resembling the upper foot of the surrounding natural surface. On the high islands or bordering terraces in the river valley, which are usually beds of pure sand with a foot or two of sandy soil on top, the mounds appear to be built of the surface soil. The material seems to have been gathered from a considerable area as no pits from which it might have been taken are ever found. All conical or round mounds are supposed to be burial mounds. But few of the Iowa, mounds in or near the proposed park area contain any skeleton remains or artifacts of any kind, so far as the writer has had opportunity to excavate them or has been able to get information from those who have. Personal experience leads the writer to believe that the ac- counts of the remarkable finds in these ancient earthworks, so far as they exist in northeastern Iowa, or southwestern Wiscon- sin, should be heard with a grave suspicion that they were very highly colored. In perhaps twenty-five mounds more or less thoroughly excavated by the writer there has been found but one arrow head and a small crude earthen vessel three inches high by two inches in diameter — nothing else. Prehistoric pottery, and artifacts of flint and other material of which arrow points, knives, and other implements were made, and of diorite, granite and copper are very common. But this material is found scattered about the fields in greater or less abundance according to locality, or is found in the ordinary NOTABLE MOUND GROUPS 45 burial places, which are very common on the river terraces but extremely rare so far as discovered on the uplands. The next most abundant type is the long earthwork, twenty to twenty-five feet wide and about three feet high in cross section, and of all lengths from less than fifty feet to six hundred. This type is sometimes regarded as having been built for defensive purposes but a study of the location and surroundings will show that this is in no case the correct theory. Like the conical mounds little or nothing of relics or anything to indicate burials is ever found in them. The reason for the building of these mounds is problematic. Following the long embankments in abundance are the effigy mounds. These are earthworks built in crude imitation of the forms of animals, birds and reptiles, in semi-relief. Near Ft. Atkinson in Wisconsin is one of a man. All are large and in most cases they are between one hundred and two hundred feet in length. It is now generally believed that these were intended to represent the totems of the family that made them. The reasons for their erection were perhaps analogous to those for The erection of the totem poles of the Indians of the northwest coast. It is usually hard to determine the particular animal, bird or reptile which they were intended to represent. Among those which have been identified with a reasonable certainty are the bear, panther, bison, wild cat, eagle, night hawk, wild goose and lizard. Groups of all types where located on the bluff tops are always on the highest part or ridge of the divides between the gulches tributary to the great river. In such locations they are found in strings following the divide from the promotory next the river bank for considerable distances inland but never so far but that the river can be seen from each mound. A string may con- sist entirely of conical mounds or these may be interrupted by a long earthwork or effigy mound. Usually the conical mounds are nearest the river, the others farther away. Where groups occur on the terraces the mounds may be in rows or scattered about promiscuously with long and effigy mounds here and there among the more numerous conical types. On Pike’s Peak directly opposite the mouth of the Wisconsin river is a fine bear mound. Another occurs on Point Ann just south of McGregor, while on a point half way between is a group IOWA ACADEMY OF SCIENCE Vol. XXIY, 1917 46 of buffalo mounds. Conical types are associated with the effigies in all three groups. About two miles north of North McGregor on a high point of St. Peter sandstone, somewhat back from the river, lies Pleasant Ridge group, probably the finest group of effigy mounds west of the Mississippi river. This consists of ten mounds representing at least two different animals and two mounds representing birds. With these are two linear mounds but none of the conical type. At a high island at the southern end of the park area is a group of eighty-eight conical, four long and four effigy mounds. In all there are probably nearly two hundred mounds within the proposed park and as many more within five miles north and south, making altogether a very interesting field for the study of the works of a race that is now gone from a land that to them, as to us, was ‘ ‘ Iowa. ’ ’ Waukon. HIGH-LEVEL TERRACES OF OKANOGAN VALLEY, WASHINGTON. CHARLES KEYES. Recent observations in the interior of Washington state in- dicate in no unmistakable terms that in late geological times the entire drainage of the region has repeatedly undergone great vicissitudes. Its juvenile lines have been profoundly disturbed, displaced, and variously modified. By floods of lava on the one hand and on the other hand by advancing glaciers the original river courses have been completely lost to view. A notable and concrete illustration is the Big Bend of the Columbia river— that stretch of the great stream nearly 200 miles long lying between 1 the mouths of the Spokane and Snake rivers. This wide diversion of the course of the Columbia river in central, Washington is the result of prodigious lava flows which have pushed out northwestward from the great Idaho volcanic fields. In glacial times immense ice tongues have advanced from the main Canadian mass into the Columbia canyon, effectually blocking the flow of the river and forming extensive lakes. An old outlet of the main lake is seen in the Grand Coulee now a long dry canyon deeply intrenched in the lava field and entirely crossing Douglass county. In brief the region under consideration is one in which a pene- plained surface has been broadly uplifted, deeply dissected, greatly eroded by overriding glaciers, and now is again subject to normal river corrasion. Few districts display to better ad- vantage the effects of the '.profound erosive power of glacier move- ments. Although the glaciers had the 'old river valleys to guide them they have deepened some of them until the bottom of Lake Chelan basin, for instance, now lies several hundreds of feet be- low sea-level. A conspicuous feature of the present river valley is the re- markable series of high-level terraces which their sides present. These embankments persist at various heights above the water- level up to 700 or 800 feet. They are manifestly of diverse origins. An old river terrace and an old lake beach attract principal attention. The first of these was formed by greatly 48 IOWA ACADEMY OF SCIENCE Vol. XXIV, 1917 overloaded glacial streams ; the second by worked-over gravels of glacial streams and moraines. It is not always easy to differ- entiate the two. On the whole the first maintain a nearly uniform level above the present stream; the second holds an absolute level upstream, thus gradually approaching the river level. The terraces of the Columbia river have already received considerable attention, but there has been little attempt at exact correlation of the different benches. For instance, what is called the Great Terrace displays discrepancies as much as 200 feet when careful comparisons are made. Above the mouth of Chelan river, the outlet of the lake of the same name, the bench about 300 feet above the water level appears to be the most important one. At least it is the largest and most persistent one for a distance of many miles upstream from the point mentioned. It probably was formed during the time when the course of the Columbia river was dammed by the great glacier which came out of the Lake Chelan valley. It seems to represent the level of the waters in the vast lake that was thus generated in the Colum- bia gorge above, the outlet of which was through the Grand Coulee or some other coulee near by. With this high level stage it seems most reasonable to associate the principal terraces of Okanogan valley. Okanogan river flows due southward and enters the Columbia river exactly at the sharp elbow of the Big Bend. The coinci- dence of the courses of the two streams in a single straight line suggests that the present Columbia river in this part of its course may be really following an old channel of the Okanogan river. Now the present Okanogan is a small stream flowing in a valley large out of all proportion to the importance of the watercourse. In fact it is a stream tremendously underfitting its valley. The latter is a rock-bound gorge sufficiently large to carry the waters of the Columbia. Viewed in its larger aspects the Okanogan valley extends far to the northward into British Columbia where it passes through one arm of Suswap Lake and on into the Columbia valley again where the latter passes around the lofty Selkirk mountains. The Okanogan valley is very straight. It originally was a structural depression with a stream-cut channel . Later a glacier occupied it down to its mouth, blocked and crossed the Columbia gorge, the south side of which it overrode and then extended far Iowa Academy of Science. Plate High level terraces of Okanogan valley, Washington. ) TERRACES OF OKANOGAN VALLEY 51 out on the lava plain as far at least as the Grand Coulee. Un- mistakable signs of profound glacial action abound on every hand (see Plate I). The high-level terraces (Plate I) which are so conspicuous in the valley of the Okanogan river are composed almost entirely of worked-over gravels with little or no fine materials. This fact seems to indicate lacustrine origin. They extend for many miles above the. mouth of the stream. The fact to be emphasized in the present connection is that the main Okanogan terrace is to be connected with the Great terrace on the Columbia river, in which case their origin is to be sought in a common cause — the damming of the latter stream by advancing ice of perhaps the Chelan glacier when the lake thus formed overflowed at the Grand Coulee. Des Moines. 4 CONTINENTAL PERSPECTIVE OF AMERICAN PRE- CAMBRIAN STRATIGRAPHY. CHARLES KEYES. To many of the delegates to the Twelfth International Geologi- cal Congress who listened to the papers and discussions on Pre- Cambrian problems and who afterwards took part in the Canadian transcontinental excursions into regions where the ancient elastics were displayed in infinite variety, the most valu- able feature perhaps, was the field evidences of the amazing taxonomic possibilities which on the American continent the Pre-Cambrian sections were opening up. Few of the travelers had ever seen so deeply into the oldest stratified rocks in so short a time, under such favorable circumstances, or under happier guidance. Some of the participants in the proceedings, pre- eminent in other fields of stratigraphic endeavor, seemed to see in this old American complex exactly the counterpart of condi- tions that were presented a century ago by the Primary (Paleozoic) rocks when they were awaiting the magic touch of English geologists to unfold the then inextricable maze. Between the two century-part problems there is one marked difference. In America there appears to be in place of only one grand succession of formations two vast piles of eral rank, either one of which very greatly surpasses in magnitude and time equivalent the entire Paleozoic sequence with which Murchison, Sedgwick and Lonsdale had to deal. As Doctor Walcott astutely remarked in the course of his informal lecture before the mem- bers of the Congress when he met them on the evening which they spent at Field Station nearby which was his now famous “Burgess Camp,” the Pre-Cambrian sediments of the Rockies present the most fruitful theme that today awaits the young and ambitious geologist. In the weighing of the evidence supporting the various hypotheses presented to them the visitors on these excursions held superior advantages over the others in that they were singu- larly free from a certain amount of bias which necessarily possesses those who work long and arduously in a circumscribed field. They were in an exceptionally commanding position 54 IOWA ACADEMY OF SCIENCE Vol. XXIV, 1917 rigidly to test the applications of the explanatory theories and to make impartial comparisons between deduced consequences and generalized records. To a degree of stupidity almost, it seemed at times, they had to be shown in the field the detailed proofs. They not infrequently gave scant consideration to many trivial features of which far too much had been manifestly made. They brought to bear upon intricate problems the in- valuable experiences of other lands. They were better able to view things more broadly than is possible in the cases of those who had worked mainly in limited areas. Altogether what they agreed upon was often quite different from what had been pre- sented to them, piecemeal as it were, in isolated localities. In the various attempts to resolve the most ancient sedimen- tary successions into their terranal elements the one great drawback is, of course, the more or less highly metamorphosed state of the rocks. This difficulty is even more serious than the one which confronted the student of the Paleozoics before use was made of fossils. Among very old formations it is often hard to distinguish between rocks which have been altered from igneous masses and those which have been changed from sedi- mentaries. Moreover, without some scheme of taxonomic loca- tion of rock-masses through the consideration of which critical criteria of stratigraphic recognition are proposed, developed and modified, very erroneous notions of mass relationship must prevail. In many places, notably, for instance, on the Atlantic Piedmont plateau, much of the supposed Pre-Cambrian com- plex recently proves to be merely highly altered Cambric, Ordo- vicic and even Siluric sediments. On the other hand, thick sections of strata in the Selkirks, for example, long regarded as Paleozoic in age are found to have beyond all doubt, Pre- Cambrian affinities. Ever since it has come to be appreciated that there is really a Pre-Cambrian stratigraphy the great desideratum has been the discovery of some spot on earth where the ancient beds still remain but little altered and where a definite terranal sequence may be made out in the same way that it is in the case of the newer sedimentary successions. Several such locations are now known; one on the north shore of Lake Superior, and another in the Rocky Mountains on the boundary between the United States and Canada, are particularly noteworthy. In neither PRECAMBRIAN STRATIGRAPHY 55 of these regions are the strata, altered scarcely more than it is customary to encounter among the Paleozoics. Since the beds are fossiliferous to depths of more than two miles beneath the typically earliest Cambric, or Olenellus, zone extensive faunas may be expected eventually to be disclosed. The fact that as yet no long sequences of faunas are deter- mined whereby the rock-sections of the various localities widely separated geographically may be analyzed, compared and grouped into units having definite taxonomic values, as is the common practice among the Paleozoics does not militate against the utilization to their fullest extent of certain physical fea- tures which have equal if not superior importance as strati- graphic and correlative criteria. These are the diastrophic features which find their most conspicuous expression in un- conformities. Their lateral extent, taxonomic rank and strati- graphic value are best indicated in diagram. These broader stratigraphic aspects of the American Pre-Cambrian complex along a given cross section, as the boundary line between Can- ada and the United States, are represented on the accompany- ing chart (Plate II). Both the relative amounts of sedimentation and the magnitude of the important stratigraphic hiatuses also are indicated. The latter mainly represent more or less great erosional intervals — times of notable emergences of the conti- nental tract. The enormous extent of denudation to which they point is no less astounding than the prodigious volume of the sedimentation in comparison with which some of the most fa- miliar Paleozoic sections sink into insignificance. Considered in their larger, or continental, relations the mag- nitude of sedimentation and the extent of removal give intrinsic suggestion of the taxonomic ranks to which many of the ter- ranes already recognized should be assigned. Conspicuous fea- tures also fo be especially noted are the almost uninterrupted degradation in the east ; the almost continuous sedimentation in the west; and the sweeping oscillatory movement of the an- cient strand-line in the continental interior. Particularly note- worthy also are the three major breaks in deposition marked by unconformities of continent-wide extent. The minor uncon- formities are likewise significant. Both larger and smaller unconformities are direct expressions of notable diastrophic movements. They are the basal horizons of new cycles of sedi- Iowa Academy of Science. IVd OIOZOd3±Odd 0I0Z03H0 dV OSD' Continental perspective of Pre-Cambrian sedimentation. PRECAMBRIAN STRATIGRAPHY 57 mentation. They are now so widely known, so well determined, and so numerous that they become prime values in the sys- tematic arrangement of the strata. For purposes of wide and exact stratigraphic correlation they far surpass any service that fossils might perform. That the primary subdivisions, here designated as Proterozoic and Archeozoic, each have eral rank in the general scheme of terranal classification rather than periodic or serial position as they are often assigned, is amply supported by many con- siderations. Laying down of a few miles’ thickness of strata which each of these divisions represents is surely a time equiva- lent of that of any known Paleozoic section in the world. The transcontinental unconformity which marks the base of both of these divisions certainly represents diastrophic revolution of the first magnitude, and movement greater than that which characterizes any other recognized eral division. In the rela- tive degree of metamorphism which the several divisions dis- play in the same vertical section is indicated also something of a time measure. Of less taxonomic importance is the com- parative amount of deformation exhibited. The lesser subdivisions1 which have been recognized in various regions under geographic designations as formations hold only a transitory taxonomic tank. In place of tens or hundreds of feet their thicknesses are often measured in thousands of feet. In the majority of cases doubtless these terranes will be found actually to possess the rank of provincial series, and to permit of further subdivisions into formations, that are comparable to those commonly defined among the Paleozoics. For classificatory purposes the fossils of the Pre-Cambrian rocks, no matter how plentiful they may occur, are not likely ever to prove so important as they have in connection with the Post-Cambrian strata. Notwithstanding the facts that or- ganic remains have been discovered in both great sections of Pre-Cambrian elastics and that they will be doubtless disclosed in more or less abundance throughout the entire succession, the W'arennesic, as a periodic title, was' proposed (Proc. Iowa Acad. Sci., XXI, 201, 1914) to take the place of A. C. Lawson’s name Ontario, which was preoccupied. It is the old French designation of Ontario Province. It is probably not co-extensive with the term Loganian Series, which a few months after Varennesic was proposed, was- adapted for the same purpose by Miller and Knight (Rept. Ontario Bureau of Mines, XXII, pt. II, 127, 1914). 58 IOWA ACADEMY OF SCIENCE Vol. XXIV, 1917 fossils are apt to retain in great measure the characteristics of the oldest Paleozoic forms as we now best know them. Neither are the fossils likely to serve in Pre-Cambrian questions the same stratigraphic purpose that they so long have else- where in the geologic column. On this account mainly the real significance of these forms already discovered is commonly overlooked; or their salient features as possible indices to re- gional stratigraphy are misinterpreted. For these reasons it is that there is such a wide divergence of opinion concerning the taxonomic ranks of the various subdivisions of these oldest sedi- mentaries. In arraying the oldest sediments, or those strata lying be- neath the commonly accepted base of the Cambric section, or Olenellus zone, with the younger rather than with the older part of the general sequence undue emphasis is manifestly placed upon certain assumed faunal affinities. This appears to be the chief reason why Dr. A. Rothpletz, for instance, would be inclined to include in the Cambric section the fossiliferous limestones of Steep Rock lake, north of Lake Superior2. In the Beltian section of Helena, Montana, the same observer is even less fortunate in his conclusions relating to the geologic age3 because here he actually worked in recognized Mid- Cambric strata instead of Pre-Cambrian beds as he supposed, as is con- clusively shown by Dr. C. D. Walcott.4 Apparently influenced partly by the Rothpletz views Prof. A. C. Lawson5 argues for drawing in the Lake Superior region the' basal line of the Paleozoic section at the horizon of the great plane of unconformity called by him the Epiarchean interval ( Anianic-Selkirkic hiatus) ; and by severe restriction of the term Algonkian the latter is made co-extensive with Proterozoic. However, the Steep Rock Lake fossils, which are the oldest or- ganic remains known, occur far beneath the level of the break representing the “Epiarchean Interval,” and the Algonkian section thus restricted proves to represent an elapse of time equal to, if not vastly greater than, the entire Paleozoic era. So there are grave objections to assigning to such a superior succession of strata so inferior a taxonomic rank. 2Oral communication. 3Die Fauna der Beltformation bei Helena in Montana, pp. 1-46, Miinchen, 1915. 4S'mithsonian Misc. Coll., Vol. CXIV, p. 259, 1916. 5Bull. Dept. Geob, Univ. of California, Vol. X, p. 18, 1916. PRECAMBRIAN STRATIGRAPHY 59 As Dr. G. Steinman judiciously observes7 the discovery of a great fauna in the Steep Rock Lake strata is not likely to ac- quaint us with forms so very different from those occurring in the typical Cambric rocks. This also was the opinion of Dr. Th. Tschernychew8 who at the same time visited the same lo- calities. Both of these conclusions coincide with the circum- stances predicted by Prof. W. K. Brooks9 more than twenty years ago — before any Pre-Cambrian fossils were known. Brooks’ reasoning was based strictly upon morphological grounds, and on this account has special value. His chief thought was that for some time prior to Olenellus times life which was entirely thalassic in nature was just beginning to find the bottom of the sea and was acquiring hard parts in order better to withstand its new shore environment. Hence for long periods previously life changed very slowly; but upon reaching shallow waters and the shore it differentiated with great rapidity. It is with these considerations in mind that the faunal aspects of the Pre-Cambrian rocks should be ap- proached, rather than with any expectation that it is going to be possible to classify the strata according to the same prin- ciples that are so universally followed in the case of the later geologic formations. At the close of the discussions on Pre-Cambrian problems at the Toronto Congress the bewildering variety of suggestions offered in correlation left the impression with the majority of delegates that the subject was in a state of hopeless confusion More mature reflection showed that this was not really the case. Identical problems were being met in distant parts of the world. Singularly, also, very similar sections had been made out on the different continents. The one feature that loomed largely in the minds of all was the fact that beneath the Olenel- lus level there existed everywhere a vast pile of sediments await- ing taxonomic grouping and systematic adjustment. It was not 'more intensive local cultivation that was most desired but some classifieatory scheme after the plan of that which we have for the later geologic formations. With such a framework upon which to hang all the accumulated facts and fancies negative testimony is as valuable as positive evidence, and the successive 7Oral communication. 8Oral communication. 9 Journal of Geology, Vol. II, p. 455, 1904. 60 IOWA ACADEMY OF SCIENCE Vol. XXIY, 1917 problems will be solved as rapidly by disproving terranal re- lationships as by showing that they exist. Rate of advance- ment is thus doubly accelerated. Inattention to these circum- stances is doubtless the chief reason why progress in Pre-Cam- brian geology has been so unnecessarily slow and why so few investigators find the field inviting. Bes Moines. EXTENT AND AGE OF CAP-AU-GRES FAULT. CHARLES KEYES. On the general geological map of Iowa there are three pecu- liarities in the areal distribution of the geological formations represented which excite particular attention. They indicate that not only has the terranal story not been yet all told but that owing to unusual misinterpretation the real facts have been unwittingly greatly distorted. One of these features is the notable southeastward straight trend of the eastern border of the basal Missourian, or Bethany, limestone as it leaves our state in Wayne county^ — a direction nearly at right angles to that which we would ordinarily expect. South of the Iowa boundary, in Missouri, the southeasterly trend of the Bethany escarpment is traceable for a distance of fully fifty miles. This basal Missourian limestone (Upper Coal Measures) is found to extend in a long tongue, cut through at several points .by the present streams. Beyond, the trend of the Bethany ridge assumes its normal course, that is, south- westward, and reaches Kansas City and far to the south finally enters Oklahoma. Twenty years ago, when I was in charge of the Missouri Geo- logical Survey, I discovered the existence of and mapped rather carefully this singular eastwardly projecting tongue of the Bethany limestone. At that time I did not fully understand the real significance of the phenomenon. Recently, in the course of professional duties, I found out the cause. Called upon to “ match up,” as it were, the '.coal seams of a number of localities rather widely separated from one another and irregularly scat- tered through several counties along the Iowa-Missouri boun- dary-line, so that diamond-drill prospecting could go on under check, I spent several days before I came to realize what the trouble actually was. In former years whenever I came across some puzzling problem I could, so soon as it failed to yield a quick solution, and before I tired, drop it instanter and turn to some more tractable topic. Now, I had either to find a satis- factory answer or admit failure which would spell disaster pro- fessionally. Moreover, it was a time when results had to be 62 IOWA ACADEMY OF SCIENCE Vol. XXIV, 1917 measured in dollars and cents. The process required the same nicety of calculation, but with more variable factors, as when Leverrier figured out for the first time the position in the heav- ens of the then unknown planet Neptune. In the region under consideration the general slope of the upland plains surface is v eastward or southward ; the general slant of the strata is to the westward. In other words the present peneplain bevels all the rock-layers between the Missis- sippi and Missouri rivers. It so happens that the coal seams of the region, in Appanoose and Wayne counties, in Iowa, and in Putnam, Mercer, Sullivan and Adair counties, Missouri, pre- sent greater individuality and cover wider areas than do the majority of the coal beds of the two states mentioned. With them also are associated several distinctive limestones which serve as guide-horizons. The especial difficulty in attempting to decipher the detailed stratigraphy of this district is that it is deeply covered by glacial till, making outcrops of the Coal Measures few and far between. Upon first reentering the field it was inferred that the existence of the long tongue of Bethany limestone was due to the fact that it lay in a trough. This soon proved to be the case. The noteworthy feature about the trough was that it was plainly asymmetrical. To the northeast all the coal beds were found to rise steeply. There was apparently present a sharp monoclinal fold having its lower limb to the west. On the section between Princeton, Missouri, and Seymour, Iowa, there was an abrupt descent just out of Powersville of nearly 200 feet. On the line between Milan and Centerville there was, five or six miles southwest of Unionville, a similar abrupt descent. Between Milan and Kirksville like- conditions and fig- ures obtained. In previous years it had been found that farther south or southeastward, near Macon, there existed what appeared to be a marked anticline, or perhaps monocline, in which the rock layers on one side sloped steeply to the northeast. Still farther to the southeast it had been noted that the coal-bearing strata were abruptly cut off from the Early Carbonic and other lime- stones along a rather sharply defined line running through Shelby, Monroe and Ralls counties. This phenomenon had never been satisfactorily explained. EXTENT AND AGE OF CAP-AU-GRES FAULT 63 When working in Missouri I had also taken occasion to trace the Cap-au-Gres fault, the features of which are so well dis- played on the Mississippi river above the mouth of the Illinois river, from near Folley Station through Lincoln and Pike counties. Now all these apparent anomalies of which mention has been made lie in a slightly curved line extending from the mouth of the Illinois river to Leon, in Decatur county, Iowa, Indeed they prove to be expressions of some line of notable displacement rather than of a line of unusual flexing. Eastward from the mouth of the Illinois river the fault-line passes through the city of Alton, the prominent bluff overlook- ing the town being in fact a fault-scarp. Although not vet actually traced on the ground beyond Alton the distribution of the coal mines and other features indicate in no unmistak- able way that it extends far beyond. The line seems to pass about three miles north of Edwardsville, about twelve miles south of Vandalia, near Louisville, through Olney and Law- reneeville, at the southernmost end of the Illinois oil fields, to Vincennes, Indiana. Between Vandalia and the Indiana boun- dary the line is parallel to the anticlinal axis of the Oshawanpe Hills, a marked structural range crossing southern Illinois and forming the eastward prolongation of the Ozark uplift of south- ern Missouri and northern Arkansas. Prom Leon, Iowa, to Vincennes, Indiana, the distance is 400 miles. At the Mississippi river the difference in level of the same layers on the two sides of the fracture is more than 1,000 feet. The Cap-au-Gres fault is the most remarkable line of displacement in the entire Mississippi valley. At the Sand- stone Headland the movement is probable near maximum. To- wards either end the amount of displacement becomes grad- ually less and less until finally in north Missouri and southern Iowa there is no fracturing of the rocks at all, the vertical movement finding expression in a sharp monoclinal fold. The typical structural features of this great line of displace- ment as exposed at the Cap-au-Gres on the Mississippi river, 1 have already, described.1 Near the fault the rocks are upturned so that in a distance of about one mile along the river almost the entire Paleozoic section from the Cambric to the Carbonic 1Proc. Iowa Acad. Sci., Vol. V, p. 58, 1898. 64 IOWA ACADEMY OF SCIENCE Vol. XXIV, 1917 terranes is fully represented and is in sight at one time. I re- call no other instance of the kind on the whole continent. The magnitude of the displacement is best shown in diagram (Plate III) in which the distance between the two parts of the Coal Measures is indicated to be approximately 1,123 feet. This figure does not represent the total movement. It is only the actual vertical movement. The lateral movement is doubtless much more ; how much it is not possible at the present time to state. In the case of the crustal rupture producing the San Francisco earthquake a decade ago the maximum vertical trans- location was about four feet, while the horizontal component was more than twice this amount. Perhaps about this ratio obtains in the Cap-au-Gres instance. One of the remarkable features of this fault is the tremen- dous extent of the “drag.” In the west bluff of the Mississippi river this is shown to be not less than 300 feet. Many faults of greater throw do not display any appreciable drag. This recognition of the wide extent of the Cap-au-Gres dis- placement has a profound effect upon the general mapping of the states through which the line passes. A broad belt reach- ing east and west entirely across the state of Illinois now sorely needs notable rectification of all of the formational boundaries. A similar wide belt traversing the state of Missouri also re- quires complete readjustment of the control on the areal dis- tribution of the rock terranes. In Iowa., where far less map- ping was done in the office and where the field work was more painstaking, the published maps demand no material revision. It is singular that in the other states so conspicuous a feature should be so long so completely overlooked, especially since the cue is so plainly given. It is instructive in this connection to peruse the field notes of J. A. Udden2 on the tracing of the Shoal Limestone in western Illinois. After following the out- crops of the formation southward entirely across Macoupin county he suddenly loses all signs of them; and they do not reappear to him until he reaches the south edge of Madison county, fifteen or twenty miles away. Now this interval where he is unable to detect the Shoal rock is right in the great fault belt and the limestone no doubt lies several hundred feet be- neath the surface of the ground. If at the last point of ex- 2Illinois Geol. Survey, Bull. 8, p. 120, 1907. 'AMEBIC ORDCmCIC £IL D CARBONIC Iowa Academy of Science. Plate III. Cherokee Shales St. Louis Limestones Keokuk Limestones Burlington Limestones Chouteau Limestones Hannibal Shales Louisiana T. imestojj.es . Saverton Shales Grassy Shales ’ Snyder Shades- Callaway Limestones Sexton Dolomites Bowling Or. iT.imestones Noix Limestones Pufallo Shales McCune Limestones Bryant Limestones Joachim Dolomites Si Peter Sandstones Jefferson Dolomites / Magnitude of the Cap-au-Gres fault. 5 / /23 66 IOWA ACADEMY OF SCIENCE Vol. XXIV, 1917 posure in Macoupin county Udden had sharply veered to the eastward towards Greenville and Vandalia he might have found abundant outcrops extending that far beyond his last. On the other hand had he traveled southwestward he might have caught up the outcrop again running from a point east of Alton south- eastward to the south line of Madison county where he actually did pick up the thread again. This belt of country extending from Alton eastward well merits close inspection anew. The period at which this great rent in the earth’s crust took place is a matter of some moment. That it was subsequent to the close of the Paleozoic era is clearly indicated by the fact that the Coal Measures are fully involved and abut Cambric sandstones. That it probably was closely associated with the up- lifting of the Ozark dome is shown by the circumstance that it is parallel to and near the margin of the broad arch ; in fact it seems as if the movement were a part of the same orographic disturbance which involved the Ozarks but that the great arch was not able fully to sustain itself on the north and dropped. The Early Tertiaric peneplanation of the region effects both the Ozark surface and the region covering the fault area. The faulting thus doubtless took place about the beginning of Ter- tiaric time. fi Des Moines. • BIBLIOGRAPHY OF THE DRIFTLESS AREA. W. D. SHIPTON. 1682. Lead ore supposed to have been discovered in Wisconsin by Nicholas Perrot. (R. D. Irving, Mineral Resources of Wisconsin: Trans. Am. Inst. Min. Eng., Vol. VIII, p. 498.) 1698. Hennepin, Louis, A New Discovery of a Vast Country in America, 1679-1682, two parts, 355 and 178 pp., London. (On Mississippi River and Lake Pepin, Vol. I, pp. 180-182, also pp. 325-327.) 1752. Bauche, Philippe, The Lead Region of the Upper Mississippi: His. toire de L’Academie Royale des Sciences. 1779. Carver, J., Travels through the Interior P’arts of North America in the years 1766, 1767 and 1768, p. 59, Dublin. 1810. Pike, Z. M., An Account of Expeditions to the Sources of the Miss- issippi and through the Western Parts of Louisiana, etc. Performed by order of the Government of the United States during the years 1805, 1806, 1807. Illustrated by Maps and Charts, 277 pp., Philadelphia. , 1821. Schoolcraft, H. R., Narrative Journal of Travels, etc., Albany. 1822. National Gazette, Philadelphia, Oct. 17. 1824. Keating, W. H., Narrative of an Expedition to the Source of the Saint P'eters River, Lake Winnipeek, Lake of the Woods, etc., etc. Per- formed in the year 1823 under the command of Stephen H. Long, U. S. T. E., Vol. I, pp. 200, 236-237, 263, 265-266, 271-272, 278-280, 287-288, 293-294, Philadelphia. 1825. Keating, W. H., Narrative of an Expedition to the Source of the Saint Peters River, Lake Winnipeek, Lake of the Woods, etc., etc., 2 Vols., London. 68 IOWA ACADEMY OF SCIENCE Vol. XXIV, 1917 1834. Schoolcraft, H. R., Remarks on the Lead Mine Country on the Upper Mississippi (Addressed to the Editors of the New York Mirror), pp. 294-307, especially p. 306, in Schoolcraft’s Narrative of an Expedition through the Upper Mississippi to Itasca Lake, etc., in 1832, New York. 1836. Feather stonhaugh, G. W., Report of a Geological Reconnoissance in 1835 from the Seat of Government by the way of Green Bay and the Wisconsin Territory to the Coteau du Prairie, Senate Document 333. 1840. Owen, D. D., Report of a Geological Exploration of Parts of Iowa, Wisconsin, and Illinois: House Ex. Doc. No. 239, 26th Cong., 1st sess., 161 pp. 1841. Nicolett, J. N., Report Intended to Illustrate a Map of the Hydro- graphical Basin of the Upper Mississippi River, made by J. N. Nicollet, February 16, 1841: Senate Doc. No. 237, 26th Congress, 2d sess. 1842. Hodge, J. T., On the Wisconsin and Missouri Lead Region: Am. Jour. Sci., ser. 1, Vol. 43, pp. 35-72. 1844. Lapham, I. A., A Geographical and Topographical Description of Wisconsin, p. 59, Milwaukee. Owen, D. D., Report Geol. Expl. Iowa, Wisconsin, and Illinois in 1839: Senate Ex. Doc. No. 407, 28th Cong., 1st sess. 1846. Lapham , I. A., Wisconsin, its Geography and Topography: Senate Ex. Doc. No. 87, 29th Cong., 1st sess., p. 57. 1847. Feather stonhaugh, G. W., A Canoe Voyage up the Minnay Sotor, 2 Vols., (on Wisconsin and Mississippi Rivers) Vol. I, pp. 191-258, 270- 273; Ibid., Vol. II, pp. 15-22, 28-33, 113, Lond’on. 1848. Norwood, J. G., In Owen’s Geological Reconnoissance of the Chippewa Land District of Wisconsin: Senate Ex. Doc. No. 57, 30th Cong., 1st sess., p. 105. Owen, D. D., Report of a Geological Reconnoissance of the Chippewa Land District of Wisconsin: Senate Ex. Doc. No. 57, 30th Cong., 1st sess., 134 pp. -J BIBLIOGRAPHY OF THE DRIFTLESS AREA 69 1851. Hall , James, Lower Silurian System: Rept. on Geology Lake Superior Land Dist. (Foster and Whitney), Senate Ex. Doc. ]SIo. 4, spl. sess., pp. 146-148; also in Am. Jour. Sci., 2d ser., Yol 17, pp. 181-194. Lapham, I. A., Geological Formations of Wisconsin: Trans. Wis. State Agr. Soc., Vol. I, pp. 125-126. 1852. Lapham, I. A., Fauna of Wisconsin: Trans. Wis. (State Agr. Soc., Vol. IT, pp. 237 et seq. Owen, D. D., Report of a Geological Survey of Wisconsin, Iowa, and Minnesota, 634 pp. and Atlas, Philadelphia. 1854. Daniels, Edward, Some Features of the Lead District of Wisconsin: Proc. Boston Soc. Nat. Hist., Vol. V, pp. 387-389. Daniels, Edward , First Annual Report of the Geological Survey of the State of Wisconsin, pp. 7-66, Madison. Tenney, H. A., In Daniels’ First Annual Report on the Geological Survey of the State of Wisconsin, pp. 69-74, Madison. Whitney, J. IX, Metallic Wealth of the United States, pp. 403-417. 1855. Lapham, I. A., A Geological Map of Wisconsin. Percival, J. G., Ann. Rept. Wisconsin Geol. Survey, pp. 7-101. Schoolcraft, H. R., “Summary of Narrative,” pp. 560-572 as Brief Notes of a Tour in 1831, from Galena, in Illinois, to Fort Winnebago, on the Source of the Fox River, Wisconsin. By Henry R. Schoolcraft. Addressed to George P. Morris, Esq., New York. 1856. Percival , J. G.. On Southern Wisconsin, including the Iron, Lead and Zinc Districts, with an Account of the Metamorphic and Primitive Rocks: Ann. Rept. Wisconsin Geol. Survey, 111 pp. 1858. Daniels, Edward, The Iron Ores of Wisconsin: Ann. Rept. Wisconsin Geol. Survey, p. 62. Hall, James, Report on the Geological Survey of Iowa, 2 Vols. Whitney, J. D., Geology of Iowa, Vol. I, Pt. I, pp. 286-295, 422-471. 1860. Long, S. H., (On Driftless Area Phenomena), Voyage in a Six-Oared Skiff to the Falls of Saint Anthony in 1817: Collections Historical Society of Minnesota, Vol. 2, Part 1, pp. 27, 29, 50. 1862. Hall, James, Physical Geography and General Geology: Rept. of the Geol. Survey of the State of Wisconsin, Vol. I, p. 11. 70 IOWA ACADEMY OF SCIENCE Vol. XXIV, 1917 Whitney, J. D., Report on the Lead Region of Wisconsin: Geol. Sur- vey of Wisconsin, Vol. I, pp. 73-424. Whitney, J. D., Report of a Geological Survey of the Upper Miss- issippi Lead Region. 1864. Winchell, Alexander, Am. Jour. Sci., 2d ser. Vol. XXXVII, p. 26. 1866.' Whitney, J. D., Geology of the Lead Region: Geol. Survey of Illinois, Vol. I, pp. 153-207. Worthen, A. H., Geol. Survey of Illinois, Vol. I, pp. 27-33. 1867. Whittlesey, Charles, Oh the Driftless Area: Smithsonian Contribu- tions to Knowledge, Vol. 15, p. 20 and map facing the title page. Whittlesey, Charles, On the Driftless Area: Proc. Amer. Assoc. Adv. Sci., Vol. 15, p. 49. 1869. Lapham, I. A„ A New Geological Map of Wisconsin, Milwaukee. 1870. White, C. A., Geology of Iowa, Vol. I, pp. 87, 171-184. White, C. A.,. Lead and Zinc: Geol. Survey of Iowa, Vol. II, pp. 339-342. 1871. Murrish, John, Report as Commissioner for the Geological Survey of the , Lead Districts, Documents accompanying Governor’s Message (Wisconsin), pp. 13-14, 16, 21-22. 1872. ' Eaton, James H., Report of the Geology of the Region about Devils Lake: Trans. Wisconsin Acad. Sci., Vol. I, pp. 124-128. Irving, R. D., On the Age of the Quartzite, Schists and Conglomerates of Sauk County, Wisconsin: Trans. Wisconsin Acad. Sci., Vol. I, pp. 129-137; also Am. Jour. Sci., 3d ser., Vol. Ill, pp. 93-99. Winchell, N. H ., Geol. and Nat. Hist. Survey of Minnesota, First Ann Rept., pp. 46, 61. 1873. Chamberlin, T. C., Some Evidences bearing upon the Methods of Upheaval of the Quartzites of Sauk and Columbia Counties: Trans. Wis- consin Acad. Sci., Vol. II, pp. 129-132. Chamberlin, T. C., On Fluctuations in Level of the Quartzites of Sauk and Columbia Counties: Trans. Wisconsin Acad. Sci., Vol. II, pp. 133-138. Eaton, James H., On the Relation of the Sandstone, Conglomerates and Limestones of Sauk County, Wisconsin, to each other and to the BIBLIOGRAPHY OF THE DRIFTLESS AREA 71 Azoic Quartzites: Trans. Wisconsin Acad. Sci., Vol. II, pp. 123-127; also Am. Jour. Sci., 3d ser., Vol. V, pp. 444-447. Shaio, James , Geology of Northwestern Illinois; Geol. Survey of Illinois, Vol. V, pp. 1-24. Shaw, James, Geology of Jo Daviess County: Geol. Survey of Illinois, Vol. V, pp. 25-56. 1875. Winchell, N. H., Geol. and Nat. Hist. Survey of Minnesota, Fourth Ann. Rept., pp. 5, 21, 59-62. 1876. Lapham, I. A., Geology, in Walling’s Atlas of the State of Wisconsin, Milwaukee, p. 19. Warren , G. K., Report of the Transportation Route along the Wis- consin and Fox Rivers in the State of Wisconsin: Senate Ex. Doc. 28, 44th Cong., 1st sess., 114 pp.; also published as Appendix T, Part 2, Report of Chief Engineers U. S. Army for 1876, with Atlas of Maps. Winchell, N. H., Geol. and Nat. Hist. Survey of Minnesota, Fifth Ann. Rept., pp. 34-41. Winchell, N. II., Alluvial Terraces of Houston County: Geol. and Nat. Hist. Survey of Minnesota, Fifth Ann. Rept. pp. 9, 34-41. 1877. Chamberlin, T. C. (Chief Geologist), Geology of Wisconsin, Vol. II. Irving, R. D., The Baraboo Quartzite Ranges: Geology of Wisconsin, Vol. II, pp. 504-519. Sauk and Columbia Counties, op. cit., pp. 579-597, with Atlas. Irving, R. D., Geology of Central Wisconsin: Geology of Wisconsin, Vol. II, pp. 409-636. Strong, Moses, Geology and Topography of the Lead Regions: Geol- ogy of Wisconsin, Vol. II, pp. 643-752. Strong, Moses (On the Driftless area), Ann. Rept. Wisconsin Geol. Survey for 1876, Madison, p. 10. 1878. Chamberlin, T. C., Ann. Rept. Wisconsin Geol. Survey, pp. 21-32. Chamberlin, T. C. (An Early Explanation of the Driftless Area; see also R. D. Irving and N. H. Winchell), in Snyder, Van Vechten Co’s Atlas of Wisconsin, Milwaukee, p. 151. Dana, J. D. (On the Driftless Area), Am. Jour. Sci., 3d ser., Vol. XV, pp. 62-64, 250-255. Irving, R. D., Origin of the Driftless Area of the Northwest: Am. Jour. Sci., 3d ser., Vol. XV, pp. 313-314. Irving, R, D., On Devils Lake Drainage: Geology of Wisconsin, Vol. II, pp. 507-509; On Lower Wisconsin River: Ibid., pp. 420-421. McGee, W J, On the Complete Series of Superficial Geological For- mations in Northeastern Iowa: Proc. Am. Assoc. Adv. Sci., August Number. 72 IOWA ACADEMY OF SCIENCE Vol. XXIV, 1917 Warren, G. E., Bridging the Mississippi River between Saint Paul, Minnesota and Saint Louis, Missouri: Senate Ex. Doc. No. 69, 45th Cong., 2d sess.; also published in Appendix X3 of the Report of the Chief of Engineers, 1878. Warren , G. K., Valley of the Minnesota River and of the Mississippi River to the Junction of the Ohio, — It’s Origin Considered: Am. Jour. Sci., 3d ser., Vol. XVI, pp. 417-431. 1880 Allen, C. J., Survey of Mississippi, Saint Croix, Chippewa and Wis- consin Rivers: House Ex. Doc. No. 39, 46th Cong. 2d sess., 108 pp. Allen, G. J., The Improvement of the Saint Croix River: House Ex. Doc. No. 40, 46th Cong. 2d sess., 8 pp. Chamberlin, T. C. (Chief Geologist), Geology of Wisconsin, Vol. III. Irving, R. D., Trans. Am. Inst. Min. Eng., Vol. VIII pp. 491, 504. Marquette, Jacques, Joliet’s Map, 1674, Reproduced in Revue de Geographie, February, 1880. 1881 Bell, Robert, Driftless Area: Journ. Cincinnati Soc. Nat. Hist., Vol. IV, No. 3„ p. 222. Chamberlin, T. C., Maps of Driftless Area: Atlas, Plate II, Geology of Wisconsin. Whitney, /. D., Driftless Area: Journ. Cincinnati Soc. Nat. Hist., Vol. IV, No. 3, p. 210. 1882 Chamberlin , T. C., The Ore Deposits of Southwestern Wisconsin: Geology of Wisconsin, Vol. IV, pp. 365-571. Chamberlin, T. C., Trans. Wisconsin Acad. Sci., Vol. V, pp. 268-270'. Shaw, James, Geology of Northwestern Illinois, Geology of Jo Daviess County, Geology of Stephenson County, and Geology of Carroll County: Econ. Geology of Illinois, Vol. Ill, pp. 1-80. Strong, Moses, Geology of the Mississippi Region North of the Wis- consin River: Geology of Wisconsin, Vol. IV, pp. 3-98. Swezey, G. D., On Some Points in the Geology of the Region about Beloit: Trans. Wisconsin Acad. Sci., Vol. V, pp. 194-204. Whitney, J. D., Geology of the Lead Region: Econ. Geology of Illinois, Vol. si, pp. 118-162. Wooster, L. C., Geology of, the Lower Saint Croix District: Geology of Wisconsin, Vol. IV, pp. 101-159. Worthen, A. H., Econ. Geology of Illinois, Vol. I, pp. 22-26. 1883 Chamberlin, T. C., (Chief Geologist), Geology of Wisconsin Vol. I. Chamberlin, T. C., U. S. Geol. Survey, third Ann. Rept., Plates 28, 29, 31 and 35. Irving, R. D., On the Nature of the Induration in the Saint Peters and Potsdam Sandstones, and in Certain Archean Quartzites in Wis- consin: Am. Jour. Sci., 3d ser., Vol. XXV, pp. 401-411. BIBLIOGRAPHY OP THE DRIFTLESS AREA 73 McGee, W J, The Drainage System and the Distribution of the loess in Eastern Iowa: Bull, of the Philosophical Society of Washington, Yol. IV, pp. 93-97. Salisbury, R. D., Notes on the Driftless Area of Wisconsin: Trans. Wisconsin Acad. Sciences, Arts and Letters. Strong, Moses, Lead and Zinc Ores: Geology of Wisconsin, Vol. I, pp. 637-655. 1884. Chamberlin, T. C., and Salisbury , R. D., Preliminary Paper on the Driftless Area of the Upper Mississippi Valley: U. S. Geol. Survey Sixth Ann. Rept., pp. 199-322. Salisbury , R. D., (On the Driftless Area), Descriptive America, Vol. 1. Squier, G. H., Depth of the Glacial Submergence on the Upper Mississippi: Science, Vol. IV, p. 160. Winohell, N. H., Final Rept. of the Geol. and Nat. Hist. Survey of Minnesota, Vol. 1, pp. 117-120, 213, 227-230, 245, 260-263, 275, 278, 311-313, 317, 406. (See also other Minnesota County Reports on Winona, Wa- basha, Goodhue, Dakota and Washington Counties.) 1885 Salisbury, R. D., Trans. Wisconsin Acad. Sci., Vol, VI, p. 48. 1886 Irving, R. D., The Classification of the Early Cambrian and pre- Cambrian Formations: U. S. Geol. Survey Seventh Ann. Rept., pp. 403-408. Chamberlin, T. C., U. S. Geol. Survey Seventh Ann. Rept., Plate 8 (on soils), pp. 678-688. 1888 Folsom, W. H. C. (On Driftless Area Phenomena), Fifty Years in the Northwest, pp. 383-384, Saint Paul. Winchell, N. H., Changes of Level in Lake Pepin: Geology of Minn- esota, Vol. 2, pp. 2-6, 14-15, 25-26, 398. 1889 McGee, W J, The Pleistocene History of Northeastern Iowa: U. S. Geol. Survey, Eleventh Ann. Rept., pp. 190-577. ******* Bull. Minnesota Acad. Nat. Sci., Vol. Ill, No. 1, p. 135. 1891 Gilbert, G. K. (On the Driftless Area), Geological Guidebook of the Rocky Mountain Excursion, Compte Rendu de la 5me Session, Wash- ington. Salisbury, R. D., On the Northward and Eastward Extension of the Pre-Pleistocene Gravels in the Basin of the Mississippi: Am. Geologist, Vol. VIII, p. 238. 74 IOWA ACADEMY OF SCIENCE Vol. XXIV, 1917 1892 Hall, C. TV., and Sardeson, F. TV., Paleozoic Formations of South- eastern Minnesota: Bull. Oeol. Soc. America, Vol. 3, pp. 331-368. Van Hise, C. R., Correlation Papers, Archean and Algonkian: U. S. Geol. Survey Bull. 86, pp. 186-187. 1893 Blake, TV. P., The Progress of Geological Surveys in the State of Wisconsin — A Review and Bibliography: Trans. Wisconsin Acad. Sci., Arts and Letters, Vol. IX, pp. 225-231. Blake, TV. P., The Mineral Deposits of Southwest Wisconsin: Am. Geologist, Vol. XIII, pp. 237-248. Buell, I. M., Geology of the Waterloo Quartzite Area: Trans. Wiscon- sin Acad. Sci., Vol. IX, pp. 255-274. Gilbert, G. K., (On the Driftless Area), Congres Geologique Inter- national, pp. 289-290, Washington; See also S. F. Emmons, Ibid., pp. 298-301. Jenney, TV. P., Lead and Zinc Deposits in the Mississippi Valley: Trans. Am. Inst. Min. Eng., Vol. XXII, author’s separate, pp. 6, 11, 38, et seq. Norton, TV. H., Thickness of the Paleozoic Strata of Northeastern Iowa: Iowa Geol. Survey, Vol. Ill, pp. 176-186. Winslow, Arthur, Notes on the Lead and Zinc Deposits of the Mississippi Valley and the Origin of the Ores; Jour. Geology, Vol. 1, pp. 612-619. Winslow, Arthur, The Genesis of Ore Deposits — A Discussion of the Paper of Prof. Posepny: Trans. Am. Inst. Min. Eng., Vol. XXIII, pp. 588-589. Van Hise, C. R., Some Dynamic Phenomena shown by the Baraboo Quartzite Ranges of Central Wisconsin: Jour. •Geology/ Vol. I, pp. 347-355. 1894 Blake, W. P., Wisconsin Lead and Zinc Deposits: Bull. Geol. Soc. America, Vol. 5, pp. 25-32. Blake, TV. P., The Mineral Deposits of Southwestern Wisconsin: Trans. Am. Inst. Min. Eng., Vol. XXII, pp. 558-568; also Am. Geologist, Vol. XII, pp. 237-248. Blake, TV. P., Discussion on Lead and Zinc Deposits of the Mississ- ippi Valley: Trans. Am. Inst. Min. Eng., Vol. XXII, pp. 621-634. Blake, IV. P., Discussion on Genesis of Ore Deposits: Trans. Am Inst. Min. Eng., Vol. XXIII, p. 587. Chamberlin, T. C., Discussion on Wisconsin Lead and Zinc Deposits: Bull. Geol. Soc. America, Vol. 5, p. 32. Jenney, TV. P., Lead and Zinc Deposits of the Mississippi Valley: Trans, Am. Inst. Min. Eng., Vol. XXII, pp. 171-225, 642-646. Leonard, A. G., Occurrence of Zinc in Northeastern Iowa: Proc. Iowa Acad. Sci., Vol. I, Part IV, pp. 48-52. BIBLIOGRAPHY OF THE DRIFTLESS AREA 75 Winslow, Arthur, Lead and Zinc Deposits: Missouri Geol. Survey, Vols. VI and VII, especially Vol. VI, pp. 135-149, 151-155. Winslow, Arthur, Discussion on Lead and Zinc Deposits of the Mississippi Valley: Trans. Am. Inst. Min. Eng., Vol. XXII, pp. 634-636. 1895 Calvin , Samuel, Geology of Allamakee County: Iowa Geol. Survey, Vol. IV, pp. 37-120. Hobbs, W. H., Contribution to the Mineralogy of Wisconsin: Bull. Univ. of Wisconsin, Sci. Ser., Vol. I, pp. 10'9-156; also in Zeitsch. f. Kryst., Vol. XXV, pp. 257-275. Kiimmei, H. B., Some Meandering Rivers in Wisconsin: Science, N. S., Vol. I, June 28, pp. 714-716. Leonard, A. G., Origin of the Iowa Lead and Zinc Deposits: Am. Geologist, Vol. XVI, pp. 288-294. Leonard, A. G., Lansing Lead Mines: Proc. Iowa Acad. Sci., Vol. II, pp. 36-38. Leverett, Frank, The Preglacial Valleys of the Mississippi and its Tributaries: Jour. Geology, Vol. Ill, pp. 740-763. Salisbury, R. D., Preglacial Gravels on the Quartzite Range near Baraboo, Wisconsin: Jour, of Geology, Vol. Ill, pp. 655-667. Thwaites, Reuben G., Collections of Wisconsin Hist. Soc., Vol. XIII, pp. 271-292. Van Hise, G. R., Origin of the Dells of the Wisconsin: Trans. Wis- consin Acad. Sci., Arts and Letters, Vol. X, pp. 556-560. Weidman, S., On the Quartz Keratophyre and Associated Rocks of the North Range of the Baraboo Bluffs: Bull. Univ. of Wisconsin, Sci. ser., Vol. I, No. 2, pp, 35-56. Winchell, N. H., The Age of the Galena Limestone: Am. Geologist, Vol. XV, pp. 33-39. 1896 Ham, M. M., Annals of Iowa, 3d ser., Vol. 2, pp. 329-344. Hershey, 0. H., Preglacial Erosion Cycles in Northwestern Illi- nois: Am. Geologist, Vol. XVIII, pp. 72-100. Leonard, A. G., Lead and Zinc Deposits of Iowa: Eng. and Min. Jour., Vol. LXI, p. 614. Leonard, A. G., Lead and Zinc: A Description of the Mines of Towa and the Upper Mississippi Region: Colliery Eng., Vol. XVII, pp. 121-122. Horton, W. H., Artesian Wells of Iowa: Iowa Geol. Survey, Vol. VI, pp. 140-148, 172, 180-183. Salisbury, R. D., Loess in Wisconsin Drift Formation: Jour. Geol- ogy, Vol. IV, pp. 929-937. Soars, C. B., Lake Superior and Mississippi Canal: House Doc. No. 330, 54th Cong., 1st sess., 65 pp. Upham, Warren, The Saint Croix River Before, During, and After the Ice Age: Report of the Commissioner of the State Park of the Dalles, pp. 45-58. * 76 IOWA ACADEMY OF SCIENCE Vol. XXIV, 1917 Van Hise, C. R., Central Wisconsin Base Level: Science, New ser., Vol. IV, pp. 57-59. 1897 Hershey, 0. H., The Physiographic Development of the Upper Mis sissippi Valley: Am. Geologist, Vol. XX, pp. 246-268. Leonard , A. G., Lead and Zinc Deposits of Iowa: Iowa Geo-1. Sur- vey, Vol. VI, pp. 9-66. Park, M. .8., Geology of an Area in Green County, Wisconsin, Un- published Thesis, University of Wisconsin. Salisbury, R. D., and Atwood, W. W., Drift Phenomena in the Vi- cinity of Devils Lake and Baraboo, Wisconsin: Jour, of Geology, Vol. V, pp. 131-147. Sardeson, F. W., On Glacial Deposits in the Driftless Area: Am. Geologist, Vol. XX, pp. 392-403. Squier, G. H., Studies in the Driftless Region of Wisconsin: Jour. Geology, Vol. V, pp. 825-836. 1898 Buckley, E. R., On the Building and Ornamental Stones of Wis- consin: Wisconsin Geol. and Nat. His. Survey, Bull. No. IV. Squier, G. H., Studies in the Driftless Region of Wisconsin: Jour. Geology, Vol. VI, pp. 182-192. Upham, Warren, Time of Erosion of the Upper Mississippi, Minne- sota, and Saint Croix Valleys: Science, new ser., Vol. VIII, p. 470. Weulman, S., A Contribution to the Geology of the pre-Cambrian Rocks of the Fox River Valley, Wisconsin: Wisconsin Geol. and Nat. Hist. Survey, Bull. No. III. 1899 Calvin, Samuel, and Bain, H. F., Geology of Dubuque County: Iowa Geol. Survey, Vol. X, pp. 379-651. Leverett, Frank, The Lower Rapids of the Mississippi River: Jour. Geology, Vol. VII, pp. 1-22. Squier, G. H., Studies in the Driftless Region of Wisconsin: Jour. Geology, Vol. VII, pp. 79-82. 1900 Calvin, Samuel, A Notable Ride from Driftless Area to Iowan Drift: Iowa Acad. Sci., Vol. VII, pp. 72-77. Hubbard, G. D., The Blue Mound Quartzite: Am. Geologist, Vol. XXVI, pp. 163-168. Johns, R, B., The Physiography and Geology of the La Crosse River Valley, Unpublished Thesis, University of Wisconsin. Marquette, Jacques, (On the Mississippi River), Jesuit Relations, 1673-1677, Thwaites edition. Vol. 59, p. 109, Cleveland; also Joliet’s Map, facing p. 86. Salisbury, R. D., and Atwood, W. W., The Geography of the Region about Devils Lake and the Dalles of the Wisconsin: Wisconsin Geol. and Nat. Hist. Survey, Bull. No. V. BIBLIOGRAPHY OF THE DRIFTLESS AREA 77 Van Hise, C. R., Ores of the Upper Mississippi Valley: U. S. Geol. Survey, twenty-second Ann. Rept., p.t. 2, pp. 33-49. 1901 Ball, S. H., and Smith, A. F., The Geology and Ore Deposition of the Benton District, Lafayette County, Wisconsin, Thesis, University of Wisconsin, not published hut in University Library. Buckley, E. R., Clays and Clay Industries: Wisconsin Geol. and Nat. Hist. Survey, Bull. No. VII, pt. 1, p. 273. Collie, G. L., Physiography of Wisconsin: Bull. Am. Bureau of Geography, Vol. II, pp. 270-287. TJpham, Warren, Pleistocene Ice and River Erosion in the Saint Croix Valley of Minnesota and Wisconsin: Bull. Geol. Soc. America, Vol. 12, pp. 13-24. Van Hise, C. R., Some Principles Controlling the Deposition of Ores: Trans. Am. Inst. Min. Eng., Vol. XXX, pp. 27-177, especially pp. 102-109. 1902 Bain, H. F., Preliminary Report on the Lead and Zinc Deposits of the Ozark Region, with an Introduction by C. R. Van Hise, and Chapters on the Physiography and Geology by G. I. Adams: U. S. Geol. Survey, twenty-second Ann. Rept., pt. II, pp. 23-227. LaSalle, Robert Cavelier, sieur, Description of Wisconsin Rivers, 1682; Collections of Wisconsin Hist. Soc., Vol. XVI, pp. 105-107. Libby, Dr. O. G., Trans. Wisconsin Acad. iSci., Arts and Letters, Vol. XIII, p. 188. Perisho, E. C., Trans. Wisconsin Acad. Sci., Arts and Letters. Smith, W. D., Geology of the Blue Mounds and the Physiography of the Region Adjacent, Unpublished Thesis, University of Wisconsin. Thioaites, R. G., Down Historic Waterways, 1890, pp. 237-293, Chi- cago, 1902. Van Hise, C. R., and Bain, H. F., Lead and Zinc Deposits of the Mississippi Valley, U. S. A.: Trans. Inst. Min. Eng. (England), Vol. XXIII, pp. 376-434, especially pp. 409-420. 1903 Bain, H. Foster, Lead and Zinc Deposits of Illinois: U. S. Geol. Survey, Bull. 225, pp. 202-207. Grant, U. S., Preliminary Report on the Lead and Zinc Deposits of Southwestern Wisconsin: Wisconsin Geol. and Nat. Hist. Survey, Bull. No. IX. 'Nicholson, Frank, The Wisconsin Zinc Fields: Eng. and Min. Jour., Vol. LXXVI, pp. 847-849. Rohn, Oscar, The Baraboo Iron Range: Eng. and Min. Journ., Vol. LXXVI, pp. 615-617, Weidman, S ., The Baraboo District: U. S. Geol. Survey Bull. 225, pp. 218-220. (Refer to Bull. No. XIII, Wisconsin Geol. and Nat. Hist. Survey.) 78 IOWA ACADEMY OF SCIENCE Vol. XXIV, 1917 Weidman, 8., The Pre-Potsdam Peneplain of the Pre-Cambrian of North Central Wisconsin: Jour. Geology, Vol. XI, pp. 289-313. 1904 Ellis, E. E., Zinc and Lead Mines near Dodgeville, Wisconsin: U. S. Geol. Survey Bull. 260, pp. 311-315. Grant, U. 8., Zinc and Lead Deposits of Southwestern Wisconsin: U. S. Geol. Survey Bull. 260, pp. 265, 304-310. Grant, U. 8., and Bain, H. F., A. Pre-Glacial Peneplain in the Drift- less Area: Science, new ser., Vol. XIX, p. 528. Weidman, 8 ., The Baraboo Iron-Bearing District of Wisconsin: Wis- consin Geol. and Nat. Hist. Survey, Bull. No. XIII. Winchell, N. H., The Baraboo Iron Ore: Am. Geologist, Vol. XXXIV, pp. 242-253. 1905 Bain, H. F., Zinc and Lead Deposits of Northwestern Illinois: U. S. Geol. Survey Bull. 246. Calvin, Samuel, Geology of Winneshiek County: Iowa Geol. Survey, Vol. XVI, pp. 37-211. Hobbs, W. H., Examples of Joint Controlled Drainage from Wis- consin and New York: Jour. Geol., Vol. XIII, pp. 363-374. Leonard, A. G., Geology of Clayton County: Iowa Geol. Survey, Vol. XVI, pp. 213-317. Tan Hisje, C. R., The Origin of the Dalles of the Wisconsin: Trans. Wisconsin Acad. Sci., Arts and Letters, Vol. X, pp. 556-560. 1906 Bain, H. F., Zinc and Lead Deposits of the Upper Mississippi Valley: U. S. Geol. Survey Bull. 294. Berkey, Charles P., Paleogeography of Saint Peter Time: Bull. Geol. Soc. America, Vol. 17, pp. 229-250, PL 24. Davis, R. E., Derivation of the Lead and Zinc Ores of Southwestern Wisconsin from the Oil Rock, Unpublished Thesis, University of Wis- consin. Gingnass, Michael, Description of Fox, Wisconsin, and Mississippi Rivers and Lake Pepin: Collections of Wisconsin Hist. Soc., Vol. XVII, pp. 24-25. Grant, U. 8., Reports on the Lead and Zinc Deposits of Wisconsin, with an Atlas of Detailed Maps: Wisconsin Geol. and Nat. Hist. Sur- vey, Bull. No. XIV. Grant, U. 8., Structural Relations of the Wisconsin Lead and Zinc Deposits: Economic Geology, Vol. I, pp. 223-242. Harder, E. C., The Joint System in the Rocks of Southwestern Wis- consin and its Relation to the Drainage Network: Bull. University of Wisconsin, No. 138, pp. 207-246. Merrill, George P., Driftless Area of Wisconsin: Contributions to the History of American Geology, Pub. No. 135, from the Report of the United States National Museum for 1904, p. 473. BIBLIOGRAPHY OF THE DRIFTLESS AREA 79 Wheeler, H. A., The Wisconsin Zinc District: Mines and Minerals, March, pp. 371-372. 1907 Bain, H. F., Zinc and Lead Deposits of the Upper Mississippi Valley: Wisconsin Geol. and Nat. Hist. Survey, Bull. No. XIX. Galvin, Samuel, Some Features of the Channel of the Mississippi River between Lansing and Dubuque, and their Probable History: Iow'a Acad. Sci., Vol. XIV, pp. 213-220. Grant, TJ. S., and Burchard, E. F., U. S. Geol. Survey Geol. Atlas, LancasterjMineral Point folio. Orr, Ellison, Exposures of Iowan and Kansan (?) Drift East of the Usually Accepted Boundary Line of the Driftless Area: Iowa Acad. Sci., Vol. XIV, pp. 231-236. Weidman, S., The Geology of North Central Wisconsin: Wisconsin Geol. and Nat. Hist. Survey, Bull. No. XVI, pp. 550-571. Whitson, A. R., and Jonas, E. R., Drainage Conditions of Wisconsin: Bull. 146, Wis. Agr. Exp. Station, 47 pp. 1908 Mansfield, G. R,, The Baraboo Region of Wisconsin: Jour. Geo- graphy, Vols. 6-7, No. 9, pp. 286-292. Mansfield,, G. R., Glacial and Normal Erosion in Montana and Wis- consin: Jour. Geography, Vols. 6-7, No. 10, pp. 309-312. Squier, G. H., Peculiar Local Deposits on Bluffs Adjacent to the Mississippi: Trans. Wisconsin Acad. Sci., Arts and Letters, Vol. XVI, pp. 258-274. Thwaites, F. T., Geology of the Southern Part of Cross Plains Quad- rangle, Dane County, Wisconsin, Unpublished Thesis, Univ. of Wis- consin. Thivaites, F. T., Mysteries of Devils Lake: Madison Democrat, Feb. 18. 1909 Alden, W. C., Criteria for the Discrimination of the Age of Glacial Drift Sheets: Jour. Geology, Vol. XVII, pp. 694-709. Lange, E. G., Caves of the Driftless Area of Southwestern Wiscon- sin, Unpublished Thesis, University of Wisconsin. Merrick, G. B., Old Times on the Upper Mississippi, 303 pp., Cleve- land. 1910 Clark, V. B., Geography of the Potsdam Sandstone Area in Wiscon- sin, Unpublished Thesis, University of Wisconsin. 1911 Bowman, Isaiah (On Plants in the Driftless Area), Forest Physio- graphy, p. 497, New York. Cox, G, H., The Origin of the Lead and Zinc Ores of the Upper Mississippi Valley District: Econ. Geology, Vol. VI, No. 5, pp. 427-448. 80 IOWA ACADEMY OF SCIENCE Vol. XXIV, 1917 Martin , Lawrence, Valley Lakes Due to Variation in Stream Load: U. S. Geol. Survey Mon. 52, pip. 429, 438, 454. Whitbeck, R. H., Contrasts between the Glaciated and Driftless Por- tions of Wisconsin: Bull. Philadelphia Geog. Soc., Vol. 9, pp. 114-123. 1912 Aldrich, Mildred, A Comparison of Agricultural Conditions in the Driftless and Glaciated Portions of Wisconsin, Unpublished Thesis, University of Wisconsin. Davis, W. M. (On the Driftless Area), Guidebook for the Transcon- tinental Excursion of 1912: Am. Geog. Soc. of New York, pp. 16, 87-89. Boston. Lapham, I. A., An Early Journey through Sauk County (Describing the Dalles and Devils Lake in 1849) : Baraboo News, Jan. 4. Norton, W. H., Underground Waters of the Northeast District: Iowa Geol. Survey, Vol. XXI, pp. 279-420; also U. S. Geol. Survey Water Supply Paper 293, pp. 239-254. 1913 Martin, Lawrence, The Western Uplands, Physical Geography of Wisconsin: Jour, of Geography, Vol. 12, pp. 226-232. Martin, Lawrence, Williams, F. E., and Bean, E. F., A Manual of Physical Geography Excursions, Madison (On Blue Mound, pp. 122-148, on the Baraboo Range, pp. 149-169.) Trowbridge, A. C., Some Partly Dissected Plains in Jo Daviess County, Illinois: Jour. Geology, Vol. XXI, pp. 731-741. Weidman, S., Pleistocene Succession in Wisconsin: Bull. Geol. Soc. Vol. 24, pp. 697-698. Whitbeck, R H., Economic Aspects of the Glaciation of Wisconsin: Annals Assoc. Am. Geographers, Vol. 3, pp. 62-87. 1914 Cox, O. H., Lead and Zinc Deposits of Northwestern Illinois: Illinois Geol. Survey, Bull. No. 21. Lees, J. H., Earth Movements and Drainage Lines in Iowa: Iowa Acad. Sci., Vol. XXI, pp. 173-180. Slothower, C. E., The Driftless Area of Wisconsin: Jour. Geography, Vol. 12, No. 8, pp. 267-274. Stickle, B. A., The Influence of the Mississippi River in the De- velopment of Wisconsin: Jour. Geography, Vol. 12, No. 8, pp. 274-279. Trowbridge, A. C., Preliminary Report on Geological Work in North- eastern Iowa: Iowa Acad. Sci., Vol. XXI, pp. 205-209. Uglow, W. L., A Study of Methods of Mine Valuation and Assessment with Special Reference to the Zinc Mines of Southwestern Wisconsin: Wisconsin Geol. and Nat. Hist. Survey, Bull. No. XLI. Williams, A. J., Physiographic Studies in and Around Dubuque, Iowa, Unpublished Thesis, University of Iowa. ******** physiographic Location of the Driftless Area: Annals Assoc, of Am. Geographers. BIBLIOGRAPHY OF THE DRIFTLESS AREA 81 1915 Howell, J. V., The Occurrence and Origin of the Iron Ores of Iron Hill, near Waukon, Iowa: Iowa Geol. Survey, Vol. XXV, pp. 54-62. Martin, Lawrence, The Discovery of the Painted Stone, An Early Observation of the Driftless Area: Jour. Geography, Vol. 14, No. 2, pp. 58-59. Shipton, W. D., The Occurrence of Barite in the 1 Lead and Zinc District of Iowa, Illinois and Wisconsin: Iowa Acad. Sci., Vol. XXII, pp. 237-241. Trowbridge, A. C., Physiographic Studies in the Driftless Area: Bull. Geol. Soc. America, Vol. 26, No. 1, March, p. 76. 1916 Colby, Charles C., The Driftless Area of Minnesota, A Geographic Unit: Jour, of Geography, Vol. 14, No. 6, pp. 165-167. Hughes, U. B., A Correlation of the Peneplains of the Driftles® Area: Iowa Acad. Sci., Voh XXIII, pp. 125-132. MacClintock, Paul, The Wisconsin River Valley below Prairie du Sac, Unpublished Thesis, University of Chicago. Martin, Lawr.ence, The Physical Geography of Wisconsin: Wisconsin Geol. and Nat. Hist. Survey, Bull. No. XXXVI. Shaw, E. W., and Trowbridge, A. C., U. S. Geol. Survey Geol. Atlas, Galena-Elizabeth folio, Shipton, W. D., The Geology of the Sparta Quadrangle, Wisconsin, Unpublished Thesis, University of Iowa. Shipton, W. D., A Note on Fulgurites from Sparta, Wisconsin: Iowa Acad. Sci., Vol. XXIII, p. 141. Shipton, W. D., A New' Stratigraphic Horizon in the Cambrian System of Wisconsin: Iowa Acad. Sci., Vol. XXIII, pp. 142-145. Trowbridge, A. C., and Shaw, E. W., Geology and Geography of the Galena and Elizabeth Quadrangles, Illinois: Illinois Geol. Survey, Bull. No. 26. Department of Geology, The State University. 6 f : .. . B . &■ POST-KANSAN EROSION.1 M. M. LEIGHTON. Visitors to the Maquoketa river gorge below Monticello in Jones county have been impressed with its rocky walls of the Niagaran formation which rise in places 100 to 125 feet above the stream. Overlying this rock formation are drift and loess. Crags, turrets, and chimney rocks, similar to the rugged fea- tures of the valleys of the driftless area, appear here and there. In fact, the characteristics of this gorge are so nearly like those of the valleys of the driftless area that in the report of the Geology of Jones County the gorge is considered to be pre- glacial in age. During the investigations of the Iowan Drift, Dr. Win. C. Alden and the writer found that this valley Is Pleistocene and 'probably post-Kansan in age rather than preglacial. Well records reveal that there is a deep preglacial or pre-Kansan valley underlying what is now the Langworthy ridge to the west and that this buried valley reaches depths considerably below those of the Maquoketa. gorge. These well records also revealed the fact that the present Maquoketa gorge has been cut through what was formerly a high rock divide, as shown in figure 1. It is thus clear that the gorge is Pleistocene in age. Is it post-Nebraskan or post-Kansan? Both the Nebraskan and Kan- san drifts are known to extend to the southeast of this locality, as shown by their superposition in the Chicago, Mil- waukee & St. Paul Railway cuts near Delmar Junction. In view of this and in view of the absence of any evidence that the gorge has been glaciated, it seems that the gorge is probably post- Kansan in age. In the bottom of the valley are the valley- train terraces of Iowan age, which indicate that the Maquoketa river had .completed cutting this valley by Iowan times. At the close of the Kansan epoch this region was apparently a flat- tish plain, a new surface made by the heavy deposition of Kan- san drift on the pre-Kansan topography, with the consequent filling of the former valleys and burying of the divides. On irThis and the following papers are published writh the permission of the Director of the Iowa Geological Survey. 84 IOWA ACADEMY OF SCIENCE Vol. XXIV, 1917 ro o S w C 03 •rH 05 c s £ a ■° is ll > o s § | £ Ml S '3 on . CQ M) ® Is I s O £ 03 ^ m - £ . <13 this new surface the surplus drain- age chose consequent courses along lines that crossed the old divides, and in cutting downward, became superimposed upon the buried rock divides. In the course of the investiga- tions it was discovered that every one of the major drainage lines of eastern Iowa, south of the Volga river are superimposed at various places along their courses. These streams include, besides the Maquoketa, the Wapsip inicon and the Cedar and their important tri- butaries. Former studies by the writer have shown that the Iowa river' at Iowa City is also a super- imposed stream. All are appar- ently post-Kansan in age. Where they have cut in rock their valleys are relatively narrow ; where they have cut in drift, they are strik- ingly broad. In 1895, Gordon, in an article in Volume III of the Iowa Geol- ogical Survey on the buried river channels of southeastern Iowa, showed that the Des Moines river in Lee county has cut through a rock divide, while to the east is a burie'd channel deeper by one hundred feet than the present Des Moines or the Mississippi in that latitude. Clearly then the Des Moines is a superimposed stream and, judging from its features, is of the same age as those above mentioned. It seems to the writer that the factor of superimposition of POST-KANSAN EROSION 85 these and possibly other streams must be taken into considera- tion in gaining the correct conception of the length of post- Kansan time. The well-known fact that the Kansan drift-plain has been quite thoroughly dissected to a mature stage of erosion is evidence in itself of the great age of the drift. But it would seem that if these valleys have been cut by streams which were superimposed here and there upon buried rock divides, the rate of erosion must have been considerably retarded, possibly giv- ing sufficient time for considerable decomposition of the Kan- san drift over the great featureless, low-gradient plain before any considerable areas had been dissected. The writer has had in mind extending his studies to include the Missouri and other large tributaries of the Mississippi river in order to determine what factors were operative in affecting the rate of dissection of the older drifts, but his call to other fields makes this survey impossible. The Missouri field is an inviting one for if if is found that the Missouri river is super- imposed at Glasgow, Missouri, as is suggested by the narrow width of the valley there as compared with that above, as shown on the topographic map, and as suggested by Todd’s descrip- tions of the buried channel to the southwest in the vicinity of Salt Springs, and by his descriptions of the drift materials in the valley walls of the Missouri above Glasgow, and if it is found for example, to be post-Kansan, then obviously this would affect the rate of dissection of much of the area upstream, which would involve southern and southwestern Iowa, It is to be notea mat the Chariton river joins the Missouri just above the rock chan- nel at Glasgow, that the mouth of the Grand river is a little farther up, and the Platte a little farther, still. If it is found that each one of these streams is superimposed at several places along its course on old rock divides this retarding factor would be still more important as applied to large areas. The results of such a study would promise to be of importance in gaining the proper conception of the erosional and weathering conditions existing during the Pleistocene. In so doing the exact dates of ' superimposition should be ascertained. Department of Geology, University of Washington. THE BUCHANAN GRAVELS OF CALVIN AND THE IOWAN VALLEY TRAINS. M. M. LEIGHTON. In the various geological reports of counties in the Iowan area and of counties through which pass drainage lines from the Iowa area, the Buchanan gravels are classified into two phases : the upland phase and the valley phase. This classifica- tion dates back to 1898, when the Report of the Geology of Buchanan County by the late Dr. Samuel Calvin was published by the Iowa Geological Survey. In this report he set forth the conception that the upland gravels were deposited while the valleys were filled with ice and that the gravels in the terraces along the present streams were laid down after the Kansan ice had retreated some distance. In both cases the gravels were regarded by Calvin gs Kansan outwash and he called them Bu- chanan gravels. During the recent investigations which were carried on under the joint auspices of the U. S. Geological Survey and the Iowa Geological Survey by Dr. Wm. C. Alden and the writer, it was found that the terrace gravels or the valley phase of Calvin ?s Buchanan gravels represent valley-train deposits from the Iowan ice, and that they are therefore much younger than the highly decayed ferruginous gravels which are exposed in Cal- vin’s type out, the Doris pit of Buchanan county. This is es- tablished both by their differences in weathering and their dif- ferent relations to the Iowan drift. Department of Geology, University of Washington. THE IOWAN GLACIATION AND THE SO-CALLED IOWAN LOESS DEPOSITS. M. M. LEIGHTON. One cannot work in the Iowan Drift area and in adjacent areas of older drift without confronting the problem of the loess. During the field seasons of 1914 and 1915 while asso- ciated with Dr. Wm. C. Alden of the U. S. Geological Survey in reviewing the field evidences for and against an Iowan stage of glaciation, the writer became interested in certain phases of the loess and their interpretations. Through the kindness of his senior colleague, the writer has the privilege of briefly dis- cussing these phases before the Iowa Academy of Science. A more complete discussion will appear in the forthcoming re- port of the Iowa Geological Survey in connection with the re- port on the investigations of the Iowan Drift, under the joint authorship of Doctor Alden and the writer. 1. The Weathering of the Loess. — In the various papers which have appeared on the loess, little attention has been de- voted to the weathering of the loess. What will be said here will concern only that loess which is associated with the Iowan drift-sheet. From a careful examination of the exposures of the loess, it has become clear to the writer that it has been partly leached of its calcareous material and oxidized to some depth since it was deposited. The features of the average ex- posure where eight feet or more are shown are as follows : Feet 3. Soil, black, changing below to dirty brown, no pebbles; usual thickness %-l% 2. Leached loess, buff to yellow, does not react to dilute hydrochloric acid, no fossils or lime con- cretions; thickness (in some cases as much as 12 feet) 6-8 1. Calcareous loess, usually of lighter color than the noncalcareous except where grayish; the grayish color may not appear for several feet -below the top of the calcareous zone; snail fossils com- monly present, also lime concretions. This zone is usually not shown in cuts less than 8 feet deep. \ V J 88 IOWA ACADEMY OP SCIENCE Vol. XXIV, l‘JJ7 The persistency of these phenomena in cut after cut makes them of significance in reading the history recorded by the loess. The buff loess and the gray loess have heretofore been generally regarded as separate and distinct deposits, differing considerably in age. The buff loess has been thought to be of Iowan age and younger, while the gray has been held to be of approximately Kansan age, it being held that the gray prob- ably has the same relation to the Kansan drift as the buff seems to have to the Iowan drift. These conclusions, however, do not seem to the writer to be well based. Of the many exposures examined, on the east and south sides of the Iowan area, there was not a single one which showed good evidence of an interval of time between the depo- sition of the gray and the buff. There is no zone of leaching at the top of the gray, such as would be expected if the two deposits belong to two different epochs, nor is there any other strong evidence of weathering effects that would differentiate the two. Indeed there is a continuance of lime carbonate par- ticles and shells from the gray up' into the buff, and in most cases there is a transition in color. It is true that in some instances rusty streaks occur at the contact, but these were found also indiscriminately at any horizon. In view of these features of gradation and the absence of any that distinctly separate the two in terms of time intervals, the writer has become convinced that the two are of the same geological age, that the mass of the loess was originally gray, and that the buff is to be regarded merely as the oxidized phase of the gray. Another important historical point to be noted from a study of the weathering of the loess is that the leached zone records the fact that the loess has been subjected to the solvent action of ground water for a sufficient length of time for the cal- careous particles and snail shells to be dissolved out to a depth of several feet. Fossils are not seen in many shallow cuts for they occur only in the zone which has not been leached. One must bear in mind, however, the possibility that the upper part of the loess was deposited as a noncalcareous clay. This may be true of some of the leached zone, but it would be an extreme view to assume that the ground water has performed no work since the loess was deposited, especially if the mass of the loess is pre-Wisconsin in age as will be shown later. But aside \ THE IOWAN GLACIATION 89 from these reasonable grounds, there is good basis for think- ing that the noncalcareous zone of the loess is largely due to the leaching process. There are to be found on the surface today living snails, which, according to Professor Shimek, who has made an extensive study of them, are mostly of the same species as the snails whose shells are found as fossils in the loess. If this is true, it is quite evident that if the loess has suffered no leaching, snail shells should be found in the non- calcareous zone as well as in the calcareous zone beneath. As to where present snails secure their carbonate of lime, it is quite possible that the lime may be obtained from the feldspar particles of the clay, which then may be carbonated by ground water. Another evidence that the loess has in reality suffered leaching is the fact that lime concretions are found near the top of the calcareous zone, the material of these concretions being that which was dissolved from the zone above. These phenomena, therefore, lead to the conclusion that the mass of the loess, which is associated with , the Iowan drift, was once calcareous and gray, and that ' it accumulated at a time when the rate of deposition was greater than the rate of leaching. This suggests strongly a special episode of deposi- tion for this particular loess. 2. The Source of the Loess. — The loess associated with the Iowan area is thickest in three situations : ( 1 ) along the river valleys leading from the Iowan drift; (2) around the border of the Iowan drift; and (3) in those elliptical hills which McGee termed paha. In some instances the buff loess is so thick along the larger valleys that the valley walls rise distinctly above the border- ing upland like low ridges. This is so noticeable along the Cedar river southwest of Marion and along the Wapsipinicon river west of Oxford Junction that one is reminded of the com- mon remark of the early geologists who studied these localities, that the streams left the plains to cut through the hills.1 Of course, in some instances dune sand is associated. In many other places along valleys the loess is thick without forming distinct ridges. The accumulation of loess in such marked de- posits along valleys is probably due to nearness tq a source U t is evident in such cases that the ridges came into existence after the valleys were cut. 90 IOWA ACADEMY OF SCIENCE Vol. XXIV, 1917 of supply, namely the valley flats, and to the vegetation and topography favoring lodgment, all of which has been pointed out by Professor Shimek. The notable thickness of the loess around the border of the Iowan drift is too well known to demand much further refer- ence. The fact that it gradually diminishes in thickness and becomes finer as distance increases from the Iowan border, to- gether with the fact that it is thick even away from valleys, indicate that the Iowan area also was a source of supply. With- in the Iowan area itself the loess is generally absent or nearly so, but to this there are exceptions as would be expected. It is obvious that deposits would be made wherever there were ob- structions. Some such conditions gave rise to the paha, the wind depositing dust and sand about rock projections, glacial drumlins or even sand dunes. Their persistent southeasterly trend probably is best accounted for by assuming either that v the winds were prevailing northwesterlies or that the drumlins trended in that direction. If the source of the loess was the Iowan drift and the valley flats, and if the mass of the loess was deposited in a calcareous and unoxidized condition, then it must have been blown from the Iowan drift before the drift was weathered. This thesis may now be tested by noting other evidences for the age of the loess. 3. The Age of the Loess. — The age of the loess can be as- certained by noting its relations to the Kansan drift, the Illi- noian drift, the Iowan drift and the Wisconsin drift. In the Kansan area the loess mantles the slopes as well as the uplands. Calcareous and fossiliferous loess in many places also overlies leached, oxidized, and decomposed Kansan drift. Such evi- dences of an unconformity tell us that the Kansan drift was not only weathered before the loess was deposited, but that the drift-plain was quite thoroughly dissected. The loess mantle continues into the Illinoian drift area in southeastern Iowa, where it shows the same amount of weather- ing as the loess about the Iowan border. Here it also occurs on the eroded surface of the Illinoian and in many places its calcareous zone rests on the weathered and decomposed Illi- noian till, there being in many places an intervening develop- ment of the gumbo as in the Kansan area except that it is thin- THE IOWAN GLACIATION 91 ner. Thus it is clear that the loess also is younger than the Illinoian drift by a considerable interval. In the Iowan area the loess is generally so thin that the leached zone extends down through the loess into the till, but it is a striking fact that in those areas where the loess averages four to six feet in thickness the leached zone passes into the underlying till scarcely more than a few inches to one and one-half feet. Evidently the leaching process has but recently reached the till. This view is supported also by the fact that the top of the till is practically the same color as the lower part of the loess. No soil or gumbo development was found any- where between the Iowan drift and the loess. Where the loess is absent or nearly so the drift is leached correspondingly more, but a little less than the loess where thick sections are exposed. All of these evidences bear out the interpretations made from the areal relations of the loess, its composition and character- istics, that the loess was deposited closely following the retreat of the Iowan ice-sheet. This conclusion may at first seem incompatible with the evi- dence of the fossil shells which, according to Shimek, indicate much the same climatic conditions as the region possesses today. But it should be recognized that the climate at the close of a glacial epoch must be decidedly different from that at the be- ginning. A glacier is the product of glacial conditions. Its development and advance are preceded first by the culmination of glacial temperatures and precipitations. Its retreat occurs only after the glacial climate ceases. Probably the climate of the zone in close proximity to a retreating continental ice- sheet’ is affected somewhat by the presence of the ice, but yet the conditions are probably much less severe than in the case of an advancing ice-sheet. In the first case, the climate opposes the existence of the ice mass, while in the second, it is respon- sible for if. Is not the close of any glacial epoch in reality that time when the climate becomes permanently effective in causing glacial retreat? Granted that present temperatures probably did not prevail in the immediate vicinity of the Iowan ice-edge, it does seem likely that after the earth’s climate had changed and the ice had melted back several hundred miles from its extreme limit, seasons approximating those of the present prevailed where the marginal loess occurs. Even though this 92 IOWA ACADEMY OF SCIENCE Vol. XXIV, 1917 distance be increased to a thousand miles, the length of time con- sumed in this retreat would be brief geologically, probably not permitting of any perceptible amount of weathering. The state- ment, therefore, seems safe that the loess was deposited imme- diately after the closing stages of the Iowan glacial epoch in which case the loess should be regarded as early Peorian in age rather than Iowan. If the loess is early Peorian in age, the relations of the loess to the Wisconsin drift should show it. In an excellent ex- posure made by the Chicago, Milwaukee & St. Paul Railway Company during the recent reconstruction of their line in Mar- shall county, at the Wisconsin margin, tangible evidence was found supporting this view. Here the loess, which is typically de- veloped to the south of the Iowan border, passes beneath twenty- five feet of Wisconsin drift. The loess itself also is twenty- five feet thick. The larger part of the Wisconsin drift has been scarcely changed by weathering, whereas the loess is al- most wholly oxidized, there being some gray left at the base, and the top of the loess in one place is leached four to five feet. Therefore, the conclusion seems warranted that the loess which is associated with the Iowan drift is chiefly early Peorian in age. 4. Bearing of the Loess on the Problem of the Iowan Drift. — Inasmuch as the deposition of the loess dates back to the time when the Iowan drift was yet unleached, the loess may be used for correlation purposes in determining the time relations of the Iowan drift to the Kansan and Illinoian drifts. The great un- conformities between the loess and the Kansan drift, and between the loess and the Illinoian drift, which have already been de- scribed, show that the Iowan ice-sheet invaded Iowa a long time after the Kansan and Illinoian glaciations, the Kansan, of course, having much preceded the Illinoian. Department of Geology, University of Washington. THE LOESS AND THE ANTIQUITY OF MAN. B. SHIMEK. Reports on the antiquity of man in Europe and on both the American continents, contain frequent references to loess, and repeated efforts have been made to establish the antiquity of man on the basis of the relation of human remains and artifacts to supposed loess. Such efforts have been uniformly unsuccess- ful, and the weakness of these cases has resulted chiefly from the following causes : 1. — In many cases, the human remains and artifacts were re- moved by laborers or unskilled amateurs, and there are doubts as to the exact nature of the material from which they were obtained. 2. — In other cases, the collectors were competent to judge of the bones, teeth, and artifacts, but not of the deposits in which they were found. Hence definite references to specific horizons in such cases have been unreliable. 3. — Where students of the Pleistocene have been called in to assist in the determination of the horizon, the results have often proved unsatisfactory because of the difference of opinion among such students, and because the rapid progress in the investigation of the Pleistocene has necessitated frequent changes in prevailing opinions. 4. — Perhaps largely because of these difficulties, there has been much superficial, unscientific work done in this connec- tion, and unreliable evidence has been greedily taken up, espe- cially when it supported some pet view or theory. The antiquity .of man has been established in Europe much more definitelv than in America, though even there, there has been much difference of opinion as to the age of various re- mains, the difference arising from the uncertainty as to the age of the horizon in which they were found. In the European reports, frequent references are made to human remains and artifacts found in loess, but the use of the term has been broad in many cases, and the determination of the character of the materials containing the remains so un- certain in other cases, that it is safe to say that not a single 94 IOWA ACADEMY OF SCIENCE Vol. XXIV, 1917 case of the occurrence of human remains in undoubted, undis- turbed loess is known in Europe. In his recent work, Osborn1 repeatedly refers to loess stations, but in most cases, encloses the term “loess” in quotation marks and does not enter into a discussion of the correctness of the designation. Not only is there doubt in the cases cited that the material is loess, but in some of the prominent cases cited by this and other writers, there is a great difference in opinion as to the age of the deposit from which the human remains were obtained. Thus Osborn2 following Werth3 refers the Heidelberg (or Mauer) man to the Second Interglacial Stage. Sehoetensack,4 who published the original account of the discovery of the lower jaw of this man, referred the sands in which it was found to the First Interglacial Stage. Babor5 refers it to the Third Glacial Stage, partly on the basis of stratigraphy, but chiefly on ac- count of the character of the mammalian and molluscan faunas. The entire section has also been carelessly included in loess, though the difference in age of the lower sands and the over- lying loess has long been recognized.6 The human, mammalian, and molluscan remains discussed by the several authors here quoted came from the older sands, and not from the overlying loess or loesslike strata. The age of the Predmost, or Briinn man, discovered at Predmosti, near Brno (Briinn), in Moravia, in 1891, is equally uncertain. Cerny7 places the remains in the Third Interglacial Stage, while Wold- rich8 considers them postglacial, as do Osborn,9 Babor,10 and others. All authors consider the deposit in which the numerous human bones were found as loess, yet in 1883 Makowsky11 re- ceived a skull taken by workmen from a sandy portion of what he also calls loess, at Husovice near Brno (Briinn). This fact, taken in connection with the conclusion reached by the later iHenry Fairfield Osborn, Men of the Old Stone Age, 1916. 2Loc. cit. 3E. Werth, Globns, Vol. XCVI, p. 15, 1909. 4Otto Sehoetensack, Der Unterkiefer des Homo heidelbergensis aus den Sanden von Mauer bei Heidelberg, 67 pp., 1908. 5J. Babor, O. atari lidstva : Priroda a Skola, Vol. VIII, No. 4, 1909. 6See E. W. Benecke und E. Cohen, Geognostische Beschreibung der Ura- gegend von Heidelberg, p. 532, et seq., 1881. 7Fr. Cerny, Pravek II. 8Vseobecna Geologie, Vol. Ill, p. 542 ; 1905. 9Loc. cit., p. 23, 10Loc. cit., p. 1, footnote. nAlexander Makowsky, Der Loss von Briinn. Verhandlung. d. nat. Verein in Briinn, Vol. XXVI, p. 237 ; 1888. THE LOESS AND THE ANTIQUITY OF MAN 5 9 Bohemian geologists that there is little, if any, true loess in Bohemia, and probably in Moravia also, and the writer’s own observations on evidently very similar deposits near Prague, lead to the conclusion that the deposits from which the Briinn skeletons were taken are not loess. Numerous human bones and artifacts have been found in the vicinity of Prague, and in other parts of Bohemia, and in most cases they have been reported as coming from the loess. The writer had the privilege of visiting orne of these localities with Doctor Babor and others, in 1914. This was the Meilbek (or Mailbek) brickyard at Podbaba near Prague, the sections in which well illustrate the structure of the deposits from which human remains have been obtained in this vicinity. In 1884, Fric12 reported a skull which was found in this vicinity in what he called loess, and his opinion of the deposit was: generally accepted until quite recently. One of the sections at Podbaba, in Meilbek ’s (or Mailbek ’s) brickyard is represented by Snajdr13, who describes two strata of “loess” (in Bohemian called “zlutka” or “spras”) separated by a gravelly layer. It is not necessary to describe the section in detail. It is sufficient to say that its horizontal stratification, the variation of the materials composing the several strata from coarse gravel to fine, somewhat loesslike elav, the lack of the ordinary loess texture and structure, and the location of the section, all indicate that there is here no loess, but that the entire deposit is a part of the terraces which are clearly * displayed along some of the streams of Bohemia, at three distinct levels. The writer could find no part of the section which could pass for true loess, and found that the Bohemian geologists had recently reached the same conclusion. The stone implements found in Svobodne Dvory near Kraluv Hradec in Bohemia, seem to have come from strata similar to those of Podbaba, if we may judge from the published .descrip- tions. Woldrich14 reported mammalian bones from underlying gravels in this locality, but Snajdr15 asserts that all the mam- 12A. Fritsch, Ueber einem Menschenschadel aus dem Loss von Podbaba bei Prag. Sitzungberichte der bohm. Gesellschaft der Wissenschaften. 1884. 13Ludvik Snajdr. Pamatky nejdavnejscr cinnosti lidske v Ceskem Polabi, tab. I, lower figure, 1909. The description of the section is given on pp. 31-34. 14J. N. Woldrich, Loziste mamutich kosti ve Svobodnych Dvorech, 1899. 15L. Snajdr, Pamatky archaeolgicke a mistopisne, Vol. XX, No. VII-VIII. 96 IOWA ACADEMY OP SCIENCE Vol. XXIV, 1917 malian bones, with which the artifacts have been associated in this locality have been found in what he designates as “zlutka.” (loess). However, his references to the stratum of alluvium separating the two so-called loesses, and to a thin layer of sand on which a skeleton of the mammoth rested, suggest that we have here a deposit similar to that at Podbaba. Other references of human remains and artifacts to loess in Bohemia are eqully uncertain. Under the aeolian hypothesisa of the genesis of loess, the preservation of human bones in the loess could not be expected unless artificial burial had taken place, for disintegration would have taken place long before natural burial by slowly accumulating dust could be accomplished. The preservation of artifacts, especially stone implements, would be much more possible, but even here the geological evidence that such implements have been found in true loess is very unsatis- factory or wholly negative for the European stations. In some of these cases, our estimate of the age of the remains may not be materially affected by the discovery that the deposit in which they occurred is not loess, but even in such cases it is desirable that the nature of the deposit be accurately determined because of the relation which this determination may have on the problems relating to the genesis of true loess. Undoubtedly both aeolian and aqueous deposition were going on at the same time during the several interglacial times, but not in the same places. Aqueous deposition of both fine and coarse material was evidently going on chiefly along streams, and at comparatively low levels, but such deposits are not loess. No doubt, much of the confusion concerning the loess of Europe has arisen from the various uses of common terms. The term ‘ ‘ diluvium ? ’ covers the entire Pleistocene, but in the region south of the border of the glacial advance, it applies only to lower alluvial deposits and upper loess or loesslike clays, and in this region these upper strata have been designated sometimes as loess and again simply as diluvium. The terms “lehm” and ‘ ‘loess” have also been variously used. Sometimes they were synonymous, but again the' term “ loess” was applied to the upper aeolian deposits and the term “lehm” to the lower fluviatile deposits of the diluviufti. The terms “zlutka” and “spras” in the rather extensive Bohemian literature on the subject, were similarly used, the term “zlutka” corresponding to “lehm” and THE LOESS AND THE ANTIQUITY OF MAN 97 the term “spras” to “ loess,” and they were often synonymous. The varied uses of these terms often leave one in doubt as to their exact meaning in specific cases. While it may be truly said that the evidence of the antiquity of man in Europe as related to loess is, to say the least, doubt- ful, it is practically wanting so far as North America is con- cerned. It is true that in several cases human remains or arti- facts have been reported from loess, but in no case has it been shown that the deposit was truly loess. On the contrary, in those eases which have received the greatest attention, it has been conclusively shown that the deposit is not undisturbed loess. Several careful American students have investigated the problem of the antiquity of man, but chiefly on the somatic side. Among them, Hrdlicka, H. F. Osborn, and MacCurdy have secured valuable results. The geological side of the problem has received less satisfactory attention on the positive side. Un- fortunately that portion of the subject which is related to loess was taken by a group of men whose methods have been erratic and unscientific. Among these, Augbey, N. H. Winchell, and G. Frederick Wright were especially active in attempting to prove the age of certain human remains on the basis of the loess. As late as 1911, Wright16 repeats the story of what he calls “the best authenticated and most significant cases”, namely the “Lansing Man”, the Nebraska “Loess” man, and a stone imple- ment found at St. Joseph, Missouri. It is unnecessary to renew the discussion of the Lansing and Nebraska cases, as the literature on that subject is well known.17 : The former is clearly a case of slumping. Wright calls this an “erroneous opinion” but he does not attempt to explain the presence of blocks of stone in the deposit, which evidently came from ledges higher up on the slope, and which create a condition unknown anywhere in loess. The case of the Nebraska Loess Man is also well known and its weakness has been shown by the writer in the paper cited in foot- note (17). Wright attempts to discredit the writer’s work and 16G. Frederick Wright, The Ice Age in North America, 2d ed., pp. 678- 686, 1911. 17For a part of the bibliography of the Lansing Man, see the Bull. Lab. Nat. Hist., State Univ. of Iowa, Vol. V, p. 327, footnote. For that of the Nebraska “Loess Man” see the writer’s paper, Bull. Geol. Soc. of America, Vol. 19, p. 254. 7 98 IOWA ACADEMY OF SCIENCE Vol. XXIV, 1917 conclusions in this case, (p. 685, 1. c.), but his chapter on the Loess (pp. 407-421, 1. c.) which is largely a compilation of older views (the later views of some of the authors quoted are disre- garded, as in the case of Chamberlin), and his occasional dis- cussion of mollusks, demonstrate that he is not in a position to judge accurately of the former, or to pass judgment on the value of the latter as a measure of conditions during the deposi- tion of loess. In his quotation from Pumpelly, Wright retains the state- ment that Vitrina is not a land-snail ! His discussion of the habits of mollusks (p. 421, etc.) also shows a lack of familiarity with the subject. Wright’s charge of bias18 on the part of the writer, because his studies of the mollusks of the loess have led him to support the aeolian hypothesis, is interesting. Presumably to avoid bias, a man must refrain from getting information on a subject at first hand ! The third of Wright’s “best authenticated” cases (pp. 685- 686. 1. c.), is based on a stone implement which was “found projecting from the face of an old cut for a road” in St. Joseph, Missouri. The description is sufficient to relegate this case to the list of those “not proven.” Incidentally it may be noted that the case reported by Witter19 as a discovery of arrow-heads from the loess of Muscatine is equally doubtful, and was so re- garded by Witter before his death. No new evidence has been presented in any of these cases, nor is there any well-authenticated, undisputed case of the occurrence of human remains or artifacts in original loess that has since come to light. Man probably inhabited much of the region in which loess was being deposited, but as yet, we have no clear evidence of the fact from anything which has been found in the loess. If such evidence should come to light, it may then be necessary to point out other difficulties in the way of using loess as a measure of time. Department of Botany, State University. 18L. c., p. 685. Wright has evidently not read the writer’s papers carefully. 19F. M. Witter, Notice of Arrow Points from the Loess in the City of Muscatine: Proc. Iowa Acad. Science, Vol. I, pt. 2, pp. 66-68; 1892. PLEISTOCENE DEPOSITS BETWEEN MANILLA IN CRAWFORD COUNTY AND COON RAPIDS IN CARROLL COUNTY, IOWA. ABSTRACT. GEORGE F. KAY. The most significant features that have been revealed by a study of the Pleistocene deposits in many deep cuts made recently between Manilla in Crawford county and Coon Rapids in Carroll county, by the Chicago, Milwaukee and St Paul Railway Com- pany, may be summarized as follows : 1. The chief kinds of material exposed are loess, Kansan gumbotil, Kansan drift, Nebraskan gumbotil, and Nebraskan drift. In no one cut is it possible to see all of these materials, nor are the two gumbotils exposed in a single cut. In some cuts the section shows loess, Kansan gumbotil, and Kansan drift; in other cuts there may be seen loess, Kansan drift, and Nebraskan gum- botil ; in still others loess, Nebraskan gumbotil, and Nebraskan drift. The most comprehensive cut is about one and one-half miles west of Manning. It shows loess, Kansan drift, Nebraskan gumbotil, and Nebraskan drift. 2. The two drifts, the Nebraskan and the Kansan, are much alike lithologically, and both appear to have undergone similar changes. On each of the drifts, gumbotil has been developed, be- low which there is a narrow zone of leached drift, which grades downward into unlea-ched drift with many concretions. 3. The maximum thickness of the Nebraskan gumbotil is about thirteen feet, and of the Kansan gumbotil more than twenty feet. The zone of oxidation of the Nebraskan drift is not fully exposed in any of the cuts; the greatest depth of oxidation seen was seventeen feet. The zone of oxidation of the Kansan drift has a maximum depth of about forty feet. Beneath this oxidized zone, in a few cuts, there was seen less than ten feet of very dark, tenacious, unleached and unoxidized Kansan drift. 4. The Kansan gumbotil is limited in distribution to a few narrow divides which are erosion remnants of a former, exten- sive, Kansan gumbotil plain. These divides are the present up- 100 IOWA ACADEMY OF SCIENCE Vol. XXIV, 1917 lands of the region. The Nebraskan gumbotil is exposed only in those cuts the summits of which have been brought by erosion considerably below the elevations of the summits of the upland cuts. 5. The loess is present as a mantle over the maturely dissected surfaces. It varies in thickness from a few feet to more than twenty-five feet. In general it thickens from the crests of the ridges down the slopes, and is apparently thicker on east slopes than on west slopes. The upper parts of the ridges have been broadened more than heightened by the deposition of the loess. In places the loess lies on Kansan gumbotil ; in places it is on Kansan drift; in other places it mantles the Nebraskan gum- botil ; and where there has been the most extensive erosion previ- ous to the deposition of the loess, it is on Nebraskan drift. 6. The loess has two phases, the upper of which is buff in color, the lower, gray. In many places the buff loess is leached for a few feet from the surface ; in a few cuts the depth of leach- ing is about fifteen feet. The buff and the gray phases of the loess are closely related, and the evidence indicates that their differences are the result of chemical reactions rather than of different epochs of deposition. / Department of Geology, The State University. OCHEYEDAN MOUND, OSCEOLA COUNTY, IOWA. GEORGE F. KAY. Among the many interesting surface features of Iowa, there are few, if any, that have attracted more attention or have excited more wonder than Ocheyedan mound, which is thought by many persons to be the most remarkable and beautiful hill in all north- western Iowa, It lies within a region of varied topographic features, including lakes, ponds and marshes, level prairies with fine farms, and precipitous hills, some of which are in groups with no distinctive arrangement, while others, perhaps best illus- trated by Ocheyedan mound, are isolated and rise somewhat abruptly above their level surroundings. The mound is about one and one-third miles southeast of the town of Ocheyedan, in Osceola county; its summit is about one hundred and seventy feet above the flood plain of Ocheyedan river, which is a short distance to the west of the mound. It is, moreover, one of the high points in Iowa, its elevation being about 1,670 feet above sea level. The general trend of the mound is northeast-southwest, in which direction its extreme length is about one-third of a mile. Its width is narrow compared with its length ; in places along its summit it is only a few yards wide. The material of the mound is chiefly sand and gravel, and on its surface lie bowlders of various sizes, including rocks of many kinds, among them being granites, Sioux quartzites, and limestones. From its summit there may be seen in all directions a beautiful landscape, dotted here and there with prosperous homes. Ocheyedan mound has historic interest and has long been recognized as a conspicuous landmark in northwestern Iowa. Nicollet, who explored this region as early as 1838-1839, refers to this mound and states that the name 1 1 Ocheyedan ’ ’ means ‘ ‘ the spot where they cry”, which alludes to the custom of the Indians to repair to elevated situations to weep over their dead relatives. Dr. Thomas H. Macbride, President Emeritus of the University of Iowa, in a report on the geology of Osceola county, published by the Iowa Geological Survey, describes the hills of the region and refers to Ocheyedan mound as follows: “The most remark- able of all these hills, a beautiful object in itself, and by far the most elegant illustration of its type, is the long time famous Ocheyedan mound.” 102 IOWA ACADEMY OF SCIENCE Vol. XXIV, 1917 The mound is a kame, which signifies that it is of glacial origin. Karnes are hills and ridges of stratified drift deposited in con- nection with glaciers at the mouths of ice tunnels or ice channels and in the re-entrant angles of the edge of the ice. They are associated in many places with unstratified drift deposited at the terminus of a glacier, or at its edge, while it was retreating. Ocheyedan mound was formed during the recession of the Wis- consin ice sheet, which invaded our state many thousands of years ago. The esthetic value of such beautiful and interesting geological phenomena as Ocheyedan mound should be fully appreciated by Pig. 2a. View of Ocheyedan Mound from the southwest. the citizens of the state, and every effort should be made to pre- vent their destruction. Already Ocheyedan mound has been somewhat marred by the removal at its summit of sand and gravel which was used for commercial purposes. To be sure, the mound is valuable for the many thousands of tons of material that might be taken from it to be used for roadmaking or other purposes, but of far greater value is it to the state as a beauty spot, a landmark, which should be conserved for future genera- tions just as zealously as we are wont to conserve our material resources. Department of Geology, The State University. A NOTE REGARDING- A SLIGHT EARTHQUAKE AT IOWA CITY, IOWA, ON APRIL 9, 1917. GEORGE F. KAY. A slight earthquake was felt distinctly by many persons at Iowa City, Iowa, on the afternoon of April 9, 1917. All of the persons who reported that they felt the chock were seated, lying down, or standing inside of buildings when the shock was detected. Those who were on the higher floors of buildings re- ported more distinctive evidences of the shock than did those who were nearer to the ground. The only statement that can be made regarding the time of shock is that it occurred at about 2:54 o’clock in the afternoon. Several persons reported two slight shocks with a few seconds between; one person reported three shocks. Not only was the shock felt but windows, doors, and furniture rattled, movable objects were swayed, and houses and other objects trembled. Similar effects were reported from many places in southeastern Iowa, including Keokuk, Burlington, Ottumwa, Lineville, Musca- tine, Davenport, Clinton, Bellevue, Mount Yernon, and Cedar Rapids. At Cedar Falls one person is reported to have felt the shock. Reports from Sioux City, Ames, Mason City, Dubuque, Des Moines, Council Bluffs, and Indianola state that no persons in those localities detected the earthquake. On the afternoon of the same day shocks were felt in Missouri and Illinois, and the evidence indicates that the center of disturb- ance was the New Madrid region of southeastern Missouri, a lo- cality which in past time has been the center of important earth movements. Department of Geology, The State University. A LARGE COLONY OF FOSSIL CORAL * A. O. THOMAS. The abundant coralline remains preserved in the Niagaran beds in sections five, six, and seven, Scotch Grove township, Jones county, have been strikingly pointed out by Calvin in his Geology of Jones County.1 In this locality the corals formed a magnificent reef and with few exceptions they are now preserved completely silicified and are imbedded in a soft dolomitic matrix which upon weathering leaves the corals among the residual products. The few corals that have not been replaced by silica occur in the form of highly crystalline limestone which upon being sectioned and polished shows the internal character of the corals fairly well. In a few cases tubular cavities in the dolomite represent the former presence of stems of colonies of Diphyphyl- lum, Syringopora, or others. Considerable weathering with resultant concentration of the silicified corals in the thin soil had evidently preceded the in- vasion of the region by the Pleistocene glaciers ; consequently, the geest, now either exposed or buried by a mantle of thin drift, the aggraded valleys, and in some cases the drift itself contain locally an abundance of well preserved corals. Post-Pleistocene erosion, especially the re-excavation of some of the eld valleys has laid bare thousands of specimens and many ravines are strewn with them for hundreds of yards. The thin-soiled hills of the region are likewise thickly dotted with large and small coralla. Near the head of a small gully developed in recent years the following section shows the succession of strata in its sides : Feet 4. Black sandy loam with chips of chert and occa- sional foreign pebbles of glacial origin. 2-4 3. A coral bed made up of long cylindrical stems, subparallel and closely aggregated. In the upper three to six inches the stems are broken into short pieces and are imbedded in a brownish, sticky geest; in the lower part the stems are less broken and are imbedded in a soft, buff- colored dolomite . 1-1% *Published by permission of the Director of the Iowa Geological Survey. Uowa Geol. Surv., Vol. V., pp. 79-81, 1896. / 106 IOWA ACADEMY OF SCIENCE Vol. XXIV, 1917 2. Chert, white in color, broken into angular frag- ments; brownish geest filling the crevices be- tween the pieces $4-% 1. Dolomitic limestone, light buff to yellow, sub- crystalline, with nodules of chert, arranged more or less in layers. A few' fossils consist- ing of bits of brachiopod shells and small col- v onies of Favosites favosus and Syringopora, exposed 14-3 The water in time of freshets on cutting through the coral bed — number three of the section — has removed the lower solid part in large irregular blocks and has scattered them down the gully for several rods. A mass roughly five feet by four feet by one foot and another six by two by one were the largest, seen in the float. Headward the gully ends at the wagon road which is along the north side of the northeast quarter of section six, township 85 north, range two west. The coral bed continues on but its extent in the upstream direction can not be determined. In the sides of the gully the coral is exposed for approximately fifty feet, its thickness, as given above, is fairly uniform and the width of the gully at the level of the coral bed will average about ten feet. This makes the cubical content of the part removed, SO'xlO'xl^', or 625 cubic feet. The slender stems of the corallites, averaging about five milli- meters in diameter, lie in a semi-prostrate position making an angle of fifteen to twenty degrees with the horizontal. In general the stems radiate as if from a center near the head of the gully but in places, for a distance of a foot or more, they lie at various angles even up to a right angle to this direction ; in a block one foot thick variations in direction of growth may be observed at different levels but the general direction is as indicated above. Since coralla of this type of anthozoans are, as a rule, more or less circular and their corallites radiate away from a common center we would seem to have here a spreading corallum of fairly uniform thickness and with a radius of at least fifty feet! This would give us a colony with a volume, u r2h, or 3.1416x502xl34, or over 9800 cubic feet, and with a surface area of 7854 square feet. Lest the assumption as to the radius of the colony appear too generous we may take the fifty feet observed in the gully as its diameter and thus disregard the evidence offered by the general radial position of the corallites ; still this dimension would A LARGE COLONY OF FOSS'IL CORAL 107 give a volume of 2450 cubic feet and a surface area of nearly 2000 square feet. The corallites are cylindrical, straight or slightly flexuose, closely aggregated, seldom more than one-half their own diame- ters apart. Contiguous stems adhere by mutual growth along their common line of contact; such connection once begun is rarely discontinued except through accident or near points where new corallites are introduced. An individual may be attached in this manner at any given level to two to six or more of its neighbors, depending on their relative sizes. This sort of attachment makes unnecessary such connecting processes between the corallites as are commonly found in species of Diphyphyllum or Syringopora, for example. Moreover, this mode of mutual support is effected without appreciable modifica- tion of the cylindrical shape of the stems while the amount of space between the corallites is reduced in much of the colony almost to a minimum and this space is filled (except where dis- solved out) by a fine-grained, buff, dolomitic matrix in which are a very few delicate fragments of minute brachiopods shells. At the contact of the larger and more firmly united corallites the epitheca is wanting and attachment is brought about by the intergrowth of the outer edges of the septa and the interlocking of the dissepimental tissue. The amount of overlapping of the circumference of one corallite upon that of its neighbor, as seen in cross section, seldom exceeds one-fourth the length of the corallite ’s radius. Other corallites are united by adhesion of the walls only and all intergradations between the two extremes may be seen. The corallites are from two to eight millimeters in diameter, the average being between four and five. Individuals have been traced for nearly a foot only to find them broken or covered over by their neighbors; that they were considerably longer than this seems reasonably certain. Multiplication is by lateral gemmation, — from one to three new individuals bud off from a given corallite at the same level and each turns abruptly to the common direction of growth and parallels the parent stem ; budding, on the whole, is rare for on a surface one foot square only five or six cases were observed. The internal structure of the corallites is in most cases well preserved although complete obliteration by a . dense filling of quartz is not uncommon. Septa, 18 to 22 in number, thin, and 108 IOWA ACADEMY OF SCIENCE Vol. XXIV, 1917 nearly all reaching quite to the center; dissepiments numerous, from two to five or more in each interseptal space in a corallite five millimeters in diameter. In longitudinal sections the vesicu- lar tissue is well shown and the vesicles are elongated with their longer diameter rising obliquely toward the outer surface. Calyx small, wall thin at the margin but gradually thickening to the bottom of the cup which is from three to five millimeters in depth. Bottom of the cup almost a point. The calyces are rarely found due to the mode of preservation of the upper part of the colony mentioned above. The epitheea is thin and weak and is marked by rather sharp, delicate, and slightly elevated annulations between which, when well preserved, are other more delicate and finer rings; slender longitudinal ridges crossing these complete the decoration of the surface best seen under a lens. On the weathered and stained stem fragments in the upper part of the bed but a portion of the epitheea remains. This interesting colony evidently belongs to the family Cyathophyllidas but docs not agree closely with any of its well recognized genera. From Diphyphyllum it differs in the absence of tabulae, and the cells are not biareal, as pointed out in Romin- ger’s diagnosis,2 Moreover, the method of mutual support by intimate adherence is not a habit of the corallites of that genus. From Campophyllum it differs in that its septa reach to the center as well as in other obvious particulars. It seems to agree best with some of the fasciculate forms of the genus Cyathophyl- lum but lacks definite tabulas and the septa cannot be said to alter- nate in length with ‘ ‘ the longer septa extending to the center. ’ ’s It may need finally to be relegated to a new genus but for the present it is placed in the genus Cyafhophyllum and the specific name calvini is offered in honor of the late Dr. Samuel Calvin who was a great admirer of the Scotch Drove reef. One or two things may be cited in concluding, first, while other coral species in the reef occur more or less abundantly at many places, Cyathophyllum calvini has not been observed at any other place than that described above. Second, the tremendous size of the colony is again emphasized when it is recalled that there were at least as many as twenty corallites to the square inch of surface. This would be equivalent to 25920 on a square " 2GeolT Mich. Vol. Ill, pt. 2, p. 120, 1876. 3Zittel, Text-book of Paleontology, Vol. I, 2d edition, p. 84, 1913. A LARGE COLONY OF FOSSIL CORAL 109 yard. Taking the more conservative area of the colony, given above as nearly 2000' square feet, there would be a population in this social group of over five and three quarters million in- dividuals. The problems of food supply, sanitation, and so forth, in such a social organization must have been great but they were successfully met. Truly, as has been said, “the coral reefs of the Silurian were the cities of those days. ’ ’ Paleontological Laboratories, The State University. PLATE IV. All figures natural size. Illustrations of the compound coral Cyathoyhyllum calvini Thomas; from the Niagaran dolomitic limestone, Scotch Grove township, Jones county, Iowa. Figs. 1, 2. Broken fragments showing in cross section the arrange- ment of the septa and the dissepiments. Note also the close ap- proximation of the corallites. Fig. 3. A small portion showing the wrinkled epitheca. ’ Figs. 4, 5. Stems showing budding; the buds are from two to four millimeters in diameter and have well developed septa and dis- sepiments from the beginning. Fig. 6. A fragment preserving the calyx. Fig. 7. A part selected to illustrate the general appearance of the coral. Note the edges of the septa and the vesicular structure where the thin epitheca has been removed. One or two buds may be seen and in the lower center may be seen a fragment of a minute braehiopod shell mentioned in the paper. This specimen is designated as the type. All the specimens here illustrated are preserved in the Geological Museum of the State University of Iowa. Iowa Academy of Science. Plate IV. ON A SUPPOSED FRUIT OR NUT FROM THE TERTIARY OF ALASKA. A. O. THOMAS. In the summer of 1910, Dr. George F. Kay, while engaged in a study of the Bering River Coal Field of southeastern Alaska, discovered some subspherical, concretion-like bodies in the “shales of the Tokun formation.” Three specimens were brought back by Professor Kay and these through his kindness have been submitted to the writer for study. The largest is a smooth oval body with long and short diameters of 8.6 and 7.6 centimeters ; the smallest is likewise smooth, irregularly oval, and with diameters of 4.3 and 3.8 centimeters. All three are dark-colored, compact, close-grained store, brittle under the hammer, and fairly heavy. The smallest one has a core largely made up of iron pyrites while the largest one, though moder- ately heavy, apparently lacks this mineral and is uniformly dark and dense throughout. The third specimen, though per- haps less heavy, is much like the largest in its physical prop- erties. Its surface, however, is rougher and is partly covered by remnants of an outer coat about six millimeters in thick- ness. Due to the strikingly nut- or fruit-like appearance of the specimen this cover is here termed an “epicarp.” The patches of the epicarp are of a brownish color on their broken edges but are darker brown, on their smooth outer surfaces. The epi- carp is softer, too, and more porous than the main body of the “fruit.” The polar diameter (see below) of this specimen is 6.6 centimeters and two equatorial diameters measure 7.3 and 7.6 centimeters, exclusive in each case of the cortex-like epi- carp. The specimen weighs seventeen and one-half ounces and its specific gravity is approximately 2.6. The most remarkable feature of the specimen is that it is marked longitudinally by four “meridians” which appear as shallow depressions on the surface except on a part of the hem- isphere which better preserves the epicarp ; here a meridian is represented for a part of its length by a low ridge. In no case where the meridians pass under the patches of epicarp is there any evidence either in or on the latter of their presence. The 8 114 ' } V IOWA ACADEMY OF SCIENCE Vol. XXIV, 1917 four meridians instead of converging to a common point are disposed in two pairs; the members of each pair are joined at their polar extremities and the two pairs in turn are con- nected at each pole by a short shallow . rectilinear depression which is similar to the meridional depressions. These two short diametrically-separated linear depressions may be called polar lines. They are of unequal length, — one being 7.1 and the other 4.5 millimeters long. The midpoint of each line may be regarded as the mathematical terminus of the polar diameter or axis of the specimen. The two polar lines are parallel to each other. This arrangement of the meridians and the short connecting lines across the poles divides the spheroidal body into tetrahedral parts. It is evident that the sum of the angles between the meridians (produced if necessary) at the poles equals 360 de- grees. The four angles about either pole differ greatly in size but corresponding angles- at opposite poles have approximately the same magnitude. See Plate V, figures 1, 2. In an attempt to saw through the specimen along the equa- torial plane the pressure of the vise caused it to break into two parts. The break, or rather cleft, followed two opposite meri- dians as far as the ends of the polar lines whence the cleft fol- lowed a narrow axial rectangular plane which terminates in these lines. After this mishap no further effort to cut the specimen was made since the break reveals no suggestion of internal structure other than that just described. It is ad- mitted, however, that if the specimen is a fruit and if the parts are preserved, that the critical structures are within the “quar- ters” limited by the meridians. From the manner in which the specimen parted when under the pressure of the vise it would appear that planes of weakness are present and that these extend inward from the meridional lines and possibly suggest that the specimen is a concretion or a part of a concretion of the type of some of the septaria or turtle stones. Moreover, the fact that the other two specimens brought in from the same formation are doubtless concretionary adds weight to the hypothesis that the third specimen also may be of the same origin. On the other hand the tetrahedral division, the fragments of what may represent an epicarp, and the precise arrangement of A SUPPOSED FRUIT OR NUT FROM ALASKA 115 the meridional and polar lines strongly suggest a four-celled ovary protected by an indehiscent epicarp while the meridional lines may represent the distal edges of septa between the seed cells. Attention is called to the point that the structure here designated as “epicarp” may be, at least in part, the wall of the ovary. Whether the plant (if plant it was) to which it be- longed was terrestrial or aquatic in habitat we can only conjec- ture. The variable beds of the marine Tokun formation and of the subjacent, coal-bearing, non-marine Kushtaka formation1 in- dicate a variety of habitats in the region in Tertiary times. The specimen was shown to Dr. R. P. Baker of the department of mathematics at the University. In his opinion “the chances are enormously against its being of mechanical origin and we should look rather to an organic derivation for so symmetrical an object.” It is hoped that students of paleobotany who may see this note will communicate their opinions should they in their wider ex- periences have encountered similar material. Likewise any sug- gestions from those who have studied concretions and their mode of formation will be gratefully received. Paleontological Laboratories, State University of Iowa. xIowa Academy of Science, Vol. XVIII, p. 88, 1911 ; also U. S. Geol. Survey Bull. 335, pp. 31-36,. 1908. EXPLANATION OF PLATE V. Figures approximately natural size. Figure 1. Diagram showing the relation of the meridians to the longer polar line. The approximate magnitudes of the angles a, fr, c and d, lettered clockwise, are 86°, 88°, 80°, and 106° respectively. Figure 2. The same as figure 1 about the shorter polar line. Angles a', c' and d', lettered counter-clockwise, equal 86°, 90°, 78%° and 106° respectively. Note that angle a, fig. 1, and angle a', fig. 2, are on opposite ends of the same “quarter”; angle & is opposite i>', etc. Their values in each case are nearly the same. Figure 3. Polar view of the specimen showing the meridians joining the longer polar line. The cleft follows the upper left hand meridian rather closely, then the polar line, and down the lower left hand meridian. It follows the last two lines and the planes extending in from them precisely. Figure 4. The opposite polar view. The cleft follows the upper right hand meridian, the polar line, and the lower left hand meridian. Fragments of the “epicarp” may be seen on both 3 and 4. Iowa Academy of Science. Plate V. 4- NOTES ON A DECAPOD CRUSTACEAN FROM THE KINDERHOOK SHALE AT BURLINGTON. OTTO WALTER. The specimen which is the subject of this paper is the same as the one noted by Professor Stuart Weller in his article on “The Succession of Fossil Faunas in the Kinderhook Beds at Burlington, Iowa. 7,1 The specimen was collected in an argil- laceous shale, — bed number 1 of the paper cited, — and was among the material illustrating the fauna of that bed submitted to Doctor Weller by Professor Calvin and Professor Udden. In Weller’s paper, page 69, the specimen is referred with some doubt to Palaeopalaemon newberryi Whitfield, with a note that it “is probably the same crustacean that Whitfield identified from Cas- cade, ” now a part of the city of Burlington. Weller further comments that “it is by no means certain that the Burlington specimens are identical with the types of the species or even that they belong to the same genus.” Whitfield had obtained his Burlington specimen from Dr. A. S. Tiffany of Davenport, Iowa. According to his description it differs in perfection from the one here discussed in having abdominal segments and telson both well preserved, while the cephalo- thorax is much less per- fect.* 2 In spite of its imperfections Whitfield believed it to be identical with his type specimen P. newberryi described3 some years before from the Erie shale at Leroy, Ohio, and re-described by Hall and Clarke.4 The Erie shale is late Upper Devonian in age5 and is thus somewhat older than the bed in which the Bur- lington specimens occur. The cephalo- thoracic portion only is preserved in the speci- men at hand but this part exhibits features not heretofore noted in this class of remains. The dorsal and lateral regions of the cephalo-thorax are quite perfect and admit of a certain degree Uowa Geological Survey, Vol. X. pp. 63-79, 1900. 2Amer. Geologist, Vol. IX, p. 237, 1892. 3Amer. Jour. Sci., 3d Ser., Vol. XIX, pp. 40-42, pi. (circulated) figs. 1-3, 1880 ; also Ann. N. Y. Acad. Sci., Vol. V, p. 505, PI. XII, figs. 19-21, Dec., 1890, and Geol. Ohio, Vol. VII, p. 461, PI. VIII, figs. 19-21, 1893. 4Pal. New York, Vol. VII, p. 203, PL XXX, figs. 20-23, 1888. 5Geol. Survey Ohio, 4th series, Bull. 15, p. li5, 1912. 120 \ ! \ * IOWA ACADEMY OP SCIENCE Vol. XXIV, 1917 of accuracy in description but the appendages are either wholly wanting or are represented by the proximal segments alone. The sides of the shrimplike cephalo-thorax are so strongly compressed that the postero-lateral portions of the branchiostegite are subparallel; the sides are longer below than above. The postero-ventral angle of the right branchiostegite is perfect, that of the left is partly broken. Transversely the dorsum is highly arcuate as far forward as the rostrum, wlpch ends in a short spine ; longitudinally the dorsum is very gently arched. The sur- face of the specimen is smooth, glossy, or polished in appearance and marked by greater and lesser punctge. The greater punctge are not very numerous and can be seen with the naked eye ; the lesser punctae are very numerous and can be seen only with the aid of a microscope. The region of the ophthalmic segment or the rostral region is not arcuate but flattened and slopes gently to the dorso-lateral angle. Extending from the posterior end of the cephalo-thorax to the transverse gastric sulcus there is a dorsal carina bearing a nar- row mesial threadlike keel ; anterior to the transverse gastric sul- cus it is continued as a low lamellar crest and terminates in a short, laterally compressed rostral spine. The hepatic sulcus (or sinus) begins at the base of the antenna, extends backwards along a slightly curved line for a distance of six millimeters thence bends abruptly upward at a right angle to the dorsal carina, for a space of four millimeters whence it bends forward in a short curve, then back upon itself postero-dorsally at a sharp angle, and finally, after describing a short semi-circle, it passes an- teriorly along the side of the dorsal carina as the gastro-dorsal groove. (See Plate Va, figure 1, gd.). There is but one spine on each side of the cephalo-thorax; each is located at the antero- lateral angle of the cephalic carapace and on a level with the base of the rostral spine. From this lateral spine a shallow but dis- tinct groove extends backward to within a millimeter of the hepatic sulcus and its course is almost parallel to the ventral margin of the cephalic carapace, — the two being approximately 1.5 mm. apart. This groove bears a delicate threadlike ridge along its bottom. Beyond the hepatic sulcus and about 1 mm. dorsally a similar groove continues nearly to the end of the cephalo-thorax, its course being practically parallel to the dorsal carina. This may be called the cardiaco-branchial groove. It is NOTES ON A DECAPOD CRUSTACEAN 121 situated along a broad angle and with its elevated edges gives su- perficially the appearance of a ridge. Anteriorly the groove has a low but well marked rim or edge on either side and these rims become more prominent and the groove less so until at the pos- terior end the two rims blend into a ridge or carina and the median groove becomes obsolete. (Figure 1, lc.) Extending from a point slightly anterior to the midlength of the dorsum and at right angles to it is a short shallow transverse gastric sul- cus; it reaches half way to the cardiaco-branchial groove or ridge and is deepest in the middle and decreases in depth to- wards both ends. Beginning at the anterior end of the cardiaco- branchial carina a broad rounded ridge extends poster o-dor sally past the ventral end of the transverse gastric sulcus to a dorso- median point immediately posterior to the midlength of the cephalo-thorax. This ridge or carina the writer will call the “cer- vical ridge” as opposed to the common cervical groove of mod- ern decapods. The portion of the cervical ridge between the transverse gastric sulcus and the dorsal end bears a fine mesial sinus. Running one millimeter dor sally and parallel to the an- terior portion of the cervical ridge from the hepatic sulcus to the transverse gastric sulcus there is a deep gastro-hepatic sulcus. Two millimeters from the ventral margin of the cephalo-thorax and beginning at the postero-ventral apex of the hepatic sulcus there is a strong marginal carina which tends, to coalesce with the free margin toward the posterior end. The entire free margin of the cephalo-thorax is slightly thickened and the ventral part of it bears a small sub-marginal groove. The portion of the branchiostegite from the marginal carina downward is inwardly inclined. The eye stalks are partly preserved. The one on the right side has a height of 5 mm. ; the left, 1 mm. A part of a laterally compressed peduncle of the right antennule is visible. The an- tennae are not shown but the proximal portions of well developed antennal scales are present forming a continuous shelf beneath the antennules, The line of demarcation has been obliterated but this condition may have been brought about by the process of substitution and by the great pressure exerted upon the thin inner margins of the scales which may have been partly imbri- cated at the time of entombment. Each scale has a prominent outer sub-marginal groove which probably represents the main 122 IOWA ACADEMY OF SCIENCE Vol. XXIV, 1917 axis of support. The dorsal surface of each scale bears a trace of a delicate diagonal pattern. Extending forward from the antero-ventral side of the cephalic region are two long subcylindrical processes which are broken off anteriorly and somewhat swollen near their proximal ends. The part of the left member which is preserved has a length of 17 mm. and its greatest diameter (dorso-ventral) is 5 mm. Their surfaces are polished and punctate. Whether these appendages represent the first joints of the antennas, -segments of extremely large maxillipeds, or the first (or second) pair of proximal seg- ments of the first pair of pereiopods the writer is unable to de- termine. From their comparatively large size it is probable that they are parts of the first pair of pereiopods. Compare, for example, the first pair of pereiopods of the modern form Sabinea princeps Smith.6 The remaining thoracic appendages are rep- resented by their proximal segments only and these are pre- served so poorly and in such a way that' the number can not be determined with accuracy. One of them has a length of 4 mm. and a diameter of 2 mm. ; others are larger but less well defined. On the ventral surface near the posterior end there is exposed a fragment which may be a part of an abdominal pleura or a part of the telson that may have become impressed on the under side of the thorax while in a flexed position. The hardness of the matrix makes it difficult to learn its exact character. Measurements : Total length of the specimen, 5 cm. ; dorsal length of the cephalo-thorax, 32 mm. ; greatest width, 12 mm. ; height of carapace, 13 mm. ; distance of antero -lateral spine from the rostral spine 7 mm. ; greatest distance across the base of antennal scales, 8 mm. This specimen agrees with the genus Palaeopalaemon, Whit- field, in that the cephalo-thorax is narrow and shrimplike as wTell as keeled on the back and sides but it differs from it in being rostrate. The appendages which Whitfield has called antennae are here considered as parts of the first pair of pereiopods. The presence of a larger number of sulci and carinae and of a right and left spine as well as the antennal scales further differentiate our specimen from P. newberryi. Indeed, the characters just pointed out are suggestive of the modern family Crangonidae 6For figure see Bull. Mus. Comp. Zool., Vol. XXIV, No. XVII, p. 38, pi. VIII, fig. 1, Cambridge, 1893, NOTES ON A DECAPOD CRUSTACEAN 123 rather than of the family Palaemonidoe. The first pair of legs strikingly suggest those of Sabinea princeps, mentioned above, while the large antennal scales are also characteristic of the Crangonidae. However, in the absence of more complete mate- rial and, too, for the lack of a more appropriate genus for its reception the writer prefers tentatively to refer the specimen to the old genus Palaeopahemon. It is felt, moreover, that the characters pointed out are sufficiently different and important to deserve specific recognition and consequently the specific name iowensis is offered. The specimen is in the paleontological collections of the State University of Iowa. It was preserved in an exceedingly hard nodule of pyritic shale, a part of which has been removed with sharp instruments and much patience. The writer wishes to express his sincere appreciation to Prof. A. 0. Thomas for the opportunity of studying this specimen and for his assistance with the literature and with valuable sug- gestions. Paleontological Laboratories, State University of Iowa. EXPLANATION OF PLATE V A. Palaeopalaemon iowensis Walter. Figure 1. Diagrammatic sketch; left lateral view, enlarged. a proximal part of antennule es eye stalk gd gastro-dorsal sulcus hs hepatic sulcus ts transverse gastric sulcus cr cervical ridge x part of pleura (?) or telson (?) gs gastro-hepatic sulcus m thickened margin of carapace sg sub-marginal groove sc marginal carina Ic cardiaco-branchial carina as antennal scale rm first joint of right first pereiopod Im first joint of left first pereiopod ta thoracic appendages rs rostral spine Figure 2. Right lateral view, natural size. Figure 3. Left lateral view, times ten-sevenths natural size. Figure 4. Dorsal view; about ten-sevenths natural size. V SOME OBSERVATIONS ON THE EROSION HISTORY OF THE YANGTZE RIVER, CHINA. C. L. POSTER. As one crosses the China Sea from Japan to Shanghai he notes little, if any, difference in its character from that of the open sea, until within about 100 miles of the coast. Then the blue- green hue gives way to the muddy, yellow color of silt-laden Fig. 2. A typical gorge view. water — a tangible evidence of the enormous load of sediment un- ceasingly born by the Yangtze to the sea. This is but the continu- ation of a process initiated ages ago by which the continent has crept eastward, slowly but irresistibly compelling the sea to retreat. .28 IOWA ACADEMY OF SCIENCE Voi. XXIV, 1917 For the first six hundred miles as one journeys up the Yangtze the monotony of the marshes and level stretches is relieved only by an occasional outlier. At some points there are levees be- hind which for many miles the land is waste, save for huge cane-brakes which, at low water, are cut for fuel. Thus far, the lands constitute the delta portion of China’s greatest river. The character of the next 400 miles gradually Fig. 3. An inter-gorge area in which the tributary valleys lie one hundred or two hundred feet above the main valley. The tops of these hills are at the same elevation. changes until at Ichang there are elevations of 1,000 feet flank- ing the stream. About five miles beyond, there is a sudden transition. The river narrows abruptly to a channel three or four hundred yards in width, its rock walls rising sheer for hundreds of feet. These are the gorges of the Yangtze, famed for their wild grandeur. For a hundred miles or more the river has carved its course through solid rock. It is no longer the calm, v / EROSION HISTORY OF THE YANGTZE RIVER 129 peaceful stream whose sluggish but determined current meets the sea, but it is churned and agitated at frequent intervals by roaring rapids and swirling eddies. As one proceeds, the walls become higher, and back from the river the mountains stand out in bold relief, carved in fantastic forms. Between the top of the gorge walls and the base of the flanking mountains there is an area of flat surface described as follows : ‘ 1 The cliffs which wall the Yangtze gorges are sometimes sheer for 2,000 feet, 600 Fig. 4. “The cliffs ***** are sometimes sheer for 2000 feet.” The upper end of the upper gorge, looking down stream. meters, as estimated in passing. Above that altitude they recede in a decided bench above which the mountains rise 2,000 to 3,000 feet, 600 to 900 meters, higher. It is probable that the level 3,000 feet, 900 meters, above the river is the floor of the valley which was occupied for some length of time prior to the last sinking of the canyon. Since the pause at that stage permitted 9 130 IOWA ACADEMY OF SCIENCE Vol. XXIV, 1917 the widening of the valley cn the harder rocks, there was, no doubt, a far more extensive broadening upon the red beds and granite, but the valley floor on those rocks has been lowered many thousand feet, at least near the river, and the higher level, if it still survives cn them, is to be seen only in the foothills of the adjoining mountains.”1 The intermediate plain above referred to, and its correlation with the section of the river above the gorges will have an im- portant bearing on the unravelling of Yangtze history. At present there are no data available for such correlation. There is, however, a region beyond the gorges which is marked by ridges Fig. 5. At Suifu, showing two ridges,, which are the . two limbs of an anticline Which has “broken down to depths of several hundred feet, leaving the limbs projected a mile or more apart, with open valleys between.” standing out above the surrounding country to heights of 500 to 1,000 feet. Near the city of Suifu one can stand on a hill and look across and along such ridges, fiat and even as far as the eye can reach. The Yangtze and its tributaries pay little at- tention to them, for at one point the eye can follow the course of the main river as it cuts through three or four gaps in these ridges. Where tributaries enter the main stream they have cut U-'ailey Willis. Research in China, Vol. I, 334. EROSION HISTORY OF THE YANGTZE RIVER 131 through similar rock walls, and because they have been unable to keep pace with the master stream they are speeded up in their lower courses, forming rapids or falls, many of which are impassible at any stage of the water. The interpretation offered for the region just described is that the tops of the ridges represent a former erosion surface, over which the streams were flowing. Their present courses were ac- quired at that time and an elevation of the land surface took place. The streams continued in the channels already formed, and so were forced to cut through the ridges. Owing to the in- creased gradient due to elevation the inter-ridge areas were rap- idly eroded, especially along the axes of the anticlines, some of which have been completely broken down to depths of several hundred feet, leaving the limbs projected a mile or more apart, with open valleys between. The elevation of this old plain is about 1,700 feet above the sea, and it is 1,500 miles inland, about 400 to 500 miles farther in than the gorge intermediate plain above mentioned, which has an elevation of about 2,200 feet. It is apparent frem these figures that if the river is following its former course, the two plains are not of the same age, unless there has been differential warping to account for the discrep- ancy of 500 feet. Only detailed work in the field will determine whether the two plains are really two or one. At the city of Suifu, a little less than 100 feet above the pres- ent river there is a terrace which gives undoubted evidence of having been the bed of the river at a higher stage. The plain stretches back from the river to a width varying from half a mile to mere than a mile. It is so thickly strewn with water worn cobbles and bowlders that over wide areas it has not been cleared for use. In places small patches have been cleared and the rocks heaped into high walls. Such plots are rich, and yield good crops. 132 IOWA ACADEMY OP SCIENCE Vol. XXIV, 1917 Let ns now summarize such evidence as we have. A glance at the accompanying profile of the Yangtze river for the last 1,500 miles of its course is sufficient to show that it has an inter- rupted profile. An intermediate plain exists in the gorges at 2,200 feet, and one at Suifu at 950 feet. The presence of even- crested ridges in the latter region over wide areas suggests a peneplain between the two intermediate plains, hence at least three erosion cycles. Entrenched meanders may be said to exist, since the course of the stream seems to ignore completely the rock structures, its determination being due to ether factors than these. That the river is an efficient worker is attested by the wide areas of delta deposits which have formed land where seas once were. There stand the gorges, great gashes in the mountains, from which the materials have been carried to the ocean floor — fitting monuments to the ceaseless toil of one of Nature’s greatest artisans. < — ' Department of Geology, State University of Iowa. SOME GEOLOGIC ASPECTS OF CONSERVATION. JAMBS H. LEES. Iowa is usually considered as primarily a prairie state, one whose chief aesthetic attraction lies in the satisfaction that ac- companies the outlook over wide spreading grain field or level plain stretching away beyond the farthest ken. In a general way this is true and it is the fundamental factor in Iowa’s agri- cultural supremacy. But it is equally true that within the limits of the state there are many spots and localities which for unique interest or quiet beauty or stately grandeur can scarcely be ex- celled within the Mississippi Valley. Since these are essentially geologic phenomena it is my purpose to discuss a few of them from the standpoint of the geologist. Unquestionably the most attractive region in this state is 1 ‘ The Switzerland of Iowa,” so named by the late Professor Calvin, formerly State Geologist of Iowa, because its picturesque hills and deep cut valleys with their winding streams make of it a land comparable with the “Playground of Europe.” No one can traverse this region or view its bold front from the surface of the great river which flows along its eastern margin without being im- pressed first of all with its ever varying charm and then — if he will but pause and consider— with the marvelous history which has made possible such a beauty-spot in the midst of the bound- less plains of the Mississippi Valley. The Switzerland of Iowa includes Allamakee county and por- tions of Winneshiek, Clayton, Fayette, Dubuque and Delaware counties, while similar phenomena, though on a diminishing scale, may be found to the south along the Mississippi and its tribu- taries. Geologically it is the oldest part of Iowa, if we make exception of a very small area in the northwestern corner of the state, where the rock is older, though the final emergence from the sea may have been much more recent. Therefore the series of events which is recorded in the rocks exposed in this region is longer and more varied than that comprised in any other area of similar size in the state. It extends from the deposition of the later Cambrian sandstones through the varying condi- 134 IOWA ACADEMY OF SCIENCE Vol. XXI V, 1917 tions of the Ordovician, the Silurian and the Devonian periods with their alternating limestones, sandstones and shales which bespeak changing relations of sea and land, or possibly arid climate, as is thought by some to be represented by the St. Peter sandstone. But what has given to this region its rugged charm is the erosion which has been ceaselessly at work for ages carv- ing deep valleys into the once level plains, sculpturing the mas- Fig. 7. Mississippi river south of Lansing-, Allamakee county. sive rocks into bold cliffs and battlemeiited towers, slowly, unob- trusively, irresistibly wearing away loose sand or solid ledge until the present picturesque topography has been developed. This region lies in what is known as the Driftless Area, an area which has not been invaded by any of the great glaciers which covered the state, unless perhaps it was the first, the Ne- braskan. Hence not only has the work of the erosive agents been uninterrupted but the region has not been subjected to the SOME GEOLOGIC ASPECTS OF CONSERVATION 135 destructive planing action of the great ice-sheet. So it is that the unique and beautiful forms resulting from the erosive work of air and water have been preserved under the most favorable circumstances. In the country immediately to the west, on the other hand, such erosion remnants have been swept away by the repeated advance of the ice, the river valleys have been filled and the resulting topography is a level or gently undulating prairie. Fig. 8. Columnar cliffs along Oneota river, Winneshiek county. One of the striking topographic features of northeastern Iowa, one which becomes apparent with a glance qt the topographic maps cf the region and is equally evident to the traveler, is the relatively straight course and smooth, parallel walls of the great gorge of the Mississippi, which is in marked contrast with the intrenched meanders and extremely irregular slopes of the tribu- tary valleys. It is as if some gigantic plow had been forced down the main valley, cutting off all jutting headlands and leav- 136 IOWA ACADEMY OF SCIENCE Vol. XXIV, 1917 the valley walls steep and rugged. And this is just what has happened. Great floods of water from the melting Wisconsin glacier, laden with rock, sand and silt, poured down the valley, scoured both floor and walls and then filled the valley to the level of the highest terraces of the present day. The lateral valleys, however, and the back slopes of the main valley, which were not subjected to this scouring, have retained their older, normal erosion forms. There are_ many spots of beauty in this scenic wonderland. Along Oneota river are the great columnar cliffs of Plymouth Rock, the vertical scarps at Bluffton, the Ice cave and Mill Spring at Decorah, Elephant Bluff, the Owl’s Head, Mount Hope and other hills of circumdenudation. The most unique of all these is the Ice Cave. This is a great gap left in the rock by the slipping out of a block of stone along the cliff face. The limestones of the region are honeycombed with fissures and into these the cold air of winter is drawn, to be forced out during the warm days of spring and summer. Coming into contact with the moisture-laden warm air of the cave this colder air causes a precipitation of the moisture along the inner wall of the cave and forms during the early summer months a boating of ice which sometimes becomes ten to twelve inches thick. Mill Spring is Fig. 9. Waterfall at Devil’s Den, Allamakee county. SOME GEOLOGIC ASPECTS OF CONSERVATION 137 a gushing stream of beautifully clear cold water which issues from a similar, though probably smaller, rock-encumbered cavern not far from the Ice Cave. In times past the stream from the spring built up a deposit of tufa at the mouth of the little ravine down which it flows. There are countless other beautiful springs in the region and indeed every valley and ravine is a dream of beauty with flowing stream and towering castellated walls clothed with the beautiful green of summer or the glow- ing colors of autumn. Fig. 10. Islands .and ponds in the Mississippi below McGregor. In a land of universal charm a spot which stands out with especial clearness in the memory of the traveler is the region around McGregor and North McGregor, the region in which it is now proposed to establish a national park. Especially favored by lavish Nature as to river, rock and bluff its charm is never- ending and its quiet beauty makes an impress which lingers through the years. The Pictured Rocks, about a mile below McGregor, are an unusual phenomenon even in this land of the unusual. A hundred feet or more of St. Peter sandstone, stained with all the browns and reds and yellows and purples of the iron oxides, in contrast with the translucent white of the 138 IOWA ACADEMY OF SCIENCE Vol. XXIV, 1917 pure sand, form cliffs and grottoes and nooks of marvelous colors and patterns, set off by groves and lanes of shady trees. At Guttenberg and again at the mouth of Turkey river are high narrow ridges nearly a mile in length which separate the tributary valleys from the valley of the Mississippi. The Gut- tenberg ridge is over 200 feet high, with a gentle slope to the south, and the Turkey river ridge is nearly as high and termi- Fig. 11. Castle Rock at mouth of Turkey river, Clayton county. nates in a bold rock tower which stands almost a hundred feet above the rivers on either side. These ridges of course owe their existence to the hard, resisting beds of rock which underlie the country and which withstand to the last the encroachments of time and the destroying elements/ And so one might continue this enumeration at great length, but it must be concluded with one or two more examples before SOME GEOLOGIC ASPECTS OF CONSERVATION 139 passing to other fields. It is well known that in the vicinity of Dubuque there are many caves, which have been formed by the solution of the limestones along cracks and fissures. Some of these have yielded beautiful specimens of stalactites and similar deposits, as well as great quantities of lead ore, and the caves themselves are interesting features. I well remember my disap- pointment a number of years ago on going through a cave in the City Railway’s park to find that it had been absolutely stripped of all its wonderful stalactitic deposits and transformed into a bare, ugly, electric lighted tunnel. Its beauty was irredeemably gone. Such treatment is nothing short of stupid barbarism. J ust west of Dubuque, too, are a number of fine examples of erosion pillars which have been carved out of the hard Galena dolomite. Some of these may be seen from the Illinois Central trains stand- ing guard as lone outposts from the main body which has wasted away during the ages. Such remnants bear in themselves witness that no glacier has invaded the region during the long ages that they have been forming by the slow processes of erosion by the ordinary agents. Another form of erosion remnant, most unique in a state like ours and of great interest anywhere, is the natural bridges of Jackson county. These are formed by the incomplete falling in of the roof of an underground drainage course, whereby por- tions are left still spanning the now open valley. They are lo- cated about six miles northwest of Maquoketa and together with a large cavern in the ravine they make a very popular resort for drives and picnics. Outside of the more rugged area of northeastern Iowa there are, of course, many isolated spots of great beauty and charm which are well deserving of the nature lover ’s attention. Among these may be mentioned the Devil’s Backbone, near the north- west corner of Delaware county, various localities along the Ma- quoketa and Wapsipinicon rivers, the Palisades of the Cedar, near Mount Vernon, Devil’s Lane, near Muscatine, Indian Spring, near Burlington, and numerous others of equal interest and value. Entirely aside from their aesthetic value all of these areas are of importance to the geologist because of the illustra- tions of natural phenomena which they furnish, and for that rea- son as well as for others they are eminently worthy of care and preservation. 140 IOWA ACADEMY OF SCIENCE Vol. XXIV, 1917 In the great central plains area of the state there are a num- ber of very charming spots, which are all the more noteworthy because of their prairie surroundings. Such are the picturesque valleys of Willow and Lime creeks at Mason City, where the streams have cut the limestone bedrock into steep bluffs and precipices which now are margined and covered with forest growth. On a still larger scale is the gorge of Iowa river at Iowa Falls. Here the river has been displaced within recent geologic times and has been forced to cut a new channel through Fig. 12. Natural bridge in Jackson county. seventy feet of solid limestone. Several small tributaries have had to undergo the same treatment and the result is a series of gorges and retreats which give the region a rare beauty and rugged charm. The older channel of the river is said to be still discernible to the south of the present one. Steamboat Rock is another locality of geological and general interest and there are several others along the Iowa, such as the stretch above Iowa City, which owes its rugged character to the vagaries of glacial occupation. The older rocky hills were buried Iowa Academy cf Science. Plate VI. The Ledges below Boone, Boone county. SOME GEOLOGIC ASPECTS OF CONSERVATION 143 with drift and when the river, whose location was determined by the topography of the glacial deposits, cut through these to the rock, it must perforce maintain its course and so was obliged to cut deeper and deeper into the massive limestones which lay athwart its path. Along the Des Moines are many beautiful spots, as at Esther- ville, at Fort Dodge, the high bluffs above Boone, and the de- lightful “Ledges” below that city, the Red Rock bluffs at the village of the same name, the charming bluffs at Cliffland below Ottumwa, and the numerous points of interest about Keosauqua. There is no spot in central Iowa which offers better natural fa- cilities for a beautiful park than the area on either side of the river midway between Boone and Fraser. The entire two hun- dred feet of the valley’s depth shows only glacial drift, and in places the slopes rise from the water ’s edge in a single sweep and are wooded from base to summit. Of an entirely different sort is “The Ledges.” Solid sandstone walls rise sheer from the water and even overhang in places, a carpet of verdure covers the floor of the little valley, while trees rise to the summits of 144 IOWA ACADEMY OF SCIENCE Voi. XXIV, 1917 the bluffs and form a setting for an exceedingly charming scene. The bluffs near Red Rock and Cliffland are also cut in sand- stone of Coal Measures age and are of interest because of their geological history as well as for their natural beauty. I have already^ spoken of the great ice-sheets and their glacial deposits as effacers of those types of topography which are due to erosion. It is partly because of this fact that the western two-thirds of Iowa has so few rock outcrops and hence relatively few spots of striking charm and beauty. Aside from a few Fig. 12b. Pilot Knob, Hancock county. It rises three hundred feet above the creek near its base. localities and these chiefly along the larger streams, the work of erosion since the retreat of the ice-sheets has been confined to the glacial drift deposits, which while easily eroded give rise to the softer, more subdued types of landscape. But there is a peculiar type of topography which is intimately associated with the depositional work of the last, the Wisconsin glacier, with the laying down of its load along its margin, and which consists of piled up mounds and intervening hollows, all without order or arrangement. This is known as the terminal moraine and along Jowa Anaderav nf SnionoA. Plate VI7- 10 Mountains of the prairie — the moraine in Wright county. Iowa Academy of Science. Plate VIII. The island and docks at Oakwood, Clear Lake. SOME GEOLOGIC ASPECTS OF CONSERVATION 149 the eastern margin of the Wisconsin drift it is developed as far south as Hardin county, while on the western front it is con- spicuous south to Carroll. An inner moraine, formed during the recession of the glacier, reaches intermittently in a broad loop from Winnebago county south into Boone and Greene and north again through Palo Alto and Emmet counties. While it differs markedly from the Driftless Area of northeastern Iowa this morainic area has many features of great charm. Its great mounds, many of them bare and gravelly, but some timber cov- ered on their slopes or summits, the depressions among the hills, with an occasional lakelet nestling calmly in quiet beauty, all of these make an assemblage which can not fail to impress him who has eyes to see and a soul to appreciate Nature’s handiwork. One of these great mounds, Ocheyedan Mound, in Osceola county, has long enjoyed the reputation of being the highest point in Iowa and while apparently it must yield precedence, at all events it is a landmark which is visible for miles around. Pilot Knob, in northern Hancock county, while not rising so high above the sea, rises twice as high above the plains about it as does Ocheyedan mound, and with its associated lakelet and timber groves is one of the charms of central Iowa. The beautiful lakes of northcentral Iowa form another group of geologic features which are intimately associated both in dis- tribution and in origin with these moraines, and which comprise one of the most attractive and valued types of Iowa’s localities cf natural interest. Everyone is drawn by the quiet beauty of a smooth-lying sheet of water set like a glistening diamond amidst low grassy shores or steeper wooded bluffs. And so it is that our lake regions appeal to all of us and we think of them and their popularity with justifiable pride. A lake is one of the most evanescent and transient of natural phenomena. A stream may expand and increase its tributary area until it grows into a river : a mountain may, for a long time at least, keep pace in its growth with its decay : but the destiny of a lake, and especially of a glacial lake; is as inevitable and as 'easily foretold as the destiny of a man. And in comparison with the vast stretch of geologic time it is as short lived. For this reason it is all the more imperative that we do all in our power to conserve what lakes we have, to lengthen their lives so far as in us lies, to preserve for the coming generations these gems of beauty in our fields of emerald. . 150 IOWA ACADEMY OF SCIENCE Vol. XXIV, 1917 You are all familiar, by experience or by reputation, with the most important Iowa lakes and I need but to mention them to recall beautiful memories to your minds. In the eastern moraine Clear Lake is without a peer and indeed will bear comparison with any in, all the lake region of the central United States. In the western moraine, which is much more extensive, the Oko- bojis and Spirit Lake hold easy pre-eminence, but a multitude of other smaller ones are held in warm regard by their local ad- mirers, and certainly lack nothing but size to make them equally noteworthy. Storm Lake is deservedly popular among its circle of friends. Wall Lake has attained a wide reputation through its great wall of bowlders. The Twin Lakes of Calhoun county are centers of local attraction, and the same is true of many Fig. 13. Pilot Rock, Cherokee county. others in the hill country which affords them lodgement, such as Tuttle Lake, on the state line in Emmet county, Medium Lake near Emmetsburg, Lost Island Lake near Ruthven, and others which will occur to your minds. Along with their loads of finer material some of the continen- tal glaciers brought down from farther north immense bowlders which now lie scattered over the surface of the drift sheets. Some of these have really enormous dimensions, as for example Pilot Rock, a bowlder of Sioux quartzite near Cherokee, which Iowa Academy of Science. Plate IX. / Loess hills of Harrison county. SOME GEOLOGIC ASPECTS OF CONSERVATION 153 measures on the ground sixty by forty feet and rises above the surface twenty feet. The Iowan drift, in northeast Iowa, is especially noted for these monuments of bygone events and has more large bowlders than any of the other drift sheets in the state. Something should be done to preserve the most notable of these glacial bowlders in view of their unique origin and char- acter. If nothing is done to prevent it they will ere long be sacrificed to the desires of their present owners for convenient building material and will be entirely lost to posterity. Closely associated with the glacial deposits of the state and yet only partly related to them in origin is a remarkable for- mation known as the loess. In northeastern Iowa it is derived directly from the Iowan drift but along the western margin of the state it owes its origin to the great quantities of silt brought down and deposited by Missouri and Big Sioux rivers. From their flood plains it is picked u;p and carried away by the winds to be dropped over the clay hills in an ever-thinning mantle with increasing distance from the source. I do not recall that I have heard or seen these loess bluffs mentioned in conservation dis- cussions, but there is no room for doubt that both botanists and geologists will agree in commending them for eareful considera- tion. The fact that wind blown deposits with thicknesses of fifty to one hundred feet have been shaped into such striking topographic forms as are found along these bluffs, and the fur- ther fact that they bear what is in reality a desert type of vege- tation, and this in the most fertile state in the world, are facts which entitle them to recognition in any plans for conservation of our beauty spots. The beautiful park at Council Bluffs with its winding valleys and steep slopes is sufficient witness to what is possible with these loess hills, but there should be preserved in an absolutely natural state a tract which would permit of the retention both of the original topographic forms and of their remarkable vegetal covering. Such areas are available near Mis- souri Valley, or near Turin, in Monona county, or in the vicinity of Sioux City, and at other localities where the phenomena are equally striking. In the extreme northwest corner of Iowa, occupying an area of not over five acres is a little spot which is unique in its interest. This interest arises both because of its rock exposures, which are scores of miles distant from any others in Iowa, with the excep- tion of a similar one a mile away, and because of the fact that 154 IOWA ACADEMY OF SCIENCE . Vol. XXIV, 1917 this rock is the oldest .exposed stratum in the state. It is really the rook foundation upon which all subsequent formations are laid. This rock is the Sioux quartzite and the center of its in- terest is the natural depression perhaps twenty feet deep known as Jasper Pool. This represents the greatest thickness of the exposure in Iowa although on the Dakota side of the Big Sioux the rock has been quarried to much greater depths. It seems much to be desired that along with the natural bridges of Jack- Fig. 14. Jasper Pool, Lyon county. son county, the Waukon Sphinx, the great drift bowlders of the central plains, this little tract might be conserved as a state mon- ument, and so with the larger phenomena in a series of state or national parks might make accessible to all posterity the evi- dence of the activity of geologic forces, past and present, and keep before our eyes the uplifting, broadening, educative beauties of the realms of Nature. Iowa has a group of beauty spots which she may well hold in esteem and to care for them and insure their perpetuation will increase the feeling of pride with which every Iowan regards his state and so will add in every way to the state’s resources and attractiveness. Iowa Geological Survey, Des Moines. SOME FUNDAMENTAL CONCEPTS OF EARTH HISTORY. JAMBS H. LEES. We have been accustomed to think, most of us, that in the early days of the world’s geologic, history Nature manifested her- self in forms different from those with which we are familiar; that God, the supreme Power of the universe, employed other types of energy than those by means of which He works today. And these conceptions have been fostered and influenced very largely, consciously or unconsciously, by our religious and theo- logical training. For we each have a theology, whether we rec- ognize and admit it or not, and we are governed in our thinking to a large extent by this theology and it is very likely to color our outlook upon life and our interpretations of the phenomena of the outside world. We have accepted the science of three thou- sand years ago because of a certain imputed authority, and have given it precedence, in the theological domain at least, over the science of today. Our religious instruction has been distinctive in the teaching that the methods which God used in creating this world were entirely apart from those by which He perpetuated it. The science of geology was founded upon this concept. The world is today peopled with certain groups of animal and plant life. In the rocks are found entombed the remains of other types differing widely from each other and from modern forms. These facts were accounted for in early days by the hypothesis of a series of creative flats and destructive cataclysms whereby new and successively higher orders of life were alternately deployed and as autocratically swept off the stage, as it were in a moment of time. Here again theology has guided science and we have investigated natural phenomena in the light of a pseudo-scientific interpretation which we have read into certain Biblical passages. Our scientific forbears at first failed to realize that the laws of development and decay operated as perfectly and inexorably in the beginning as now, that the perpetuation or the extermination of any form of life depends upon its ability to adapt itself to external conditions and also upon what I may call its adherence to standard. It is the plainer, simpler, more mobile types which 156 IOWA ACADEMY OF SCIENCE Vol. XXIV, 1917 have persisted from the past. The bizarre, the ultra-radical as well as the ultra-conservative, have disappeared, or, what is .just as fatal to real progress, have failed to keep pace with the march of the race, have fallen hopelessly behind in the onward sweep of life toward higher and higher development. The trend of modern scientific thought has been away from the cataclysmic toward a more uniformitarian point of view. We are coming to understand that present forms of life differ from those existent during earlier periods not because they belong to a distinct creation but because they have progressed during the ages, have developed those traits and characters which fitted them to compete with untoward conditions and unfavoring cir- cumstances. If we turn to inanimate nature the same rule of uniformity holds good. The rock foundations of the continent to the :pro- foundest depths yet penetrated bear every evidence of formation by the same agencies and under control of the same laws as those now operative. The only differences are those of location and degree. There was a time when, according to the most modern and reasonable theory of earth history, the upbuilding of the earth’s mass by accretion from outside sources was the dominant activity. At other and successive periods volcanic forces have raged with tremendous violence and enormous vol- umes of liquid rock have poured over the surface or have been thrust into the solid body of the earth. During still other pe- riods, and these have been the dominant ones of the earth’s later history, the quiet processes of erosion of the lands and deposition in the seas have been uppermost in importance. These latter processes have given us our sandstones, the beds of shale which enclose our coals and the limestones which form such an impor- tant resource for constructional purposes. To them we owe in large measure our vast resources of iron, of rock salt, of gypsum and of other minerals. And these processes are today as active as ever they were. The mud banks and sand bars at the mouths of our great rivers, the limy clays and beds of shell and coral in the quiet, shallow off-shore reaches of the modern oceans, these will as surely consolidate into solid rock as have similar deposits of the past. It is my purpose to outline briefly the progress of the ideas which have been held successively by students of natural his- SOME FUNDAMENTAL CONCEFTS OF EARTH HISTORY 157 tory regarding the origin of the earth and the operation of nat- ural phenomena. From the beginning of man’s history as a thinking being he has been impressed by the outstanding forces of Nature and the more obtrusive features of the earth’s surface. Storm and flood, thunder and lightning, 'volcano and earthquake inspired him with fear and led him to invest them with supernatural origin and power, while on the other hand the pleasant shady vale or the bubbling spring suggested to his facile imagination the pres- ence of harmless sprites and reveling nymphs. Monotheism has displaced these manifold and ill-assorted divinities by one Su- preme Ruler and an orderly and neverfailing body of law. But it has always been the curse of science, popular as well as tech- nical, that from the observed body of fact and experience un- warranted conclusions have been drawn and fantastic hypotheses have been formulated. There is always the tendency to devise the extraordinary, rather than the ordinary explanation for natural phenomena. On the other hand it must be recognized that this tendency to speculate when it has been backed up by solid fact and proven law, has been the source of all advanced ideas regarding the past history of our world and the method of operation of the forces which have been and are shaping it. While, then, the laity among the Greeks and Romans were con- tent to ascribe such forces to supernatural causes their philoso- phers, from Herodotus and Aristotle to Strabo and Pliny, were coming to appreciate the natural causes of physical phenomena. Thus Herodotus, 500 years before Christ, attributed the Yale of Tempe to an earthquake, rather than to the work of Hercules, and Strabo, about the beginning of the Christian era, never al- ludes to the legendary mode of its origin, as if there could be no reasonable doubt, Aristotle (384-322 R. C.), who wrote exten- sively on scientific subjects, discussed earthquakes and volcanoes as due to internal fire and wind, an explanation which was accepted for centuries. While some of the attempted explana- tions of these thinkers were crude and fantastic yet in many cases they show accurate observation and acute reasoning. Seneca (-65 A. D.) remarks that “ Though the processes below ground are more hidden from us than those on the surface of the earth, they are none the less equally governed by invariable laws.” The fact that fossil shells have been found far from the present 158 IOWA ACADEMY OF SCIENCE Vol. XXIV, 1917 seas and at considerable altitudes above sea level has led to much speculation. The Greek and Roman scholars are positive in their opinion that these record the former .presence of the sea — a con- clusion which might well have been accepted by their successors of the Middle Ages and later. How such changes of level were effected they could not explain, any more than they could tell how the mountains and the valleys, the rivers and the plains attained their present forms. Indeed it was not until the last pentury that the true explanation for these features was found — again, the most reasonable and natural explanation, lying ready to hand when some observer should be clear minded enough to grasp it. But before the fall of the Roman empire the operation of certain well defined natural laws had been ap- preciated and it is noteworthy that the development of the scien- tific spirit in investigating Nature was unhindered by theological preconceptions or popular misconceptions. If the same tolerance had been manifest in Christian Europe the history of scientific research would have been far different than it actually has been. During the Middle Ages the Arabs endeavored to enlarge the bounds of natural science and one of them, Avicenna (980-1037), states with admirable clearness that “Mountains may arise from two causes, either from uplifting of the ground, such as takes place in earthquakes, or from the effect of running water and wind.” By the time of the revival of learning the Church had ob- tained such a hold on the minds of men and on their methods of study that they were allowed to express no opinion on the age of the earth or its geologic history which was counter to the words of the first chapter of Genesis. This effectively dis- posed of the notion that the sea had once overspread the lands and that in it had lived animals whose remains are now entombed in the rocks. For had not the Creator separated land and sea before animal life was called into being? Neither was there any place for the heresy that the fossiliferous rocks, though perhaps several thousand feet thick, had accumulated during immense periods, for there was no escaping the dogma that the world had been created out of nothing about 6,000 years ago. So to escape martyrdom and the irrefutable facts of Nature at the same time there was adopted the expedient that these SOME FUNDAMENTAL CONCEPTS OF EARTH HISTORY 159 fossils never represented living creatures, but were mere sports of nature, liisus naturae, lapides sui generis, lapides figurati. Those who could not accept this hypothesis had recourse to Noah’s flood, although the impossibility of this explanation is equaled only by that of the other. But the “ Diluvialists ” formed an important theologico-scientific school during the 16th, 17th and 18th centuries, although they were combated by such men as Leonardo da Vinci (1452-1519), the sculptor-engineer, Nicolas Steno the Dane (1631-1687), who was among the first to see that the earth’s strata constitute a chronological record, and Robert Hooke the Englishman (1635-1703), who argued against the insufficiency of the Noachian Deluge in length, just as some other scholars had come to question its universality. During this period there were devised a number of cosmogonies, whose chief aim was to harmonize natural events with theological interpretations and whose chief characteristic seems to have been their disregard for natural phenomena. The limitations under which their authors labored, both as to their knowledge of Nature and as to the time within which they must compress the history they treated, resulted in many ludicrous suppositions, such as the one already mentioned, that the immense thicknesses of fossiliferous rocks were formed during the Flood. There is a group of writers who deserve special mention be- cause their theories carry the first foreshadowings of the truly scientific attempts to explain origins and forces. These men were Descartes • (1596-1650) , Leibnitz (1646-1716) and Buffon (1707-1788) who all held that the planets were originally glowing bodies like the sun. Buffon went further and conceived of the planets as having formed a part of the sun’s mass, whence they were separated by the shock of a comet. While these men were limited by lack of data regarding the composition and mechanics of the heavenly bodies, their honest efforts to really use such knowledge as they had must command our admiration. Buffon indeed looked forward to the time when the oceans would erode away and cover the lands and when the planet would become gradually refrigerated and unfit for human occupancy. During the latter part of the 18th century there were probably no scholars who influenced geological thought as profoundly though in totally divergent directions as did the German Werner (1749-1817) and the Scotchman Hutton (1726-1797), founders 160 IOWA ACADEMY OF SCIENCE Vol. XXIV, 1917 respectively of the schools of Neptunists and Plutonists. Werner and his school revived the old idea that the entire earth had been covered to the summits of the mountains by a universal ocean, and believed that from this ocean all the rocks had been deposited by chemical precipitation ; hence the geological formations were > universal in extent and uniform in character. At a suitable time this universal ocean conveniently disappeared but it had to be recalled in order to deposit some other formations which had been discovered out of their natural order. Then it again van- ished like a well trained servant. The Neptunists also insisted on the aqueous origin of the vast systems of rocks which are now known to be and many of which were then claimed by other in- vestigators to be of volcanic or igneous origin. On the other hand it was one of the fundamental doctrines of Hutton and the Plutonists that the internal heat of the globe has frequently forced great masses of molten rock into higher formations or onto the surface of the earth. However, Hutton realized that large bodies of rocks are of sedimentary origin. While Werner scouted the idea of The importance of earthquake and volcanic phenomena, Hutton saw in them and in their allied forces a sufficient agent for the tilting of the strata and the elevation of the dry lands above the oceans. Unlike his predeces- sors Hutton attributed volcanic activity to the internal heat of the globe rather than to the combustion of inflammable sub- stance, such as coal, bitumens, pyrite, &c. It was Hutton’s clear eye, too, which saw more than anyone before him had seen the importance of running water as a land sculptor. What we today accept as commonplace was by Hutton’s contemporaries rejected with scorn or quietly ignored. Previous to the early years of the 19th century geologists almost to a man had been Catastrophists — whether Diluvialists or Vulcanists — concerned in explaining all striking and unfamiliar phenomena, all well marked stages in earth history, by some great convulsion of Nature, by the intervention of some agent or force not now evident and of which modern science knows nothing. But Hutton taught that we have no right to appeal, in formulating the history of the earth, to any causes or forces which are not in operation at present. In other words the dominant idea in his philosophy was that the present is the key to the past. He thus laid the foundation for the school of Uni- SOME FUNDAMENTAL CONCEPTS OF EARTH HISTORY 161 formitarianism, of which Lyell (1797-1875) rising to prominence a few years later, became the chief exponent. This school, carry- ing to its logical conclusion the statement of Hutton that “no powers are to be employed that are not natural to the globe, no action to be admitted of except those of which we know the principle, and no extraordinary events to be alleged in order to explain a common experience,” denied that there was any reason to suppose that geological agents have ever varied in their activ- ity, or in their potency to modify the features of the earth. While they served to break the shackles with which Catastro- phism had bound the science, the Uniformist doctrines have been displaced in large part by the principles of Evolution. The Evo- lutionist, although he holds on the one hand to the permanence of the laws and forces of Nature through all the earth’s history, also holds on the other hand that these forces have acted with varjdng intensity during different periods of that history. Thus there has been an interplay of laws and agents which has re- sulted in exceeding diversity of events and resultant forms. It may be said here that by the time Buff on published his Epoques de la Nature in 1778, Geology was becoming freed from the thrall of theological dogma; hence he felt at liberty to ascribe long periods of time to the development of the earth — that is, long as compared with the brief time previously alloted. He estimated from his experiments with cast-iron globes that the world began about 75,000 years ago and would come to an end 93,000 years hence. While these figures seem small to the mod- ern geologist they represent a great advance beyond the limita- tions of earlier writers, and may be said to mark the beginning of an intelligent attempt to estimate the duration of geologic time. Undoubtedly the theory of earth origin which more than any other since .the beginning of the 19th century has influenced geologic thought, is that of La Place, known as the Laplacian or Nebular Hypothesis. Pierre Simon, Marquis de La Place, was born in 1749 of very poor farmer parents and died in 1827. He was one of the most brilliant of mathematicians and astrono- mers and through his studies of celestial mechanics was able to formulate more clearly than any other scholar of his own or previous time a theory of the origin of the solar system. This was published in 1796 as a footnote to his Exposition du systeme da mondc. According to this hypothesis the material of the solar 11 162 IOWA ACADEMY OP SCIENCE Vo£. XXIV, 1917 system was originally in an extremely heated gaseous spheroid extending far beyond the present orbit of Neptune. This spheroid contracted and rotated as a result of loss of heat. In time an equatorial ring of gaseous matter was left behind in the orbit now occupied by Neptune. After further shrinkage other rings were formed where the other planets now revolve. As these rings cooled they parted and collected into spheroids which gradually condensed into the planets. Most of them while still gaseous gave off secondary rings which evolved into satellites. In those cases where cooling progressed far enough the masses liquified and at length their surfaces hardened into rock. A modification of the theory suggested that owing to pressure solidification would begin at the center, while on the contrary other students urged that the temperature at the center would be too high for the original gas ever to liquify. Now it will be conceded that there are many features of the solar system which seem to harmonize beautifully with this theory. It is certainly true also that the earth’s interior is hot and that vast quantities of molten rock have been thrust forth from within. And it is also true that most of the oldest known rocks are igneous or derived from igneous rocks. But on the other hand there have developed, especially in recent years, a number of serious objections. (1) Lord Kelvin computed that the density of the nebula when it was expanded forty times beyond the orbit of the earth (Neptune’s orbit has a radius thirty times that of the earth) would be 1/570,000,000 that of common air. It is difficult to understand how such a diffuse body coul'd maintain such an ex- ceedingly high temperature as postulated, and why its substance would not have cooled to solid particles long before these could become aggregated. (2) It has been urged that definite rings might not be formed but that the equatorial matter would separate particle by particle. (3) Mathematical calculations show difficulties in the way of a ring forming into a spheroid so simply as the theory demands. The earth ring would have a cross section of about twenty-five miles and its center of gravity would be at the center of the sun. Such a ring of gas with its exceedingly low gravitative force and with the high temperatures necessary to keep all the earth sub- stances in gaseous form could not hold together by its own SOME FUNDAMENTAL CONCEPTS OF EARTH HISTORY 163 gravitative control the atmospheric constituents, nor the waters of the ocean, nor probably even the much heavier rock sub- stances of the future earth. (4) In any rotating system the momentum of rotation re- mains constant through all changes of state. As the nebula contracted it rotated faster and hence assuming the present momentum of the solar system, the sun should today have an equatorial velocity of 270 miles per second. Its actual velocity is about one and one-third miles per second. There seems to be no agent competent to have caused this enormous retardation. (5) If the mass of the solar system be theoretically converted into a gaseous spheroid as postulated by La Place and be given all its present momentum, by the time the Neptunian ring is ready to be separated the nebula will be found to have less than of the momentum necessary for that separation. In like manner at the Jupiter stage the momentum of the nebula will be only yUg- of the necessary value, at the earth stage TsVo and at the Mercury stage ygVo. Reversing the statement — at the time the Neptunian ring was ready to be formed there would be required for separation a momentum 200 times as great as the actual momentum at that stage. In the Jovian stage the needed momentum would exceed that available by 140 times; in the earth stage by 1800 times ; in the Mercury stage by 1200 times. These figures not only reveal a serious weakness but they show alarming discrepancies among themselves. (6) Directly in line with these facts is the demonstration that if, assuming again the original nebula, the whole mass re- mained together until the rate of its rotation became sufficient to force the separation of a ring, it would not acquire this rota- tion until it had shrunk well within the orbit of the innermost planet. (7) If again we assume the system to have developed to the stage when Jupiter ’s ring was ready to be left behind we can see that Jupiter ’s momentum must be proportioned to that of the nebular material inside his ring as the masses and velocities and radii of the two bodies were proportional. Now the mass of Jupiter and his satellites is about Jifc that of the system ex- clusive of the planets outside his orbit. But computations by Sir George Darwin show that Jupiter and his moons carry 96 per cent of the whole momentum of the solhr nebula at that stage. 164 IOWA ACADEMY OF SCIENCE Vol. XXIV, 1917 Other planets show similar disproportions between masses and momenta, some of them even greater than this one. The planetary system as a whole carries 1/745 of the mass of the en- tire solar system but it contains over 97 per cent of the total momentum. Tidal reaction between the central and outlying bodies might help this difficulty slightly but it is entirely in- adequate to fully meet the case. (8) It would seem that the rings should have a certain symmetry and regularity in masses. But this does not hold good, as has always been recognized. The masses of the planets from outermost to innermost, taking the earth as unity, are 17, 14.6, 94.8, 317.7, 0.1073, 1, 0.82, 0.0476. (9) The rings should have been circular when formed and no great divergence should result during later evolution. Most of the planets satisfy this law fairly well, but the orbits of the planetoids are neither circular nor concentric, but are singularly interlooped. (10) If we consider the evolution of the satellites from their primaries we will see that the former should revolve in the same direction as the rotation of thqunaster spheres, from the very mode of their origin, and that these master spheres should rotate in less time than the revolutions of their respective satellites. But Phobos, the inner satellite of Mars, revolves around that planet more than three times while the planet rotates once, and the little bodies which form the inner border of Saturn’s inner ring revolve in about half the time of Saturn’s rotation. (11) As additional evidence of the same kind may be cited the discovery that Saturn has one moon and Jupiter two wdiich revolve in retrograde direction. The necessity of uniformity of motion under the Laiplacian hypothesis was so patent that it was taught that a single exception would prove fatal to the hypothesis. It must be remembered that La Place propounded his theory at a time when less was known of the heavenly bodies and their mechanics, and also of the laws of gases, than is known now. For many years the theory seemed to fit the observed facts, astronomic, physical and geologic. It would be hard to over- estimate its value to advancing science, substituting as it did something specific and tangible and reasonable for the wild SOME FUNDAMENTAL CONCEPTS OF EARTH HISTORY 165 speculations which had preceded it. Some of the facts of astronomy and physics which recent research has marshalled against the theory have been stated above. It may be added here that the Nebular Hypothesis provided an immense atmosphere during the early stages of the earth’s evolution with gradual diminution until presumably its rarity would allow the total drying up and freezing of the earth. As it has been expressed, “Our recent icy stage was but an October frost; December was yet to come.” But recent studies have shown the presence of glacial epochs almost from the beginnings of known geologic his- tory as written in the stratified rocks. Furthermore, evidences of dry periods far back in the past have come to light and have still further disturbed the regularity of the supposed course of events. Again, the granitic masses which were once supposed to represent the very rock foundations of the earth’s crust have proved to be later intrusions and not the original crust at all. The globe itself seems to be adding its testimony to the insufficiency of the old theory of its origin. Some, years since, while Dr. T. C. Chamberlin was engaged in a study of the glacial deposits of Wisconsin, of which state he was State Geologist, he became interested in an investigation of the causes of glacial periods. This led him gradually back- ward to the broader theme of the origin of the earth and the sufficiency of the Laplacian Hypothesis. After he became presi- dent of the Univeristy of Wisconsin and since he has been head of the department of geology at the University of Chicago he con- tinued his researches, with the cooperation of Dr. F. R. Moulton, the able astronomer and mathematician. The discrepancies which were discovered as a result of their computations and which have been outlined above weakened their faith in the old^r view and after several attempts to patch it up or to use some other existing hypotheses, such as the meteoritic of Lockyer and of Darwin, they found it necessary to set about the more difficult constructive task of formulating a new hypothesis which would avoid the pitfalls that had wrecked the old one and which would fit observed facts and demonstrated laws. Their progressive results were subjected constantly to the most rigorous mathe- matical scrutiny and the completed hypothesis — the Planetesimal Hypothesis — seems to meet the most exacting demands of modern science. A brief outline of this hypothesis must suffice here. 166 IOWA ACADEMY OF SCIENCE Vol. XXIV, 1917 It is postulated that the solar system originated from the slight disruption of an ancestral sun by the distant approach of another star. This resulted in the throwing out of a part of the sun’s mass into two opposite; spirally curved arms — a spiral nebula was formed. Now it seems to he a well established fact that such approaches are not uncommon events, as celestial events go, and are recorded by the flashing out of new stars. It is true, too, that the spiral nebula is the predominant form in the heavens. When it is realized that only T J-g- of the solar system ’s mass is con- tained in the planetary bodies it will be realized how compara- tively insignificant may have been the event which caused the initiation of the system, especially in consideration of the enor- mous volumes of matter which are constantly being shot out from the sun under ordinary conditions and apparently without any external stimulus. Reasoning from the analogy of observed spiral nebulge it is assumed that the matter contained in the two arms was embraced partly in knots or masses of more aggregated matter, between which were immense spaces more sparsely occupied.- As the sun- substance was shot forth it must have expanded enormously and before long much of it passed from the gaseous state through the liquid to the solid, though of course it remained in an extremely finely divided state. The spectra of the spiral nebulae show that they are in this finely divided, chiefly solid condition. Perhaps the larger knots, even in their most expanded and cooled state, had gaseous centers. The smaller knots doubtless were composed of solid particles. The attraction of the passing star had imparted a rotatory motion to the arms of the nebula, hence the whole mass swept around its center of gravity, the knots exerting a secondary pull of their own, the more scattered matter controlled directly by the central parental body. Some of the matter shot out was doubtless drawn back into the sun but the remainder proceeded in its evolution to form the planetary system. The knots served as the nuclei about which revolved a great swarm of matter, most of which was in time gathered into closer relationship to form planets, planetoids or satellites. The knots also acted as har- vesters of the celestial reaping grounds, if I may use the figure, and drew in such of the scattered particles, the planetesimals, which had been revolving directly around the sun, as came SOME FUNDAMENTAL CONCEITS OF EARTH HISTORY 167 within their spheres of attraction and as they were competent to hold. In the case of the larger planets these doubtless included even the lightest gases, such as hydrogen and helium, but the smaller planets such as the * earth could hold only the heavier atmospheric gases, and these only after the temperatures had fallen to those of their present surfaces. The smallest planets, Mercury and Mars, and the planetoids and satellites never were , able to hold atmospheric gases or water vapor. Some smaller knots in the vicinity of the larger ones were within their spheres of control and so became satellite knots. From their smaller gathering power they would always remain relatively small. As a result of the nature of their origin the different knots would nave irregular spacings and masses. Hence their growth would be unequal and in ultimate character they would be different. It seems probable that the largest of the planets, Jupiter, has always been very hot. Indeed he is held by some astronomers to be self-luminous, a miniature sun. In the case of the earth knot the smaller size permitted rapid and probably complete cooling so that the juvenile earth was not very hot, either inside or out- side. Probably the core was never liquified, either from its original condensation or from later accretions of planetesimal matter. Whatever tendency there was in this direction because of friction or compression would be antagonized by the increasing pressure of overlying rock. The atmosphere of the earth is thought to have been derived, first from gases entrapped in the planetesimal matter and later released; second from gaseous matter which had been revolving about the growing earth — “the irreducible gaseous residium of the knot”; and third from matter which came in with iplanetesi- inals or as planetesimals. Its evolution began early and in a minor way is continuing at the present day. The hydrosphere, the water of the earth, was somewhat later in forming. Molecules of water-vapor have a greater velocity than do those of the atmospheric gases and hence would not con- dense into water until after an atmosphere had been well de- veloped. If, as computation shows to be probable, the earth- knot had 30 or 40 per cent of the present mass of the earth, it no doubt held water-vapor from the first, and so the hydrosphere would begin its development early in the planet’s evolution. In 168 IOWA ACADEMY OF SCIENCE Vol. XXIV, 1917 the very nature of things the young earth probably had arid regions and periods as well as humid ones. Probably it was not long after this that volcanic action began on the growing earth. With the continual infall of material there was a parallel tendency to readjustment, reassortment, and con- sequent condensation. This would cause increased pressure and pressure generates heat. The heat at the center moved outward into regions of lower pressure and here the melting points of some substances were reached. The tendency was for these fused masses to ascend and hence in time the surface was reached. In many cases the lava so formed cooled as great masses within the porous outer zone. In other cases it welled quietly out upon the surface, and in yet others, where gases were confined within the molten rock, violently explosive eruptions took place. The climax of vulcanism seems to have been reached during Archean time, at the very beginning of observable geologic history. Since then the processes of weathering, erosion and sedimentation have be- come more and more predominant, although there have been re- peated outbursts of volcanic activity such as those which gave us the trap rocks and granites of New England and the great lava flows of the Columbia river basin. But most of the post- Archean rocks are sedimentary deposit^Tormed by the agency of wind and water. It is probable that radio-activity was a contributing factor in initiating and perpetuating volcanic activity, just as electricity and magnetism were influential in helping on the growth of the earth knot. It was inevitable that there should be irregularities in the surface of the young sphere, both from the infall of planetesimals and from volcanic activity and deformative movements. In the hollows thus formed the hydrosphere first appeared at the sur- face. As more and more water-vapor condensed and the hydro- sphere grew the lakelets increased in size and numbers until the .oceans of today were developed. The material which underlay these water bodies and which fell into them was less subject to weathering processes than the material which formed the land areas and as a result the land masses' came to have a lower specific gravity than the suboceanic masses. This resulted in pro- gressive compression and depression of the ocean basin and cor- responding laying bare and crowding of the land masses. Crump- SOME FUNDAMENTAL CONCEFTS OF EARTH HISTORY 169 ling and distortion were attendant upon these events and the irregularities of the continents were continually aggravated. Lines of weakness developed and here, as we might expect, vol- canic and earthquake activity are in evidence. Conditions favorable for the maintenance of life no doubt ensued long before the earth attained its full growth, but we have no means of knowing when or whence or how or where that life was initiated, except that doubtless it was in the water, and the first forms were plantlike in nature. By the time the first available legible record was made in the oldest exposed sedi- mentary rocks, both animal and plant life were highly developed and widely deployed. A great lapse of time must be represented by this development, a period, it may be, equal to or greater than all subsequent time. By way of summary, then, it may be stated that the Planetesi- mal Hypothesis provides for the beginning of the solar system by a spiral nebula, from the arms of which have developed the planetary bodies, while the central part has become, or remained, the sun. Limiting our attention to the earth we may trace first the growth of the lithosphere, the solid part, by accretions of planetesimals, then the development of the atmosphere, and a little later of the hydrosphere, by release and closer in drawing and capture of their component elements. The oceans have always occupied essentially their present basins and have merely overlapped more or less the continental margins and from time to time have transgressed the interiors of the great land masses. Unlike the Laplacian Hypothesis this one does not demand symmetry and uniformity either in the spacing and masses and motions of the planetary bodies or in the progress of their de- velopment and history, but provides latitude for all observed and probable variations. The occurrence of arid and glacial con- ditions on the earth is thus not only allowable, but is a probable, an almost necessary feature of actual reactions and interactions between lithosphere, hydrosphere and atmosphere. The hy- pothesis seems to meet the necessities of the solar system and so far no critical objections have been advanced against it, although it has been abundantly discussed before the learned societies of the United States. 170 IOWA ACADEMY OF SCIENCE Vol. XXIV, 1917 In concluding* this outline of the progress of thought regard- ing geologic history I am reminded of Tennyson’s beautiful and expressive lines : “There rolls the deep where grew the tree. O earth what changes hasythou seen! There where the long street roars hath been The stillness of the central sea. “The hills are shadows, and they flow From form to form and nothing stands; They melt like mists, the solid lands, Like clouds they shape' themselves and go.” Iowa Geological Survey, Des Moines THE ORIGIN OF THE ST. PETER SANDSTONE. ARTHUR C. TROWBRIDGE. Originally, all sedimentary rocks were thought to he marine. When the St. Peter sandstone was first recognized as a distinct formation, it was assumed to have had a marine origin. More recently, however, the marine origin of many sediments has been doubted, and the criteria for distinguishing various sorts of sedi- mentary rocks have been worked out. As early as 1907 evidences were presented for the eolian origin of the St. Peter sandstone, although there are those who have never accepted the evidence as conclusive. In the literature of the subject, the matter is not settled. In connection with field work in the Driftless Area during the last twelve years, the writer has had opportunity to study the formation in many places and to collect evidence bearing on the problem of its origin. The conclusions arrived at are here re- corded. The characteristics of marine sediments deposited in agitated water and of eolian deposits have been listed.1 Reference to these lists will help to render the present argument clear. The St, Peter sandstone certainly has some of the characteris- tics of eolian deposits. The material is sand of uniform texture and of a size which is commonly transported and deposited by the wind. The formation contains so few fossils that many geologists believe that it contains none. No wind-deposited sand contains abundant fossils. The thickness of the sandstone formation varies greatly within short distances, as is true of all eolian de- posits. There are places where an irregular stratification ap- pears in the sand, which suggests eolian stratification. The shapes of the sand grains, when seen under the compound microscope, are not notably different from the shapes of sand grains taken from existing sand dunes. There are, however, other features of the sandstone and other interpretations of the above-mentioned points, which are in har- mony with the marine rathei tlian with the eolian theory. These points are discussed in separate paragraphs. 1Trowbridge, A. C., Jour. Geol. Vol. XXII. pp. 422-3, 432, 435. 172 IOWA ACADEMY OF SCIENCE Vol. XXIV, 1917 It is difficult to understand how eolian deposits could be dis- tributed continuously over so wide an area as the St. Peter sandstone covers. The formation is known in Minnesota, Wis- consin, Iowa, Illinois, and Missouri at least, and it probably covered originally practically the whole area of these states. Its extension west, south, and east from this area is not known accurately. The eolian theory presupposes that this whole area was a desert during1 the St. Peter epoch and that deposition of sand was so great and so general that the underlying rock sur- face was buried everywhere. Sand could be so distributed by deposition near shore in a shallow sea, provided the shore was migrating toward or away from the land areas of the time. Such seems to have been the history of the St. Croix sandstones which are distributed even more widely than the St. Peter is known to be. There is no known source for such a great amount of eolian sand, so widely distributed. There seems to be no deposit of eolian sand today far from its source. The sands of the At- lantic Coast, of the vicinity of the Great Lakes, of Kansas and Nebraska, of the Great Basin, of the Sahara, can all be traced to a near-by source. Within the area over which the St. Peter is distributed, there is no possible source for the sand. The Prairie du Chien dolomite formation which everywhere under- lies the sandstone could not have furnished the sand. So far as is known, there was no considerable area of Cambrian sand- stone exposed anywhere, at the time the St. Peter was deposited. More likely the sand was prepared by the mature weathering of igneous rocks in the land area of Canada, transported by streams or by waves and currents to its present position, and then deposited in the sea. It is pointed out by the writer elsewhere in this volume, that the St. Peter sandstone lies on the irregular surface of the Prairie du Chien formation. The relief of this surface is more than 200 feet. In it are sharp, steep-walled, narrow valleys 150 feet or more in depth. The surface seems to have been in maturity when the deposition of the sandstone began. Rough topographies, such as this, interfere with sand depositing winds, and it is unlikely that sand could be so laid as to fill up all the valleys, spread over all the divides, and bury all the hills. THE ORIGIN OF THE ST. PETER SANDSTONE 173 On the other hand, sand could and would be so deposited if a sandy sea existed over the surface for a long time. The variation in thickness of eolian sand is due to the ir- regular piling up of the sand into dunes. It is most commonly the surface rather than the base of the deposit which is irregu- lar. Save for a slight structural dip the surface of the St. Peter formation is horizontal. Its variable thickness is due to unequal altitudes of its base rather than of its upper surface. Such variability could be obtained more easily under marine than under eolian conditions. The St. Peter sandstone is conformable with the Platteville limestone above. Between the sandstone and the limestone there is the Glenwood shale. The contacts between sandstone and shale and between shale and limestone are parallel with the general dip of all the strata and there is no evidence of erosion or other break in deposition on either contact. The change from sand to shale and from shale to limestone is nor- mal as a result of a gradually deepening or advancing sea. It is not clear that an eolian deposit could grade conformably up- ward into marine deposits. The Glenwood and Platteville are known to be marine. The stratification of the sandstone, as an evidence of its origin, is inconclusive. Indeed it is doubtful if sand deposited by the wind can ever be certainly distinguished from marine surf deposits by the means of stratification alone, Eolian sand is deposited on the lee slopes of sand dunes and assumes its angles of rest. These, slopes may be oriented in any direction. Similarly sand is dumped over the fronts and sides of deltas, bars, spits, hooks and barriers along irregular coast lines, and takes certain angles of rest. These slopes also are oriented irregularly. The only difference is that in the one case the sand is dry and in the other case it is wet. This difference would give rise to slight differences in the degree of dip in cross bedding. But this dip is influenced by so many other fac- tors, such as the sizes, shapes and specific gravities of the grains, and perhaps by the strength of air or water currents, that the presence or absence of water at the time of deposition might, well be obscured. For the most part the St. Peter sandstone' is massive and devoid of stratification lines. In a few places,, irregular stratification appears, but the writer has not beeir 174 IOWA ACADEMY OF SCIENCE Vol. XXIV, 1917 able so far to determine whether it is due to wind or to waves and littoral currents. The deposit might be either eolian or marine, so far as can be determined from the stratification. Although it is true that the St. Peter sandstone is not highly fossiliferous, it does contain fossils and all of the remains are those of marine animals. Sardeson2 has described thirteen species of pelecypods, seven species of gastropods, three species of cophalopods, three species of brachiopods, one doubtful bryozoan and one porifera. In addition the borings of marine worms have been found in the formation at various places. Most of these forms have been collected from the upper part of the formation, but others occur lower down. Certain it is that they occur in the sandstone itself. Geographically, they have been found at Fountain, and near St. Paul in Minnesota, and near Beloit, Waterloo and Baraboo in Wisconsin. Sardeson ex- plains the relative rarity of fossils in the formation on the ground that most of the shells were dissolved from the porous sandstone by ground water. This, explanation seems to be sat- isfactory. After all, the formation is little if any less fossilif- erous than other well-known sandstones, such as the Jordan. It is doubtful if there are in this country sand grains which owe their shape entirely to wind action. The sand dunes are the result of reworking marine, lacustrine, fluvial or fluvio- glacial sands. It cannot be known then what the shape of a strictly eolian sand grain is. It is possible that the St. Peter sandstone is eolian and yet its grains might have been shaped by a sea and been only slightly modified by the wind. The fact is that the grains of the St. Peter cannot be distinguished from those of the Gambian marine sandstone, under the low objective of the compound microscope. Finally the St. Peter sandstone is so nearly identical, litho- logically, with the marine Cambrian sandstones that it is im- possible to distinguish them, except by stratigraphic position or fossil content. The texture, textural range, and stratification found anywhere in the St. Peter can be duplicated in the Cam- brian sandstones. They seem to have had the same origin. It is believed, therefore, that at least the most of the St. Peter sandstone is marine. A sea probably covered the area now occupied by the formation. It seems to have advanced 2Sardeson F. W., Minn. Acad. Naf’l ; S'ci., Vol. IV, pp. 64-87, 1896.' THE ORIGIN OF THE ST. PETER SANDSTONE 175 slowly, probably from the south. To the north, there was the Laurentian land area, on which igneous rocks were maturely weathered. Quartz, liberated from granitic rocks by the de- composition of associated silicate minerals, was broken to pieces, transported by streams, shaped somewhat, moved about by waves and currents in the sea, and deposited near the shore, as the sea advanced over the land. It is entirely possible that some sand was picked up by the wind from the beaches, trans- ported a little way inland, and later submerged beneath the advancing sea. In this way some eolian deposits may have been incorporated within the formation which is generally marine. Geological Laboratories, State University. THE PRAIRIE DU CHIEN -ST. PETER UNCON- FORMITY IN IOWA. ARTHUR C. TROWBRIDGE. Unconformable relations between the Prairie dn Chien and St. Peter formations have long been known in Minnesota, Wis- consin, Illinois and Missouri. The existence of this unconfor- mity in Iowa, though long suspected, has never been demon- strated, or if it has been known to exist here, the fact has not been recorded. There is nothing in the reports of the State Geological Survey suggesting anything but conformable rela- tions between the two formations. The purpose of this paper is to place on record various evi- dences of unconformity at this stratigraphic horizon within the boundaries of the state. The data here presented have been gathered within the last few years during the progress of field work in that part of the state commonly known as the Drift- less Area. The Prairie du Chien and St. Peter formations outcrop abundantly in the rough topography of Allamakee, Clayton and Dubuque counties, There are hundreds of exposures of each formation in this part of the state. In spite of this fant, the writer does not know of a point where the exact contact between the two formations can be seen. The dolomite is resistant and the overlying sandstone is so non-resistant that it washes down over the contact and obscures it. This doubtless explains why the discovery of the unconformity was so long delayed. How- ever, it is possible to get the altitude of the contact approxi- mately in a great many places. There are several evidences of unconformable relations be- tween the Prairie du Chien and St. Peter formations in Iowa. (1) The contact between the two formations is irregular. The top of the St. Peter and the base of the Prairie du Chien are parallel and dip almost uniformly in a south by southwest direction at an amount of about seventeen feet to the mile. But between these two horizons the interformation contact is found at all stratigraphic positions from just above the base of the Prairie du Chien to just below the top of the St, Peter. The 12 / 178 IOWA ACADEMY OF SCIENCE Vol. XXIV, 1917 surface of the Prairie du Chien formation where cov- ered by the St. Peter has a relief of as much as two hundred feet. The roughness of this surface is illustrated south of Chien and St. Peter one and one-half miles south of Waukon Junction. Waukon Junction where it has a slope of eighty-four feet in fifty yards (figures 15 and 16), in the northwest corner of McGregor where its relief is one hundred nine feet in less than one-half mile, and at the Clayton sand pit, where it changes Fig. 16 — Diagrammatic sketch of the relations between the Prairie du Chien and St. Peter formations seven-eighths of a mile south of Waukon Junction. altitudes by an amount of fifty feet within the pit. The irreg- ularity of this surface is further illustrated by figures 17 and 18, \ PRAIRIE DU CHIEN-ST. PETER UNCONFORMITY IN IOWA 179 (2) The thickness of each of the two formations varies greatly from point to point, but the sum of the thicknesses of the two at given places is practically constant and not far from 300 feet. This is best shown at Pikes Peak and Pictured Rock. 1 j 1 ! 1 1 1 f\ \ 1 \ 1 1 i ■ \ \ I ' i lx ' Ati i \ \ \ 1 1 i I i 1 1 i Y /til) i L n i 1 ! , / S 1 >111 1 1 Pd j J l 1 I L ■ 1 J T s \ } i i i i i i i i i r r i i i i t t i f r i i i i i i > i_Lf Fig. 17— Diagram illustrating the conditions one and one-half, miles south of Church. The Prairie du Chien overlies the Jordan sandstone conformably along the Mississippi river at 632 feet above tide and on the slopes of Pikes Peak the St, Peter-Platteville contact is found. There are three trails leading from one of these contacts past the other, Three parties of students each making a traverse Fig. 18— Cross section of the' valley of Pictured Rock Creek. up one of these trails, with a handlevel, ascertained the thick- ness of the St. Peter and Prairie du Chien formations. All the time they were within shouting distance. The results are shown in the accompanying table. 180 IOWA ACADEMY OF SCIENCE Vol. XXIV, 1917 TABLE SHOWING VARYING THICKNESSES AND THE SUMS OF THE THICKNESSES OF THE PRAIRIE DU CHIEN AND ST. PETER FORMATIONS AT PIKES PEAK AND PICTURED ROCK. Trail. Thickness of Prairie du Chien Thickness of St. Peter, Sum of Thick- nesses of Prairie du Chien and St. Peter. Short trail up nose of peak 177 ft. 123 ft. 300 ft. Long trail by way of falls and 84 ft. 223 ft. 307 ft. spring Middle trail 115 ft. 178 ft. 293 ft. (3) Not only are the sums of the thicknesses of the two formations approximately constant around 300 feet at specific points, but the sum of their average thicknesses is approxi- mately the same. The greatest known thickness of the Prairie du Chien formation is 268 feet and the least known thickness is 80 feet. Corresponding figures for the St. Peter are 238 feet and 50 feet respectively. The average of thirteen known thickness of the Prairie du Chien formation is 167 feet. The average of an equal number of known thicknesses of the St. Peter is 146 feet. The sum of these two averages is 313 feet. (4) In several places, notably in the vicinity of Church, the basal portion. of the St. Peter sandstone contains fragments of chert which came from the Prairie du Chien dolomite. This shows that calcareous materials had been deposited, cementa- tion, dolomitization and silicification had been accomplished, and the dolomite had been exposed and partly disrupted before the deposition of the St. Peter. The four points discussed above seem to demonstrate that the St. Peter formation lies unconformably on the Prairie du Chien. The irregular surface of the Prairie du Chien is due to ero- sive agencies operating after the withdrawal of the Prairie du Chien sea and before the deposition of the St. Peter sandstone. The basal portion of the St, Peter, where the formation is thick, is quite different from the lowermost beds where the sand- stone is thin. That is, there are two phases of the St. Peter in Iowa; namely, a valley phase and an unland phase. The sand- PRAIRIE DU CHIEN-ST. PETER UNCONFORMITY IN IOWA 181 stone which occurs down in the valleys, below the general sur- face of the Prairie du Chien, is soft, friable, highly and va- riously colored. It breaks to pieces in the fingers and can be excavated easily with the chisel-edge hammer. Some of it is massive, but most of it is so bedded as to weather out in small, thin, wavy scales. The upland phase of the formation, on the other hand, is massive, firmly cemented, and gray. These dif- ferences within the formation are due doubtless; to the different conditions which existed in the valleys and on the divides during the early part of the St, Peter stage. This unconformity also explains the discontinuity of the New Richmond member of the Prairie du Chien formation. In Min- nesota the formation is subdivided into the Oneota dolomite at the base, the New Richmond sandstone above that, and the Fig. 19 — Diagram explaining the discontinuity of the New Richmond sandstone in Iowa. Shakopee dolomite at the top. The basis for this division is the New Richmond sandstone separating the two dolomites. It has been a source of worry to some workers in Iowa, because this sandstone, although it occurs at many places, is clearly wanting in the section in other places. The pre-St, Peter ero- sion period resulted in the removal of Shakopee, New Richmond and part of the Oneota, where the main valleys were, so that the St. Peter was deposited here on Oneota and there on Shakopee. The New Richmond is missing where the Prairie du Chien for- mation is thin, and present where the formation is thick. At the Clayton sand pit the New Richmond is thirty-four feet from the top of the formation where it is thickest. Two and one-, half miles west of McGregor the sandstone is fifty feet below the top of the formation. This explanation of the irregular occurrence of the New Richmond is made clear in figure 19. 182 IOWA ACADEMY OF SCIENCE Vol. XXIV, 1917 The magnitude of the Prairie du Chien-St. Peter uncon- formity in Iowa is impressive. It represents a time during which many valleys 150 or more feet in depth were cut in silicified dolomite. If it be assumed that half as much was re- moved over wide areas as was taken from the valleys and that the degradation took place at the average rate of a foot in 6, 000. years, the time involved amounts to almost half a million years. This constitutes one of the two greatest physical breaks in the Paleozoic of Iowa, the other being between the Missis- sippian and Pennsylvanian systems. The unconformity is also important taxonomically. The Cam bro-Ordovieian line should be drawn at the top of the Prairie du Chien where the unconformity is, rather than at the base of the Prairie du Chien where conformability with the Jordan sandstone is demonstrated by the presence of twenty feet or more of transition beds. Geological Laboratories, State University. JgP^i / CERTAIN FEATURES OF RHEOSTAT DESIGN. ABSTRACT. H. L. DODGE. Everyone who has used rheostats of the sliding-contact type has experienced inconvenience in obtaining the desired values of current and voltage. If the rheostat is connected in series with the load, small currents cannot be obtained. If the load is shunted across a portion of the rheostat on the potentiometer principle, part of the winding carries a double load and con- sequently only a fraction of the full current capacity is avail- able. To secure the advantages of both methods of connec- tion there must be a complete rewiring of the circuit. This re- quires time and attention and especially in the case of students affords an opportunity for injury to the rheostat and other ap- paratus. These difficulties have been eliminated in a new de- sign1 in which the line and load terminals are completely dif- ferentiated and properly labeled and the change from series to shunt connection is made by closing a simple knife switch. Figure 20 shows the manner in which this result is accom- plished. If one traces the circuits, he finds that when the switch is open the load is in series with that portion of the winding to the left of the slider. When the switch is closed the load is shunted across that part of the winding to the right of the slider and at the same time the entire winding of the rheostat is connected across the line. With the switch open, values of current up to the full capacity of the rheostat may be secured ; with it closed small values of current and voltage, down to zero, are obtainable. ' The importance of these features is at once apparent but ease of connection and manipulation mean but little if not had in connection with a resistance element so designed that the vol- tage and current ranges overlap for any load, no matter what its resistance. The inadequacy of the ordinary rheostat in this respect is a matter of common experience. For example 1A complete description of the new rheostat and of the various applica- tions of the principles involved may be found in U. S. Patent No. 1,195,- 660, Aug. 22, 1916. 184 IOWA ACADEMY OF SCIENCE Vol. XXIV, 1917 let us assume that there is available a 110-volt source and one wishes to pass a current of 2.5 amperes through a load of 15 ohms resistance. A 12-ampere, 5.2-ohm rheostat of the ordi- nary type certainly has sufficient current capacity,- but if it is connected in series with the load, the smallest current which can he secured is 5 amperes. As it is impossible to shunt the rheostat across the 110-volt source without extreme, overload, the desired amount of current cannot be secured. Let us take a rheostat of the same size, wound with a wire of smaller gauge, so that it may be connected across the line. One with 18 ohms resistance, rated at 6.5 amperes, will serve. The lowest current which can be secured with this instrument in series is 3.3 amperes, which is not low enough; the highest current which can be secured with the shunt or potentiometer connection is 1.5 amperes2 3 which is far too small. Although this particular instrument is able to furnish both large cur- rents and small currents the ranges do not come anywhere near overlapping and there is a large range of current which it can- not supply. Using one of still smaller current capacity, let us say a 3- ampere, 83-ohm rheostat, we find that it can give a current on series connection as low as 1.1 amperes. With shunt connection currents from 0 to 2.3 amperes can be obtained without over- loading the rheostat. With an instrument so wound the desired value of current can be obtained, hut the two ranges now over- lap by a considerable amount and it is evident that a winding of wire somewhat larger than that which will carry 3 amperes could be used. If we try a rheostat wound so as to have a resistance of 30 ohms and a current capacity of 5 amperes, it is found that when the rheostat is in series with the load, currents from 5 amperes down to 2.5 amperes may be obtained, and when it is in shunt relation currents from 0 up to 2.5 amperes can be ob- tained. Thus with this winding the greatest current capacity which is possible with overlapping ranges is secured. 2The rheostats which are compared are of the sliding-contact tube type. The tubes are all of exactly the same size and can dissipate energy at the same rate. 3When the slider is at a point distant 4.5 ohms from the full-resistance end of the winding the remaining 13.5 ohms is carrying its full load of 6.5 amperes. The 4.5 ohms which is shunted with the load carries 5 amperes, while the load receives but 1.5 amperes. I nAAAAAAAAAAAAAn Fig. 22. “Cenco” Dodge design rheostat. V* CERTAIN FEATURES OF RHEOSTAT DESIGN 187 If similar computations are made for tubes of different sizes, loads of different resistances, and for various voltage and cur- rent ranges it is found that for a given voltage and size of tube (watt capacity) there is one and only one winding which will give the maximum current capacity and yet provide, in the case of any load, for overlapping of the series and shunt ranges. With the ordinary rheostat, rated by current capacity and resistance, one has no means of knowing with what voltage it can be used. Nor can one know whether it is capable of giving overlapping ranges. That these important facts have been en- tirely overlooked in the design of laboratory rheostats is due largely to the fact that the prime importance of the voltage as a determining characteristic has been ignored. In fact the laboratory rheostat has been pretty generally looked upon as equivalent to a resistance box of large current capacity. With the new design, voltage and current capacity are made the determining characteristics of a rheostat and the resistance is entirely incidental. If the windings are properly worked out the resulting current capacity is the greatest which can be se- cured with the given voltage and within these maximum limits all values of current and voltage down to zero may be secured, no matter what the load. Thus we find not only that this new type is easy to connect and to operate but also that it pos- sesses the highest possible efficiency. The method of mounting and the principles involved in the proper design of the windings may be applied to any form of resistance element but are particularly suitable to the sliding- contact tubular type. Figures 21 and 22 represent two differ- ent examples of the way in which manufacturers have applied the principles of the new design. Physical Laboratory, The State University. AN INTERESTING CASE OF RESONANCE IN AN ALTERNATING CURRENT CIRCUIT. H. L. DODGE. The phenomena of voltage and current resonance are familiar to all students of alternating currents. The former occurs in series circuits and complete resonance is secured when the con- densive reactance is equal to the inductive reactance. The lat- ter occurs in connection with parallel circuits, the necessary condition being that the sum of all the susceptances, both con- densive and inductive, equals zero. The expression for the impedance of a series circuit is Z = V r2 +(2 fff L - 'Lhlb)2 This becomes a minimum when the condensive reactance, ‘LTfc? .just balances the inductive reactance, 2 K f L. This occurs at a frequency f = 2V "vTA current is equal to E/Z, this is also the condition for maximum current and as the current is in phase with the voltage, the power-factor is unity. If the frequency is less than that determined by the above expression then the reactance of the condenser becomes greater and that of the inductance less. The result is that the current becomes smaller and smaller with decrease in frequency and leads by an increasing angle. If, on the other hand, the fre- quency is increased, the inductive reactance is made more prom- inent and the condensive reactance is reduced. The current be- comes smaller and smaller and lags by an increasing angle. Thus we see that in a series circuit, as the frequency is in- creased the current begins at a small value, increases to a maxi- mum and then returns to a small value again. At the same time the power-factor increases to unity and then decreases. The current leads for the lower frequencies and lags for the higher. Therefore, with a given voltage, as the frequency is increased every value of current or power-factor occurs twice, since each value of current or power-factor that is obtained at a frequency less than that required for resonance occurs again at some higher frequency. 190 IOWA ACADEMY OF SCIENCE Vol. XXIV, 1917 These facts are clearly brought out in figure 23 (c) in which is plotted the curve representing the variation with change of frequency of the admittance1 of the series portion of the cir- cuit represented diagrammatically in the figure. Figure 23 (b), which is a polar diagram, shows the admittance plotted vectori- ally. It shows that at a frequency of thirty cycles the current leads the applied voltage by nearly ninety degrees. As the frequency is increased the phase angle becomes less and the cur- rent greater, the change in both being very pronounced in the neighborhood of the resonance frequency, which is a trifle less than sixty cycles. Just the opposite occurs in a circuit in which the inductance and capacitance are in parallel. The current becomes a mini- mum at resonance, lags for low frequencies and leads for high frequencies. This is brought out in figure 23 (c), and in the polar diagram, figure 23 (a). As it is not practicable to draw a large number of vectors in this and other figures only a few are shown. The end points of a few more are indicated by large dots marked with the corresponding frequency. These are sufficient in number not only to determine the hodograph which is shown as a heavy continuous line but also to enable one to estimate the vector corresponding to any frequency. lrThe admittance of an alternating current circuit is that factor which multiplied hy the applied voltage gives the current. It is therefore pro- portional to the current and equal to the current flowing with unit voltage impressed on the circuit. AN INTERESTING CASE OF RESONANCE 191 One example will show how the positions of the points on such a hodograph are determined. If we assume a voltage of forty volts to be impressed upon the parallel portion (a) of the circuit the coil branch receives a current which can be repre- sented by the vector 0 40, while the condenser branch re- ceives a current 40 40. The total current will be represented by the vector sum of the two, which is the vector O' 40. It is possible to compute the magnitude and phase of the cur- rent for each frequency, as indicated by the lower hodograph and to add to these the corresponding' currents in the con- denser branch giving the upper hodograph as the locus of the ends of the total currents or total current hodograph. As shown by the vector diagram and the curve of figure 23 (e) the total current in such a parallel circuit lags at low frequencies and with increase of frequency decreases in magnitude, passes through a minimum near the frequency corresponding to unity power-factor, and then increases as a leading current. Thus in the case of inductance and capitance in parallel there are two frequencies at which the current has the same value and two frequencies at which the power-factor has the same value. A consideration of the characteristic current curves for series and parallel circuits containing both inductive and condensive reactance led the writer to believe that it might be possible to combine a series and a parallel circuit in such a way as to obtain much more complicated phenomena than those just de- scribed. It was conceived as possible that identical values of current and power-factor might be obtained at more than two frequencies, A little thought at once revealed the inadequacy of any conclusion based on current (admittance) curves like those of figure 23 (c) for they take no account of phase rela- tions. Also it is from the standpoint of impedance that cir- cuits are added in series. Some romgh calculations led to the belief that such a circuit as is represented diagramatically in figure 23 would yield interesting results. The circuit was made up of inductance coils, non-inductive resistances, and telephone condensers. A variable frequency generator was employed and the voltage kept constant at fifty volts. The current curve represented by the heavy line of fig- ure 24 (e) was secured. This curve was something of a dis- appointment but the power-factor curve, figure 24 (d) was more encouraging. Two attempts were then made to adjust the con- 192 IOWA ACADEMY OF SCIENCE Vol. XXIV, 1917 stants of the circuit so as to improve the results but they proved unsuccessful, showing that a careful analysis had to be made before any accurate prediction of the effect of changes in the circuit 'could be made. Some of this work has already been described. Although the current characteristics of the circuits gave the clue to the results to be expected it is, of course, as .impedances that the two circuits must be added. The impedance of the parallel portion (a) and the series portion (b) of the total circuit are plotted in figure. 24 (a) and (b). They are plotted vectorially and when added give figure 24 (a) + (b) which rep- resents the change in the total impedance with variation of frequency. From this figure the broken curves of figure 24 (d) and (e) are computed. If the total impedance hodograph is followed one will see that with increase of frequency (voltage constant) the corre- sponding current must increase slightly from thirty to thirty- five cycles and then decreases until sixty cycles is reached. It will then increase to a maximum at about ninety-five cycles and finally decrease. The power-factor increases rapidly to unity at forty cycles. Between forty and fifty-five cycles it is very nearly unity and the current is lagging. From fifty-five Iowa Academy of Science. Plate X. 1 1 € lead c 9 J -f- C f \ J \ • •• observed current Computed c urr enT 1 1 fretj )uer icy 30 Id) 60 70 00 00 -7.6 x-,37 30 (i) HO SO bO ao io ico no no \ \ l l i i /] -H rr !;f Ay?Az, are those of the in- dex point with reference to the fixed axes, and they have oc- cured by motion of the index point along the curve of location during the time interval (t2— tx). The stroboscopic velocity is, vs — ^ (9x /9t)2 + (0y / d\) 2 + (9z/ dt)2 , (^1) where the values of the partial derivatives may be obtained from (19). For the stationary stroboscopic condition we have, li x + 12 y +. la z m, x'+m2 y'+m3 z'+j==C2 (22) nx x'+ n2 y'+ n3 z'+k=C3, where the C ’s are constants. For the tonoscope and the tonodeik, if the tangent plane of the drum is taken as the stroboscopic screen, the conditions are, 1,=!, 4= 13=0 m2=l, m3=m1=0 (23) n3=l, nx= n2=0 k=0, provided that the plane stroboscopic screen moves in its own plane without rotation and along the y-axis, and that the axis of x' is parallel to the axis of x, the axes of y' and y lie in the THE STROBOSCOPIC EFFECT 229 same straight line, and the curve of location is a straight line parallel to the y' axis. Then, ( vs )x = 9 / 9t (x'+h)=0 ( vs )y =^/9t (y '+]) (24) ( vs )z =d/ 9t (z /+0) =0 By (21) vs ~d /dt (y '+j). With the stationary condition 9y'/9t= -&j/ ^t , (25) which shows that for this condition the index point has a velocity with respect to the moving axes equal and opposite to that of the screen with respect to the fixed axes. Similar treatment holds for the vertical component of strobo- scopic velocity for an elementary image in the movies, although the general equation (21) is applicable to them if the curve of location is suitably chosen. This curve may be considered as confined to the surface of the film, thus reducing the problem to one of two dimensions. The movie audience interprets the motions in three dimensions as they actually occurred in nature, and the curves of location in two dimensions on the film are projections of curves of location in three dimensions. THEORY OF THE STROBOSCOPIC EFFECT BY DIRECT REFLEC- TION OF LIGHT FROM VIBRATING MIRRORS. An examination of the values of D in the equation, D=D0/m, for the distance between simple stroboscopic images in the tono- deik when the stroboscopic effect is 'produced first by manometric flame and then by vibrating mirror, reveals that with a given frequency of vibration the values of D are identical in the two cases. This indicates that the chief determining factor in the effect by vibrating mirror is the intensity difference on a small area of the screen at the two half-period pauses. Intensity maxima occurring during the half-periods should, on the con- trary, have the effect of doubling the frequency, which would make the value of D by vibrating mirror equal to 1/2 D by manometric flame, and this is not in harmony with observed fact. The importance of the half-period pause of a vibrating light pencil of constant intensity is strikingly seen in photographs of oscillating beams where there is relative motion between the plane of vibration of the beam and the plate during the photo- graphing. Some excellent photographs of this character, taken with the aid of the phonodeik, are given in Professor D. C. Mil- ler ’s recent book, ‘ 1 Science of Musical Sounds. ’ ’ PRECONTACT CONDUCTION CURRENTS. L. E. DODD. During some work1 in which capacity measurements were made of plane conducting plates (silver films) in air at very short distances, the writer was able to take some incidental read- ings of small currents that passed between the plates when they apparently lacked several wave lengths of being in contact. Three sets of measurements were taken in one evening. Figure 1 of figure 38 shows the electrometer deflection plotted with the time. The characteristic shape of the curves suggests an ex- ponential relation. This view is supported by the curves of figure 2 of figure 38 which give linear relations expressed by the equation, log D = k2t + b. (i) From (1), D=eb • ek 2t = Do ek 2t • (2) For the current, i = dtQ = C dt V = Cki dtD . (3) where kx is the electrometer constant. From (2) dtD = Do k2 ek 2t . (4) . Substitute (4) in (3), i = kik2CDo ek2t . (5) The potential gradient between the plates is p. g. = k,D/ d, where d is the distance of separation. In the curves of figure 3 of figure 38 the relation between i and p.g. appears to be linear. The straight lines as drawn include fhe origin. Since d was constant, within the reading limits of the apparatus, for the three cases, the x-values are proportional to Y, and thus Ohm’s Law seems to hold consistently. The slopes decrease in the order in which the sets of data were taken, showing that the resistance increases in that order. A factor known to be changing continually in one direction was the room temperature, but temperature readings were not taken at the Physical Review, Vol. V, No. 1, p. 78, Jan., 1915. 232 IOWA ACADEMY OF SCIENCE Vol. XXIV, 1917 time and the temperature variation was relatively small. An- other factor that varied, at least between the first and second sets, was the initial p.g., at which the conduction current began. Still another possible factor was a progressive drying effect due Figure 38 to the slow stream of dried air that was being continually passed through the apparatus, although the effect of drying on the minimum insulating distance appeared to have ceased before the first set of readings of current was taken. PRECONTACT CONDUCTION CURRENTS 233 There are various interpretations of the results. The most obvious is that of metallic conduction, based on the presence of Ohm ’s Law. The changing resistance could hardly be attributed to the variable temperature, as this would call for a negative temperature coefficient of large value. Or the resistance varia- tion might be explained on the ground of variable contact area. But computation of the small areas needed to account for the observed currents shows that they are exceedingly minute. For a single approach of the plates an extremely small contact area might be obtained, but to be able to get so nearly the same re- sults three times in succession, with the relatively crude means of adjustment, so as to give contact areas varying from 6.02x 10"12 cms. 2 to 3.62x10 *12 cms. 2, is difficult of belief. Expressed in terms of the diameter of a circular contact area the range would be from 1/20 to 1/25 wave length, sodium light. The dis- tance was constant to within 0.25 wave length, while the diam- eter of the contact area, supposed circular, varies within 1/100 wave length. The presence of Ohm’s Law, while being a necessary condi- tion of metallic conduction, is not a sufficient condition. It might be expected to hold if the conductors were bridges of for- eign matter of high resistance, such as dust particles between the plates, or if the conduction was due to ionisation currents of values considerably below saturation, or again if the conduc- tion was electrolytic in nature, as suggested by Prof. G. W. Stew- art, without polarization. It did not appear difficult to clear the film surfaces of dust particles of any appreciable size. Also there was no known constant source of ionisation as is the case with the ordinary ionisation current curve. The question arises whether there could be ionisation by collision at atmospheric pressure and ordinary room temperature under relatively low potential gradients when the thickness of a given volume of gas is very small compared with its other dimensions. In the present case, if the depth of the volume between the films is represented by 1 mm., the length and breadth of the same volume would be represented by about 1% m. The currents may conceiv- ably be due to a coalition of surface films of moisture, gases, etc. There is also a possible application of the theory of electron at- mospheres as advanced by Prof. R. W. Wood2, but according to Philosophical Magazine, p. 316, Aug., 1912. 234 IOWA ACADEMY OP SCIENCE Vol. XXIV, 1917 experimental results by Dr. F. C. Brown3, and the writer (loc. cit.) such atmospheres of any appreciable depth must have very low density values. At present the writer favors the view that the conduction currents are due to ions of some kind between the plates. TABLE ii. Curve D. Curve E. Curve C. t (mins.) D t D t . D 0.00 40 0.0 72 0.0 76.5 0.25 36 0.5 63 0.5 68 0.50 33 1.0 56 1.0 61 0.75 30.5 1.5 49 1.5 55 1.00 28 2.0 43 2.0 49 1.25 25.5 2.5 38 2.5 44.5 1.50 24.5 3.0 40 1.75 23 3.5 36.5 2.00 21.5 Department of Physics, The State University. 3Physical Review, Vol. II, No. 4, p. 314, Oct., 1913. EFFECT OF DRAWING ON THE DENSITY AND SPE- CIFIC RESISTANCE OF TUNGSTEN. WM. SCHRIEVER. It is known that the density of ductile tungsten wire changes when the wire is drawn to smaller diameters but the results of several experiments do not agree as to the nature of the varia- tion. Fink (Trans. Amer. Electro. Chem. Soc., 17, p. 229, 1910) gives data to show that the density increases with the drawing, the variation being 18.81 g/cm3 before drawing to 20.19 g/cm3 when drawn to a diameter of 0.038 mm. His method of meas- urement was not described. Doctor Sieg, in working with a number of tungsten wires, also found an increase of density with the drawing. In a letter to Doctor Sieg, Doctor Worthing of the Nela Research Laboratory, National Lamp Works of the General Electric Company, gave Doctor Lorenz’s results on the variation of density with drawing. Doctor Lorenz used pyk- nometer and other ordinary specific gravity methods and found that the density decreases as tungsten is drawn finer and finer. His results are given in the following table : The following experiments were undertaken to determine whether the density increases or decreases as ductile tungsten is drawn to smaller diameters and also what effect this has on the specific resistance. It is known to those who have worked with tungsten that the physical properties vary if the heat-treatment is varied or if the mechanical working previous to drawing is varied. Since the material is heated during the process of drawing and since this heating cannot be maintained exactly the same we would expect the wires drawn at different times to have slightly different prop- erties. It is also impossible to swage two pieces of the metal in exactly the same manner previous to drawing and therefore wires made from different pieces of tungsten cannot be expected to behave in any regular manner. In order to eliminate, as far as possible, variations which might arise from these causes two Diameter of Wire. 50 mils (swaged) 20 mils (drawn) 10 mils (drawn) 5 mils (drawn) Density, g/cm3. 19.1 18.8 18.5 17.9 23(5 IOWA ACADEMY OF SCIENCE Vol. XXIV, 1917 sets of five wires each were used, each set being drawn from a single block of tungsten. The diameters were measured by means of a micrometer- microscope which was first thoroughly cleaned and oiled. The micrometer-screw was tested for uniformity of pitch by measur- ing the distance between two fine parallel ^cratches on a pol- ished brass plate along a scratch perpendicular to them. Fif- teen measurements were made with each quarter of the screw and -the following results were obtained: Part of Screw Used Distance in Revolu- tions of Screw Left end quarter 8.864 Left center quarter 8.832 Right center quarter 8.836 Right end quarter 8.817 Probable Error 0.0050 .0050 .0043 .0041 The two outside quarters are undoubtedly more uniform than the data indicate since it was impossible to line up the cross- hairs accurately for the outside readings, owing to a slight blur- ring at the edge of the field of view. The center half of the screw only was used in measuring the diameters of the wires and this part is uniform far within the probable error of the measurements. The micrometer screw was then calibrated by measuring, us- ing the central part of the screw, six separate millimeter divi- sions of a standard meter, the different divisions being chosen at various places along the bar. Five measurements were made of each division and from these data the length of each division together with the probable error of a measurement was calcu- lated. The greatest probable error of a single measurement of any one of the six divisions was 0.0197 revolution of the microm- eter screw. The mean of the six separate sets of measurements was 21.510 revolutions per millimeter. Since thirty observations were taken the probable error of the mean is 0.0036 revolution. The wire whose diameter was to be found was held stretched between two round brass clamps, with triangular heads, mounted so that they could be rotated about their geometric axes, which were also the geometric axis of the wire. Two readings of the diameter at a given point were taken with the micrometer-micro- scope. The wire was then rotated through sixty degrees by means of the triangular heads of the clamps and two more read- ings were taken at the same point. After rotation through an- other sixty degrees two more readings of the diameter were made RESISTANCE OF TUNGSTEN 231 making six determinations for the given point. Six such sets of six readings each were made along the wire, one set for each of six different points. The mean of these observations was found and the probable error of the mean calculated. This process was repeated for each of the ten wires. Rotation of the wire is necessary since the cross section of a wire is seldom, if ever, a circle. The relatively large values of the probable er- rors of the diameter measurements are due to this same fact. The specific resistance of the wires was next determined. Each end of a wire was held in a clamp made of a piece of one-quarter inch brass rod which could be fastened to the terminals of the Wheatstone’s Bridge or Kelvin Double Bridge as the case might be. The use of the clamps made it possible to measure the re- sistance of the same length of wire by both methods. Also the length of the wire was determined by measuring the distance between the faces of the damps, when the wire was held stretched, by means of a pair of dividers and a steel scale. Each length used in the calculations is the mean of three measure- ments. The resistances as found by the Kelvin Double Bridge, wTith one exception, were used in the computations, since this; method gives a gyeater accuracy. The percentage probable er- rors of the resistance and length measurements are far less than those of the radii and were therefore neglected in computing the probable errors of the specific resistances. The results are given in table 1. TABLE 1. SET 1. No. of wire Length cm. Radius cm. x 103 Resistance Specific Resistance ohms/cm3 x 10® Wheatstone | Kelvin A 19.10 2.396±0.003 6.507 6.142±0.019 B 32.16 7.836± .007 1.018 L018 6.106± .0111 C — _ 29.21 12.61 ± .015 0.3480 0.3474 5.940± .013; D _ __ 33.81 17.61 ± .018 0.2043 0.2046 5.894± .012: E 37.55 22.70 ± .025 0.1342 0.1339 5.763± .013; SET 2. A' _ , 31.86 5.086±0.006 2.381 2.404 6.128±0.014- B' 33.84 10.33 ± .015 0.5980 0.6051 5.990± .017 C' 34.31 15.03 ± .009 0.2872 0.2867 5.930± .007 D' 39.32 21.90 ± .075 0.1550 0.1546 5.909± .041 E' 37.27 25.84 ± .023 0.1050 0.1050 5.900± .011 238 IOWA ACADEMY OF SCIENCE Vol. XXIV, 1917 If the radii are plotted as abscissas and the specific resistances as ordinates the curves in figure '39 result. (The radii of the circles equal the probable errors of the respective specific re- sistances.) From the curves it is evident that the two sets of wires do not vary in the same manner. The curve for Set 2 seems to approach some limiting value of the specific resistance. This is what we would expect if the change due to drawing is a surface effect but the number of wires in a set is too small to draw any definite conclusions. In general, however, the specific resistance increases as the radius decreases, both sets agreeing in this respect. 2 6 10 14 18 22 26 Radius times lO^cm. Figure 39 In each of the density determinations a known length of the wire was necessary in order that its volume might be calculated. The wire was held taut between two clamps and the distance between the faces of the clamps was determined as stated before. The wire was then cut off as near the faces as possible with a pair of diagonal cutters and the length of the ^tub-ends was measured with the micrometer-microscope. The length used in the computation was the measured length minus the length of the stub-ends. The mass of this known length of wire was then determined on a chemical balance which had a sensibility of about four scale divisions per milligram, weighings being made on each pan so as to have a check on the results. The zero of the balance and the sensibility were determined for each weighing for each wire. The percentage probable errors of the masses and RESISTANCE OF TUNGSTEN 239 lengths are much less than those of the radii and were therefore neglected in calculating the probable error of the density. The results are shown in Table 2. TABLE 2. SET 1. No. of Wire Length cm. Radium cm. x 103 Masses in Grams Density Grams/ cm3 Left Plan Right Pan Mass Used A 19.24 2.396±0.003 0.007012 0.007012 0.007012 20.26 ±0.06 B 34.65 7.836± .007 .12922 .12925 .12923 19.345± .034 C 29.90 12.61 ± .015 .29057 .29063 .2906 19.477± .044 D 34.89 17.61 ± .018 .64655 .64655 .6465 19.025± .039 E 38.65 22.70 ± .025 1.19529 1.1953 1.1952 19.126± .042 SET 2. A' 35.26 5.086±0.006 0.05575 0.05575 0.05575 19.47 ±0.045 B' 32.27 10.33 ± .015 .20848 .20844 .2084 19.278± .056 C' 34.59 15.03 ± .009' .46855 .46853 .4685 19.091± .022 D' 40.40 21.90 ± .075 1.15222 1.15220 1.1522 ‘ 18.96 ± .13 E' 38.62 25.84 ± .023 1.54572 1.54571 1.5457 19.106± .034 If the radii are plotted as abscissas and the densities as ordi- nates the curves in figure 40 are obtained. (Here too the radii of the circles represent the probable errors of the respective; densities. ) Both curves indicate that the density reaches a minimum when the radius is about 0.02 cm. The points for the curve of set 1 are scattered while those of set 2 fall closely along; the curve. In working with the same set of wires, Doctor Sieg finds that the rigidity increases as the radius decreases ; that the wires of set 1 are more irregular in their behavior than those of the other set, and that the relative positions of the radius- rigidity curves are the same as those of the radius-density curves as well as being of the same general shape. This is what we. would expect. 240 IOWA ACADEMY OF SCIENCE Vol. XXIV, 1917 It is thus seen that the specific resistance increases as the density due to drawing increases, P. W. Bridgman1 finds that the resistance of tungsten decreases as the density due to hydro- Radius tin.es 10^ Co.. Figure 40 static pressure increases. This also indicates that the drawing has some sort of a surface effect and not a volume effect as is the case in Doctor Bridgman’s work. Physical Laboratory, The State University. hFrom lecture given at the State University of Iowa on April 18, 1917 THE EFFECT OF HYDROGEN-SULPHIDE ON THE UNI- LATERAL CONDUCTIVITY OF ZINCITE- COPPER CONTACTS. R. B. DODSON. Of the many experiments concerned with the unilateral con- ductivity of the so-called crystal rectifiers very few have had to do with the effect of gases. The experiments described in this paper show that an artificial rectifier can be produced through the action of hydrogen-sulphide upon zincite-copper contacts. Such contacts show little or no unilateral conductivity in vacuo but possess the property to a considerable degree in an atmosphere of hydrogen-sulphide. In air the behavior of such contacts is extremely erratic. The greater current is as likely to pass from zincite to copper as from copper to zincite. Often there is no difference between the two currents. Sometimes the greater purrent may flow from copper to zincite for a few days and at the end of a week the greater current may pass from zincite to copper. The zincite and copper were placed in a glass tube with suit- able electrical connections and the tube evacuated with a Gaede mercury pump to as low a pressure as could be obtained with- out freezing mixtures. A piece was then broken off the zincite and the end knocked off the copper point. The two freshly made surfaces were then brought together and a direct electro- motive force impressed on the contact for fifteen or twenty min- utes in one direction and then in the other. Readings were taken at the end of every minute and curves plotted from the points so obtained. In order to economize space the curves are plotted with the same origin instead of consecutively with respect to the time. Curves No. 1, figure 41, show the flow of current shortly after the two substances were brought into contact in air. It will be noted that the greater current flows from copper to zincite. After a few days the amount of rectification began to fall off and at the end of three days the situation was as shown in No. 2. Curves No. 3 show the same contact at the end of a week. There is now 16 242 IOWA ACADEMY OF SCIENCE Vol. XXIV, 1917 about one milliampere difference between the two currents with the slightly greater current flowing from zincite to copper. Curves No. 4 show the behavior of the same contact when rever- sals of the electromotive force are made at the end of every minute. The general effect of the quick reversals is to lessen the difference between the two currents. Curves No. 5, figure 42, show a zincite-copper contact in vacuo. In this particular case there is a difference of about two mil- liamperes between the two currents with the greater current flow- ^5 no. MilllQ 1 t^peres In Air 50 .no.; > 63 V "\y — •ZnO 45 [\ A ~Z.nO- •Cu \ \ 40 V./ V f Cu-: — X 58 O-Cu 35 1 4 6 a •\.y aa aM»N 4 6 8 lO ia NO 3 NO .1 b 90 $5 ■' \ / — - — TnZR Ctr-2-N u 0 $5 ZJSfO- Cu — J * \ cu-z NO Z. 4 6 S to 12 Z 4 § s_ 10 tz Figure 41 ing from zincite to copper. Usually the difference between the two currents was less than a. milliampere in vacuo. Immediately after letting in the hydrogen-sulphide there was an increase in the apparent resistance of the contact, causing the current to fall from seventy-four milliamperes, zincite to copper, to sixty-nine milliamperes, zincite to copper. This effect is characteristic of hydrogen-sulphide and never failed to appear whenever the gas was let into the vacuum tube. Curves No. 6 show the action of the contact shortly after letting in the hydro- gen-sulphide. The difference between the two currents is now about five milliamperes with the greater current from zincite- EFFECT OF HYDROGEN — SULPHIDE ON COPPER 243 to copper. The observations for curves No. 7 were taken two days after the previous curves. The difference is now about seven milliamperes. The observations for No. 8 were taken about ten days after No. 6 and show a difference of about seven mil- liamperes. These curves are typical of the behavior of zincite-copper con- tacts. Of the several contacts studied none departed from the results shown here to any extent. The behavior of zincite-copper contacts in vacuo and in hydrogen-sulphide has a bearing on the theories of rectifier ac- 75 NOv In Vacu 0 NO 6 In Hj S 73 1 "I'zz*' V ZnO- C u 63 / ..ZnO ■Cu 71 ^ — \ — — Co-Zn O 67 \ \ 4 IN R & JO 12. \ 1 3 2 7~' c 0 i-Zn 0 u 7ft t ^ o Z r ZnO -Cu_ 2 fi NO 8 X yd -N.. In h2s O-Cu 74 — • — ' 74 / 7? 72 \ 70 \ Cu-2 1 NO 70 ' - . \ a 2 S 7 9 i2_ 2- s 7 _^Ct7 2 ‘ZfTO 11 Figure 42 tion. It is direct evidence that unilateral conductivity is entirely a surface phenomenon so far as the so-called crystal rectifiers are concerned. There is considerable indirect evidence favoring a surface film theory of rectifier action. Unilateral conductivity is certainly not a volume effect for small thin pieces of crystal possess the property to as high a degree as large thick pieces. Again almost the entire resistance of the contact is concentrated at the sur- faces as is shown by the fall of potential across the contact. The fact that uot all points on a given crystal surface possess the 244 IOWA ACADEMY OF SCIENCE Vol. XXIV, 1917 property of unilateral conductivity to the same degree is also significant. Mr. Goddard1 working with Tellurium- Aluminum contacts in vacuo, and in oxygen and air finds that such contacts possess unilateral conductivity in air and oxygen but not in vacuo. Mr. Goddard’s work and the behavior of zincite-copper contacts in vacuo and in hydrogen-sulphide constitute direct evidence that unilateral conductivity is a surface effect and that surface films of some sort are the seat of the action. It is possible that there are other gases capable of producing the same effect under proper conditions; some of the halogens for instance. However, no such compounds possessing rectifying properties, have been found in nature. Department of Physics, The State University. Physical Review, Vol. 34, p. 449. BIRD RECORDS DURING THE PAST WINTER, 1916 - 1917, IN NORTHWESTERN IOWA. T. C. STEPHENS. The winter of 1916-1917 has shown a number of uncommon things concerning the avifauna of the region under considera- tion, of which Sioux City is the central station. The notes will be presented in the form of an annotated list of the birds found, but account will not be taken of a number of late migrating species which were seen within the limits of time hereinafter adopted, such, for example, as the Pipit, and others. Winter visitors and summer stragglers only will be listed. Some writers regard November, December, January and Feb- ruary as the winter months, and confine their winter records to such a period. However, there is very good ground for open- ing the books of the ornithological winter with the first arrival of. the winter visitors from the north, and continuing this sea- son until the same birds finally depart in the spring. Then our season will be based, not so much upon the calendar, as upon the actual movement of the birds whose habits we may wish to study. Upon such a basis our records may include October and March, and thus cover fully half of the year. The following account will cover this period. Little need be said about the topography of the region. The Missouri valley is an important highway of migration for the birds of passage. Whether it serves in such a way for the movement of our winter visitors, probably has not been determined. The Missouri valley is bor- dered on both sides by rather high “ bluffs,” which are cut at frequent intervals by ravines and gullies. These sheltered de- pressions are usually more or less wooded, and furnish cover and food for many of the winter birds. In some localities also on the river bottoms there are patches of rather heavy timber, which are identical with the ravine woodland insofar as they form a bird habitat. The open fields and prairies also form a habitat for certain winter species. There seems to be little difference in the distri- bution of the winter birds in the uplands and lowlands. 246 IOWA ACADEMY OF SCIENCE Vol. XXIV, 1917 The terms woodland and prairie may be used here to desig- nate these two general winter habitats. The prairie habitat might very properly be subdivided to distinguish the habitat of. the Horned Lark, which requires no shelter, from that of the Tree Sparrow, Junco, etc., which do require some low cover. So we may distinguish the Field, or Meadow, habitat, and the Fence row, or Weed thicket. • Some of the woodland birds seem to be confined to the dense woods because of their shy and timid natures, while others are not so limited by temperament, and will be found among trees more sparsely located. There may be some slight distinction here in habitat grouping, but I suspect that the chief factor would be a temperamental one, and will not attempt to carry it out. The following listing shows the usual winter habitat of the birds of cur list : In the Woodland: Chickadee, Downy Woodpecker, Hairy Woodpecker, Cardinal, White-breasted Nuthatch, Red-breasted Nuthatch, Flicker, Brown Creeper, Bluejay, Golden-crowned Kinglet, the Crossbills, the Waxwings. In the Fence rows and Weed Thickets: Tree Sparrow, Slate- colored Junco, Song Sparrow, Pine Siskin, Redpoll, Goldfinch. In the open Field : Prairie Horned Lark, Short-eared Owl. The particularly uncommon occurrences for the Sioux City territory might be summarized as follows: the flight of Gos- hawks, the fall abundance of Red-breasted Nuthatches, and the great flocks of Redpolls. In addition the winter records of the Golden-crowned Kinglet, Towhee, Carolina Wren, Red Cross- bills and large numbers of Cedar Waxwings, are noteworthy. That the occurrence of certain species in large numbers was not purely a local matter is indicated in the following notes communicated by Prof. M. H. Swenk, of the University of Ne- braska, at Lincoln: ‘‘The flight of Goshawks reached all over Nebraska (I have over a dozen records) as well as parts of Kansas, Missouri, Iowa and South Dakota. About New Year’s Redpolls were more numerous about Lincoln than I have ever seen them before — literally thousands of them in flocks on New Year’s day. Red-breasted Nuthatches also have been unusually numerous and we have more records for this winter than for all years previously. Crossbills and Pine Siskins have been un- BIRD RECORDS DURING THE PAST WINTER 247 commonly numerous and the latter bird has been breeding com- monly about Lincoln during the past few weeks. Several nests have been found, two with full sets of eggs. The Golden- crowned Kinglet has been wintering with us this year. No Evening Grosbeaks or Pine Grosbeaks have been noted, but the Bohemian Waxwing has been seen.” It may be well also to note the absence of certain species. The Snowy Owl, for instance, in former years was received by Mr. Anderson for mounting in considerable numbers. This winter he did not receive any. Snowflakes and Longspurs have never been recorded here. Evening Grosbeaks have been reported here in some winters cn good authority, but not during 1916- 1917. The Northern Shrike was not seen, and it seldom is found in this locality. So far as I know the Bob-white was not seen here during this winter, though it probably did winter with us. The absence of records, however, tells its own story. Purple Pinches have never been recorded here. No Magpie records were obtained in this season. For eight years without intermission a Christmas Day bird census has been taken in this locality, and the results have been published in Bird-Lore. All of these reports have been made by Walter W. Bennett, although companions have been with him usually. A tabulation of these reports covering eight winter seasons is of interest and is here given. The totals in the right hand column give a very fair idea of the relative abundance of the different species, while the regularity of occurrence may be judged by the frequency of enumeration in the vertical col- umns. The number of Tree Sparrows noted in 1909 and 1910 is probably somewhat exaggerated, though there can be little doubt that this species properly heads the list at this season. 248 IOWA ACADEMY OF SCIENCE Vol. XXIV, 1917 THE BIRD-LORE CENSUS. 10th 1909 llth 1910 12th 1911 13th 1912 14th 1913 15th 1914 16th 1915 17th 1916 *3 o H 1. Tree Sparrow _ _ 200 400 30 30 30 15 30 150 885 2. Crow 13 100 15 50 40 5 15 0 238 3. Chickadee 19 30 12 25 10 6 18 25 145 4. Slate-colored Jimon . 7 15 O' 25 2 10 16 60 135 5. White-breasted Nuthatch, 1 5 5 3 4 4 10 9 41 6. Downy Woodpecker. 0 10 2 4 5 2 12 1 36 7. Pine Siskin 4 27 31 8. Brown Creeper 2 8 5 2 2 1 3 2 25 9 Prairie Horned Lark 5 8' 2 7 1 23 10. Hairy Woodppcker 3 1 ~~6~ 2 1 3 20 11. Redpoll 6 12 18 12. Goldfinch 1 2 12 15 13. Prairie. Chicken 12 12 14. Flicker 6 2 2 10 15. Blue jay 2 3 ~~2~ 3 10 16. Cardinal 2 6 8 17. Red-tailed Hawk 2 T 1 4 18. Bluebird 4 4 19. Magpie _ 2 2 20. Screech Owl 1 1 2 21. Northern Shrike 1 1 22. Great Horned Owl 1 1 23. Snowy Owl 1 1 24. Winter Wren 1 1 25. Goshawk 1 1 26. Golden-crowned Kinglet 1 1 No attempt will be made to relate the bird life of the past winter to any set of weather conditions. While snch a relation- ship no doubt existed, one would need to have access to very complete and detailed weather records, and the problem would then consume a great amount of time. In a general way, how- ever, it may be recalled that the winter was a long and continu- * ous one, with very few warm spells. Late in December there was a slight thaw which melted the snow, only to be frozen again into a solid sheet of ice which then remained on the ground for at least a couple of months. It may be interesting to note that the northern Indians early in the winter predicted a mild season, and later on some of the South Dakota farmers joined in this prophecy on the basis of seeing musk rats migrat- ing from one pond to another in the winter. There follows a list of the birds found during the past winter with some field observations. BIRD RECORDS DURING THE PAST WINTER 2i$ 1. Goshawk. Astur a . atricapillus. One of the most note- worthy occurrences in the winter bird life was the flight of Gos- hawks. Nearly all of the records mentioned here were obtained through Mr. A. J. Anderson, taxidermist, who receives speci- mens from a considerable radius of territory. In all of his pre- vious experience, covering nearly twenty years, Mr. Anderson received only two specimens of the Goshawk, both in 1907, and one from Woodbury county, the other from an unknown source. Following are the data of the specimens reported to me by Mr. Anderson for the winter of 1916-1917 : (a) A male which had been shot by a farmer near Badger Lake (Monona county), on October 4, because it had been “rob- bing the chicken yard” for some time. Now in the Anderson collection. (b) October 8. Field record. A. J. Anderson saw an adult about a mile above the Stony Point on the Big Sioux. (c) October 15. A female, locality unknown, but believed to have come from Ponco, Nebraska. Mounted for a customer. (d) October 16. Field record. Mr. Anderson saw a Gos- hawk on this date near the mouth of the Big Sioux river, on the Iowa side. (e) October 27. A male killed near Conway’s at Riverside Park, Woodbury county. Mounted and retained in the Ander- son collection. (f) October 29. A male from Le Mars, Plymouth county. Length 21.75 inches. This seems to be an immature bird, show- ing two or three cordate markings on the thighs. There is also some rufous color in the dorsal plumage. Mounted for 0. W. Remer, of Le Mars. (g) November 17. An immature specimen sent to Mr. An- derson from Freeborn, Minnesota. Length 22 inches. Sex not distinguishable. Much brown in dorsal plumage. Tarsi dull yellow-green, yellow predominating. Iris is vermillion, but when the eyeball is fully distended the apparent shade is more nearly a carmine. All five of the collected specimens have a fairly distinct broad white line over the eye, and a more or less irregular white patch on the nape. The general shade of color on the back was about the same in all adults, viz., plumbeus, tending to bluish, without any blackish. Each specimen was carefully compared with the 250 IOWA ACADEMY OF SCIENCE Vol. XXIV, 1917 description in Ridgway’s Manual, and other authorities, and we concluded that none of them could properly be referred to the subspecies striatulus. 2. Red-tailed Hawk. Buteo b. borealis. This large hawk was seen in Stone Park by different observers on December 25 and 26. I believe it often remains in this locality throughout the winter. 3. Golden Eagle. Aquila chrysaetos. Six specimens of this eagle were received by Mr. Anderson for mounting, as follows: (a) October 22, 1916. One from Naeora, Nebraska. (b) October 29, 1916. One from Waukee, Iowa. (c) November 10, 1916. One from an unknown point in South Dakota. (d) December 2, 1916. A male from Chamberlain, South Dakota. (e) December 6, 1916. One from Orchard, Nebraska. (f) December 15, 1916. A female killed at Norman (or Gor- man), Nebraska. 4. Short-eared Owl. Asio flammeus. One was noted in the South Ravine on January 28, 1917 (Eiffert) and a pair were seen in the same locality on February 24 by several observers. 5. Screech Owl. Otus a. asio. A common winter resident. This winter it occupied an artificial nesting box on the premises of Mr. and Mrs. E. C. Currier, and was frequently observed by members of the Bird Club. W. R. Griffith also saw another specimen in Peter ’s Park on December 29. 6. Hairy Woodpecker. Drijobates v. villosus. Not as nu- merous as the Downy, but is regularly found in certain localities. It is usually very wary, and not so easy to see for that reason. Specimens have not been taken, and the status of leucowielas is uncertain. 7. Downy Woodpecker. Dryobates pubescens medianus- This is one of the most generally distributed woodland birds of the winter season, and seems to be able to withstand the severest weather. Present this winter in about the usual number. 8. Northern Flicker. Colaptes aural us luteus. This is not a common winter species. Three were seen on January 7, in different localities (Mir. Allen, Mrs. Bailey). It was seen on three other dates in January by other observers. On February BIRD RECORDS DURING THE PAST WINTER 251 13 Mr. A. J. Anderson saw four Flickers in the possession of a . squatter, who had shot them along the Missouri river. 9. Prairie Horned Lark. Otocoris alpestris praticola. Noted on December 25 by Arthur R. Abel, who found a flock of ten. The same observer saw these birds frequently during January and February. 10. Bluejay. Cyanocitta cristata. This bird was heard al- most daily throughout the winter in Morningside. However, it is only an occasional straggler that remains over the winter. 11. Crow. Corvus brachyrhynchos. The Crow is very abun- dant at all seasons. Its winter roosts in this vicinity have not been located. They begin to fly in certain lines early in March, and are then seen in large flocks ; by the first of May the flocks have almost completely broken, no doubt because of domestic duties. 12. Red Crossbill. Loxia curvirostra minor. Early in No- vember, 1916, a flock of fifteen to twenty were seen in a pine tree in Morningside. They were again seen on the 28th in about the same number. Throughout December the birds were occasionally seen, but the flock had scattered. A single in- dividual was seen on January 20, which was the last record. They probably left the vicinity after consuming the limited sup- ply of pine seeds. 13. Redpoll. Acanthis l. linaria. This is one of the. erratic species, wdiose movements must form an interesting problem. In the winter of 1910-1911 the Redpolls were noted in this locality by several observers, and there may have been a fairly general visitation by them at that time. On January 10, 1915, Mr. W. J. Hayward reported a flock of eight at Crystal Lake. Aside from this record the writer has no knowledge of this species oc- curring in our region since 1910 until 1916. The first record of this winter was a single male noted at McCook Lake by Mr. A. F. Allen on October 29. On November 5 Mr. G. O. Ludcke saw a flock of about twenty near Crystal Lake. Two males were seen by Edwin Hickman on December 21. Mr. Wier R. Mills wrote me of seeing a flock of about twenty Redpolls in the town of Pierson, Woodbury county, and that they were seen intermittently for some time afterward. During January they became much more numerous, and were seen oftener and by more observers. The same condition pre- ■252 IOWA ACADEMY OF SCIENCE Vol. XXIV, 1917 vailed throughout February, but, as before, they were seen in small flocks containing eight to twenty, and occasionally thirty- to forty. The writer was later satisfied of the identity of several large flocks of about fifty individuals which flew over, giving their, then unfamiliar, call notes. During March, how- ever, they began to appear in larger flocks. On March 4 Mr. Paul Eiffert reported a flock of about a hundred Redpolls in the South Ravine. On the same date Mr. G. O. Ludcke saw large numbers of Redpolls in the fields near Logan Park ceme- tery, and estimated the number to be between four and five hundred. He noted his observations as follows: “Never have I seen so many birds together at one time. A five-acre corn field was alive with them. I made considerable noise just to see them take wing, but they seemed loath to leave this particular field. When I would shout or whistle they would appear confused and fly all around me.” Mrs. H. M. Bailey saw “hundreds” of Redpolls in Grand- view Park on March 10. On the same day another observer reported a “flock of two thousand flying north.” On March 23 Mrs. H. J. Taylor reported a flock of about five hundred near Leeds. And on March 25 Mrs. Bailey saw a flock of about one hundred go to roost in a large patch of wild sunflower in Grandview Park. This seems to be the latest record of them in this vicinity. Some facts were obtained on the winter food of the Redpoll in this region. In various localities here we find large patches of the wild sunflower (Helianthns annuus L.), most often on the open hillside and along the fences. The Redpolls frequented these patches, probably for the seeds in the heads, as they al- ways alighted and remained in the tops of these tall weeds. In fact, Mrs. Bailey states that she saw them picking the seeds out the heads, just as do the Goldfinches and Pine Siskins. On March 4 I saw several Redpolls picking and eating winter buds from an unrecognized tree along the Big Sioux river. On February 18 Mr. A. F. Allen and I followed a small flock of eight or ten Redpolls on a hillside, and found that they were flying from one stalk to another of a weed which carried many dried seed receptacles, from which the birds were extract- ing and eating the seeds. A stalk of this plant was sent to Professor L. H. Pammel, who found it to be the Evening Prim- BIRD RECORDS DURING THE PAST WINTER 253 rose ( Oenothera biennis ). This plant is very abundant on the hills and prairies throughout this region, and may form an im- portant food of this group of birds, since it stands well above the snow and retains its seeds throughout the winter. 14. Pine Siskin. S'pinus pinus. The Pine Siskin was seen only twice through the winter, incidentally confirming its repu- tation for irregularity. In 1914 large numbers were continually about throughout March, April and the greater part of May. In That year a pair even nested in Sioux City.1 The writer is in- clined to think that the bulk of the Siskins pass south of this station for the winter, and that we see them here in the early spring on their return northward. 15. Goldfinch. Astragalinus t. tristis. This species was quite common through October. Eight were seen on November 5, and one on December 26. They were seen on six different days in January, and may be considered as a tolerably common winter bird. 16. Tree Sparrow. Spizella m. monticola. This is one of our most common winter visitors, and if arrived this winter on the 22d of October. It is often found in good sized flocks, which linger until the first of April. After the middle of this month only stragglers are seen. On January 21, in company with Messrs. A. P. Allen and G. 0. Ludcke, I watched a small flock of these birds feeding on the seeds of Squirrel-tail grass ( Hor - - deum jubatum L.), which projected above the deep snow. They picked the seeds from the heads within reach. Sometimes they would hop, or even fly, up to those just beyond reach. But what surprised us most was to see several birds deliberately hop onto the weak grass stem and bring it down to the snow, where the seeds could then be easily got at. At other times it seemed as if the birds simply flew against the grass heads, thus shaking out the seeds on to the snow, where they were readily picked up. I have not seen any previous mention of this interesting be- havior, and have since regretted that I did not give more time to the observations. Even by field observation there is an apparent wide range in the plumage color of this species; many are noticeably paler, and I have suspected that these may be the Western Tree Spar- 4S!ee Wilson Bulletin. XXVI, Sept., 1914, pp. 140-146. 254 IOWA ACADEMY OF SCIENCE Vol. XXIY, 1917 row, S, m. ochracea. An effort will be made in the future to determine this point. 17. Slate-colored Junco. Junco h. hyemalis. This is another of our very common winter visitors, and was especially nu- merous this year. They appeared in volume during the first week of October; and by the third week they seemed to be everywhere, invading the whole residence district of the city. But this seemed to be a “wave,” for by the middle of November few were seen in the city. Throughout the winter a few were seen on nearly every trip to the field, but by the third week in March a wave was again apparent, and large numbers were now observed on all trips until the middle of April. From the latter date onward they decreased in numbers, and the last record was on May 6. But on the spring northward movement there was no such invasion of the city yards and parkings as occurred in the fall. 18. Song Sparrow. Melospiza m. melodia. Ordinarily the Song Sparrow does not arrive at this point until the middle of March. This winter two were seen on January 7 (Allen and Stephens). They were among a flock of English Sparrows be- yond the city, and may have wintered. 19. Cardinal. Cardinalis c. cardinalis. This beautiful and picturesque bird is a permanent resident, and is increasing in numbers in this locality. It is frequently observed in the woods along the Big Sioux river, in the wooded ravines east and south of Morningside, and in the thickets across the river in Nebraska. On January 7 Mr. Allen and I counted nineteen (nine males and ten females) up along the Bix Sioux. All but two of these were in one neighborhood, and evidently associating together in a flock such as described by Nuttall.2 When a flock of Cardi- nals moves about the flight is characteristic ; the movement is in single file, so that the group does not present the appearance of an ordinal flock of birds. The peculiar dippy, and irregular flight of the Cardinal probably is an acquirement which has pro- tective value, making a much more difficult target in motion, as well as enhancing his beauty as he flits through the bare trees, and over the snow-blanketed earth. The Cardinals on this date were not singing but frequently uttered a short, incisive call which sounds like “ peet, peet,” etc. 2Popular Handbook of Birds of the Eastern United States and Canada.. By Thomas Nuttall. Revised edition, 1911, part I, page 363. BIRD RECORDS DURING THE PAST WINTER 255 Some of these birds were feeding upon the oats from some straw that had caught on the trees from a passing load. Much might be learned of the winter food of our common birds by patient field observation, affording at the same time the incentive and the reward for the winter study of birds. On February 18 in the same locality we found only one Cardi- nal, a male who made a few feeble attempts at song. Not more than three notes were uttered at a time, and these were not loud. The performance was such as to give one the impression that the bird was tuning up and getting his vocal cords under con- trol. Mr. Allen has published his impression of this same song in the following words : “It was a hesitating and limping song that came from his throat, showing that he was sadly in need of ipractice, that his vocal chords had grown weak and husky from disuse, or that he had not complete confidence as yet in his equipment for the great adventure which he was about to undertake.”3 On March 4 Mr. Ludcke covered the same territory and found eleven Cardinals, most of whom were in full song. After this date the birds were usually singing, and by the last of Marcn many of them seemed to be mated. There is some ground for suspecting,, however, that the Cardinals occasionally remain mated throughout the winter. A very full account of the song of the Cardinal, and its winter habits, is given by Nuttall4 which should be read by every one who is interested in this species. 20. Towhee. Pipilo e. cry ihroph thalmus . Although an early spring arrival this species is never thought of as forming part of the winter fauna in this region. However, a female was found in the thickets along the Big Sioux river on December 26, being seen by myself and Arthur Abel. It flew from the ground ten feet in front of us and alighted in a bush within twenty yards of us, where we had a full view for some time. We saw it again in the same place on January 2, but not after- ward, and it may have succumbed to the very severe weather of January. 21. Bohemian Waxwing. Bomby cilia garrula. This species was not as plentiful this winter as in some previous years. A few were seen from time to time during March in Grandview 3Notes of a Nature Lover, by A. F. Allen. Sioux City Journal, February 25, 1917. 4Loc. cit., pp. 362-367. •256 IOWA ACADEMY OF SCIENCE Vol. XXIV, 1917 Park by Mrs. Bailey, when they were associating with B. cedro- rum. Mrs. Bailey informs me that they were nearly always in the Russian Olive trees, which are very numerous in the park, and that she had observed them eat the fruit. None were seen after March 19. 22. Cedar Waxwing. Bomby cilia cedrorum. This waxwing is rather a common winter species, but is not usually seen be- fore February, and then frequently during March, April and May. No record of its nesting in this vicinity is known, how- ever. This winter the first seen were a flock of twenty in Peters Park by W. R. Griffith. In February they were seen by many observers, and in large flocks. In Grandview Park during March they were, on differ- ent dates, estimated at numbers varying from one hundred to two hundred and fifty ; the largest number being noted on March 19. Small numbers of this species also frequented the yard belonging to Mrs. W. S. Warfield, being attracted, probably, by the large variety of berry fruit planted there for that purpose. They may have fed to some extent on the wild Russian Olives, though I am not sure that they were actually observed to do so. They were, however, observed to eat the red fruit of the native Wahoo tree. Mrs. Warfield also saw them eat the berries of the Purple and Japanese Barberry. The bulk of the flock in Grandview did not remain afteb March 19, though a few were seen throughout the month. 23. Chickadee. Penthestes subsp. ? The writer is unable to state whether atricapillus or septentrionalis is the common win- ter form here, but probably both occur. But whichever it is, it is exceedingly abundant and very generally distributed, and seemed to be about as plentiful as usual this winter. 24. Golden-crowned Kinglet. Begulus s. satrapa. These kinglets were noted on October 8, and were seen a number of times during that month and up to the middle of November. A few, however, remained later, for one was reported by Walter Bennett on. December 25, six were noted on January 7 (Allen and Stephens), and two on January 14 (Allen and Ludcke). I believe this is the first time the kinglets have been recorded here at this season of the year. The winter call of the Golden- crowned Kinglet closely resembles that of the Brown Creeper,, and either might be mistaken for the other. BIRD RECORDS DURING THE PAST WINTER 257 25. Brown Creeper. Certhia f. mnericana. Brown Creepers occurred in about the usual numbers during this winter, but appeared earlier than usual in the fall. Two were seen on October 9 (Stephens and Abel) ; three were reported on the. 10th by Mrs. E. A. Fields ; three on the 12th (Eiffert) ; and so on, throughout October, November, December and January. In February and March none were seen (and their absence during this ‘period is apparent in the records of other years) ; two records are given during April by Mr. Himniel, and several records during the last two or three days of April and first of May, the latest being May 6, by Mrs. H. J. Taylor. 26. White-breasted Nuthatch. Sitta c. carolinensis. This species was seen frequently during the winter, and in about the usual numbers. Possibly S. c.. nelsoni also occurs here. 27. Red-breasted Nuthatch. Sitta canadensis. The numer- ous fall records of this species provide one of the unusual orni- thological notes of the year. Two specimens were secured by Mr. Eiffert on October 9. On the 16th one entered the house of Mrs. W. P. Manley and posed before a considerable number of observers. Another one visited the suet box in Mrs. F. W. Marshall’s yard occasionally from the 20th to the 26th of Oc- tober, and was then driven away by a White-breasted Nuthatch. The bird was also seen by at least three other observers on dif- ferent occasions in the early winter. It was seen again on Jan- uary 14 (Allen and Ludcke), on January 21 (Allen, Ludcke and Stephens) and on April 22 (Stephens). Mr. Wier R. Mills at Pierson, Iowa, saw one specimen almost daily from December 24 to January 15. This gives more records for one season than the writer has known of for the past eight years. 28. Carolina Wren. Thryothorus l. ludovicianns. Early in October Mr. G. 0. Ludcke captured a strange bird on his prem- ises and caged it. It was later examined by himself and Mr. A. F. Allen, who compared it with pictures and descriptions, and concluded that it was the Carolina Wren. Upon measure- ment it was found to be longer than any other species of wren. The color of the plumage tallied with the pictures and descrip- tions and they were both fully satisfied with the diagnosis. The bird was then liberated. Inasmuch as the species has never been observed here before, the specimen should have been pre- 17 258 IOWA ACADEMY OF SCIENCE Vol. XXIV, 1917 served ; but there can probably be no doubt as to the identifica- tion. It is not a rare species in Minnesota, according to Hatch’s catalogue. 29. Bluebird. Sicilia s. sialis. Four individuals were seen by Messrs. Walter Bennett and A. W. Lindsey near Stone Park on December 26. The Bluebird is by no means a common winter bird, but a few late November records have been obtained in other years. Department of Biology, Morning side College. A LIST OF THE BIRDS OBSERVED IN CLAY AND O’BRIEN COUNTIES, IOWA. IRA N. GABRIELSON. Clay and O’Brien counties lie in a section of Iowa which; has received little attention from ornithologists. O’Brien is the more westerly; it is the second from the western boundary of the state, with Clay county adjoining it on the east ; and each lies within one county of the Minnesota state line. The following list of the birds observed in these counties is based on notes made through a number of years and is by no means, complete. Previous to 1907 the writer lived at Sioux Rapids, which is just south of Clay county, and made from there numerous trips into that county. The period from February, 1907, to September, 1908, was spent in this county on a farm near Webb. Later, notes were made on summer and holiday trips during which Webb in Clay and Sheldon in O’Brien county were visited more than any other points, although many other parts received some attention.1 Unfortunately, many of the notes previous to 1909 were accidentally destroyed and this has made necessary the omission of some species from this paper. A migration season spent in the Little Sioux valley would un- doubtedly have added many species to the list. The number of* warblers and other migrants added during the few days spent in Sheldon in May of different years is an indication of what might be expected. Plans for this work had been made but cir- cumstances have rendered the possibility of their fulfillment re- mote. The only excuse offered for publishing an admittedly in- complete list lies in the fact that conditions have changed so much in this territory since 1912 that the completion of the work is no longer possible. The region has been so rapidly ' VTlie, following are the dates and principal points visited on each trip: Webb, Clay county, June 10-Sept. 1, 1909 ; Webb, Nov. 23-26, 1909 ; Webb, Dec. 18, 1909-Jan. 3, 1910; Webb, March 26-April 9, 1910 ; Sheldon and Hartley, O’Brien county, and Everly, Clay, April 9-12, 1910 ; Sheldon, May 14-16, 1910 ; Webb, June 11-Oct. 1, 1910 ; Clay county north of Sioux Rapids, Oct. 1-Nov. 30; Webb, Nov. 30, 1910-Jan. 30, 1911; Webb, April 8-15, 1911 ; Granville (near the O’Brien county line but lying in Sioux county), Paulina, O’B'rien, and Peterson and Webb, Clay, June 13-20, 1911 ; Sheldon, May 19-22, 1912; Sheldon, Spencer and Webb, Aug. 6-17, 1)13. 260 IOWA ACADEMY OF SCIENCE Vol. XXIV, 1917 drained that comparatively few swamps or ponds were left when it was last visited, in August of 1913. Where, in 1909 and 1910, cattails and other aquatic vegetation, teeming with bird life, flourished, solid fields of corn now stand and the birds have vanished. This is particularly true of southeastern Clay county, where most of the time was spent. These notes are pre- sented as a partial record of the conditions existing in this region before man eliminated the swamps and “kettle holes” and changed entirely the conditions found there. It is believed that the list of water birds is reasonably complete except among the migrating sandpipers and rarer ducks. Little has been published regarding the avifauna of this re- gion. Tinker2 published a list of eighty-six species based on material secured by the University of Michigan- Walker Expe- dition, which visited Clay and northwestern Palo Alto counties between July 1 and September 1, 1907. A papei by the writer3 contained a list of fifty species found breeding on a farm near Webb. Aside from these two articles only scattered notes in reference to this locality have appeared. Tinker’s list includes eight species which were not found by the writer, namely Virginia Rail, Stilt Sandpiper, Greater Yel- lowlegs, Long-eared Owl, Alder Flycatcher, Western Henslow Sparrow, Bay-breasted Warbler, and Wilson. Warbler. These added to the 136 recorded here make a total of 144 species for the region. Little need be said regarding topography. The dominant fea- ture is the gently rolling prairie land which is now practically all under cultivation. Innumerable lakes, ponds, swamps, and “kettle holes.” dotted this prairie at the time these notes were made and the land was cultivated between them. The only stream of any importance is the Little Sioux river wdiich crosses Clay county from north to south just east of the center and then turns west along the southern edge of the two counties, running here within and there without the borders. The valley is more or less wooded throughout the course with the heaviest timber in southern Clay. Ash ( Fraxhms americanus var.), elms .(Ulmus americ ana and U. racemosa) , maple (Acer saccharinum) , 2Tinker, A. D., Notes on the Ornithology of Clay and Palo Alto counties, Iowa: Auk, Vol. XXXI, p, 70-81, January, 1914. 3Gabrielson, Ira N., Breeding Birds of a Clay County, Iowa, Farm : Wilson Bulletin, Vol. XXVI, p. 69-80, June, 1914. BIRDS OF CLAY AND O’BRIEN COUNTIES 261 boxelder ( Acer negundo), cottonwood ( Populus deltoides) and willows ( Salix sp.) are the most common bottom land trees, while burr oak ( Quercus macrocarpa) is the most conspicuous upland form. The Floyd river, flowing for a short distance across the northwestern corner of O’Brien county, is a typical prairie stream with only an occasional fringe of willows. The smaller streams tributary to the Little Sioux are much the same, being open water courses with little or no timber. Many of these are dry during the summer months. A straggling mar- ginal growth of timber, locally widening to form groves of sev- eral acres, along the shores of the larger lakes, forms the only other native timber in the territory. Artificial groves, usually of willow, maple, boxelder, or cottonwood, are almost univer- sally planted about the farm buildings. These groves attract numbers of such species as the kingbird, bronzed grackle, cat- bird, reel-eyed vireo, warbling vireo, brown thrasher, western house wren, Baltimore and orchard orioles, robin, downy and red-headed woodpeckers and others. It is unquestionably true that such birds as these have a more general distribution and have been present in greater numbers in the two counties since these groves wrere planted. 1. *Podily mbits podiceps. Pied-billed Grebe. A common breeding species, one or more nests of which could be found in every little pond. 2. Gavia immer. Loon. A single individual alighted on a small pond among the duck decoys during a snowstorm on No- vember 28, 1909. I have also at different times found dead birds of this species around the ponds. 3. Larus delaw arensis. Ring-billed Gull. These birds ap- peared in the spring either in small flocks or in company with the Franklin Gull. I saw one individual repeatedly among the gulls following the plow during the spring of 1907. 4. Larus franklini. Franklin Gull. A- very common mi- grant which was most abundant in April and October. It came in large flocks and followed the plows, picking up insects. If not molested they became very tame and often engaged in a wild scramble to be the first into the furrow after the plow had (Note). Species marked with an asterisk (*) in the following list are those recorded in the writer’s paper on the “Breeding Birds of a Clay County, Iowa, Farm” (op. cit.), as breeding. 262 IOWA ACADEMY OF SCIENCE Vol. XXIV, 1917 passed. During the summer of 1904 about a dozen remained in a little swamp near Sioux Rapids. They joined the black terns in a -demonstration against me when I invaded the swamps but no nests of this species were found. 5. * Hydrochelidon nigra surinamensis. Black Tern. A com- mon breeding species. They often followed the plow after the manner of Franklin Gulls and occasionally mingled with that species at such times. 6. M erg us americanus. Mer ganser . A male was shot on one of the ponds near Webb during the last week in March, 1910. I examined the skin later. Flocks of Mergansers (probably this species) were noted several times but could not be identified with certainty. 7. Lophodytes cucullatus. Hooded Merganser. This species was a common migrant and possibly a breeding bird as from three to five were often noted about a chain of small ponds dur- ing June and July, 1910. 8. *Anas platyrhynchos. Mallard. An abundant migrant, being probably the most common duck of the region. It nested occasionally. 9. Chaulelasmns streperus. Gad wall. This duck was not common in my experience. One female collected in March, 1908, is the only definite record that I have. 10. Nettion carolinense. Green-winged Teal. Although these ducks were shot during the spring migration every year they never appeared in any numbers. 11. *Querquedula discors. Blue-winged Teal. One of the most abundant ducks of the region during migrations and the only species which nested regularly. 12. Spatula clypeata. Shoveller. A regular migrant. 13. Dafila acuta. Pintail. As a spring migrant this duck equalled the mallard in abundance but was not noted in the fall. It was often killed in large numbers and I once saw 125 of the species which had been killed by two gunners in one day’s shooting on a small lake in Clay county. 14. Aix sponsa. Wood Duck. This duck is reported to have nested along the Little Sioux in past years. I shot one bird out of a flock of five in the fall of 1905 (exact date missing) in southern Clay. BIRDS OP CLAY AND O’BRIEN COUNTIES 263 15. Marila americana. Red head. This species was regularly secured in small numbers by hunters and I have handled a num- ber killed in eastern Clay. 16. Marila valisineria. Canvas back. This duck undoubtedly occurs although I have never seen one. Mr. Gilbert, of Marshall- town, Iowa, who hunted regularly at Trumbull lake, informed me that he secured them every spring. In August, 1913, while waiting for a train at Spencer, I saw a mounted male in a store window in a collection of local birds. I was unable to find the owner and so have no definite information regarding it. This species is included on the basis of Mr. Gilbert’s statement, 17. Marila affinis. Lesser Scaup Duck. A very common migrant. It is curious that among the dozens of scaups handled from this region no specimens of Marila marila were found, al- though undoubtedly it occurs. 18. Marila collaris. Ring-necked Duck. This duck was a tolerably common migrant and I shot it every spring around Webb where it was known as “Ring-bill” or “Black Jack” by the gunners who distinguished it from the scaup. 19. Charitonetta albeola. Bufflehead. A tolerably common spring migrant in 1907. Rare after that time. 20. Chen liyperboreus liyperboreus. Snow Goose. “White Brant,” A very common spring migrant. They often were as- sociated with blue geese and white fronted geese in flocks of con- siderable size. 21. Chen caerulescens. Blue Goose. “White-headed Brant.” This species was a regular migrant. I collected one in March, 1907, and usually saw three or four each year that were killed by hunters. 22. Anser albifrons gambeli. White-fronted Goose. “Brant.” A common spring migrant. 23. Brant a canadensis canadensis. Canada Goose. The most common goose of the region. The smaller ones are called “Brant” or “Black Brant” and possibly B. c. hutchinsi occurs among them, but I have no definite records of this subspecies. 24. Olor columbianus. Whistling Swan. At various times swans, probably this species, have been killed in this region. I have one definite record — a bird killed by Mr. Gilbert, of Mar- shalltown, at Trumbull lake, during a two weeks" hunting trip 264 IOWA ACADEMY OP SCIENCE Vol. XXIV, 1917 in March, 1908. This bird was presented to me in 1913 and is now in the Marshalltown, Iowa, Public Library. 25. *Botaurus lentiginosus. Bittern. A common breeding: species which usually selected the marshy hay lands for nesting sites. 26. *Ixobryefous exilis. Least Bittern. Fairly common breed- ing species. 27. Ardea herodias herodias. Great Blue Heron. A com- mon migrant, most abundant in July and August. 28. Butorides virescens virescens. Green Heron. This heron bred commonly along the Little Sioux and could usually be found about any large pond with timber near it. 29. Nycticorax nycticorax naevius. Black-crowned Night Heron. A common summer resident which was reported as nesting along the Little Sioux in scrub oak. From one to six birds appeared every evening at the farm near "Webb. This was about six miles from the nearest possible breeding place. I have never visited a colony in this territory but Paul C. Wood reported a colony at Spencer in June, 1895. (Iowa Ornithologist I, 2, 1895, p. 13.) 30. Grits americana. Whooping Crane. On April 9, 1911, ! saw five birds near Webb which were undoubtedly this species. These birds were standing near the edge o'f _a small pond and I was able to approach within 300 yards and examine them through the glasses. After- watching them for approximately half an hour I attempted to approach closer, but was unsuccess- ful as they immediately took wing and flew slowly off to the north. 31. Grus mexicana. Sandhill Crane. This species was a fairly common migrant, flocks of from forty to fifty often being seen standing about in cornfields or drifting along in great spirals far overhead. 32. *Rallus elegans. King Rail. A locally common breeching species. The writer has found nests in various swamps in eastern Clay in addition to those previously reported from the farm near Webb. The King Rail has the most startling voice of any of the breeding marsh birds. It may be described as a loud, abrupt, bnp-bup , repeated rapidly and explosively. My first ornitho- logical experience was with a king rail intent on keeping three youthful egg-collectors from appropriating her clutch. She flew BIRDS OP CLAY AND O’BRIEN COUNTIES 265 at. our bare legs, her feathers ruffled until she looked twice nat- ural size ; and used her beak with such good effect as to put us to flight momentarily. AVhen we mustered up courage to return we found the probable explanation of this behavior was that the eggs were just hatching. 33. *Porzana Carolina. Sora. A common summer resident mid breeder. The plaintive note of this species was one of the most characteristic sounds of the summer evenings. 34. *Gallinula galeata. Florida Gallinule. A common breed- ing species. 35. *FuUca americana. Coot. This species is the most abun- dant breeding water-fowl in this region. Every small slough harbored at least one pair and nests could be found by the score in the larger cattail or wild Tice marshes. 36. * Steganopus tricolor. Wilson Phalarope. An occasional migrant, rare summer resident, and possibly a breeding species. One pair remained all summer in 1910 near Webb. 37. Gallinago delicata. Wilson snipe. Common migrant. 38. Pisobia maculata. Pectoral Sandpiper. An abundant migrant. 39. Pisobia fuscicollis. White-rumped Sandpiper. While not so abundant as P. maculata this sandpiper was found in numbers during migrations. 40. Pisobia minutilla. Least Sandpiper. Common migrant. 41. Ereuneies pusillus. Semipalmated Sandpiper. Also a common migrant but not usually so abundant as P. m in a t ilia. They were present in numbers along the Floyd river at Sheldon, on August 6-8, 1913. 42. Tetanus flavipes. Yellow-legs. ' Common migrant. 43. Helodromas solitarius solitarius. Solitary Sandpiper. Common migrant. 44. *Bartramia longicauda. Upland Plover. This species bred commonly in eastern Clay count}^. 45. Act itis macular ia. Spotted Sandpiper. Nested commonly along the water courses and on the shores of the larger ponds. 46. Oxyechus vociferus. Kildeer. One of the common breeding species of the region. They nested in the cornfields, de- positing their eggs on a few pebbles and bits of corn husks gath- ered together at the base of a hill of corn. 266 IOWA ACADEMY OF SCIENCE Vol. XXIV, 1917 47. Acgialitis semipcilmata. Semipalmated Plover. A single bird observed at Sheldon, August 7, 1913, is the only record for the two counties. It was probably a regular migrant as I have found it quite common both north and south of here. 48. *Oolinus virginianus virginianus. Bob-white. The Bob- white was locally a common breeding- species. Where hunting was forbidden they frequently nested about buildings and became quite tame. 49. * Tympanuchus american us americanus. Prairie Chicken. This bird was only a tolerably common breeding species although considerable flocks often appeared during the winter. The last nest record I have is June 10, 1909. This nest contained twelve eggs and was built in the weeds and grass along a fence. 50. * Z enaicliira mmroura carciinensis. Mourning Dove. This common breeding species was found nesting in artificial groves and feeding about barnyards. 51. * C ircus kudsomps. Marsh Hawk. This was the only common hawk of the region. It nested in marshy hay lands. The three- or four nests I found usually had a little corn about each. This grain probably came from the cheek pouches of the striped gopher {Spermophilus tridecemlineatus} and gray squir- lels (8. franklini) brought to the nestlings though some of the farmers accused the hawk of eating corn. 52. Accipiter covperi. Cooper Hawk. A young bird barely able to fly, was found in the city park at Sheldon, August 6, 1913, and it is the only definite record that I have. It probably nested in the heavier timber along the Little Sioux. . 53. Buteo borealis Jtrideri. Red-tailed Hawk. Red tails were common in migration, and possibly nested in the heavy timber: H. C. Oberholser says that breeding birds of this re- gion as well as most migrants are of this subspecies. 54. Haliaeetus leucocephaius leucocephaius. Bald Eagle. .1 have examined two specimens taken in the county and there are probably others in existence, as one of these birds is shot every few years. 55. Falco' sparverius sparverius. Sparrow Hawk. This little hawk was common in the fall. At this season it was usually found perched on the telephone and telegraph poles on the look- out for grasshoppers, locusts and other insects. BIRDS OF CLAY AND O’BRIEN COUNTIES 267 56. Pandion hairnet us ckrolinensis. Osprey. On September 25, 1910, while watching a number of herons, I noticed a large hawk diving into the waters of a small lake. It remained about for several hours and I identified it as this species. I was not familiar with the bird at this time but subsequent acquaintance serves to confirm the identification. 57. *Asfo flammeus. Short-eared Owl. A common breed- ing species and permanent resident. Most of these birds migrate during the winter, but a few usually remain about the frozen meadows. 58. *Otus asio asio. Screech Owl. The most common owl found. It breeds both in the native timber and in artificial groves. 59. Xyctea nyctea. Snowy Owl. This species Avas said to be a common winter visitant during some seasons and entirely absent during others. I saw one on December 22, 1909, and an- other A\ras reported to me in April, 1910. Mounted specimens usually without dates, were not uncommon in the various towns. 60. Speotyto cunicularia hypugaea. Burrowing Owl. On June 16, 1911, I made a special trip to Gramulle, Avliich lies just about on the line between Sioux and O'Brien counties to see a colony of this species reported from there. Three pair Avere nesting iii burrows dug in low ridges in a swampy pasture. One pair Avhich Avas dug out had tAvo fresh eggs. The female re- mained on the nest and, after the burrow Avas partially exca- vated, Avas caught and handled for some time. She struck viciously at every one within reach of her claws. Several skins or pieces of skin of the striped gopher ( Spermophilus triclecem- lineatus) and a number of unidentified bones Avere about the nest entrance and in the tunnel. 61. Coccyzus americanus am erica tins. Yellow-billed Cuckoo. Nested regularly in the timbered areas. 62. Coccyzus erythrop thalmus. Black-billed Cuckoo. This species was less common than the yellow-bill but Avas found regu- larly. 63. Ceryle alcyon. Belted Kingfisher. Nested commonly wherever suitable nest sites were found. 64. Dryobates villosus villosus. Hairy Woodpecker. One bird observed June 19, 1910, in the Little Sioux valley is the only summer record I have. The birds undoubtedly nested more 268 IOWA ACADEMY OF SCIENCE Vol. XXIV, 1917 or less regularly and were common winter residents of artificial groves and timbered areas. 65. *Dry abates pubescens mediant p. Downy Woodpecker. A common breeding species and permanent resident. 66. *Melanerpes erythrocephalus. Red-headed Woodpecker. Nested commonly. 67. *Colaptes auratus \ miens. Northern Flicker. Common permanent resident. 68. Chordeiles virginianus virginianus. Nighthawk. A com- mon migrant, most abundant in August, when it often appeared in considerable numbers. 69. * Chaetura pelagica. Chimney Swift. Nested commonly. 70. Archilochus colubris. Ruby-throated Hummingbird. Tol- erably common summer resident. 71. * Tyrannus tyrannus. Kingbird. An abundant breeding species and one of the conspicuous birds of the region. 72. Tyrannus verticalis. Arkansas Kingbird. According to Anderson4 this species was rather rare in northwestern Iowa up to 1905. It appears to be increasing in this section as by 1910 and 1911 it was tolerably common in these two and surrounding counties. 73. *$ayomis phoebe. Phoebe. Nested commonly. 74. Myiochanes virens. Wood Pewee. A common breeding species in. timbered areas and found frequently in artificial groves. 75. Empidonax minimus . Least Flycatcher. Common sum- mer resident in the same localities as the Wood Pewee. 76. *Otocoris alpestris praticola. Prairie Horned Lark. An abundant permanent resident. Two and possibly three broods were raised each year. In winter they fed in barnyards and about stacks in company with large numbers of Lapland Long- spurs. 77. * Cyanocitta crist at a crist-ata. Blue Jay. A common res- ident, most abundant about towns. 78. *Corvus brachyrhynchos brachyrhynchos. Crow. Com- mon permanent resident. 79. *Bolichonyx oryzivorus. Bobolink. The bobolink was locally abundant throughout the region. One meadow would 4Anderson, R. M., Birds of Iowa : Froc. Davenport Academy of. Science, Vol. XI, p. 285. BIRDS OF CLAY AND O’BRIEN COUNTIES 269 contain numbers of these birds while another a few miles away, apparently equally favorable, would not contain one. 80. *Molothrus ater ater. Cowbircl. An abundant breeding species. I rarely found a nest of any of the smaller birds which did not contain at least one Cpwbird egg. 81. # A anthocephalus xanthoeepltalus. Yellow-lieadecl Black- bird. The yellow-heads were abundant in the swampy parts of the country. In the larger wild rice swamps hundreds of nests could be found. 82. *Agelaius phoeniceus phoeniceus. Red-winged Blackbird. These birds, by far the most abundant breeding species, nested not only in the cattails and flags but in the willows along water courses and on bogs in bunches of heavy grass. 83. *8turnella neglecta. "Western Meadowlark. Nested com- monly. 84. Icterus spurius. Orchard Oriole. An uncommon summer resident, found only in certain groves and absent over the re- mainder of the country. One pair nested for two years (1908- 09) in a small orchard near Webb. 85. # Icterus galbula. Baltimore Oriole. Common breeding species. 86. Euphagus carolinus. Rusty Blackbird. The rusty was found in considerable numbers in the great fall flocks of black- birds which roamed over the country. 87. *Quiscalus quiscula aeneus. Bronzed Grackle, This species seemed to be particularly fond of artificial groves and appeared to nest exclusively in them. One of the most inter- esting sights of the region was the immense blackbird flocks which formed in the fall. Grackles, red-wings, yellow-heads, rusty blackbirds, and cowbirds banded together in almost in- credible numbers. 88. *Astragalinus tristis tristis • Goldfinch. Common breeder. 89. Plectropkenax nivalis nivalis. Snow Bunting. The Snow Bunting was an irregular winter visitor. It was present in small numbers near Webb in the winter of 1907-08. I failed to see it in other years although it was occasionally reported. 90. Calcarius lapponicus lapponicus. Lapland Longspun. An abundant winter visitor, generally appearing in flocks with prairie horned larks. 270 IOWA ACADEMY OF SCIENCE Vol. XXIV, 1917 91. Calcarius pictiis . Smith Longspur. Probably a more common species than my records indicate. I found it on April 8, 1910, in company with the Lapland Longspur s and Prairie Horned Larks. Five birds were watched through field glasses, at this time, at short range. 92. Pooecetes gramineus gramineus: Vesper Sparrow. A flock of six birds remained in a farm yard near Webb from April 9 to 11, 1911. 93. * A m m o d ra m us s av a nnaru m biniaculatiis. Western Grass- hopper Sparrow. In Tinker’s list ( op tit.) his specimens of the grasshopper sparrow are referred to this subspecies. It was a common breeding species.5 91. *Ghb'nclestes grammacus grammacus. Lark Sparrow. Tol- erably common summer resident and breeder. 9 o. Zonotrichia querula. Harris Sparrow. Abundant in southern Clay .on October 30, 1910. The only other record was of a few noted at Sheldon, May 14, 1910. 96. Zonotrichia albicoUis. White-throated SparroAV. Com- mon migrant. 97. Spizella monticola monticoia. Tree Sparrow. Common winter visitor. 98. Spizella passerina passerina. Chipping SparroAV. A breeding species most abundant about towns. 99. Spizella pusilla pusilla. Field SparroAAe A common breeding bird along the Avatercourses and lakes, wherever there is sufficient brush to furnish nesting sites. 100. J unco hyemalis hyemalis. Slate-colored Junco. A com- mon winter visitor. 101. M elospiza melodic melodia. Song SparroAV. Nested com- monly. 102. M elospiza gecrgiana. Swamp Sparrow. Common mi- grant, most abundant in September. 103. Passerella iliaca iliaca. Fox SparroAV. Tolerably com- •mon migrant. 104. Pipilo erythrophthalmus erythrophthalmiis. Chewink. Common summer resident in timbered sections. 105. Zamelodia ludoviciana, Rose--breasted Grosbeak. Nested commonly. 5In my first paper on the “Breeding Birds of a Clay County, Iowa. Farm”, (op. cit.) grasshopper sparrows were referred to as A. s. australis. This was done without specimens and as the birds of this region prove to be the western subspecies, the error is corrected at this time. BIRDS OF CLAY AND O’BRIEN COUNTIES 271 106. Passerina cyanea. Indigo Bunting. Common during spring migration and a tolerably common summer resident. 107. *'8piza americana. Diekcissel. An abundant breeding species ; nested in weeds and vines along fences. 108. Passer domesticus. English Sparrow. Abundant per- manent resident. 109. Piranga . erythrpmelas. Scarlet Tanager. Tolerably common breeding species. 110. *Progne subis subis. Purple Martin. There were breed- ing colonies in Spencer, Everly, Sheldon, Peterson, and Webb. Other towns that probably had them were not visited at the right seasons. 111. *Petrochelidon lunifrons lunifrons. Cliff Swallow. Lo- cally common throughout the territory, dusters of their mud nests were hung under the eaves of barns. 112. * Hirundo erythrogastra. Barn Swallow. One or more pairs of these swallows could generally be found about every cluster of farm buildings. They occasionally nested under wooden bridges and were then known as “bridge swallows.” 113. Jridoprocne bicolor. Tree Swallow. An abundant fall migrant in July and August. At this season great mixed flocks of swallows appeared to feed over the marshes. Between meals they rested on telephone wires and fences and often filled all the wires for rods. All five species here recorded were well repre- sented in these flocks. 114. Riparict riparia. Bank Swallow. Nested commonly. 115. Stelgidopteryx serripennis. Rough-winged Swallow. Occurred in numbers in the fall flocks. 116. Lanius ludovicianus migrans. Migrant Shrike. A pair with four young just out of the nest were found near Sheldon, August 7, 1913. The species seemed to be generally distributed over the region as I noted it at Spencer, Webb and in southern Clay. 117. V'ireosylva olivacea. Red-eyed Yireo. Tolerably common breeding species. 118. Vireosylva gilva gilva. Warbling Yireo. Common sum- mer resident. 119. Mniotilta varia. Black and White Warbler. One noted at Sheldon, May 14, 1910. 272 IOWA ACADEMY OF SCIENCE Vol. XXIV, 1917 120. Vermivora peregrina. Tennessee Warbler. This war- bler was common at Sheldon, May 14-16, 1910. 121. *Dendroica aestiva aestiva. Yellow Warbler. Nested commonly. 122. Dendroica coronata. Myrtle Warbler. Two observed in the city park at Sheldon, May 14, 1910. 123. *Geothlypis irichas tried) as. Maryland Yellowthroat. Common breeding species. 124. Setophaga ruticilla. Redstart. One recorded at Shel- don, May 19, 1912. 125. *Bumetella carolinensis. Catbird. Nested commonly. 126. *Toxostoma rufum. Brown Thrasher. Common breeder. 127. * Troglodytes aedon parkmani. Western House Wren. Common breeding species. 128. *Cistothorns stellaris. Short-billed Marsh Wren. A small colony of these birds was found near Webb and one nest containing six eggs was discovered. 129. *Telmatodytes palustris iliacus. Prairie Marsh Wren. Common breeding species. 130. Gerthia familaris americana. Brown Creeper. Com- mon winter visitant. 131. Sitta carolinensis carolinensis. White-breasted Nut- hatch. Common permanent resident. It probably bred though I never found a nest. 132. Penthestes atricapillus septentrionalis. Long-tailed Chickadee. Common permanent resident, bred in timbered sec- tions. 133. Hylocichla mustelina. Wood Thrush. Common breed- ing species in timbered sections. 134. Hylocichla ustulata sivainsoni. Olive-backed Thrush. One found dead, Sheldon, May 14, 1910. 135. *Plunesticus migratorius migratorius. Robin. Common breeding species. 136. Sialia sialis sialis. Bluebird. Tolerably common breed- ing bird. United States Department of Agriculture. AN ANNOTATED LIST OF THE MAMMALS OF SAC COUNTY, IOWA. J. A. SPURRELL. My purpose in writing this list is to place on record data gath- ered principally from the pioneers of Sac county about the con- ditions in pioneer days and since. While these data are not as accurate as though they were confirmed by specimens, they are better than no information at all. I have used extreme care in differentiating species, and have included some observations of my own made in the more recent years. I have also included some data on adjoining counties, I have numbered my contributors of data and will refer to them by number. 1. Asa Platt. Mr*. Platt was a fur trader, trading with the Indians and whites in 'early days. He came to Sac county first in 1856. 2. C. Orville Lee. Mr. Lee was born in Sac county in 1864. His parents came to the county in 1854. He hunted and trapped a great deal in his youth and still has an active interest in game birds and animals. 3. Hugh Cory. Mr. Cory came to the county in September, 1854. at the age of ten years. He hunted and trapped much in the earlier days. 4. Shelt Tiberghien, Mr. Tiberghien came to the .county in 1856, when he was fifteen years old. He also was a hunter and trapper. All four of the men previously named still live at Sac City. 5. C. Everrett Lee. Mr. Everrett Lee is a brother of C. Or- ville Lee and resides at Lytton. 6. Platt Armstrong. Mr. Armstrong moved to the vicinity of Lake View in 1878 and at present lives in that town. 7. John Spurred. My father, who settled one mile north of Wall Lake in 1875, and still lives there. 8. Dr. A. S. Havden. Dr. Hayden came to Sac county in 1873, when he was eleven years old, and lived with his parents near Sac City. He now lives at Wall Lake. 18 274 IOWA ACADEMY OF SCIENCE Vol. XXIV, 1917 9. Mrs. E. B. Hayden. The wife of Dr. Hayden. She came to the county in 1878 and lived at Lake View, but was a fre- quent visitor to the Raccoon river woods. 10. H. B. Smith. Mr. Smith came to the vicinity of Odebolt in 1876. He died a few years ago but his wife still maintains the collection of birds and animals which they formed. 11. H. P. Dudley. Mr. Dudley traveled through Sac county in early days with his father, who was an itinerant minister. 12. J. A. Spurred. “I have always taken a keen interest in birds and animals since early childhood, and have kept a note- book of my observations since July, 1907/’ A part of the scientific names I obtained by correspondence with the Biological Survey, U. S. Department of Agriculture, and the remainder from “The Mammals of Illinois and Wiscon- sin,'” by Charles B. Cory, Publication 153, Zoological Series, Field Museum of Natural History. Sac county was first settled in 1854, at Grant City and Sac City. For many years the settlers depended on wild game and trapping to furnish a large part of their living. Not until the railroads came about 1870, and furnished markets for bulky farm products, did the county become thickly settled. The topography is a rolling prairie, and at first settlement there were many marshes, sloughs, and ponds in the eastern half of the county. The eastern half is drained by the Raccoon river which, at the time of settlement, was bordered by a timber fringe from one to four miles wide. The principal enlargements were Grant grove at Grant City and Lee’s grove eight miles north of Sac City, also Cory grove south of Sac City. The western half of the county is drained by the Boyer river which was, and is, timberless except for some willow brush and trees along a few miles in the southern part of the county. Today, the timber fringe of the Raccoon river is very much reduced, and artificial groves are scattered all over the prairie portions of the county. ANNOTATED LIST. Bison or buffalo ( Bison bison). Buffalo were found only as stragglers after the first white settlers came to the county in 1854, but must have existed much more abundantly previously as shown by the hundreds of buffalo bones thrown up by the dredge when Rush lake was drained in 1911 (2). Many bones MAMMALS OF SAC COUNTY 275 were dug out of a miry place on the Platt Armstrong farm just east of the town of Lake View and one-fourth mile north of Wall lake (6). Bones and teeth were dug up about one mile north of the town of Wall Lake (7). I have a tooth dug up at this point, also a horn dug up in Wall Lake, and another horn plowed up several miles northwest of this town. A female buffalo was killed in June, 1858, on the county line between Buena Vista and Sac. The person killing her stated that the tallow was as yellow as gold, that she was a three year-old, and had never had a calf. He had also heard of two buffalo crossing the southwest corner of the county in 1860. They were killed near Jefferson (1). Three other buffalo were killed in Sac county west of Lake City by the Sifford boys (3). In 1862 the Johnny Green Indians killed two buffalo on a hunt commencing one and one-half miles south of Newell and extend- ing to Ida Grove (5).. One buffalo was seen in 1863 one and one-half miles south and three miles west of Sac City, but it plunged through a slough and escaped*. The same man reported that he heard of five being killed near Lake City in 1862 (4). Elk or Wapiti ( Gervus canadensis). All the earliest settlers united in saying that elk were plentiful. They were found from solitary individuals to five hundred in a herd. This large herd was seen running seven miles north of Fonda. It covered two acres of ground and could be heard three miles away (4). The elk scattered out in summer time but in October herded together, remaining in herds until spring (4). In case of storms in win- ter they took refuge in reed and rush grown ponds, where the reeds and rushes were ten feet or more in height. At other times they would lie on the highest hills (3). An elk that swam Wall lake from the north in 1855 was shot by Hugh Cory’s father before it recovered from its exhaustion enough to leave the water (3). The elk were an important source of meat of the earliest settlers (1), their place being taken by deer later. Elk horns could be picked up by the wagon load in 1856 (1). One man captured three calves, running one down afoot, and raised them to over one year old (4). The last elk in Sac county was a herd of about forty, which was seen in October. 1869, and went from east of Storm lake, south through Sac county, crossing the “Goosepond” at Wall Lake (4). ' 276 IOWA ACADEMY OF SCIENCE Vol. XXIV, 1917 Quotation from the “Biographical and Historical Record of Greene and Carroll Counties of Iowa,” published in 1887 by the Lewis Publishing Company, of Chicago. About Greene county: “Game such as deer and elk was in great abundance until the winter of 1855-56. The snows of that winter were so deep that it was impossible for them to escape the pursuit of men and dogs, and the number destroyed seems almost incredible. It is said that they were overtaken by men, boys, and even women, and beaten to death with clubs. Since then there has scarcely been an elk or deer seen within the county. Their rapid and sudden disappearance astonished everyone.” Quotation about Carroll county, from same publication : “When the first settlers came, deer, elk and antelope were not plentiful, the Indians having hunted them down and thinned their numbers. Still venison, could be had without much trouble, and deer became annually more plentiful for several years. “Antelope were occasionally seen but soon disappeared.” Indirect quotation from another county history of Carroll county. On June 7, 1864, a buffalo was shot in Carroll county. Deer ( Odocoileus am eric ami s) . There were many deer till 1855-56, when in snow about three feet deep on the level, the wolves and men killed nearly all (3). Another man said that there were practically no deer for four or five years after this winter ; then the deer increased and were most numerous from 1865 to 18701. He further stated that one hunter killed thirty deer as fast as he could shoot, at Mason’s grove in Crawford county; and that over one hundred and fifty were killed by the settlers of that grove during the winter of 1855-56. The saddles (two hind quarters) of these deer were sold for fifty cents each in Sioux City (4) . The deer stayed on the prairies and hid in the rushes and tall grass around the ponds in summer, and took refuge in the hol- lows and cuts of the hills in winter (7). If there were any cleer in the county they were always to be found between the Boyer river and Indian creek where these come nearest to each other (4). Pour deer were killed near Lake View in 1880 (6), prob- ably the last in the southern part of the county, although one was killed about 1890 in northern Sac county by George .Cory, Tom Gary, and the Basler boys (3). MAMMALS OP SAC COUNTY 277 Antelope ( Antilocapra americana) . I found no definite records for Sac county. See the previous quotation about game condi- tions in Carroll county. Otter ( Lutra canadensis). Otter were plentiful. Wall lake looked as if sled runners had passed all over it in the winter of 1855 so numerous were the otter slides in the snow (3). They were most plentiful in 1856 and one man reported trapping five in one day. For these he received $2.50 to $3 apiece (4). An otter was caught near Sac City in 1912 and it is probable that a very few still exist along the Raccoon river (2). Raccoon ( Procyon lot or) . Raccoon were common. Mr. F. M. Cory took twelve from an abandoned beaver hole in the bank of the Raccoon river in the winter of 1855-56 (3). In 1857 their pelts were worth 50 to 75 cents apiece. The raccoon is now rare but occasionally one is captured. Two were taken near Sac City in the winter of 1913-14. One was captured near Wall Lake, in a corn shock, about 1910. Black Bear ( Ursus americanus) . One black bear was chased by Jim Butler and two other hunters on horseback from south of Wall lake to the Boyer river in 1855, but the bear escaped (4). “I found a bear skeleton at Pond grove in Buena Vista county” (4). Mink I Mustela vison letifera Hollister) . Specimen in the Smith collection. Mink were more abundant in early days than now, according to one man (4) ; and of about the same abun- dance as now, according to another man (2). Another observer reports mink most common about 1905 (8). They were more common at- that time than now (1916) according to my observa- tions. One man caught ten mink in one clay along about a mile of the Raccoon river in early days (3). Fisher ( Mustela pennantii). I found no direct records for Sac county. ‘ ‘ I saw a few fisher in the later ’50 ’s and traded for two skins” (1). This man’s trading territory was principally north of Sac county. “In 1862, I followed a track in Calhoun county, which was twice as large as a mink’s and of the same style, which I think was a fisher’s” (4). Weasel ( Mustela longicauda Tongicanda) . There are two speci- mens in the Smith collection. Weasels are only tolerably com- mon now. I have always found individuals trapped after cold weather started, to be white in color. I have also found much 278 IOWA ACADEMY OF SCIENCE Vol. XXIY, 1917 variation in size, some being twice as large as others. Weasels have always had about the same abundance as at present, ac- cording to two observers (4, 8). Badger (Taxidea taxus) There is a specimen in the Smith collection, which was captured when it was small and was raised as a pet until the approach of the first winter after its capture. Badgers were common all over the prairies until about 1870 but there were none in the timber (3). Other men reported them common (2, 4). A few badger remain yet. One of my neigh- bors trapped one near Wall Lake in the winter of 1913-14. Some are still found in the hills south of this town, according to re- ports given in the summer of 1916 by farmers living in the vicinity. In the years 1911 and 1912 a badger dug many holes in the pasture and fields of my father’s farm while it was pur- suing thirteen-lined and Franklin’s spermophiles. Large Striped Skunk {Mephitis mesomelas avia). Specimen in the Smith collection. These are rare at the present day, and there are. ten or more little spotted skunks to one large striped skunk. In early days they were found all over the prairie and in the timber (3). One man saw twelve taken from one hole (4). One man reports them not common about 1870 but that they became common fifteen to eighteen years later (8). Little Spotted Skunk ( Spilogale interupta) . This skunk is commonly called “civet cat.” The first civet cats were trapped in 1858, but they must have been at Grant grove before (3). They did not spread out from the timber and become plentiful until about 1890 to 1900 (8, 2). They are now common in both the prairie and timbered portions of the country. About 1905 I trapped thirty-two in one year on my father’s farm. Red Fox, Cross Fox, Silver Fox ( Vulpes fulva f-ulva) . Red fox were common before 1880 to 1885. About this date there was brought to Sac City a pack of hounds, which ran nearly all the foxes out of the country (2). The red foxes and varieties all stayed on the prairie and not in the timber, in the early days (3). The same man reported that many foxes were killed by the use of strychnine (3). In 1864 one man and his partners trapped thirty-seven foxes. A few of them were cross foxes worth $5 each ; one, a silver fox which was worth $15 • and the others were red foxes worth $1 to $1.50 each (4). My father saw a red fox near Wall Lake in 1875 (7). An occasional red MAMMALS OF SAC COUNTY 279 fox is still trapped, and the newspapers usually report the cap- ture of about one a year in various parts of the county. The last one reported was captured by Jim Basler near Sac City in the winter of 1913-14 (3). Gray Fox ( Urocyon cinerogentus) . One man only (3), re- ported gray fox, and he stated that they were as common as red fox, the same size, and of similar habits, the only difference being color. Swift Fox (Vulpes velox) , Reports as to the abundance of this fox vary. One man (1) states that they were rather plen- tiful; another, that they were scarcer than red fox. This man (4) said that- they stayed mostly on the prairie and that their track was about the size of a cat track. He caught six in 1858 and never saw any more. Another man (2) told of a small “red” fox about one-half the size of a common red fox and a trifle lighter in color, which he called the “sampson” fox. Still another man reported trapping one at Correction pond in 1862 (3). He said they stayed on the pairie and were about one- half the size of the red fox. This same man (3) reported a “fist© wolf,” which he described as exactly like a prairie wolf or coyote, gray in color, but only about the size of a house cat, and making a track about the size of a cat track. He stated that it lbed in muskrat houses in winter and on the hills in summer, feeding on prairie chickens and mice. He trapped the last one in 1857 and had seen twenty or thirty skins which were worth 25 to 30 cents apiece. I could not identify this ani- mal from the description, and wrote the Biological Survey. Mr. E. W. Nelson’s reply stated that it must have been a gray phase of the swift fox. Coyote (Canis latrans). Coyotes were reported very common at the time of the first settlement (2, 3, 4) . One man reported that the coyotes hunted and killed red foxes but did not eat them (4). After the country settled up the coyotes decreased very much in numbers, but a few have always persisted. Of late years they seem to be increasing in numbers. Reports ap- pear in the newspapers of from one to three dens of cubs being dug out every spring, with the female only occasionally cap- tured. I trapped three in the winter gf 1913-14 near Wall Lake, and two others were trapped in other parts of the county, according to newspaper reports. At the present day the coyotes 280 IOWA ACADEMY OF SCIENCE Vol. XXIV, 1917 occasionally kill sheep, young pigs, calves and chickens; but they do not make this a habitual practice, as they live largely on cottontail rabbits. Timber Wolf ( Cams nublis) . The timber or large gray wolf was very rare. One was killed in 1859 (1), one in 1867 (4), and one in 1868 (3). One man stated that the timber wolves used to catch foxes and that they would eat them when they were caught in his traps (3). Black Wolf' ( Canis nublis). The black wolves were said to have a smaller body (4) but longer legs than the timber wolf (3). In 1858 F. M, Cory found a den and captured one of the pups which he kept a year. This was the last black wolf seen (3). My father and mother both reported a black wolf killed in Clinton county in early days or along in the 1860’s. Canada Lynx ( Lynx canadensis). All four men reported Canada lynxes rare (1, 2, 3, 4). Three were trapped in 1869 and one in 1875 (3). Bob Cat or Wild Cat ( Lynx ruff us ruff us). Bob cats were re- ported as being more common than lynx (2, 4). One man re- ported many, and that the last one was killed in 1885 (3). Panther or Puma (Felis concolor) . I found no definite records of the puma, but was told that “Winnebago John,” an old In- dian, used to recount adventures with pumas (9), presumably along the Raccoon river. Another man reported rumors of their being seen along this river, although I do not know whether the report referred definitely to Sac county, or not (11). Porcupine ( Erethizon dorsatum.) . This animal was rare. One man reported seeing one that was caught at Grant City in 1857 (3). One other person reported hearing of them (9). Opossum ( Didelphis virginiana) . Opossums were found at Grant and Lee groves when the first settlers came (3). For many years they were rare, first appearing at Sac City about 1900 (2). I saw two that were trapped near Wall Lake in 1907 and one was captured near the same town in 1911. They are spreading out oyer the prairie wherever there is a little timber. Prairie Hare or White-tailed Jack Rabbit ( Lepus campestris) . The earliest settlers report that there were no jack rabbits pres- ent at the time of the settlement of the county (2, 3, 4). The first record I find is of one seen in the southern half of the county in 1868 or 1869 (11). One man' at Lake View saw and MAMMALS OF SAC COUNTY 281 killed his first jack rabbit in 1879, and did not see another for five years (6). They were first seen at Sac City in 1880 (2, 3). They became numerous about 1890 to 1900 (7). They are now common but their numbers seem to vary over a term of years, as they are more common some years than the next series of years. When I visited some of my cousins in Clinton county about 1905, they reported that jack rabbits were just begin- ning to be captured occasionally in their locality. Cottontail ( Lepus floridcmus mearnsi) . Cottontails or gray rabbits were always common, but in early days were always to be found in the brush and timber in winter, on account of the numerous coyotes (2). Today, almost none can be found in the timber in winter, while they are common in the cornstalk fields (2). In the vicinity of Wall Lake they are usually found in the corn fields but in severe weather they often seek shelter about farm buildings. They are also numerous in the long marsh grass of the “Goosepond” in winter. Jumping Mouse ( Zapus hudsonius campestris) . One man re- ported a “kangaroo” mouse which had a tail about eight inches long and was found in the fields (4). Another man reported an extremely long-tailed mouse (2). Pocket Gopher ( Geomys tnisarius) . In early days the pocket gophers were not as numerous as now (8). Before the prairie was broken up, the pocket gophers were found in the morning glory patches (2). Today, the pocket gophers are numerous in clover and timothy fields, and often are found in pastures or along roadsides. I have found spotted skunks, weasels, and minks living in freshly opened pocket gopher tunnels, and I be- lieve that all these species prey upon the pocket gophers. Muskrat ( Fiber zibethicus). Specimen in the Smith collec- tion. Muskrats were very abundant at the time of settlement. The skins were worth from 8 to 10 cents each in 1857 and from 12 to 15 cents each in 1870, when Shelt Tiber ghien and two partners trapped 6,250 musk rats from October, 1870, to May, 1871. The highest day’s catch was eighty-one rats (4). A num- ber of the early settlers could not have lived except for the musk- rat trapping. A man could make good wages at 10 cents each, with the storekeepers willing to accept furs the same as they do eggs at the present day (8). The muskrats were called the “saviour of the people,” and taxes were paid from the proceeds of trap- ping in the days before the railroad furnished a market for 282 IOWA ACADEMY OF SCIENCE Vol. XXIV, 1917 bulkier products (2). Today, muskrats are fairly common along the Raccoon river and the Boyer, also along some of the smaller creeks and About Wall lake and the “Goosepbnd. ” In the winter of 1915-16, after the “Goosepond” was full of water all sum- mer, a local trapper stated that over two thousand muskrats were trapped. Meadow Mouse (Micro his pennsylvanicus) . These were com- mon in early days (4). Today, they are found in every slough or field where there is a rank growth of vegetation. In the win- ter they often infest stacks of clover hay and do much damage. They do not frequent corn fields, except sometimes in winter, and where there is a rank growth about the edges. Prairie White-footed Mouse (Persy sens maniculatus bairdi). This mouse is very common in corn fields at alb times of the year. .It is also found in stubble fields, but to a lesser extent. While disking a fall-plowed clover stubble in the spring, I have disked these mice out of the ground in the center of a thirty acre field. I also saAv a Franklin gull capture and swallow entire, one of these mice, when I was disking the same field. Brown or Norway Rat (Mas decumanus) . The first barn rat came in a box of goods from New York state in the spring of 1858. It escaped and was trapped the next fall in Cory’s groA7e (4). Brown rats were next reported in 1868 (2) and 1870 (3). House Mouse (Mas musclus) . I obtained no first data for the house mouse, but they were here in 1870 (8). Beaver (Castor canadensis). Beaver were very common. The darns they built across the Raccoon river were so numerous (about one-half mile apart) that there was slack water nearly all the way up the river (1, 3, 4), “My partner and I caught the last beavep, thirteen of them, on the ‘Coon’ river straight east of Lake View in 1870 (4). This was the last dam built on the Raccoon river (4). The last beaver on the Boyer river were seven which were trapped in 1886 by Mr. Levey, to the west of Wall Lake (7, 8). One man trapped six beaver in seven nights with one trap (1). The beaver steadily decreased from the time of the first settlers (4). One pioneer said that a man on the Maple river in Ida county protected beaver and that there were always beaver there (3). I know a local trapper who reported beaver along this river in 1904. MAMMALS OF SAC COUNTY 283 Woodchuck or Ground Hog ( Marmot a nionax ) . There were always woodchucks at Grant and Lee groves (3), but they never spread out much until about 1905, when they appeared at Sac City (2). They have now spread through the timber (2) and my father trapped one near Wall Lake August 27, 1912. Gray Ground Squirrel or Franklin’s Spermophile ( Citelius franklini). Specimen in the Smith collection. It is now com- mon in clover and timothy fields ; and when the hay is cut it removes to the grain fields and digs new burrows. It is very rarely found in pastures. My father has seen one of these squir- rels rob a meadow lark’s nest, and one of our neighbors who had moved to Saskatchewan, Canada, reported seeing a squirrel of this species sucking a wild duck’s egg. This species was not as common in early days as it is now (4, 8). Striped “ Gopher” or Ground Squirrel or Thirteen-lined Sper- mophile ( Citelius tridecemlineatiis) . This species also was not as common in early days as it is now (4, 8). It is now common, frequenting pastures where there is short grass, and a more or less permanent sod, almost entirely. I have . seen it catch and eat grasshoppers. Prairie Dog ( Cynomys ludoviciamis) . One man (2) reported a prairie deg town of about twenty burrows in Jackson town- ship in 1900. There were no other prairie dogs reported and I would consider it probable that these were the descendants of escaped pets. Chipmunk ( Tamis striatus) . Chipmunks were very common in the timber at first settlement. One man told of five in one bush (4). They are still found in the timber along the Raccoon river but I would consider them onlv tolerably common. Gray Squirrel ( Scirus caroUnensis) . None were reported for Sac county but one man (3) reported some at Jefferson in Greene county in 1860. My father said that in the 60 ’s, there were numerous gray squirrels and no fox squirrels about Char- lotte, Clinton county, Iowa ; and that in 1915 when he returned there for a visit, fox squirrels were numerous, but there were no gray squirrels. Western Fox Squirrel ( Scirus ludoviciamis) . The early set- tlers report this species as rare at first (2, 4). Only in late years have they become common and started to spread over the prairie to the farmers’ groves. They first appeared at Wall Lake about 1904 and are now common (1917). I have shot one 284 IOWA ACADEMY OP SCIENCE Vol. XXIV, 1917 specimen on which the reddish hair on the underp.arts was re- placed with black, and I saw another snch specimen at Sac City. Flying Squirrel ( Sciuropeterus volans). A few flying, squir- rels were said to be found in every grove at the time of settle- ment (2, 3), and some are still to be found (2). Common Shrew ( Sorex personatus haydeni). On July 13, 1917, I obtained a specimen of this shrew which Mr. Guy Martin captured in a clover field, three miles west of Sac City. It was identified by Mr. E. W. Nelson of the U. S. Biological Survey. Short-tailed Shrew ( Blarina brevicauda) . This shrew is com- mon in the vicinity of Wall Lake. After heavy and prolonged beating rains, I have often found them lying dead on our lawn. I have also seen domestic chickens kill them, not without fierce and shrill squeaking on the part of the shrew, however. Its ridges are more commonly found in pastures and hayfields, but only rarely in corn fields until after cultivation ceases. Prairie Mole ( Scalops aquations machrinus) . Specimen in the Smith collection. This species is quite common in the vi- cinity of Wall Lake. I have found it principally about farm yards, fences, pastures, and other undisturbed places. Several times in the spring I have found their dead bodies upon the surface of the ground, together with evidence that they had been making tunnels through the snow drifts. This evidence was in the form of channels in the remnants of ice left from snow- drifts. On one December day I found a mole crawling over the surface of the ground although this was frozen to a depth of two or three inches. At another time I heard a shrill squeaking and upon investigating,- found two moles fighting just below the sur- face. One was soon forced out upon the surface, but immedi- ately started to burrow under again. Red Bat ( Lasiurus borealis). This bat is common in the vi- cinity of Wall Lake. I have captured six or eight specimens which I identified by the aid of the North American Fauna on bats. I have usually found them hanging in a tree or bush a few feet from the ground. The first specimen I kept a record of was captured July 5, 1908. Hoary Bat ( Lasiurus cinereus). I captured a specimen of this bat August 23, 1908, and have seen two others of whose identity 1 was certain. It is rather common. Wall Lake. BELL’S VIREO STUDIES ( VIREO BELLI AUD.) WALTER W. BENNETT. ( WITH PHOTOGRAPHS BY THE WRITER.) There exists in the central United States, from South Dakota - and Illinois to Texas and Mexico, a bird which has interested students in that region to no small extent. It has been interest- ing not because of any phenomenal habits or any beautiful colors, but because of its modesty of dress and its elusive habits. Although common in its range it seems to have been little studied by the bird student. In the following few paragraphs the results of a miscellaneous series of studies of this bird are related. They extend over a period of eight years, from 1908 to 1915 inclusive, and were largely made in the vicinity of Sioux City, Iowa, where the species is rather common. They are entirely field studies pur- sued with definite objects in view. Some are still incomplete but In those cases the results thus far obtained are put down with the idea of encouraging further effort on the part of someone else. SPRING ARRIVALS. The Bell’s Vireo, Vireo belli Aud., is not an early spring arrival from Mexico and Central America but rather appears quite late. Records of five different years at Sioux City, Iowa, show it to come during the second and third weeks in May. The first ones have been noted on May 17, 16, 14, 14, and 18. This would average up at May 16, with the earliest noted on the 14th. Because of the bird’s retiring habits in late summer the fall departures have not been easily noted but it has been observed at Sioux City as late as September 16. DATES OF NESTING. Records of the nesting of the species at Sioux City show the eggs to be laid during the first or second weeks in June. 286 IOWA ACADEMY OF SCIENCE Vol. XXIV, 1917 The earliest date for eggs has been June 5, 1908. The following are dates of nesting: Nest T. June 5, 1908 — 3 Cowbircl’s and 1 Vireo’s eggs. Aban- doned. Nest 2. June 14, 1909 — 2 Cowbird’s eggs. Nest 3. June 1, 1910 — Partly constructed. June 11, 1910 — 3 Vireo’s eggs. June 18, 1910 — 5 Vireo’s eggs. Nest 4. June 1910 — 1 Cowbird’s egg. Nest 5. June 5, 1910 — Empty, just finished. Nest 6. June 18, 1910 — 1 Vireo’s egg. June 22, 1910 — 4 Vireo’s eggs. Nest 7. June 24, 1910 — 3 Cowbird’s eggs. Nest 8. June 24, 1910 — 1 Cowbird’s egg. Nest 9. June 24, 1910 — 1 Cowbird’s egg. Nest 10. June 20, 1915 — 1 Cowbird’s and 2 Vireo’s eggs. June 27, 1915 — 1 young Cowbird, Vireo’s eggs infertile. July 3, 1915 — Yng. Cowbird dead, no eggs. Abandoned. Nest 11. June 20, 1915 — 4 fresh Vireo’s eggs. June 27, 1915 — 4 Vireo’s eggs. July 3, 1915 — 2 young and 2 eggs. July 11, 1915 — 3 young Vireos. Nest 12. June 20, 1915 — Just finished. No eggs. June 27, 1915 — Vireo’s eggs chipped. Abandoned. Nest 13. July Q 1915 — Partly constructed. July 11, 1915 — Abandoned. SITUATION OF NEST. The smaller shrubbery bordering upon thickets and woods is the habitat usually selected by the Bell’s Yireo for a home. Many different kinds of trees and bushes are found in such places but those to which the above thirteen nests were at- tached included wild plum, gooseberry, small willows, wild haw, snowberry and dogwood. In these the nest was hung from a horizontal crotch not far from the ground, the distances of the above being 2 y2, 2, 5, 3, 2, 3, 2y2, 2%, 2y2, 2%, 2%, 2 and 5 feet. These will average 2 11-16 feet high. NEST ARCHITECTURE. There is a great field for study in the architecture of the Bell’s Yireo ’s nest. Its hanging nature must present many un- usual demands for special construction. Some of these were noted in nest number 13 above, but a forced absence of the writer prevented a continuance of the study. In this nest the first materials were placed on the horizontal branches and al- BELL’S VIREO STUDIES 287 lowed to hang down. Then coarser materials, such as grasses, were laid across the crotch about 2% inches from the angle This was to form the unsupported edge of the nest which was built up relatively strong. At this stage most of the material was at this unsupported edge. The art of nestbuilding from this point has not been worked out by the writer any more than for him to realize that there is much of vital interest to be learned from a further study of it as practised by the Bell’s Vireo. How the bird weaves the nest material in and out, how the grasses are made to cling to Fig. 43. — The typical Bell's Vireo’ s nest is always hung from a low horizontal crotch. It is made of leaves, grasses and plant fibers very com- pactly woven together. The eggs are pure w'hite with a few small brown spots mostly at the larger end. the branches, and how a definite shape is given to the mass under such trying circumstances are all questions yet to be worked out. The completed nest -of the Bell’s Vireo is somewhat different in shape from that of some of the other vireos. Whereas the War- bling and Yellow-throated build rather shallow hanging struc- tures, those of the Red-eyed and Bell’s are deeper and more bulky. Such a structure, as illustrated by nest number two 288 IOWA ACADEMY OF SCIENCE Vol. XXIV, 1917 above, measures on the inside ll/2 inches across by iy2 inches deep and on the outside 21./> wide by 4 inches deep. It is made of plant fibers, grasses and leaves and is lined with plant fibers and very fine grasses. In other cases a few occasional hairs may be found in the lining. All of these materials are very com- pactly woven together into a rather firm structure. THE EGGS. In such a nest the four or five eggs are laid, and incubation Fig. 44. — The three young vireos which hatched from the four eggs in the above nest. begins immediately. The duration of the incubation period, as illustrated in nest number 11, is about thirteen days. A SITTING HABIT. During incubation several nest habits characteristic of the Bell’s Yireo have been found. For instance, in nest number 10 the bird had a habit of sitting absolutely motionless at the edge of the nest — this at more or less regular intervals. While in this attitude the bird would not even move its head from BELL’S VIREO STUDIES 289 side to side, so stonelike was its posture. Each of these sitting periods would last from ten to twenty minutes. Although other nesting birds occasionally have been seen to sit at the nest edge, they have seldom been known to sit for such long periods or with such regularity on the part of both male and female as with • Fig. 45.— This- shows the adult as she appears in the nest. She is hardly noticeable and while an intruder is nearby she never makes a sudden move with her head lest the act attract attention. Both male and female take turns at incubating. (Nest number 10.) tlie Bell’s Yireo. The reason for this habit could not be ascer- tained. SINGING FROM THE NEST. While out on field trips the writer has frequently noticed that by going to a place where he has heard a Bell’s Vireo sing- 19 290 IOWA ACADEMY OF SCIENCE Vol. XXIV, 1917 mg lie could usually find a nest. It has seemed, in fact, that location of song and nest coincided to a marked degree, which soon led to the theory that possibly the bird sings on the nest Fig. 46. — During incubation both male and female had the habit of sitting motionless at the nest edge for periods of from ten to twenty min- utes at a time, this with an unusual frequency. as does the Warbling Yireo. Nothing had been published to this effect before 1911 when the writer told in Bird Lore of BELL’S VIREO STUDIES 291 the discovery of this habit. Nest number 6 was the object of investigation and on June 22, 1910, the writer observed the bird singing from the nest. Whether or not this vireo practices it as a general thing has not yet been worked out, but the fact that the writer has in an unusual number of cases found the Fig. 47. — The young Cowbird in this nest was fed many a large cater- pillar but the two vireo’s eggs failed to hatch. (Nest number 10.) nest where the bird had been singing, would seem to be pretty strong circumstantial evidence of a more or less general habit. A POSSIBLE DECREASE IN NUMBERS. In this clay of bird conservation little effort seems to have been made so far to ascertain whether the Bell's Vireo is in- 292 IOWA ACADEMY OP SCIENCE Vol. XXIV, 1917 creasing or decreasing in numbers. However, at a meeting of the Sioux City Bird Club on October 1, 1914, one of the best known bird authorities for northwestern Iowa, Dr. Guy C. Rich, made the statement that “the Bell’s Yireo has decreased in numbers in the last thirty years.” A study of the above series of nests seems to support Doctor Rich in his statement. PEW SUCCESSFUL BROODS. The extreme difficulty in raising young vireos is much em- phasized in the above series. With the exception of nest number 5, which was empty, there were only three successful broods of vireos raised out of the thirteen nests. These were numbers 3, 6, and 11. All others were either abandoned or had Cowbird’s eggs. Considering the well known characteristics of the latter in hatching early and in preventing the young vireos from get- ting sufficient food it is safe to presume that very few vireos were raised in the nests containing Co whir ds ’ eggs. This pro- portion of only three successful broods out of thirteen, if it is representative, and it appears to be nearly so, does not present a very bright future, at least for an increase in numbers, for the Bell’s Yireo. THE MORTALITY IN POUR NESTS. During the summer of 1915 close watch was kept of four dif- ferent Bell’s Yireo nests to find out the rate and causes of some of this mortality. The last four of the above nests were the ones observed. In nest number 10 the Cowbird’s egg hatched, while the two vireo’s eggs were infertile, but on July 3 the young Cowbird was found dead and the nest abandoned. Out of four vireo’s eggs in number 11 three hatched and the young were raised. Both nests 12 and 13 were abandoned, the former after the eggs had been chipped and the latter before any eggs had been laid. The result of this study was to determine that only one out of the four pairs of birds was actually successful in raising young vireos. Only three birds came from the four nests. Nat- urally the parents nested somewhere else after an unsuccessful attempt but, if these observations are representative, they prob- ably met with a similar degree of failure to raise progeny in their further attempts. Storms, animals, Cowbirds and vermin BELL’S VIREO STUDIES 293 are all possible causes of this unusual lack of multiplication of the species. These two things, then, an unusual number of Cowbirds’ eggs in nests and the raising of only three vireos in the four nests — 10, 11, 12, and 13 — point to a probable diminution in the numbers of Bell’s Vireos, at least in 1 he neighborhood of Sioux City, Iowa. Department of Zoology, Grinnell College. AN ANALYSIS OF THE CRANIAL GANGLIA OF SQUAWS ACANTHI AS. SALLY P. HUGHES. ■J . ' This analysis confirms to a large degree the observations of Strong (1903) and Landacre (1916). In Sqitalus acanthias the fifth, seventh and eighth nerves arise close together from the wall of the medulla and form a complex of roots^ ganglia and fiber tracts. Taking them up in order, the gasserian or fifth nerve ganglion is seen to be a large hourglass-shaped mass, ex- tending out ventro-laterally from the brain wall ; the distal part gives rise to the maxillaris V and the proximal part to the super- ficial opthalmic Y and the mandilubar Y. The profundus gang- lion is entirely distinct from the gasserian. It is in contact dorsally with the anterior lateral line ganglion which sweeps out in a semicircle laterally, nearly hiding the trigeminal ganglia. The fibers of the superficial ophthalmic Y join those of the pro- fundus at the ventro-medial edge of the profundus ganglion and pass together with them in a compact tract along the dorsal edgle of the gasserian, entering the brain as the first and prob- ably the third roots of the fifth nerve. The second root is of visceral motor fibers from the mandibular Y, the third is sensory, then two small motor roots, followed by the main sensory root of the trigeminus, with a few motor fibers running with it. The lateral line fibers of the complex are restricted to the seventh. There are three lateral line ganglia in this complex — one for the superficial ophthalmic, one for the buccalis (these two are in contact where the flattened head of the infraorbital trunk meets the ophthalmic), and one situated out on the hy- omandibular trunk, the external mandibular ganglion. This last is a round column of cells which does not affect the shape of the nerve trunk. The fibers of the mandibularis externus join those of the bueealis to form a large ascending root which arises from the lateral line lobe of the brain. The superficial ophthal- mic fibers pass through this cauclally, forming the ventral lateral line root. The VUIth ganglion is closely bounded ventrally by the lat- eral line root. It comprises a proximal vestibular portion and a 296 IOWA ACADEMY OF SCIENCE Vol. XXIV, 1917 I more columnar posterior saccular portion. The auditory fibers enter the brain in a compact root just posterior and ventral to the lateral line roots. The geniculate or visceral VII ganglion is a triangular mass quite distinct from the rest, in contact caudally with the pos- terior lateral line ganglion. The roots of the YII-VIII complex are, from anterior to posterior : . (1) the large ventral lateral line root, (2) a visceral root soon separating into a distinct dorsal communis and a ventral motor root, (3) the dorsal lateral liiie root, (4) most posteriorly, the large auditory root. These do not follow each other in succession, but overlap to a large extent so that lateral line, communis, visceral motor, and audi- tory fibers may be seen leaving the brain in a single section. The IXth nerve contains visceral sensory, visceral motor and lateral line components. It rises from the wall of the medulla by a series of five roots. The first three are small motor roots, extending in an attenuated tract much farther anteriorly than the main root which is largely visceral sensory. The lateral line root is a small distinct tract entering the brain just ventral to the lateral line root of X. The ganglion lies at the end of a long root, in a cavity of the cartilage of the ear capsule. The visceral ganglion forms a large oval enlargement on the nerve. The lateral line ganglion is a small mass of cells beginning some- what anterior to the visceral ganglion. Though lying close to the latter, it is perfectly distinct from it, and its presence is indicated by an appreciable indentation in cross-section. The vagus nerve contains visceral sensory, visceral motor, gen- eral cutaneous and lateral line components. The last two are distributed through supra-temporal and auricular rami to the canal organs of the posterior head regions and through a large lateralis trunk to the canal organs of the body. The lateral line fibers rise in one large compact root just dorsal and ex- tending slightly posterior to the lateral line root of IX. They pass posteriorly in a flat ribbonlike band closely appressed to the brain wall. The lateral line ganglion shows evidence of seg- mentation into three parts. The first is the most anterior part of the vagal ganglion, a slender column of cells which gives rise to the supra-temporal ramus. Just posterior to this and for some distance in contact with it lies the major part of the ganglion, two scarcely separable masses of cells from the first of which CRANIAL GANGLIA OF SQUALUS ACANTHIAS 297 rises the lateral line component of the auricular ramus. The third ganglion and the remaining fibers from the second ganglion form the main lateralis trunk. I fail to find a distinct root or ganglion for the small general cutaneous element in the vagus. Its fibers are distributed with those from the first two lateral line ganglia, a few entering the supratemporal X and the major part uniting in approximately equal portions with lateral line fibers to form the auricularis X. The visceral roots of the Xth extend for a long distance postero-dorsally along the medulla wall. In the specimen studied there is a series of seventeen visceral roots. The majority of these are mixed, comprising a wide sensory strand and a small onotor strand. The posterior (4) roots are all motor. The motor fibers arrange themselves in fairly definite strands and are traceable through the large fibrous root of X to their distribution in the branchial and visceral nerves. The visceral X ganglia show a segmentation into four branchial and one intestinal divisions, all more or less in contact, and the last two quite fused. The cervical plexus is composed of the two occipital nerves and a large motor and a small sensory element from each of the first three spinal nerves. Though closely in contact with the vagus for some distance there is no interchange of fibers. Department of Zoology, Grinnell College. r • ■ THE EYEBALL AND ASSOCIATED STRUCTURES IN THE BLINDWORMS. H. W. NORRIS. Incidental to a more extended investigation of coecilian anat- omy the following observations were made upon the ocular muscles and nerves. Typically two groups of muscles are attached to the eyeball in vertebrates : a rectus group of four muscles, dorsal, ventral, lateral and medial ; and an oblicpie group of two muscles, dorsal and ventral. The dorsal, ventral and medial rectus and the ven- tral oblique muscles are innervated by the oculomotor ; the dor- sal oblique is supplied by the trochlear nerve, and the lateral rectus by the abducens. This is the arrangement in a shark and in man. In some other cases there is a retractor bulbi muscle of the eyeball. In such forms as the cat, dog and ox the re- tractor bulbi is in four slips, which in their insertion alternate with the four rectus muscles. It is quite commonly stated in works on the anatomy of the domestic animals that the retractor bulbi is innervated wholly or in part by the oculomotor nerve. Hopkins has recently shown that such statements are wholly in error, the muscle always being innervated by the abducens nerve. In many of the amphibians we see another muscle related to the movements of the eyeball, a levator bulbi muscle, innervated by a branch of the mandibular ramus of the trigeminal nerve. In the coecilian amphibians the optic apparatus is always more or less rudimentary or modified. Two distinct types occur. In the one the eyeball is situated beneath the maxillary bone; the optic nerve and all the eye-muscles and eye-muscle nerves, except the retractor bulbi and its nerve, the abducens, have completely disappeared. The retractor bulbi becomes the re- tractor muscle of the tentacle. In the other type the eyeball is situated just beneath the skin, and while rudimentary is never- theless probably affected by light. Some or all of the eye- muscles and their nerves may be present, but for the most part in a vestigial condition,, or modified for purposes other than op- tical. In Herpele ocliroceplialum we have an example of the first type. The large retractor tentaculi is innervated by the sixth 300 IOWA ACADEMY OF SCIENCE Vol. XXIV, 1917 nerve. Corresponding* apparently to the levator bulbi of urodele and anurous amphibians there is a compressor muscle of the or- bital glands, like a true levator bulbi innervated by a branch of the ramus mandibularis Y. Inserted upon the sheath of the orbital glands is another muscle which acts apparently as a dila- tator of these glands, also innervated by the same branch as the compressor muscle. In Dermophts mexicanus only the internal rectus muscle is lacking. There is an extremely vestigial retractor bulbi. The retractor tentaculi is a well developed muscle. All three eye- muscle nerves are present, but only the abducens is of any con- siderable size. A compressor and a dilatator muscle of the or- bital glands are present and more strongly developed than in Herpele. In the larva of Ichthyophis all the eye-muscles are present, but only the retractor tentaculi is of functional importance. In stages before the tentacle is formed the retractor tentaculi is in- serted upon the eyeball. Compressor and dilatator muscles of the orbital glands are present. In Geotrypetes petersii there are two well formed muscles re- lated to the tentacle. One is the retractor tentaculi innervated by the abducens; the other is innervated by the oculomotor nerve .and evidently corresponds to an internal rectus muscle. It is inserted upon the tentacular sheath. The other muscles of the eyeball are vestigial. A compressor muscle of the orbital glands is present, but not a dilatator. Thus we see that in the coecilians the typical amphibian eye- ball musculature has been modified first by the degeneration of muscles and nerve to the point even of complete disappearance in some instances; second by the transfer in function and ana- tomical relations of certain muscles from the eyeball to ad- jacent organs, as the retractor bulbi transformed into a re- tractor tentaculi, the rectus internus changed into a retractor of the tentacular sheath, and the levator bulbi modified to com- pressor and dilatator muscles of the orbital glands. Department of Zoology, Grinnell College. i THE BERMUDAS AS A TYPE COLLECTING GROUND FOR INVERTEBRATES. H. A. CROSS, JR. Eighty hours from Chicago lands one at the wharf of Hamil- ton in the Bermuda Islands. Temporally these islands are near, although 700 miles southeast from New York, and 560 miles due east from Charleston, South Carolina. Topping the summit of a huge submarine mountain, built up by the secretion of corals, shifted, torn down, and stratified by the action of wind and wave, these islands project to the number of one hundred and fifty, forming nineteen square miles of land whose surface is a thin ten inch layer of red brown soil. In the aggregate, these islands assume the form of a fishhook. The portion neees- say to convert the fishhook into a complete oval is filled with sea gardens containing many forms of Gorgonacea and other garden fauna. These gardens lie at varying distances under the surface, making collection with nippers and chisel easy, while on a smooth day collecting may be accomplished without the aid of instruments. The Gulf Stream two hundred and fifty miles to the north imparts to the islands a semi-tropical climate, with a mean temperature of 72°, a maximum of 86°, and a mini- mum of 58°. As a consequence, we find a semi-tropical or sub- tropical fauna on a parallel of thirty-two degrees, the point farthest north in the Atlantic where such can be found. As a collecting ground, the Bermudas, as they are called, present many advantages to the midwestern man. For two hundred dollars the trip can be made to and from Chicago, with a stopover of six weeks on the islands. As stated before, transportation takes but little time, and facilities for the same are very good. Harvard University maintains a biological station there the year round. Two years ago but little literature was available at the station. Since that time they have put a man in charge per- manently and undoubtedly the literature at the present time covers more ground. The library at Hamilton affords a set of Reports of the Challenger Expedition which is of great value. The increasing number of publications made by the summer 302 IOWA ACADEMY OP SCIENCE Vol. XXIV, 1917 residents at the Laboratory renders the amount constantly more varied. Running water, together with collecting apparatus and a fair complement of laboratory equipment are other advantages which the laboratory offers. The attending people have free use of the aquarium located on Agar’s Island. A private laboratory, if desired, may be erected and main- tained at little expense, which permits more freedom for the col- lector. Save the slight amount of literature and the running water such a laboratory presents as many advantages to two or three men as does the Laboratory on Agar’s Island. Three men from Grinnell maintained such a laboratory, and the expenses for the stay there were less than for the same time spent at the Harvard Station, while the individual freedom was consid- erably greater. During a term of more or less superficial collecting, on account of a limited knowledge of invertebrate forms, the following types were secured : Porifera Calcarea Non-Calcarea Myxospongiae Silicispongiae Hexactinellida Desmospongiae Coelenterata Hydrozoa Leptolinae Anthomedusa Leptomedusa Hydrocorallina Scyphozoa. Discomedusae Semostomae Actinozoa Zoantharia Actiniaria Madreporaria Alcyonaria Gorgonacea Platylielmintlies Turbellaria Polycladida Molluscoida Echinodermata Asteroidea Cryptozonia Orpliiuroidea Ophiurida Echinoidea Regularla Clypeastridea Holothuriodea Pedata Apoda Annulata Chaetopoda Polychaeta Errantia Sedentaria Cephyrea Inermia Arthropoda Crustacea Entomostraca Malacostraca Decapoda Macrura Brachyura THE BERMUDAS BOB Mollusca Pelecypoda Filibranchia Pseudo-lamellibranchia Eulamellibranchia Sinupalliata Amphineura Plachophora Gastropoda Aspidebranchia Docoglossa Pectinibranchia Platypoda Enthyneura Opisthobranchia Tectibranchia Nudibranchia Pulmonata Cephalopoda Dibranchiata Decapoda Octopoda These as stated before are but a few of the numerous species obtainable. No doubt even the type forms are more numerous. For instance, there should be included Nemahelminth.es, Trochel- minthes, etc. Worthy of mention are the protochordates. The following forms were found : Adelochorda Balanoglossus Urochorda Tunica nigra Rhodozona picta, with larvae in the test Acraniata Amphidxus Caribbean Thus it is seen that as a type collecting* ground for inverte- brates, the Bermudas are excellent, considered both geographi- cally, financially, and from the standpoint of completeness. Department of Zoology, Grinnell College. THE INFLUENCE OF THE MALE ON LITTER SIZES.1 EDWARD N. WENTWORTH. A common belief among practical breeders is that the male in multiparous species affects the number at a birth. This be- lief has even permeated scientific writing ; many biologists ap- parently taking the supposed observation at face value, while others have sought biometrical proof in the various accumula- tions of the data regarding fertility inheritance found in bio- logical records. Thus Ewart reports the case of a long-haired Skye terrier bitch that was infertile to two males of her race and was the dam of one weakly pup to the service of a third, which produced four strong pups to a vigorous West Highland terrier. Harris, in some calculations made on litter frequencies reported by Wentworth and Aubel, calls attention to the fact that there is a statistically significant correlation between the size of litter in which boars are produced and the size of litters in which their daughters are produced, while he discovers the same thing in data reported on Shropshire sheep studied by Rietz and Roberts, Several other series of statistics show sim- ilar characteristics, although they are not as extensive as those discussed. From purely logical grounds it is difficult to conceive why the male should affect the number per litter. It would seem obvious that among the millions of sperm cells in each seminal discharge of the male there would be sufficient gametes not only to fertilize the relatively few ova released by the female, but also to reach them in time to form an effective union. Theoreti- cally there seem to be only three ways possible in which there might be differences between males. First, the male although functional to a certain degree, might produce such weak cells that their vitality would be exhausted before they could reach the ova. Second, even though they reach the ova, they might not form strongly viable zygotes, a condition which is frequently found in multiparous animals. Hammond reports that in swine there are normally several fertilized ova which atrophy during the gestation period, although he seems unable to determine the JPaper No. 7 from the Laboratory of Animal Technology, Kansas State Agricultural College. 20 306 IOWA ACADEMY OF SCIENCE Vol. XXIY, 1M.7 cause. There is a possibility that one cause for atrophy might be inherent in the sperm. Third, it is possible that there may be an influence of the sperm on the egg similar to that which causes duplicate twins. This is difficult to prove. Recognizing that there are three such classes of possibilities, all of which were impossible to test with data the writer had at hand, an examination of a large amount of new material was made with the view of discovering whether such conditions ex- isted inherently in all cases. Southdown sheep and Chester White hogs were chosen for this purpose, as well as a few records on Collie dogs. In Southdown pedigrees begun from single births the average progenies were of course decidedly, lower than in those begun from multiple births, since there were only seven possible matings on each pedigree blank (the great-grandparental generation be- ing the last). Furthermore, in many cases the sire, grand- parents, or great-grandparents, were imported, with few data obtainable as to birth rank. This gave considerable statistical weight to. the mating from which the pedigree started. ITence the results from Southdown pedigrees begun with multiple births are presented separately. The data for each are presented in Tables I and II. TABLE I. BREEDING PERFORMANCE OF SOUTHDOWN MALES IN PEDI- GREES STARTED FROM SINGLE BIRTHS. Birth Rank of Sire Number Cases Birth Rank of Progeny 1 2811 1.2864±.0059 886 1.2776±.0103 3 18 1.3888±.0775 TABLE II. BREEDING PERFORMANCE OF SOUTHDOWN MALES IN PEDI- GREES STARTED FROM TWIN BIRTHS. Birth Rank of Sire Number Cases Birth Rank of Progeny 1 4120 1.5296±.0054 2 1165 1.5682±.0072 3 26 1.6154±.0644 INFLUENCE OF THE MALE ON LITTER SIZES 307 Iii Table I the differences between sires of different birth rank as far as breeding qualities are concerned, are in no case signifi- cant, if the conventional ratio of the constant being at least three times its probable error is assumed. In Table II, the dif- ference between singles and twins, .0386 ± .0091 is possibly signifi- cant, the others are not. Since five out of six such constants are not significant, it is doubtful if the sixth one is, even though the chances of its being significant are approximately 216 to 1. Of Chester White hogs the following statistics were collected. TABLE III. BREEDING PERFORMANCE OF CHESTER WHITE BOARS OF DIFFERENT BIRTH RANK. Birth Rank of Sire Number Cases Birth Rank of Progeny 5 2 8.0000±.4769 6 _ ___ 7 7.2857±.3531 7 31 65 7.9644±.2061 8_ __ S.3235+1889 9 _ _ 112 8.1447±.1473 10 __ 100 7.8623±.1542 11 54 7.9466+1894 12 _ ___ __ 30 8.1121±.2013 13 H 11 7.6524±.28177 14__ _ 2 9.0000±.4769 15 1 8.0000 In no case in Table III is the difference between any two types of sires statistically significant. Table IV shows the results obtained from a few records on Collies. The figures are not comparable statistically, but since the evidence is the same as in the previous cases, the data, are presented. TABLE IV. EFFECT OF BIRTH RANK OF SIRE IN COLLIES ON NUMBER OF PUPS PER LITTER. 4. 5. 6. 7. 8. Birth Rank of Sire Number Cases Average Number Progeny 3 7 7 4 2 5.3333+1836 5.5714+2304 5.7142+1805 5.7500±.2500 .5.0000+ 4769 308 IOWA ACADEMY OF SCIENCE Vol. XXIV, 1917 While these numbers are by no means large enough to be conclusive, yet in the face of the conflicting evidence from other sources it would seem that the male has no significant effect upon the litter number. Such conclusion seems just on logical grounds in spite of the possibilities suggested earlier in the paper, and until more definite evidence is adduced it seems only, reasonable to conclude that the female determines the number at a, birth. Kansas Agricultural College. LITERATURE CITED. EWART, J. C., The Breeding and Origin of Domestic Animals: 27th Report Bureau of Animal Industry, pp. 125-186, 1910. HARRIS, J. A., Variation, Correlation, and Inheritance of Fertility in the Mammals: American Naturalist, Vol. 50, pp. 626-636, 1916. RIETZ, H. L., and ROBERTS, E., Degree of Resemblance of Parents and Offspring with Reference to Birth as Twins for Registered Shropshire Sheep: Journal of Agricultural Research, Vol. 4, pp. 479-510, 1915. WENTWORTH, E. N., and AUBEL, C. E., Inheritance of Fertility in Swine: Journal of Agricultural Research, Vol. 5, pp. 1145-1160, 1916. A LIST OF ENTOMOSTRACA FROM THE OKOBOJI REGION. FRANK A. STROMSTEN. The following is a list of Entomostraca collected by the writer at the Macbride Lakeside Laboratory during the August ses- sion, 1916. The starred forms have been previously reported from this region by Prof. L. S. Ross in volumes III and IY of the Proceedings of the Academy. CLADOCERA. SIDIDAE. *Sida crystallina (0. F. Mueller), West Okoboji. Abundant. DAPHNIDAE. *Daphnia hyalina Leydig. West Qkoboji Lake. vDaphnia kahWergensis. East and West Okoboji and Gar Lakes. Scapholeibris mucurata (0. F. Mueller). West Okoboji Lake. Abundant. Simocephalus vetulus (0. F. Mueller). West Okoboji and Drain- age Canal. Abundant. *Simocephalus serrulatus (Kocli). West Okoboji Lake. Abundant. Simocephahis americanus Birge. Drainage Canal. BOSMINIDAE. *Bosmina longirostris O. F. Mueller. Very abundant in this region. LYCEIDAE. Gamptocercus macrurus 0. F. Mueller. West Okoboji Lake. Alonella excisa Fischer. Kettlehole near West Okoboji Lake. Pleuroxus stramineus Birge. Spirit Lake and West Okoboji Lake. *Pleuroxus clenticulatus Birge. Kettleholes and West Okoboji Lake. * Pleuroxus procurvus Birge. Kettleholes and West Okoboji Lake. ( Pleuroxus hcnnatus Birge. Iowa City). COPEPODA. CENTROPAGIDAE. Diaptomus siciiis Forbes. West Okoboji and Gar Lakes. Diaptomus signicauda Lilljeborg. West Okoboji Lake. Diciptovius oregonensis Lilljeborg. Kettleholes, Okoboji and Gar Lakes. Abundant and some specimens highly colored. Diaptomus clavipes Schacht. East Okoboji Lake. Diaptomus pallidus Herrick. Middle Gar Lake. 310 IOWA ACADEMY OF SCIENCE Vol. XXIV, 1917 CYCLOPIDAE. Cyclops signcitus var. coronatus Koch. Kettleholes. Cyclops signcitus var. tenucornis Koch. Kettleholes. Cyclops insignia Claus. West Okoboji Lake. Cyclops serrulatus Fischer. Marble Lake. Cyclops macrurus Sars. Marble Lake. Cyclops fluviatilis Herrick. Very abundant everywhere. Cyclops affinis Sars. West Okoboji Lake. Cyclops bicolor Sars. Kettleholes. Abundant. Cyclops phaleratus . Koch. Very abundant in kettleholes and lakes Cyclops fimbriatus Fischer. Very abundant in lakes. Laboratories of Animal Biology, The State University. THE DEVELOPMENT OF MUSK GLANDS IN THE LOGGERHEAD TURTLE. (ABSTRACT.) FRANK A. STROMSTEN. Musk glands were first described in turtles by Dr. William Peters in 1848, and independently, in the same year, by Rathke. The glands do not appear to be present in all turtles, but when present consist of one or two pairs according' to the species of turtle. One pair is located at the anterolateral angles of the carapace, just beneath the peritoneum. The second pair, when present, is found at the posterolateral angles, one on each side. According to Peters, the secretion is a brownish, watery fluid, tasteless, but having a very penetrating odor. The glands are compared to the “ Kief erdrusen ” of Crocodiles (Mueller’s Ar- chives, 1848, 492-6). In a loggerhead turtle embryo at the time of hatching there are two pairs of musk glands. The anterior pair are double, having a cranial and a caudal portion, opening to the exterior by separate ducts. The duct of the larger cranial portion opens just beneath the lateral border of the carapace between the third and fourth marginal plates. The duct of the smaller caudal por- tion opens between the fourth and fifth plates. The posterior glands are single and lie beneath the eighth marginal plate of each side. Histologically, the wall of the gland is made up of three lay- ers, more or less distinctly defined. The outer layer consists mostly of striated muscle fibers, the middle layer of connective tissue, and the inner layer of more or less flattened epithelial cells. The gland at this stage of development is of the simple branching alveolar type. The epithelium is derived from the ectoderm and the muscu- lar layer from the deep muscles of the ventral thoracic region. Development is initiated by the elongation and proliferation of the ectodermal cells of the ventrolateral border of the carapace just caudad of the anterior limb (figure 48, a, b). The mesen- chyme in the immediate region of the proliferating ectodermal 12 IOWA ACADEMY OP SCIENCE Vol. XXIV, 1917 cells shows a condensation due to rapid multiplication of cells and to the intrusion of wandering leucocytes. There is thus Figure 48. — Loggerhead turtle embryo of about 20 days incubation. a. Section showing region of elongating ectodermal cells and condensation of mesenchyme, b. A portion of, same region enlarged. formed in an embryo of about twenty-four days incubation (fig- ure 49) a small elevation on the inner surface of the ectoderm Figure 49. — Loggerhead Beginning of musk gland. turtle embryo of about 24 days’ incubation. 1. 2. Muscle.. 3. Lung. 4. Liver. which grows upward, rodlike, through the mesenchyme of the carapace (figure 50). After passing through this denser tissue Figure 50. — Loggerhead turtle embryo of about 25 days’ incubation. 1. Developing gland. 2. Muscle. 3. Muscles of anterior limb girdle. 4. Car- tilage of anterior limb girdle. of the carapace this rod of cells penetrates the peripheral portion of the deeper breast muscles of this region and divides into sev- THE LOGGERHEAD TURTLE 313 eral brandies. The rod of cells with its branches then becomes hollowed out and forms the duct and secreting alveoli of the gland (figure 51). The muscle mass and connective tissue im- Figure 51. — Loggerhead turtle embryo of about 31 days’ incubation. 1. Musk gland. 2. Muscular and connective tissue wall. 3. Liver. 4. Costal cartilage of carapace. mediately surrounding the epithelial gland condense to form the walls of the gland. Laboratories of Animal Biology, The State University. SOME NEW ENJDOPARASITES OF THE SNAKE. THESLE T. JOB. In the fall of 1916 a large, live specimen of Black Snake, Zamenis constrictor (Linn.), was sent from Garrison-on-Hudson, New, York, to Miss G. Van Wagenen of the State University of Iowa. In December the snake was killed and dissected. At that time three different endoparasites were found which were classified according to the present inadequate and chaotic liter- ature on these groups, as Porocephalus globicephalus Hett, a new Benifer and a larval Gigantorhynchus. It is not the purpose of this paper to add new names to the al- ready complicated list, but rather to record the characters of the male P. globicephalus Hett, which Mary Hett did not have in describing the species, and to give additional notes on the habits and anatomy; also to .record the data of what is appar- ently a new species of Benifer. Porocephalus globicephalus Hett. This is a Linguatulid worm. Mary L. Hett of the London Zoological Society described and named the species from a single, mature female specimen, procured from the lung of an American specimen of “moccasin,” Tropidonotus fasciatus (Linn.). In the Proceedings of the Zoological Society of London, 1915, pages 115-121, she gives the following characters: length 50 mm.; an- nulations about 50 ; hooks simple and sharply curved ; mouth is pear-shaped with pointed anterior end; head globular; well marked reck; anus transverse slit on terminal segment. There were five males and five females found in the host re- ported here. One female was taken from the middle portion of the lung and two other females from the posterior end of the lung, while three males were taken from the same general region. Another male and female were taken from the dorsal body wall of the air sac about one foot posterior to the lung, and still an- other pair a foot further back, also from the dorsal body wall of the air sac. The females were found with only the head embedded in the lung tissue, or, those in the air sac, in the musculature of the body,, where a copious hemorrhage was found. The rest of the 316 IOWA ACADEMY OP SCIENCE Vol. XXIV, 1917 body of the parasite was free from attachments, hanging limply in the Inmen of the lung or air sac. The heads of the males were not embedded in the tissues of the host, but only superfi- cially attached to the walls of the lung and air sac by the hooks. The females vary in length from eighty-two mm. to ninety- six mm., and are somewhat larger than the specimen described by Hett, while the males were from fourteen mm. to thirty mm. in length. The color of the females is lemon-yellow and the body wall is transparent and thus permits easy observation of the mass of embryos and digestive tract within. The males are pale cream in color and the body walls are opaque. The head is globose dorsally; ventrally it is slightly concave with four sharply curved hooks at the anterior edge of the con- cavity, two on either side of the pear-shaped month. The neck is markedly constricted ; the body is subcylindrical, slightly taper- ing to the posterior end which is blunt. There are about fifty annulations, though the number varies in different individuals from forty-eight to fifty-two. The digestive tract, which was gorged with blood, was readily seen in the living specimen. The Distome. The second parasite found belongs to the genus Renifer and is evidently a new species. It is most nearly allied to R. ellipticus Pratt, but differs from it in many points, as a comparison of the following data with those of H. S. Pratt in “Description of Pour Distome, Mark Anniversary Volume, 1903, will show. r “Length 6.5 mm. Maximum breadth 1.72 mm. Ventral surface flattened, dorsal quite convex. Spines seem to me lacking, except perhaps anteriorly. Oral sucker sub-terminal, diameter 0.52 mm. Acetabulum 0.74 mm. in diameter, about 1.11 mm. from oral. Genital pore 0.37 mm. from left edge of body. Much farther for- ward than in R. ellipticus, opposite the hinder edge of the oral sucker or anterior one-half of the pharynx. Ventral. Pharynx 0.296 mm. long. Oesophagus 0.11 mm. long. Intestinal coeca simple; pass beyond the testes (apparently right beyond the right testes). Union of the vasa efferentia behind the equator of the acetabulum. Cirrus sac about 1.24 mm. long by 0.40 mm. wide at middle.” These data were taken by Mr. A. R. Cooper. The six specimens of this species were found attached to the lateral walls of the coelomic cavity and on the outer surface of SOME NEW ENDOPARASITES OF THE SNAKE 317 the intestine, in the posterior sixty cm. of the coelomic cavity. They appeared as black spots. LARVAE OF ACANTHOCEPHALIA. Genns Gigantorh yn chns. This parasite was found only in the encysted stage. The pos- terior forty cm. of the intestine was almost covered with these encystments, which were just under the mesenteric covering. The species is not determinable as yet, because of the lack of in- formation of the larval stages of the whole genus. Laboratories of Animal Biology, State LTniversity of Iowa. FURTHER NOTES ON THE VENOUS CONNECTIONS OF THE LYMPHATIC SYSTEM IN THE COMMON RAT. THESLE T. JOB. As long* ago as 1825 the Italian anatomist, R. Lippi, published a paper on * ■ Ulustrazioni fisiologiche e patologiche del sistema linfaiicQ-chilifero mediante la seoperta di un gran numero di comunieazioni de esso col venoso” in which he brought out the fact that the lymphatics not only connect with the veins at the Jugulo-subclavian juncture but also join the Inferior Vena Cava and Portal vein. J. Jolly .in his work ‘ ‘ Rescherches sur les ganglions lymphatiqueS des oiseaux, ” 1910, discredits Lippi’s work because he thinks Lippi described the testes of the duck as lymphatic nodes ; if such a mistake as this were made, he thinks all of Lippi’s work should be doubted. However, this may be it is quite evident now that there are lymphatic connections with the venous system at other points than the Jugulo-subcla- vian taps in the common rat, which, even if they are not con- stant, appear at least in a good percentage of cases. Whether they are constant or variable is significant as will be shown later. Two years ago the writer presented before this Academy a paper “On the Lymphatic System of the Common Rat” in which it was shown that the Jugulo-subclavian taps were not the only connections in the rat. A portal vein connection was proven then, and in addition the renal vein connection found by Chas. F. Silvester in the South American monkey, was demonstrated in the rat. Moreover, two specimens were observed in which there were ilio-lumbar connections. Two instances out of 100 would seem insignificant, but when one comes to interpreting the meaning of venous, connections, they are very important. With the renal, portal and ilio-lumbar connections proven, the writer wishes to present still another connection, that of the inferior vena cava at the level of the lumbar nodes. Before considering the proof and significance of these con- nections it might be well to point out some; important phases of the technic. The stab injection method, which lias been em- ployed in these studies, must be used with the greatest care and 320 IOWA ACADEMY OF SCIENCE Vol. XXIV, 1917 the movement of the injecting mass watched very carefully to render the results trustworthy, because filling the veins with the mass directly from the point of injection does occur in some instances. In this connection the writer has considered as le- gitimate proof only those instances in which the injecting mass has been seen to leave the lymphatic channels and enter the veins, or, in which a dissection could be made to show a con- nection between a lymphatic vessel and a vein. Such conditions do not occur in every specimen injected, so a large number is necessary to furnish a basis for drawing conclusions. Further- more, the physiological condition of the animal must be taken into consideration. There is evidence that specimens killed with illuminating gas give a higher percentage of instances of venous connections and show a finer network of plexuses than specimens killed with ether or chloroform. There is a basis also for the belief that the degree of activity, the length of time after feeding and the physical condition of the^animals are facts which vary the response of the lymphatic vessels to the inject- ing mass. Thus it may be that in part the lack of constancy in the venous communications is due to these conditions. In aboat twenty-five per cent of the specimens injected, portal vein taps can be shown by observation and dissection. Two cases of particular interest were observed. When the most distal intestinal node was injected the mass was seen to run along the lymphatic channel from this node to the region just dorsal to the pyloric end of the stomach ; there it entered the portal vein and ran into the liver and out toward the injected node, thus giving as clear a demonstration of this connection as could be demanded. The connection in the portal vein is of particular interest in connection with the experiments carried on by physiologists. If the amount of fat contained in the lymph taken from the thor- acic duct, after feeding an animal a known quantity of fat, be added to the amount lost in the feces, a variable amount is shown to have disappeared by some other route. Physiologists have considered that this amount must be taken up directly by the venous capillaries of the villi, even though it is not a satisfactory explanation to them. The portal vein communica- tion of the intestinal lymphatic channel can account for this variable difference. THE LYMPHATIC SYSTEM OF THE RAT 321 In the inferior vena cava there is a larger percentage of com- munications shown. The writer is confident that this connec- tion has been overlooked by him in many injections, because of either a complicated net-work of vessels between the two lum- bar nodes, thus masking the connection, or in instances where the plexus was slight, by the communication being directly from the node and thus taken for a ruptured vein and not a lymphatic vessel. By careful dissection and observation this lymphatic communication has been demonstrated in about one- half of the specimens used since the first connection was noticed. Instances have been noticed where the mass left the main lym- phatic channel and entered the vein by one or more taps, giv- ing again undoubted evidence of the connection. There is no correlation between the number and position of the venous communications in any one specimen. All connec- tions may be present in one specimen, while only three or two or even just the jugulo-subclavian taps may be present in others. The significance of these venous communications and their vari- ability can be explained only after a thorough embryological investigation has been made. A¥hefher they can be explained most satisfactorily by the sprouting theory, which is advanced by Dr. F. R. Sabin, as representing the original points of origin, or whether these taps represent later connections of the lymphatic system with the venous system, constitutes the prob- lem now under investigation. Grateful acknowledgment is made by the writer to Professor G. L. Houser and Dr. F. A. Stromsten for timely suggestions and helpful criticism. Laboratories of Animal Biology, The State University. 21 MITES AFFECTING THE POISON OAK. H. E. EWING. According* to the plan of natufe animals are compelled either directly or indirectly to lay under tribute the plant world in order to obtain food ; and so completely have they done so that it is doubtful if any, among* the many thousands of species of the latter, are exempt from attach. Being thus exposed to the wholesale appetites of higher creation plants have been forced into the evolution of devices for warding off animal attacks. We are all familiar, and probably to our sorrow, with the way in which many plants protect themsebces from the larger ani- mals by means of thorns or spines, thus lancing or even lacer- ating the hungry herbivor that comes too near or reaches with open mouth to devour them. Other plants obtain much .protec- tion, especially from their arthropod enemies, by the very tough tissues that make up the bulk of their substance, or by a well developed layer of hard cells that cover most of the ex- posed parts. But of all the devices that nature has contrived through the guiding hand of natural selection, to protect plants from animal attacks, it is doubtful if any Is more successful than the development of poisonous properties. That these poi- sons do protect plants possessing them observations clearly show. Thus our poison ivy ( Rhus toxicodendron) is known to be almost exempt from insect attacks. Only four species are known to feed upon it. Other species of poisonous plants also are known to be alibost exempt from attack. We have on the Pacific slope, a species of Rhus (Rhus diversiloba) , known as the poison oak, which is much more abundant there than the poison ivy is with us, and also its toxin is, I believe, far more injurious to man. I have a photograph showing a large portion of a sheep pasture, located near Cor- vallis, Oregon, that is so completely overrun by poison oak that little of it is left available for grazing. In connection with the toxic effects of the poison oak, I remember seeing a woman who had both eyes swollen shut and her lips puffed out over an inch on account of a slight contact with poison oak. But con- tact is not necessary in order to be affected with the poison. 324 IOWA ACADEMY OF SCIENCE Vol. XXIV, 1917 Many people have been badly poisoned by standing around camp fires on which poison oak branches had been carelessly placed. Again after being once affected with the poison of this plant, instead of becoming immune from further attack, one becomes more susceptible than before. At least this is the tes- timony that I have heard so often from friends who have been poisoned. During the summer of 1915, I undertook a survey of the arthropods attacking the poison oak, and after continued search over large areas in western Oregon found only a single species that was generally distributed and found to be commonly feeding on this poisonous plant. This species was a gall mite. Besides the gall mite two other arthropod species were listed; the common spider mite Teiranychus telarius Linn., and a leaf-roller. In this paper I shall report only on the mites, as the leaf-roller certainly was not a normal feeder on the poison oak, as neither full-fed nor live caterpillars were found. The gall mite found on the poison oak was widely distributed, and produced very conspicuous, reddish pouch galls on top of the leaves (see figure 52). These galls were at times so nu- merous that they ran together giving a “cock’s comb” effect. Upon dissection the galls were found to be thickly erinosed on the inside, and each had an opening on the under surface of the leaf. Among the hairs of the erineum were found many gall mites of various sizes; some were females with eggs; and free eggs also were found inside of the galls. A technical de- scription of the mite is here given : Phyllocoptes toxicophagus n. sp. Capitulum prominent, extending to the end of segment 111 of leg I. Shield covering cephalothorax. Dorsal setae about equal in length to dorsal shield. Abdomen curved downward considerably toward the tip, with from 36 to 45 dorsal half rings. Lateral setae prominent, equal in length to second pair of legs. Ventral setae I reaching over half the distance from the point of their origin to the tip of the abdomen, and extending to the bases of ventral setae II. Second ventral setae almost half as long as the first setae. Legs subequal. Third segments of first pair of legs each bearing a long seta which reaches to the tip of tarsus. Plumose tarsal setae, each with four pairs of bars. Length of male, 140 v- ; width, 50 A Length of female, 160 f1 ; width, 60 A MITES AFFECTING THE POISON OAK 325 This mite is so abundant in certain places that every leaf on practically every plant is galled. Further, some of the leaves are so badly galled that they show general distortion and curl- ing. On the other hand a considerable area may be free from Fig. 52. Leaf of poison oak ( Rhus diver sitoba) showing galls produced by Phyilocoptes toxicopliagus n. sp. this mite. I have usually found it present in any large field where poison oak was growing, but not always. Plants badly infested are stunted and lack their normal vigor. 326 IOWA ACADEMY OF SCIENCE Vol. XXIV, 1917 The other mite found feeding on the poison oak is no other apparently than our common Teiranyckus telarius Linn., or spider mite. It differs from most of the forms of this variable species in being smaller, and in never being orange in color. This species was found in only one place, in a pasture inside of the city limits of Corvallis, Oregon, but was found here some- what in abundance. The infested leaves were somewhat paled and cupped, but not seriously injured. On their undersides were found many mites, including males and females in about equal abundance ancl some eggs. What do we know of the host distribution of these two spe- cies? The gall mite, Phyllocoptes toxicophagus sp., is, as far as we know restricted to tlie poison oak. The spider mite is found on many kinds of plants throughout the most of North America and Europe. Recently I compiled a list of seventy- eight species of plants belonging to many families, on which this mite had been recorded as feeding. It is in fact almost omniv- orous. We have in this case, therefore, a species that is espe- cially noted for its hardiness, its wide distribution, and its varying food habits feeding on a poisonous plant. But liow about the gall mite? Here it is possible that the mite species itself became so adapted that it could withstand the toxin, so deadly to most species. But could it not be that this gall mite has been evolved along with its host species? Could it not be that the parasitic habit was established on an ancestor of the poison oak that did not possess the poisonous properties, apd that the mite has persisted ever since as a parasite on succeed- ing generations of hosts? I see no reason why the latter sug- gestion js not a logical one. Zoology Department, Iowa State College. ODONATA OF IOWA, LLOYD WELLS. Iowa Odonata have not been given their due consideration in entomological records of the state. The few articles that have been written dealing with these insects as they occur ■ within the state have been very local in nature. It is the purpose of this paper to list those species that have been recorded in the past, and to give new records that have been obtained during the writer’s recent collecting trips. In each case the locality, date, and collector’s name are given, where these are known. It was during the summer of 1916, while acting as insect col- lector for the Department of Z'oology at Iowa State College, that the writer did most of his collecting, and it was then that he had many opportunities to notice species of this order in their natural habitats. The Odonata have very interesting habits, and it is a real fascination to study them in their natural haunts. Any one who is interested in the group should read E. B. Williamson’s account of collecting dragonflies, as recorded in his publication, “With its advent into an aerial life our dragonfly becomes one of the most beautiful of insects. Strong, rapacious and daring, possessed of striking individualities, they offer the rarest sport to the collector who frequents their haunts, observing the many idiosyncrasies of these lords of insect creation. Here little Peri- themis domitia goes quietly and politely about his business, flit- ting from lily-pad to sedge stem, making his observations on the beauty of the day and the large number of diptera which are abroad. Plathemis lydia comes along, rudely inquiring into everyone’s affairs, for our Plathemis is either a restless busy- body or an immaculate dandy who displays himself on some sunny log or rock. Then piratical Anax junius rushes up, makes a dash at Platliemis, glances at Perithemis and passes out of sight into the woods along the shore. And in the sedges all this time myriads of 'emerald and sapphire forms fight and make love in their different ways.” In order to appreciate this quotation one should see Peri- tJiemis go about his business, and piratical Anax rush up. It 32S IOWA ACADEMY OF SCIENCE Vol. XXIV, 1917 is an education in itself just to' watch these insects go through their countless performances. Collections were made by the writer in four vicinities, namely, that area within a radius of three miles of Iowa State College at Ames, along the Des Moines River at Boone, on the Mississippi in the vicinity of Muscatine, and near the ponds of the United States Biological Station at Fairport. The latter is an ideal place for Odonata; especially do we find here those which inhabit sluggish streams, this doubtless being because the ponds are nearly stagnant. A few hundred feet away is the river, and here may be found Gomphus, Enallgama, E picordelia and scores of others. Near by in the fields Sympetium may be found. On damp days, early mornings and late afternoons, many species are to be found in the tall grass neighboring the ponds. Dr. C. B. Wilson of State Normal School, Westfield, Massachusetts, has made extensive collections in this vicinity, and these are men- tioned in this paper. Recorded collections have been made in Iowa by the follow- ing individuals: Dr. C. B. Wilson. Fairport, Iowa ; Newton Miller, Waterloo, Iowa; Morton J. Elrod, Des Moines, Iowa; A. D. Whedon, from northern Iowa. Publications recorded are “Some Notes on the Dragonflies of Waterloo, Iowa,” by New- ton Miller, Entomological News, December, 1906; “Iowa Odon- ata,” by M. J. Elrod, Entomological News, January, 1898; “Preliminary Notes on the Odonata of Southern Minnesota,” by A. D. Whedon, 15th Report State Entomologist of Minne- sota, 1914. (Herein are contained several records of Odonata collected by Miss Alda M. Sharp of Gladbrook, Iowa.) The natural arrangement followed in this paper is that given by E. B. Williamson, in his “Dragonflies of Indiana.” Unless it is otherwise mentioned all observations were made by the writer. Specimens taken by him are in the college col- lection at Iowa State College. The following is a list of the species that have been reported from Iowa. CALOPTERYX Leach. C. mandat a Beauvois. Ames, July 11, 1916; Boone, July 20, 1916; Muscatine; Fairport, August, 1915 (Wilson) ; Des Moines, July, 1893 (Elrod) ; Waterloo, 1906 (Miller) ; Tama county, ODONATA OP IOWA 329 June 21, 1899 (Miss Sharpe). Found in abundance along shaded streams in early summer. Found also in woodlands to a small extent. C. aequabilis Say. Waterloo, 1906 (Miller). ‘ ‘ Twenty-five males, twenty-three females ; open woods along Elk Run in shady places. Forty-eight specimens taken in less than two hours,” Newton Miller. HETiERINA Hagen. II. americana Fabricius. Ames, July 10, 1916 ; Boone, July 20, 1916; Muscatine; Fairport, August, 1915 (Wilson) ; Des Moines, 1893 (Elrod) ; Webster City, 1896 (Elrod) ; Waterloo, 1906 (Miller). Taken in large numbers at Ames in middle of July. Scattering at Muscatine about August 1. Found along sluggish streams. . LESTES Leach. L. eurinus Say. Fairport, 1915 (Wilson) ; Lake Okoboji, June, 1909 (Whedon). L. unguiculata Hagen. Ames, June 18, 1901 (Collection) \ Ames, August 29, 1916; Fairport, July, 1915 (Wilson) ; Water- loo, 1906 (Miller) ;. Des Moines, June 29, 1893 (Elrod).. A very abundant species found in the grass near small streams and ponds. L. uncata Kirby. Ames, June 20, 1892, June 18, 1901 (Col- lection) ; Waterloo, 1906 (Miller). Habits similar to L. u%- guiculatus. L„ ford pa to Rambur. Fairport, August 17, 1916; Waterloo, 1906 (Miller) ; Des Miles, July, 1896 (Elrod). Found in grass around ponds. L . red angular is Say. Muscatine, July 28, 1916 ; Le Claire, Ames (Collection) ; Waterloo, 1906 (Miller) ; Fairport, August, 1916 (Wilson). Found along slough on Muscatine Island. L. disjunct us Selys. Spirit Lake, July, 1909 (Whedon). A. putrida Hagen. Fairport, July, 1916 (Wilson). A. tibialis Rambur. Fairport, July, 1916 (Wilson). A. apicalis Sav. Muscatine, August 4, 1916; Des Moines, July, 1893 (Elrod). Found along Mississippi river. A. violacea Llagen. Lake Okoboji (Whedon). S30 IOWA ACADEMY OF SCIENCE Vol. XXIV, 1917 NEHALENNIA Selys. N. irene Hagen. Ames, June 18, 1901 (Collection) ; Fair- port, July, 1915 (Wilson) ; Waterloo, 1906 (Miller) ; Des Moines, 1893; Clinton, 1897 (Elrod). A species found low in the grass. N. posita Hagen. Muscatine, July 8, 1916. Found in same conditions as N. irene in low grassy places. AMPHIAGRION Selys. A. saueium Burmeister. Waterloo, 1906 (Miller). “ Slough at north edge of Waterloo,” Miller. ENALLAGMA Charpentier. E. Hagen i Walsh. Waterloo, 1906 (Miller) ; Des Moines (El- rod) ; Fairport, July, 1916 (Wilson). “More numerous than any of other 27 species,” Miller. “Fairly abundant, ” Elrod. E. ehrium Hagen. Fairport, July, 1916 (Wilson); Des Moines, June 29, 1893 (Elrod); Waterloo, 1906 (Miller). E. civile Hagen. Ames, June 23, 1892' (Collection) ; Fair- port, August 17, 1916 ; Muscatine, August 1, 1916. Found in abundance during August. E. carunculatum Morse. Fairport, July, 1916 (Wilson). E. aspersum Hagen. Fairport, July 2, 1916. E. geminatum Rellicott. Fairport, July, 1916 (Wilson). E. aniennatum Say. Des Moines, 1898 (Elrod) 1 Fairport, July 3, 1916 (Wilson); Waterloo, 1906 (Miller). E. signatum, Fairport, August 17, 1916 ; Clinton, June, 1897 (Elrod) ; Center Lake, Dickinson county, July 13, 1909, and Lake Okoboji, June 29, 1909 (Whedon). ISCHNURA Charpentier. 7. veriicalis Say. Muscatine, August 4, 1916 ; Fairport, Au- gust 17, 1916; July, 1916 (Wilson) ; Waterloo, 1906 (Miller). “One of earliest species out.” Miller. ANOMALAGRION Selys. A. Jiasiatum Say. Des Moines, 1896 (Elrod) ; Waterloo, 1906 (Miller). GOMPHUS Leach. G. vastus Walsh. Fairport, August 3, 1916; Clinton, June, 1897 (Elrod); Fairport (Wilson). ODONATA OF IOWA 331 G. crass us Hagen. Fairport, 1916 (Wilson). G. fraternus Say. Boone/ July 14, 1916; Fairport, August 3, 1916; Fairport (Wilson); Waterloo, 1906 (Miller). Pair taken in copulation at Boone. G. externus Say. Muscatine, August 7, 1916; Fairport (Wil- son) ; Lansing, July, 1907 (Wilson). G. pallidus Rambur. Fairport, July 1, 1916 (Wilson) ; Mus- catine, August 10, 1916. G. furcifer Hagen. Ames (Collection). G. notatus Ram bur. Muscatine, July 23, 1916; Fairport (Wil- son) . G. amnicola Walsh. Fairport, August 3, 1916; Fairport (Wilson) ; Des Moines, July, 1892 (Elrod)-. G. plagiatus Selys. Muscatine, August 4, 1916 ; Fairport (Wilson) . BOYERIA MacGachlan. B. vinosa Say. Ames (Collection). BASIAESCHNA Selys. B. janata Say. Fairport (Wilson). AESCHNA Fabricius. A. verticallis Hagen. Ames, 1892 (Collection) • Fairport, July 3, 1916; Fairport (Wilson). A. constrict a Say. Ames, July 21, 1916 ; Boone, July 20, 1916. Several individuals taken at Ames in pastured woodland. A. pentacantha Rambur. Waterloo, 1906 (Miller). ANAX Leach. A. junius Drury. Ames, June 10, 1916 ; Fairport, July 3, 1916; Boone; Muscatine; Waterloo, 1906 (Miller); Dunreath, August 4, 1896 (Elrod) • Tama county (Miss Sharp); Clinton (Elrod) ; Fairport (Wilson)/ Found in abundance from June to September. MACROMIA Rambur. M. illinoiensis Walsh. Waterloo, 1906 (Miller). M. tavniolata Rambur. Fairport (Wilson). EPICORDELIA Selys. E. princeps Hagen. Muscatine, August 10, 1916 ; Fairport (Wilson) ; Waterloo, 1906 (Miller). Taken while flying in 332 IOWA ACADEMY OF SCIENCE Vol. XXIV, 1917 groups. Found in company with A. junius, P. flavescens, P. hymenaea, T . lacuata and others. TETRAGONEURIA Hagen. T. cy nosura Say. Waterloo, 1906 (Miller). SOMATOCHLORA Selys. 8. tenebrosa Say. Ames, July 21, 1916. Taken in pastured woodland early in morning before a flight had been taken. PANTALA Hagen. P. flavescens Fabricius. Muscatine, August 17, 1916 ; Fair- port, August 14, 1916. Found in abundance along Mississippi river. P. hymenaea Say. Fairport, August 14, 1916 ; Muscatine, August 10, 1916; Fairport (Wilson). Taken in grass near ponds or sloughs. TRAMEA Hagen. _ T. Carolina Linne. Ames (Collection). T. lacerata Hagen. Muscatine, August 10, 1916 ; Fairport, August 3, 1916; Ames (Collection); Fairport (Wilson); Clin- ton, May, 1896 (Elrod). Found in abundance on sloughs near Mississippi river. PERITHEMIS Hagen. P. flomitia Drury. Muscatine, July 28, 1916 ; Fairport, August 3, 1916; Fairport (Wilson). CELETHEMIS Hagen. C. eponina Drury. Fairport, August 3, 1916; Clinton (El- rod) ; Fairport (Wilson). LEUCORHINIA Brittinger. L. intacta Hagen. Ames, June 28, 1916; Fairport, June 30, 1916 (Wilson) ; Waterloo, 1906 .(Miller) . Scattering near small ponds. SYMPETRUM Neuman. 8. rubicundulum Say. Ames, July 6, 1916; Boone, July 20, 1916 ; Muscatine, August 7, 1916 ; Fairport, August 17, 1916 ; Des Moines, August, 1892 (Elrod) ; Tama county, July 12 (Miss Sharp) ; Fairport (Wilson). Found almost everywhere; a very abundant species. Common in woodlands, near streams. ODONATA OF IOWA ' 333 S. obtruswm Hagan. Ames, July 11, 1916; Muscatine, August 1, 1916; Fairport, August 14, 1916; Clinton (Elrod). S. vicinum Hagen. Muscatine, August 1, 1916; Fairport, July 3, 1916; Des Moines, August, 1893 (Elrod). S. corruptum Hagen. Ames (Collection) ; Fairport, August 3, 1916 ; Fairport (Wilson) • Dunreath, August 4, 1896 (El- rod). MESOTHEMIS Hagen. M. simplicicollis Say. Muscatine, July 29, 1916 ; Fairport, August 3, 1916; Ames, July 6, 1916; Fairport (Wilson) ; Water- loo, 1906 (Miller) ; Sabula, June, 1897 (Elrod). PACHYDIPLAX Brauer. P. longipennis Burmeister. Muscatine, July 28, 1916; Fair- port, August 17, 1916; Boone, July 20, 1916; Waterloo, 1906 (Miller); Dunreath, August 4, 1896; Clinton, June, 1897 (El- rod). LEBELLULA Linne. L. basalis Say. Fairport, July 3, 1916 ; Muscatine, August 4, 1916; Boone, July 20, 1916; Ames (Collection); Waterloo, 1906 (Miller) ; Des Moines, Clinton (Elrod) ; Fairport (Wilson). Found along Mississippi in abundance during July and August. L. quadrimaculata Linne. Ames, June 16, 1916 ; Sabula, June, 1897 (Elrod). L. pulchella Drury. Ames, June 16, 1916 ; Boone, July 20, 1916; Muscatine, August 1, 1916; Fairport, July 28, 1916; Waterloo, 1906 (Miller) ; Fairport (Wilson) ; Dunreath, August 4, 1896 (Elrod) ; Clinton (Elrod) ; Tama county, July 29 (Miss Sharp). A very common species, found nearly everywhere in the state. PLATHEMIS Hagen, P. lydia Drury. Fairfax, Iowa (Collection) ; Muscatine, Au- gust 7, 1916; Ames, June 15, 1916; Fairport, July 30, 1916; Boone, July 14, 1916; Fairport (Wilson) ; Waterloo, 1906 (Mil- ler) ; Des Moines (Elrod) ; Tama county, July 29, June 28 (Miss Sharp). Zoology Department, Iowa State College. OBSERVATIONS ON THE PROTOZOA. WITH DESCRIPTIONS AND DRAWINGS OF SOME PROBABLE NEW SPECIES. CLEMENTINA S. SPENCER. In 1906 The Davenport Academy of Sciences published a thesis by Dr. C. H. Edmondson on the Protozoa of Iowa which is the best list, so far compiled, of the protozoa known to occur in the waters of this state. During my recent observations of these always interesting organisms I have found a number of species which may be considered an addition to Edmondson’s list, including some forms Avhich further observation may prove to be new. With the list of these are included some notes on more common forms . which may be of interest to students of protozoology. The classification which I follow is that of Professor Calkins in his Protozoology (1909), with the exception of a single group which follows the Euglenoidina of Ohio, by Professor L. B. Wal- ton (1915). Those species marked with an asterisk are an addi- tion to Edmondson’s list, while those unmarked are included for other reasons. Unless specified, the forms were all found near the State University of Iowa during the year 1915-1916. Subphylum SARC'OMNA Class I Rhizopoda Subclass PROTEOMYXA Vampyrella spirogyrae Cienk. 1 and 2, figure 53. Body nearly globular, pseud op-odia raylike, moving with the amoeboid motion of the hyaline periphery. Endoplasm densely and brilliantly orange red, finely granular with a few darker pigment (?) granules. Within a few moments the animal changes from having nearly all capitate pseudopodia to nearly all simple rays. Capitate pseudopodia are shot in and out very rapidly. Both kinds may be withdrawn from a considerable portion of the periphery and short amoeboid lobes occasionally appear. Nucleus and vacuoles not visible. Motion a swimming glide. Diameter of body in red specimen 1 microns. Formerly this organism was classified with the Heliozoa, but both Calkins and Doflein now place it in the Proteomyxa on the 336 IOWA ACADEMY OF SCIENCE Vol. XXIV, 1917 basis of miscible and anastomosing pseudopodia. However, neither of the specimens under my observation exhibited this character. The first one found was the typical brilliant orange red, as described by Leidy, extremely small and active. With a thread siphon it was kept moist and under observation for a day, but its minute size precluded its transfer to another slide, and when its travels during the night took it under a pile of debris it was hopelessly lost. The second Specimen was clear OBSERVATIONS ON THE PROTOZOA X 337 and colorless, and established within an algal filament. Edmond- son reports having seen Vampy fella but once, and then only in a dark granular phase. His specimen assumed the inter- esting flagellated stage, which mine did not. Subclass AMOEBEA. *Hyalodiscus Umax (Duj.I 3 and 4, figure 53. Body oval or disc-shaped. Progression snail-like with a broad, clear anterior region and very little change occurring in out- line. Ectosarc relatively extensive. Nucleus visible without re- agents. Size 44 microns. So far as I have able to ascertain, this amoeba has not pre- viously been recorded in Iowa. Whether this indicates its rarity or a rather prevalent skepticism as to its being a distinct species I cannot say. I have never seen other amoebae so active as these are while they retained such regular outline. They were ob- tained in small numbers in December from under an inch of ice in an old stone quarry pond near the University. An in- teresting point was the presence of a minute, black, dancing organism in the contractile vacuole of one specimen (see figure) . *Difflugia species./ 5, figure 53. Shell hemispherical, proportions like Arcella but structure like Difflugia. An inverted rim within the mouth as is often seen in Arcella. Color white. Diameter 70 microns. Only one dead shell of this form was found. It does not correspond to any species described by the authors in my bib- liography. However, Difflugia is now believed to be extremely variable within its species, and this is probably nothing new. Arcella vulgaris Ehr. 6 and 7, figure 53. Observation of even , this most common of all rhizopods may occasionally be rewarded by a glimpse of something a little out of the ordinary. In October, in an old jar in the laboratory there suddenly appeared countless numbers of active, minute and colorless individuals. Figures 6 and 7 show a case of sup- posed conjugation of two of these young shells, a. smooth and a pitted variety . Since the two shells were not actually seen to approach each other and fuse there is of course a possibility that the process was division. Many writers record the union of two or more rhizopods, but remark upon the rarity of seeing 22 338 IOWA ACADEMY OF SCIENCE Vol. XXIV, 1917 an actual approach and fusion. In, either event, the case in question is of interest since it emphasizes the fact that the smooth and pitted shells of Arcella are merely varieties of the same species. The interchange of protoplasm between the shells was active, the direction of flow reversing seven times in eight minutes. Height of one shell 44 microns. ^Unknown rhizopod. 8 to 11, figure 53. A single specimen of this large and sluggish rhizopod was under observation an entire afternoon, hut its unusual trans- parency and a cloudy day combined against the observer. When it was revolved, the body was seen to be shaped like a football with a few long, firm pseudopodia, the periphery and center being finely granular with a space or clear plasm lying between. No mouth, nucleus, or vacuole were apparent, and when elec- tric light was finally thrown in it was fatal to the specimen. Size 200 microns. * Euglypha mucronata Leidy. 14, figure 53. Shell cylindrical, tapering toward the mouth, transparent, composed of circular imbricating plates which later become al- most homogeneous. Pseudopodia delicate and geniculate. This form is similar to the common Euglypha alveolata Duj.. but with the fundus prolonged into an acute tip. Class II Actinopoda Actinoplirys sol Ehr. 12 and 13, figure 53. This is another form almost too common to mention except when especially favorable conditions bring out some interesting phase or mechanism. The contractile vacuole in this species is a permanently thin place in the peripheral plasm or membrane which upon collapse falls into folds and gives the appearance of a tuft of hairs. Figure 12 shows the stages of slow refilling and sudden collapse. Average time of action forty seconds. xlOOO. 1* Nuclmria delicatula Cienk. 15 to 22, figure 54. Body both amoeboid and lieliozoan-like, with pseudopodia in turn amoeboid, short and spicule-like, long and raylike, deli- cate and intricately branched, .capitate (rarely) but not suc- torial, stocky for attachment, and anastomosing in at least one instance under observation. Length of body 20 to 100 microns. Maximum extent of pseudopodia 315 microns. OBSERVATIONS ON THE PROTOZOA 339 This most interesting and problematic species lias been taken regularly in large numbers from gold fish tanks about town. Given moderate warmth and quiet the individuals rapidly in- crease in size and numbers for a few weeks, when they die off and a new culture must be started. In a sluggish condition the animal resembles Actinophrys sol, or it may at times with- draw nearly all of its rays ; but in active state it becomes the 340 IOWA ACADEMY OF SCIENCE Vol. XXIV, 1917 most variable amoeboid form within my knowledge. During two months observation these abundant animals were a most interesting study and their phases filled many drawing plates. A nucleus could not definitely be made out, though many re- agents, including osmic acid, were tried. At no time was a contractile vacuole seen,, nor were the animals seen to divide. Figure 22 shows an individual which I regard as the same species, but which lias a gelatinous covering like Heterophrys. Conn, in his Protozoa of Connecticut, also records Xuclearia with a gelatinous envelope. Professor Calkins who kindly confirmed my identification of this species says: ‘ ‘ F rom your sketches I have no hesitation in saying that your organism is one of the questionable heliozoa most closely related to Aclinopkrys, and you are right in identifying it as Nuclearia delicatula Cienk. ” In Calkin’s Protozoology (1909) he places Xuclearia with V amp\yrella in the Proteomyxa on the basis of its amoeboid character and the rare anastomosis of pseudopodia. Edmondson does not record the genus. Subphylum MASTIGOPHGRA Class I Zoomastigophora Subclass FLAGrELLIDIA. *Olkomonas species 1. .25, figure 55. Minute, plastic, sometimes attached by a temporary posterior prolongation. Flagellum single with a fissure at the base. Body oval, not compressed, crenulated in optical section, with a minute posterior tip. Flagellum vi'bratile. Vacuole large, an- terior. Nucleus posterior. Found in old infusions in the lab- oratory. Uncommon. Length of body 19 microns, flagellum 20 microns. * Oikomonas species 2. 26, figure 55. Similar to the preceding, but lacking crenulations and pos- terior tip. Flagellum longer, vacuole and nucleus not visible. Transparent. Abundant in gold fish tanks with Xuclearia. Body length 20 microns. *Rhipidodendron splendidum Stein. 23 and 24, figure 55. Monads ovate, similar to Antliophy sa, living in a social zoothe- cium, a rust brown ‘ Mabellate or dendriform aggregation of closely approximated tubules,” the distal ends of which are each inhabited by a single zooid. Only a large number of dead OBSERVATIONS ON THE PROTOZOA 341 fragments of these zootliecia were found in a small pond, but these were sufficient to identify the beautiful flabellate colony figured by Kent in his Plate XVI. As the tubules were never found growing in more than one layer the species huxleyi was ruled oui. Maximum length of fragments found 100 microns. Diameter of tubule .8 micron. 342 IOWA ACADEMY OF SCIENCE Vol. XXIV, 1917 uglena rubra Hardy. 27 and 28, figure 55. Body large, cylindrical, anterior end rounded. Posterior end with short acute tip. Periplast finely spirally striated without punctuations. Color densely bright red. Length of body 115 to 230 microns. I am indebted to Professor R. B. Wylie for bringing these specimens in formalin from Little Spirit Lake in August where they were abundant. This is not strictly an Iowa, record, as the lake is across the Minnesota. border line; but it is very likely that the species may be found in this state and the record is of interest. Walton regards this species as distinct from E. san- guinea. *Euglena new species. 29 and 30, figure 55. Body elongated, ribbon-like, habitually twisted into three areas. Conspicuously beaded in longitudinal rows, of which there are seven at the anterior end and only five at the poste- rior. Flagellum about half as long as the body. Nucleus oval, central, with a larger flattened paramylon body before and be- hind. Vacuole reservoir very large and circular, posterior to the large stigma. Cytopharynx plainly visible. Solitary. Color dense bright green, somewhat clearer at the tail. Size 190 mi- crons. This remarkable form was found in a vial of water from Fairport, Iowa, which had been standing in my laboratory for some weeks. It was large and active, apparently cramped for space under the cover glass. It would attach the tail to the slide and give the long body a twisted motion in a semicircle. The body was not strongly metabolic, but the raised beaded lines on the periplast were seen to move forward on one side and at the same time backward o.n the other. Professor Walton, prob- ably the foremost authority on the Euglenoidina, was kind enough to examine these drawings and notes, and writes : ‘ ‘ The probabilities are that a new form is represented.” *Trachelomonas oblong a punctuata Lemm. 31 to 33, figure 55. Shell oval, brown, dotted with punctae which show a spiral arrangement from the aboral end, but which from the side ap- pear to be irregularly scattered. In optical section the shell appears to be made up of small sections or to have pores (see figure). Stigma present; chloroleucites two, elongate; flagel- lum nearly as long as the body and thickened at the tip. Size 23 microns. OBSERVATIONS ON THE PROTOZOA 34: The spiral arrangement of the punctae at the aboral end seems to have been overlooked in Lemmerman’s account of this form. It is a point which is not brought out except when the active little creature is spinning on its head. *Trachelomonas urceolatus Stokes. 34, figure 55. Shell- large, light brown, sparsely dotted. Neck obliquely truncate, a tail-like point at the aboral end, into which the cav- ity of the shell extends. Only dead shells were found. * Trachelomonas species? 35, figure 55. Shell regularly cylindrical rather than oval, without collar or posterior spike. Surface smooth, brown. Length 14 microns. As this shell does not conform to any description and was empty when found it can be placed in this group only tenta- tively. Trachelomonas (new species?) From Arkansas. 36, figure 55. From liie Trachelomonas teres group. Shell brown, oval, with a conspicuous collar flaring at its base and a short rounded posterior appendage into which the cavity of the shell does not extend. Endoplasm green; stigma large. Length 22.8 microns. The single specimen of this Arkansas form which was found was in an encysted state and lacked a, flagellum. The oval pro- toplasmic body was somewhat constricted at the equator and had a thin layer of colorless ectoplasm over the green endo- plasm. Three irregular granules (paramylon?) were present. It is the opinion of Professor Walton that a new form may be represented here, and it is hoped that additional specimens can be obtained later. *Phacus triqueter (EhrP Not figured. Much like the common P. pleur onset es but having a sharp keel extending down the center of the dorsal side, and the ven- tral surface deeply concave. Edmondson does not record this form, but in my experience it has been more common than pleuronecA.es. otosolenus orbicularis Stokes. 37, figure 55. Anterior flagellum one and one-half times the length of the body, carried obliquely to the right. Secondary flagellum ven- tral, appearing as a small longitudinal line through the body. Endoplasm colorless, a circle of minute granules around the periphery. Dorsal concavity conspicuous and deep. Not abun- IOWA ACADEMY OP SCIENCE Vol. XXIV, 1917 34 l da nt. Body length 13 microns, anterior flagellum 20 microns. (The species is separated from N. opocamptus Stokes by the relatively greater width of the dorsal concavity.) Subclass CHOANOFLAGELLATA. *Diplosiga species. 38, 39 and 40, figure 55. A minute, delicate, stalked form, having an elongate, parallel- sided loriea whose base is drawn into a point and whose distal end flares into a collar with a second less flaring collar within. Flagellum single ; body not filling the proximal end of the loriea. Nucleus central ; two posterior vacuoles. Stalk 34 microns ; loriea from base to top of outer collar 35 microns ; flagellum 30 microns. At no time was the flagellum in this species seen to wave, although other signs of life were manifested in the vacuoles and in an amoeboid motion within the shell. In one specimen the protoplasm rose to the top of the loriea, was protruded in a shapeless mass and then retracted. . The dotted lines in the drawings indicate the probable limits of the concentric col- lars, which were however too delicate to be defined in any way. Professor Calkins after seeing the drawings has placed the form in the genus Impiosiga. The forms were found rather rarely in the goldfish tank which yielded the supply of Nuc- learia. Class II Phytomastigophora Subclass PHYTOFLAGELLATA. *Mallomonas fresenii S. K. 41 and 42, figure 56. Yellow-green chromatophores. Flagellum long, single. Shell oval,- of glassy imbricating circular 'plates bearing setose spines, or setas. Setas not more than thirty, immovable, curved. Mo- tion rapid. Shell without spines 25 microns. Only a few specimens of this rare form were found in water sent from Fairport, Iowa. The addition of dilute chlorotone to the water caused a sudden expulsion of protoplasm from the shell, which demonstrated that the spines belonged to the shell proper and not to its contents (see figure 42). Edmondson records finding a Mallomonas which he considers to be the species plosiii, although he was not able to make out the structure of its shell. OBSERVATIONS ON THE PROTOZOA 345 *Symira uvella Ehr. 43, figure 56. Spherical rosettes of about fifty individuals, each bearing two unequal flagella. Two olive-brown, bandlike chromatophores. Vacuoles numerous. Colony 76 microns in diameter; maximum zooid 15 microns. Found late in March at the edge of a melting ice pond in the city park. This plantlike colony is said to be a source of of- fensive tastes and odors in drinking water. 34G IOWA ACADEMY OP SCIENCE Vol. XXIV, 1917 * H aemato coccus lacustris Girod. 44 to 46, figure 56. Body field by delicate threads in a large lorica. Chromato- phores green, often wholly or partly red. Stigma present, flag- ella two. Nucleus central, irregular. In the free swimming stage the body is pyriform, with a rather pointed anterior end. Chromatophores rounded and numerous. Cyst or shell oval in free swimming stage, spherical in resting phase. Proximal ends of flagella stout. Size 30 to 45 microns. In the late autumn these forms were discovered in an old geode in a city garden. Most of the cells were in a resting stage, and all were more or less red. A culture was brought into the laboratory and various conditions of warmth, light, and fresh rain water were supplied in the effort to force activity; but it was toward the end of a cold’ May before the encysted forms revived out of doors, and those indoors never revived. Binary fission and multiple division within the cyst were observed in the spring. At this time the red color was much reduced and it was possible to see definite stigmata. The red color of the protoplasm is due to the change in color of the chloroleucites, and is not concerned with the stigmata. This form is claimed by both botanists and zoologists. #Two unknown chlorophyl — and stigma — bearing flagellates. 47, figure 56. A minute free swimming form, not metabolic while under ob- servation, yet delicate and plastic in appearance. Color very faint light greenish blue. One large anterior median stigma, and two equal divergent flagella longer than the body. Pos- terior part of the body drawn out into two short tail-like processes. A large clear central body of undetermined nature. Length of body 15 microns. Professor Walton says of this: “This is something quite new to me. I wish very much that I could examine a living specimen, undoubtedly an impossibility unless you obtained a culture. I suspect it may belong to the order Chrysomona- dinese. 9 ■ 48, figure 56. Body pear or bell shaped, apparently enclosed by a firm, clear pellicle or lorica. The posterior end is either concave or has a clear space between the endoplasm and the pellicle, giving the effect of a concavity. Endoplasm clear bright green OBSERVATIONS ON THE PROTOZOA 347 throughout. Pharynx and stigma present. Two pairs of longi- tudinal folds or striations in the pellicle. Flagella unequal, one as long as the body, the other about half as long, both being directed in advance. A conspicuous dense disc (or sphere) near the center of the body, with two small irregular granules, one apparently within and the other close beside the disc (para- mylon and pyrenoids?). Not metabolic. Motion a rapid for- ward spiral. Length of bell without flagella 28 microns. Professor Walton says of this: “An extremely interesting form. If you can find the number of chloroleucites and be sure that the dagella are always of unequal length, I am inclined to think it may prove to be something quite new.” Unfortunately I have never found but one specimen. Subphylum INFUSORIA Class I Ciliata Coleps hirtus Ehr. 49, figure 56. This form is too common to need description here. The fig- ure is that of a peculiarly flattened individual which ap- peared normal from the broad view. It was active and normal in its actions. In spite of its “ armor 'plates” Coleps appears to be an easy prey to the impaling spines of the Heliozoa, and I have found one side of the little infusorian being digested and absorbed by Actinophrys while the outer side continued its customary activities of waving cilia. Reagents of any kind are apt to cause Coleps to disintegrate almost instantly, sug- gesting that the armor plates are not hard or dense. On the other hand the voracious mouth, which seems at once to bore, to tug, and to suck, sometimes provides a way of escape from other enemies. In one case the digestive processes of a Stent or were not so rapid as the means an ingested Coleps applied to its own rescue. It was an amusing sight to see the tiny Coleps bore its way to freedom through the ectoplasm of its captor. *Ckenici species. 50, figure 56. Elongate, contractile, uniformly ciliated, with longer ante- rior cilia. Mouth terminal, usually closed (not made out in this specimen). Nucleus moniliform. A row of fourteen vacu- oles placed longitudinally. Size 200 microns. Found with de- caying vegetation. But one specimen was found, which disin- tegrated with the application of osmic acid. 348 IOWA ACADEMY OF SCIENCE Vol. XXIV, 1917 *CoIpoda cucullus Ehr. 51, figure 56. Shape reniform, compressed laterally. Mouth ventral in a deep depression, the animal, however, ■ frequently swimming on its side with the mouth on the right margin. Pharynx dilated at the lower end into a globular pit. Surface deeply grooved, the lines following the curved outline of the body until they reach the anterior end where they form crenulations on the right lateral margin anterior to the mouth. Nucleus central, beside the dilated end of the pharynx. Vacuole posterior. En- doplasm packed with dense granules. Common in ponds. Length 60 microns. *Strombidmm species. 52 and 53, figure 56. This genus is described as like II alter la but without the jump- ing bristles, and having the anterior portion protrusible. A large culture wTas obtained from pond water in which the form figured in 53 was common. There were, however, one or two specimens found which had a circlet bf long weak hairs, occu- pying the position of the jumping bristles of Ilalteria. How- ever, the much greater size, the plastic body, protrusible ante- rior portion, swollen lateral vacuole, and absence of springing motion, seem sufficient for taking both these forms from the genus Ilalteria. They were found associated with Stent or but did not long survive laboratory conditions. Size 60 to 80 mi- crons. Subclass SUCTORIA. *Podophrya maupasii Butschli. 54 and 55, figure 57. Pedicel cylindrical, rather thick, slightly curved, enlarging at the summit. Body subspherical or club shaped, concave at the base for insertion of stalk. About twelve heavy tentacles slightly longer than the body, not conspicuously capitate. (Fun- nel shaped and not exceeding the diameter of the body, accord- ing to the Monographiquh sur le groupe des Inf usoires Tenia- culiferes of Sand. ) Cytoplasm bluish gray, nucleus central ; vacuoles two. Length 42 microns. Found in goldfish tank in winter. *Podophrya libera Perty. 56, figure 57. Only the characteristic annulated cyst of this species was found in some pond water, and as it did not revive there is a question involved in the identification. My opinion is that it is OBSERVATIONS ON THE PROTOZOA 349 V. libera as figured by Butschli on Plate 76 of Bronn’s Klassen und Ordnungen des Tierreichs. The cyst of the more common P. fixa is nowhere described as presenting so many annulations. *Tokophrya species 1. 57 and 58, figure 57. With the characters of the genus. Extremely minute sub- globular forms borne in clusters on a slender rigid stalk whose 350 IOWA ACADEMY OF SCIENCE Vol. XXIV, 1917 length is two or three times the diameter of the body. Endo- plasm colorless, much vacuolated, nucleus not visible without reagents. Tentacles borne in a circlet near the distal end, some- times extending to a length of twice the body diameter. Body 4 microns. Myriads of these suctorians were found in the city park dur- ing November, and again in April with dimensions twice as great. The spring specimens were slightly elongated and not so numerous. Sand does not give any figures or descriptions agree- ing with this form, the most nearly approximate being T. frem- cottei Sand. *Tokophrya species 2. , 59, figure 57. Body subpyriform, solitary, on delicate stalk more than twice the body length. Endoplasm colorless with a few granules and two posterior vacuoles. Tentacles cylindrical, straight, capitate, as long as the body, borne near the crown, and equidistant from each other. Number of tentacles as observed in the only speci- men under observation, four. Total length 37 microns. Found in the gold fish tank with N'uclearia. This is another species which does not correspond with any available description, the most closely approximate being T. francottei. As these two unknown T oiophryas were found under entirely different conditions, as they have a different number of tentacles, and as one is solitary while the others found in large numbers were never solitary, it seems reasonable to sup- pose them to be distinct. *Metacineta new species. 60 and 61, figure 57. Body incompletely filling a flattened hexagonal lorica, with a fascicle of tentacles issuing from each angle. One main tentacle of each group has an axial rod running some distance into the finely granular endoplasm. Nuclear material (?) scat- tered in irregular granules. Vacuole very large. No apparent aperture to lorica other than the perforations for tentacles. Lorica 50x61 microns. Average tentacle 30 microns. Maximum tentacle 133 microns. This remarkable suctorian was found early in the fall in company with a great many heliozoa in an infusion of pond water with many half decayed leaves. When it first came under my notice there was a violent commotion in its vicinity owing to the fact that two or three of its long tentacles had pierced a OBSERVATIONS ON THE PROTOZOA 351 stvlonichian longer than its own body. Despite most vigorous efforts the stylonieliian was held fast, and impaled by more ten- tacles until in a short time two wThole fascicles were imbedded to their bases in the victim’s body, the flow of protoplasm being plainly seen through the tentacles. With a thread siphon this slide was kept moist and under observation for twelve hours. At no time did the body of the suctorian move (in fact it was so large it had little room under the cover glass) but the free tentacles were shot in and out with rapidity. The central ten- tacle of each group w^as less mobile and only gradually increased its length. Seldom did the tentacles curve. The victim, how- ever, kept up a frantic struggle for perhaps two hours, and a continuous oscillation of the cilia and styles for six or eight- hours more. About nine P. M. the almost empty cuticulum was abandoned and the suctorian, apparently too well gorged to ac- comodate even the vacuole, had withdrawn all save the stub of the central tenta des (see 61, figure 57). It was now impossible to distinguish any space between lorica and contents. No nu- cleus was visible, but the scattered fragments which seemed to resemble nuclear material were interpreted as an indication of a possible spore forming stage. Hoping to be able to establish the life history of this remarkable new carnivore I prepared a thread and feeding reservoir for the night ; but the night watch- man closed the crack at my window, the room became over- heated, and the slide dried up. I have not been so fortunate as to find another specimen. The species wdiich most nearly approaches this form is Meta- c hie la mysticina Elir. as figured by Butschli (Plates 7 and 8). Me lac in eta mysticina, however, has a stalk with the lorica open- ing at the top like a long stemmed vase. Careful focusing upon this specimen did not bring out either aperture or trace of a broken stalk. It does not seem at all likely that they can be the same. Department of Zoololgy, Coe College NOTES ON SOME IOWA RODENTS* DAYTON STONER. During portions of the past three summers some investiga- tions of the rodents of Iowa have been made under the auspices of the Iowa Geological Survey. These studies have been carried On more particularly in an attempt to determine the economic status of this group of animals in the state but other phases of the work such as matters of distribution, local abundance, etc., of the various species have also been included. In pursuance of this problem, various parts of the state have been visited for the purpose of making observations and obtain- ing data and an attempt has also been made to secure the in- terest. and cooperation of others in this work. In part, as a re- sult of the assistance thus obtained, material has been received from various sources. Some of this material is of especial in- terest regarding the distribution of certain -species and it is with the idea of briefly presenting these facts1 that a report is offered at this time. In this paper two forms are for the first time recorded from Iowa and the known distribution of some others has been extended. Acknowledgment for the determination of material is due Mr. E. W. Nelson, chief of the United States Biological Sur- vey and to Mr. A. IT. Howell, assistant biologist in the United States Biological Survey. Family SCIURIDAE. Sciurus hudsonicus minnesota Allen. — Minnesota Chickaree. Two specimens of this form have come to hand from Charles City, Floyd county, and afford the first definite record for the state. The type locality was Fort Snelling, Hennepin county, Minnesota, and the geographical distribution will now include northern Iowa as well as southern Minnesota and Wisconsin and eastward to northern Indiana. The form minnesota aver- ages a little larger than h, hudsonicus, which latter is much more common in the state. ^-Published by permission of Prof. G. F. Kay, Director of the Iowa Geo- logical Survey. 23 .354 IOWA ACADEMY OF SCIENCE Vol. XXIV, 1917 Family MURIDAE. Peithrodontomys megalotis dychei Allen. — Prairie Harvest Mouse. This is a western form that is apparently working is way to the north and east. The type locality was Douglas county, Kansas, and the geographical distribution includes Kansas, Mis- souri, Nebraska, South Dakota, Iowa, southern North Dakota, southeastern Montana, eastern Colorado and eastern Wyoming. Specimens are at hand from the following localities in Iowa: Tama, Wall Lake, Ottumwa, Logan and Jefferson. In addition to these localities, this form has been recorded from Fairport, Atlantic, Hillsboro and Palo Alto county. These Iowa records thus indicate that this form is ciuite generally distributed over the state. Pitymys pinetorum nemo rails (Bailey). — Woodland Meadow Yole. Another southern form that is apparently extending its range northward. It has previously been recorded from Iowa but not from Iowa City or Ottumwa, 0 the localities of the two specimens thus far obtained. The type locality was Stilwell, Boston Mountains, Indian Territory. Synaptomys cooperi gossi (Merriam). — Goss’ Lemming Yole. This is probably the form recorded by Professor Herbert Os- born (Proc. Ia. Acad. Sci., I, 43, 1887-89) and from Fairport by Mr. T. Yan Hynihg (Proc. Ia, Acad. Sci., XX, 311, 1913). In his work on “The Mammals of Illinois and Wisconsin” (Pub. Field Mus. Nat. Hist., Zool. Ser., Yol. XI, 236, 1912), Mr. Charles B. Cory records a specimen from Knoxville. In our work thus far one specimen has been received, from Logan in Harrison county at the extreme western border of the state. Family LEPORIDAE. Sylvilagus floridanus mearnsi (Allen). — Mearns Cottontail. Common or abundant in practically all parts of the state and in some localities does considerable damage to nursery stock. In one of the large nurseries in southwestern Iowa men are em- ployed during the winter months to spend their entire time hunting these pests. Lepus townsendi campanius (Hollister). — White-tailed Jack Babbit. This form seems to be increasing its distribution in Iowa very rapidly, the wave of dispersal moving east and south from the north and west. At Waukon, in the extreme north- NOTES ON SOME IOWA RODENTS 355 eastern portion of the state it is reported to have come in only during the last five or six years. In the two northern tiers of counties all the way across the state this form is now quite com- mon, particularly to the north and west, and it is not an un- common thing to find it in counties much farther to the south. Its exact limits of distribution in the southern portion of the state have not yet been definitely ascertained. Lepus calif or nicns melmiotis Mearns. — Great Plains Jack Rab- bit. Mr. E. W. Nelson, in his paper on ‘‘The Rabbits of North America” in North American Fauna No. 29, August, 1909, page 146, gives the geographic distribution of this form as follows: “Great Plains from east-central and northern Texas, north- eastern New Mexico and north through western half of Indian Territory, all of Oklahoma, extreme southwestern part of Mis- souri, all of Kansas and Nebraska, except perhaps extreme east- ern parts, southwestern Dakota, southeastern Wyoming, and all of Colorado east of Rocky Mountains.” A single specimen of this variety has been taken in the southern part of Johnson county and makes a notable addition to the leporine fauna of the state. The known distribution of what has been supposed to be a strictly western form is hereby increased considerably to the eastward, although it can scarcely be considered more than accidental in Iowa. In the three families of rodents above mentioned the delimita- tion into varieties and geographic races has been carried to the extreme and the writer here desires to enter his protest upon this minute and seemingly uncalled for division. In many cases the real evidence seems insufficient to substantially bear out the true facts. This minute differentiation by a few so- called “specialists” creates much confusion for the average worker in the group and results in the expenditure of much time and energy that could more profitably be spent in other phases of the work. Even the specialist is sometimes “hard put” to recognize one of his own creations. In conclusion, it may be of at least passing interest to dwell for a moment upon the attempts that have been made to reduce the numbers of the more noxious rodents through the method of offering bounties. By enactment of the thirty-second general assembly of Iowa, a state-wide bounty of ten cents is paid upon each pocket gopher brought in to the office of the county audi- 356 IOWA ACADEMY OF SCIENCE Vol. XXIV, 1917 tor of the county in which the animal was taken. As evidence of the destruction of each animal the front feet are demanded. In some counties where this pe,st is extremely abundant more than $2,000.00 are paid out annually in bounty without, appar- ently, lessening the amount of destructive work done by the animals. In a few counties visited the annual bounty on pocket gophers totals more than $3,000.00 and the question is raised as to whether the results secured are commensurate with the expense incurred. The offering of this bounty has also some- times led to fraudulent practices. Bounties may be offered upon some other species of animals including other rodents such as woodchucks, Franklin’s spermo- phile and the 13-striped spermophile. It is left optional with the various county boards of supervisors whether a bounty shall be paid and if so the amount to be paid on each animal. This procedure has resulted in a good deal of difficulty and incon- sistency in regard to these matters. For example, of four ad- joining counties in northeastern Iowa, two pay a bounty of twent}^ cents each on woodchucks, another county pays ten cents each while the other county offers no bounty whatever on these animals. The possible difficulties are at once apparent and it is very evident that such an arrangement is not the key to the situation. It would seem that if bounty is to be paid at all the amount paid on each animal should be uniform in all the counties of the state so that all claimants would be treated alike. If the pest is not abundant in one county the drain on the funds will be light while, on the other hand, if the pest is abundant and is brought in numbers for bounty that locality will in the end benefit thereby. On the wdiole, the bounty system as a means of combatting noxious rodents appears to have met with small success and it is questionable whether the practice should be continued. If every farmer would see to it that the pests are destroyed on his own premises without consideration for the bounty the difficulty would be solved and the funds now expended in bounties could be invested in some manner that wmuld be likely to yield greater returns. This matter will be more fully dealt with in a future bulletin of the Iowa Geological Survey. State University of Iowa. SOME ADDITIONAL NOTES ON POLLINATION OF RED CLOVER. L. H. PAMMEL AND L. A. KENOYER. ' ■ ■ • : i-> ( . Many years ago Charles Darwin conducted some experiments to determine whether red clover is self fertile. This investi- gator found that when insects were excluded, reel clover did not produce a single seed, while flowers exposed to insects produced an average of twenty-seven seeds per head, The experiments of Darwin and many of the older investigators who conducted experiments with red clover were faulty since they did not re- lease the anthers from the keel. The experiments of Frandsen, according to Lindhard,18 Waldron,7 Kirchner,4 Witte,6 Fru- wirth,3 Pammel and King,11 Sirrine,5 Beal,9 Cook,1 Shamel12 and Bolley13 confirmed the results of the work of Darwin.19 These authors find that bumble bees and in some cases honey bees are the important pollinators. Several years ago H. S. Coe, H. D. Ilughes, L. H. Pammel, J. N. Martin and J. N. Westgate published a lengthy account of the pollination of the red clover.* The more important conclusions arrived at are given in the fol- lowing summary from the bulletin, “Red Clover Seed Pro- duction.” A study of the cytology of red clover flowers showTs that many of them contain infertile ovules. The percentage of infertile ovules is greater in the first crop than in the second crop. In the first crop many plants produce 100 per cent of infertile ovules, while in the second crop the percentage of infertility ranges from none to a high per cent. The percentage of infer- tile ovules in red clover is probably correlated with moisture conditions. The pollen grains of red clover are very sensitive to moisture. On account of this there can be little effective pollination when the flowers are wet. Germination of the pollen grains takes place only within a limited range of variation in the water supply. It is probably true that the only function of the stigma is that of supplying the requisite amount of water to the pollen for germination. *Red Clover Seed Production, Bull. U. S. Dept. Agr., Con.tr. Bur. PI. Ind., 289 :1-31. 358 IOWA ACADEMY OF SCIENCE Vol. XXIV, 1917 The time between pollination and fertilization varies with the temperature of the atmosphere. The time between pollina- tion and fertilization in July is approximately 18 hours, while in October it varies from 35 to 50 hours. An examination of 30 flowers which had been self-pollinated for 55 hours showed good germination on the stigmas but no fertilization. The pol- len tubes made a slow growth and none exceeded 4 mm. in length. In flowers which had been self-pollinated for 90 hours one pol- len tube attained a length of 7.5 nun., while the rest were 5 mm. or less in length. The pistils of red clover average about 12 mm. in length. Eggs were found to be disintegrating four days after the flower opened. The self-pollination and cross-pollination experiments which were conducted in the field checked up very closely with the results obtained from the cytological studies. The average yield of seed obtained on heads which were not pollinated, and on heads which were self-pollinated in different ways, was less than one-half of 1 per cent. This small amount of seed may be accounted for by the occasional access of bees to these heads for a very short time on account of rains or grasshoppers mutilat- ing the tarlatan which was used to cover the heads. The bumblebee is an efficient cross-pollinator of red clover. Bumble bees are able to pollinate from 30 to 35 flowers a minute. The honey bee proved to be as efficient a cross-pollinator of red clover as the bumble bee in 1911. In 1911 when the pre- cipitation was considerably below normal in June, July and August and but few nectar producing plants were to be found at the time, honey bees collected a large amount of pollen from red clover. In order to collect pollen they must spring the keels of the flowers. In doing this they cross pollinate the flowers. A clover cross-poll enizing machine which was offered for sale on the market did not prove to be an efficient cross-pollinator of red clover. The various types of hand operated brushes which were used did not prove efficient as cross-pollinators of red clover. In nearly all cases where these brushes were used the seed yield was decreased instead of increased. This was undoubtedly due to the bristles of the brushes injuring the flowers since the av- erage seed yield of the plots given in Table VI II is lower than that given in Table IX. The plots given in Table VIII received NOTES ON POLLINATION OF RED CLOVER ;59 three treatments with the brushes while the plots in Table IX received but one treatment. It will not be necessary to describe the method of pollination since this has been done in several papers by Hermann Mueller, L. H. Pammel and Charlotte M. King, Roberts15 and others. We might note in this connection that any insect with sufficient weight to press down the keel of red clover can pollinate it. For this reason various butterflies observed on red clover like the large monarch butterfly ( Danais ar chippies) , the cabbage butterfly ( Pieris rapae and P. Brassipae) , the yellow butterfly ( Coleus philodice and C. eurytheme) as well as certain Noe- tuidas which are especially common in September, are not nor- mal pollinators. Certain Coleoptera also visit red clover but they are not normal pollinators though they sometimes no doubt transfer pollen from, other plants. The normal pollinators are bumble bees, of which we have observed the following at Ames : The Bombus pennsylv miens, B. fervidus, B. americanus ; and the honey bee Apis mellifica. The bumble bees are generally not common on the first crop. In 1915 we observed two bumble bees over an area sixteen by sixteen feet in ten minutes on a partly cloudy afternoon. In order to determine the length of the corolla tubes under the most favorable weather conditions we had H. L. Rothschild measure the corolla tubes of 1,000 corollas of first crop clover and J. H. Frazier measured the corolla, tubes of second crop clover. The conditions for the development of red clover flow- ers were most favorable this year (1915). Rothschild found the average length of first crop to be 9.52 mm. and Frazier found the corolla tubes of 500 second crop to have an average length of 9.42 mm. The Rothschild measurements were made between June 27 and July 6 and the Frazier measurements be- tween July 10 and 15. For the purpose of obtaining an aver- age the length of ten flowers of each head was measured. 360 IOWA ACADEMY OF SCIENCE Vol. XXIV, 1917 LENGTH OF COROLLA TUBES AND SIZES OF HEAD IN MILLIMETERS. First Crop Clover. No. Flowers - l 2 ' 'i . ■ 1 ! 3 1 4 5 6 1 • ! a 9 10 Average H eight of Head 1 10. I 9.5 9. 9.2 9. 9.4 8. 9. 9.5 9.2 9.2 27.5 2 8. 8. 7.5 8. 8. 8. 8. 8. 9. 8.1 8.1 30. 3— 10. 10.5 10.5 10.5 10.5 10. 10.5 9.5 9.5 11. 10.25 30. 10 10.5 10. 10. 10.5 11. 11. 10.5 10.5 10.5 10. 10.4 31. 13—— 1 8.5 ! 8.5 9. 8.5 8. 9. 9. 8. 9. 8.5 8.0 23. Second Crop Clover. 1 8. 7.5 8. 8.5 7.5 7.5 8. 8. 9. 8. 8. 22. 3 10. 9.5 11. 10. 10.5 10. 10. 9.5 9.5 10. 10. 28. 6 12. 12. 12.5 12. 12.5 12.5 12. 12.5 12. 12.2 12.2 12 11. 11. 10.5 10.5 11. 11. 10.5 11. 10.5 10.5 10.2 33. 42 9. 9.5 8. 9. 9. 9. 8.5 9. 9. 9. 8. 31. 45—— 8.5 8.5 8.5 8.5 8.5 9. 8.5 9. 9. 9. 8.7 31. The measurements reported by Pammel, and by us in 1911 and those made by Rothschild and Frazier show a pretty close agreement. The longest corolla tube reported was of second crop clover. The general average is, however, somewhat shorter than first crop. This statement seems to bear out the one usu- ally made by beekeepers that the corolla tubes of second crop clover are shorter than for the first crop. The difference is, however, slight and the amount of nectar collected by honey bees from the second crop because of the shortness of the corolla tube is practically nil generally. It might, however, be noted that a number of investigators referred to in the paper, “Pollination Studies of Red Clover,” state that red clover is self fertile. This is not borne out by the studies of H. S. Coe referred to in the above paper; more- over, J. N. Martin in the same paper points out that sterile ovules in red clover are of common occurrence. “During the first crop many plants produce 100 per cent of infertile ovules, with such plants the presence of bees is not a matter of impor- tance for the ovules have no reproductive cells, hence there can be no fertilization and no production of seeds. During the sec- ond crop when the season is generally dry and favorable for seed setting, there is some infertility ranging from a low percentage or none in some plants to a high percentage in others. It is very probable that this infertility of ovules is to a greater or less degree a hereditary character and that the selection of a high yielding strain will consist, among other features, in se- NOTES ON POLLINATION OF RED CLOVER 361 lectrng those plants with the least tendency toward infertility. ’ ’ Quoting from the paper, “Red Clover Seed Production,” the results published by previous investigators on cross pollination and self-pollination of red clover do not agree. Frandsen and Fruwirth also show that pollen must come from an entirely separate plant in order to fertilize the ovules of red clover flowers. The relative efficiency of the bumble bee and honey bee as cross pollinators of red clover has also been discussed by scien- tific investigators as well as by agricultural papers and bee keepers. Bee men generally agree that the Italian races of honey bees can extract nectar from red clover flowers. Little, how- ever, has been said about the ability of the honey bee to collect pollen from red clover. In view of the above diverse opinion in regard to self-pollina- tion and cross pollination of red clover, a number of experi- ments were outlined in order to determine (1) whether red clover flowers were self fertile, (2) if self fertile, whether any effective method of self pollination could be found which would be applicable for use on a field scale; and (♦.3$ the relative effi- ciency of the bumble bee and honey bee as cross pollinators of red clover. In the matter of the bumble bee as a cross pollinator of red clover, in addition to the foregoing data the following additional data will be of interest. TABLE GIVING THE RESULT OF EXPERIMENTS CONDUCTED IN 1911 AND 1913. Year Location Bumble Bee Cage .Field Conditions No. of Heads Average No. of Heads Average 1911 Ames _ _ 311 ' 30.4 1302 52.5 1913 Ames — _ 970 13.3 79 12.9* (First crop) 1913 Le Mars 242 49.7 244 5.3* (First crop) 1913 Harpers Ferry 250 46.6 237 ffl* (First crop) jj( . . (Second crop) 220 20.3 244 45.0 1913 Essex 200 34.5 224 36.1 (First crop) 1913 Knoxville 245 50.5 250 54.9 (First crop) General average 28.5 41.0 *It is not surprising- that the average is smaller in bumble bee cage for reason that the bumble bee does not work as well under restraint. 362 IOWA ACADEMY OP SCIENCE Vol. XXIV, 1917 On the whole, bumble bees are shown to be quite efficient pol- linators of red clover. H. S. Coe summarized the previous investigations in regard to the honey bee as follows : HONEY BEES AS CROSS POLLINATORS OF RED GLOVER. The ability of the honey bee to cross pollinate red clover has been discussed by scientific investigators and bee keepers for some time. Those who do not believe that the honey bee is able to pollinate red clover base their statements for the most part on the fact that the proboscis of the honey, bee is not long enough to reach the nectar located at the base of the staminal tube. Some investigators and bee men state that some strains of the Italian race of honey bees are able to obtain some nectar from red clover flowers while other investigators say that honey bees collect pollen from red clover flowers and thereby cross pollinate them. According to Knuth20 the proboscis of the honey bee is 6 mm. in length, which is 3.6 min. shorter than the average length of the corolla tubes of first crop red clover flowers. Pammel states that nectar lies from 7 to 9 mm. deep. Honey bees may be able at times to obtain some nectar from the sides of the staminal tubes of red clover flowers when a large amount is secreted, or when the flowers are not in an upright position. On pulling the red clover flower out of the calyx the nectar is visible to the naked eye. J. H. Frazier found that in rainy weather the nec- tar may be reached at a depth of 6 mm. from the upper part of the tube of the corolla, but in dry weather the nectar was found at a depth of 8 mm. Chemical analyses of the nectar washed from clover corollas, however, show that in rainy weather it is not very rich in sugar. Indeed, much of the accumulated liquid may be rain water drawn by capillarity into the corolla. It wras also found that the amount of nectar secreted varied greatly. After a heavy dew on July 20, 1915, the amount varied from a small drop at the base of the tube to 6 mm. The tightly fitting calyx evidently crowded the nectar up. The small corolla tube causes the nectar to rise by capillarity. Opinions differ as to whether honey bees actually collect nec- tar. Dadant17 makes the statement that honey bees do sometimes collect nectar because of the shorter corolla tubes. The same statement is also made by A. I. Root.21 NOTES ON POLLINATION OF RED CLOVER 363 C. E. Bartholomew, who has charge of the college apiary, in- forms us that he saw bees gather nectar from red clover in the college apiary. He states that bees usually gather pollen and because the bee is highly specialized that some bees gather pollen, others only nectar. The statement is made by bee authorities that both honey and pollen may be gathered at the same time. Our observations made in the college apiary indicate that 80 per cent of the bees had pollen on their legs and on 20 per cent of the bees pollen could not be seen. Several bees without pollen were tested for the presence of honey in the honey bag, but we could not detect it. It is interesting to note that honey bees were abundant on the first crop of red clover in the college apiary, but on August 11, bees were as numerous as one to the quadrat (4 feet square) on a field a quarter mile from the apiary. Of nine that were captured seven were found to have pollen on their legs. Microscopic examination showed this to be red clover pollen. On subsequent days, bees were rather fre- quently seen on red clover. Some of them were evidently gath- ering nectar, others pollen. In 1914, a very dry season, honey bees were more numerous on red clover than in 1915. At one time during August, 1914, the month of their greatest abun- dance, as many as nineteen were counted on one cpiadrat. This may account for the difference in the pollination experiments noted later. Knufh observes that Bombas terrestris, a species of bumble bee found in Europe, pierces the tubes of clover flowers and honey bees later gather nectar through these slits. Bombas terrestris has a proboscis from 7 to 9 mm. in length. While working on the experiments given in this bulletin several corolla tubes were observed which had been slit at the base but it can not be stated, that these were probably not slit by bees. The structure of the mandibles of the honey bee is not adapted for, cutting. Schneek22 states that Virginia carpenter bee ( Xylocopa virginica) slits the lower end of the corolla tubes of red clover flowers and that he has observed honey bees obtaining nectar through the slits. Pammel23 has made similar observations. In order to determine the efficiency of the honey bee as a cross pollinator of red clover, a cage, 12 feet square and 6 feet high, made of galvanized wire screen having 4 meshes to the linear inch, was erected in the same field as ,the bumble bee 364 IOWA ACADEMY OF SCIENCE Vol. XXIV, 1917 cage. It was previously determined that a mesh of this size would permit a honey bee, or any insect smaller than a honey bee, to pass through, but would not permit bumble bees to do so. Two weeks before the clover came into bloom a small colony of honey bees was placed in one corner of this cage. The bees soon learned to pass through the screen. By the time the clover began to bloom the bees had become accustomed to the cage and while most of them worked on- flowers outside, yet some could always be seen at work on the clover within the cage. Bees working on the clover within the cage were observed to collect pollen from the flowers and carry it to the hive. As soon as all the flowers in the cage were mature, an area 4 feet square was measured off and all heads within this area were collected, kept separate and threshed by hand. Of the 623 heads collected from this area an average of 37.2 seeds per head 'was obtained. The higher yields of seed obtained in the honey bee cage than in the bumble bee cage may be attributed at least in part to the larger number of bees which had access to this clover. How- ever, the ratio of honey bee to bumble bee was no greater in the cages than in the clover fields in the vicinity of Ames, in 1911. In 1911 the precipitation at Ames, Iowa, was 2.48, 3.83, and 0.39 inches below normal for June, July and August respect- ively. When the clover was in bloom very few nectar producing plants were to be found. Whether the honey bee would work on red clover to this extent in a year of normal rainfall when the number of other nectar-producing plants is larger, is prob- lematical, but our observations and results show that the honey bee is able to spring the keels of red clover flowers and thereby cross pollinate them. A repetition of the experiment was made at Ames in 1913 on first crop clover. It was found that 940 heads from the cage containing honey bees and excluding bumble bees yielded an average of 0.8 seeds per head, while 79 heads of the uncov- ered clover yielded an average of 12.9 seeds and 970 heads from a cage containing bumble bees yielded an average of 13.3 seeds. The summer was rather dry, but rains were more uniformly dis- tributed than in 1911. Perhaps first crop clover is less visited by bees than second crop. In 1914 practically the only time honey bees were seen on red clover was during August. In 1915 the experiment was repeated. This summer proved to be exceptionally cool and moist, quite the opposite of that of 1911. The cage was erected June 26 and the crop harvested three months later. These three months had an aggregate pre- NOTES ON POLLINATION OF RED CLOVER 365 cipitation of 17.55 inches, which is much above* the normal for Ames. The bees seemed rather bewildered by being: enclosed in the cage, and many of them died in the efforts to find their way out. They did not, however, work very freely on the clover heads in the cage, although one or two bees could be seen on these heads at almost any time that the weather was favor- able for their activities. It was found that 500 heads in the cage produced an average of 18.7 seeds, while 500 heads in the field twelve feet away from the cage produced on an average of 35.0 seeds. The results are not such as to give much confidence in the ability of the honey bee as an effective pollinator, under all cir- cumstances, although they do seem to be able to accomplish pollination during some seasons. Department of Botany, Iowa State College. BIBLIOGRAPHY. (1) Cook, A. J., Report of agricultural experiments in 1891: U. S. Department of Agriculture, Bureau of Entomology, Bull. 26, 83-92, 1892. (2) Bailey , H. L ., Fertilization of clover and alfalfa: North Dakota Agricultural Experiment Station, Annual Report, 17, 34, 1907. (3) Fruwirth, C Rotklee, Selbst — und Fremdbestatibung: Die Zuch- tung der Landwirtschaftlichen Kulturpflanzen, 3, 163-166, 1906. Ibid. .Enclosing single plants and its effect on a large number of important agricultural species: American Breeder’s Asso- ciation, 2, 197, 1906. (4) Kirchner, O.. Uber die Wirtung der Selbstbestaubung bei den Papilionaceen: Naturwissenschaftliche Zeitschrift fur Land- und Fonstwirtschaft, 3, 1-16, 1905. (5) Sirrine, F. A., Notes on methods of cross pollination: Iowa Agricultural Experiment Station, Bull. 13, 89-90, 1891. (6) Witte, Hernfrid, Om Sjalfsteriliteten hos Rbdklofvern: Svensk Botanisk Tidskrift, 2, 333-339, Stockholm, 1908. (7) Waldron, L. R., Fertilization of clover: North Dakota Agricul- tural Experiment Station, Report of the Dickinson Substation, 1910, 7, 8, 1908. (8) Muller, Hermann, The Fertilization of Flowers, English trans- lation by D. W. Thompson, 184-ls6, London, 1883. Beal, W. J Grasses of North America, 1, 325-328, New York, 1896. (9) 366 IOWA ACADEMY OF SCIENCE Vol. XXIV, 1917 (10) Beal , W. J.. Planning an experiment to show to what extent bumble bees aid in pollinating red clover: Proceedings of the Society for the promotion of Agricultural Science, 1961, 136- 138, 1907. (11) Pommel, L. H.. and King , C. M.. Pollination of clover: Iowa Academy of Science, .18, 35-45, 1911. (12) Shamel, A. D.. The effect of inbreeding of plants: U. S. Depart- ment of Agriculture, Yearbook 1905, 377-392. (13) Bolley, H. L.. Fertilization of clover and alfalfa: North Dakota Agricultural Experiment Station, Annual Report 17, 34, 1907. (14) Martin , J. A.. Comparative Morphology of some Leguminosae: Botanical Gazette, 58, 154-167, 1904. (15) Roberts, Chas., Flowers and insects: Botanical Gazette, 11, 177, 1892. (16) Martin. J. A.. The physiology of the pollen of Trifolium pretense : Botanical Gazette, 46, 112-126, 1913. (17) Dadant, C. P.. Langstroth on The Honey Bee, 121, 1913. (18) Lindhard , E., Om Rodkloverens Bestovning og de Humlebiarter som herved er virksomme: Tidsskp. Landbr. Planteavl, Bd. 18, Haefte 5, p. 719-737, illus., 1911. (19) Darwin , Chas., The Effects of Cross and Self Fertilization in the Vegetable Kingdom, 361, New York, 1885. (20) Knuth . Paul, Handbook of Flower Pollination, 2, 289, Oxford, 1908. (21) Root, A. I. and E. R., A. B. C. and X. Y. Z. of Bee Culture, 88, Medina, Ohio, 1908. (22) Schneck, Jacob. Further notes' on the mutilation of flowers by insects: Botanical Gazette, 16, 312-313, 1891. (23) Pommel , L. H.. The pollination of Phlomis Tuberosa, L., and the Perforation of Flowers: Trans. St. Louis Acad, of Sci., 5; 248. THE GERMINATION AND JUVENILE FORMS OF SOME OAKS. L. H. PAMMEL AND C. M. KING. The question of how some of our oaks germinate and the fact that little has been recorded upon tliis subject has come to us .on several occasions. It is definitely known that the white oak germinates in the fall and the red oak in the spring. The bur-oak, according to the statement of a Minnesota correspondent, germinates in the fall. We have held the opinion that this oak, although not closely related to the red and black oaks, also germinates in the spring, an opinion recently verified by actual observation. This fact is undoubtedly due largely to its environmental conditions, the bur-oak occurring in situations that are somewhat dry. There is some difference of opinion regarding the germination of the English oak. The botanical authors in the Encyclopedia Brit- tannica1 state that the acorns of this oak germinate in the spring. This is contrary to what we find to be true in the East-European form of the English oak, commonly known as the Russian oak ( Quercus Robur var. pedunculata) which is grown on our college campus. The acorns of this oak germinate in the fall. In view of this lack of well established information, it, seems timely to publish a few preliminary notes on the germination of some Iowa oaks. Figures of germinating acorns of some oaks have been used to illustrate texts on Morphology ; as the classic figure in Gray ’s Structural Botany2 used by various authors and illustrations from Sach’s and from Rossmassler in Marshall Ward’s3 treatise on the oak. Dr. George Engelmann4 made a study of the germination of the live oak ( Q . virginiana) , in which he records the develop- ment of little tubers, a fact well known to the negro children of the South, by whom they are eaten. CEncycl. Britt.. 19, 931 (11 Ed.). Also in the previous edition. 2Lessons in Botany, Gray (6 ed.), 20. 3The Oak, H. Marshall Ward, 20, 22. 4E'otanical work of the late George Engelmann, edited hv Gray and Trelease ; also Trans. Acad. Sci. St. Louis 4, 408-410. 368 IOWA ACADEMY OF SCIENCE Vol. XXIV, 1917 This led him to make a study of the germination in a num- ber of species of oaks. He noted the fleshy cotyledons, the “little caulicle, and at the upper end, toward the center of the acorn, the two stalks or petioles of these cotyledons.” The plu- mule is hut slightly developed. These structures vary some- what in different species. In the black oaks ( Q . nigra), etc., he found that the stalks are longer than the caulicle. In Q. macro- car pa-, Q. Ro'bur and Q. chrg solepis , the caulicle is nearly three times as long as the stalk. In the majority of white oaks (Q. alba, Q. stellata), etc., the caulicle is shorter than the stalks of the cotyledons. The longer stalks are found in Q. virginiana. Sargent5 gives the following general description of the germina- v tion of the acorn : The radicle is imbedded near the apex of the seed between the fleshy cotyledons with the minute plumule or growing point between thin petioles toward the middle e»f the seed ; the radicle in the North American black oaks and in a few of the white oaks being longer than the petioles of the cotyledons, and shorter in most of the white oaks. In germination the petioles of the cotyledons with the plumule, lengthen pushing the plumule outside the cracked shell of the nut within which the cotyledons remain ; the plumule develops into the ascending axis of the plant, which is covered in its lower nodes with minute scales, and is nourished by the food contained in the cotyledons, which rot and disappear toward the end of the first season after the radicle, by absorbing some of their nutritious material, has be- come swollen and enlarged. That the cotyledon may furnish food supply for the second season, is stated by H. Marshall Ward: The two cotyledons remain inclosed in the coats of the acorn ; the developing root obtains its food materials from the stores in the cells of the cotyledons, as do all the parts of the young seedling at this period. In fact- these stores in the cotyledons contribute the support of the plant for many months, and even two years may elapse before they are entirely exhausted. Sir John Lubbock6 describes the germination of two European 'Species, e. g. the Q. Robur var. pedunculata and Q. Ilex. These species are said to be very similar in their germination. Like all oaks the germination is hypogaeous, the primary leaves are re- duced to scales, and the hypocotvl soon becomes woody ; the cau- 5The S'ilva of North America, 8, .2, 4. Contribution to our knowledge of seedlings, 534, London, 1892. GERMINATION AND JUVENILE FORMS OF SOME OAKS 369 line leaves are alternate, stellately pubescent on both surfaces, the pubescence soon disappearing, distantly serrate in the seed- ling stage, nearly always entire in the adult tree ; stipules linear, subulate. Dr, Englemamr notes that the young, leaves of almost all oak seedlings are stellate pubescent, and that the trichomes of Q. macro carpa, and Q. nigra , and Q. marylandica have articulate hairs. C. K. Schneider2 notes that the hairs should be called “Buschelhaare77 instead of ‘'Stern harre.77 The percentage of germination of the red oak is rather low. Richard IT. Boerker7 * 9 found in the case of red oaks that it requires fifty-four days for germination in gravel, forty-six days in sand ; forty-two days in dense shade and eighteen days in medium shade. The germination of. acorns of this species in open light was 28 per cent; in medium shade, was 12 per cent; in dense shade 12 per cent. In regard to soil, it was found that there was no germination in dry soil and medium wet soil ; but in wet soil the germination was 28 per cent. In the case of soil texture he found germina- tion in loam soil 28 per cent, in sand 24 per cent, in gravel 16 per cent. He found also that it recpiired forty days for the germination to start. In a study of the germination, of the oaks we tried two methods ; in one the acorns were placed in moist sphagnum moss and in the other in moist sandy humus in the greenhouse. Ob- servations were made in the field also, (though by examination of the ground under some trees it was found that in case of the red oak ( Quercus rubra ) up to May fifteenth none of the acorns had germinated. Some were covered up with earth, a yellow loam, and some were left lying openly on the ground. Only a very small number of the Quercus Robur var. pedunculata had produced any living plants in the spring. We also planted a con- siderable number of acorns of the following species on a yellow clay hill; Quercus velutina, Q. alba, Q. rubra, Q. palustris, Q. imbricaria, Q. stellata, and Q. acuminata. The gardener covered the acorns with ten inches of soil. On May 15 none of the acorns had germinated, but by June 15 a small percentage had germi- 7Botamcal works, etc., 391. Jlllustriertes Handbuch der Laubholzkunde, 1, 161. 9Ecological Investigations upon the germination and early growth of forest trees. Doctor’s thesis University of Nebraska, 1-89, pi. 1-5, 1916. 24 370 IOWA ACADEMY OF SCIENCE Vol. XXIY, 1917 nated. The fact that so few of the acorns of the red oak covered with a little earth grew leads us to believe that germination, is low in nature, except in very favorable seasons and conditions, at least so far as the red oak and other Iowa forms are concerned. In some years a considerable portion of the acorn crop is injured by species of Curculio. White oak ( Quercits alba L.). The large acorns of the white oak occur abundantly and in nature may often be found ger- Fig. 58. — Young stem of white oak. Planted on October 8. 1, condition on October 25. 2, condition on October 31. 3 and 4, scales and young leaves. The leaves dropped off early in January. 5, condition in March. Drawn by C. M. King. of this species were gathered on September 25 and planted on September 27 in the laboratory. They were kept moist in sphagnum mess. Another batch was planted in the greenhouse in sandy loam and kept moist with sphagnum. In a few days the acorns in both cases split at the apical end and sent out urinating soon after they have fallen. A number of fresh acorns and a second radicle and caulicle. 4, on November 14. Three stems pro- duced, long root and a . cuplike depression from which the three stems arise, scales, stipules, and leaves also shown. Drawn by C. M. King. 372 IOWA ACADEMY OF SCIENCE Vol. XXIV, 1917 the hypocotyl. The hypocotyl made a rapid growth, in five days it became somewhat woody and was more than twice as long as the acorn. Small lateral roots were soon produced. On No- vember 14 the longest root measured 28 cm., while the longest stem measured 8 cm. The first leaves on the stem were reduced to scales, these scales successively increased in size ; both scales and leaves were covered with trichomes. The trichomes of the stem are long pointed and frequently curved, generally occurr- Fig. 60. — 1. Trichomes of white oak from stem. 2. Trichomes of white oak from leaf. Drawn by C. M. King. ing singly or sometimes in groups of two or three, not strictly stellate. Some trichomes woolly, especially on very young stems ; the walls colorless, thick, contents brownish. On the green leaves trichomes simple, long pointed, thick walled, occasionally in clusters of two or three. Trichomes of upper surface similar to those on lower. On very young leaves the upper and lower surfaces are woolly, trichomes occurring singly or in groups. The first fully formed leaf was serrate. In the greenhouse the GERMINATION AND JUVENILE FORMS OF SOME OAKS 373 leaves dropped during the month of January and buds were formed. April tenth a new set of leaves appeared, the earlier ones were pinkish in color, drooping and covered with hair. One of the interesting features of the germinating white oak was that in many cases multiple stems come from between the short stalks of the cotyledons. It is well known that in white oak the stem is at first woolly, later becoming smooth. The white oak seems to have a higher percentage of germination than the red oak. A part of the higher germination for last season ’s crop was no doubt due to the less frequent attacks of insects. The total germination of the white oak at the close of the period was 73.6 per cent. On May tenth these seedlings ranged in height from three to four and one-half inches. Fig-. 61.— To the left young- white oaks ( Quercus alba ) in greenhouse May, 1917. The central plant just unfolding. The ones to right and left ot this, a later stage with drooping leaves, the one on the left fully expanded. The one to the extreme right of figure is ( Q . imbricaria) . Photographed May 1, by Colburn. Chestnut Oak ( Quercus acuminata) (Michx.) ITauba. The germination of the chestnut oak is hypogaeous and the acorns germinate soon after falling from the tree. Acorns were gather- ed on September 25 and planted on the 27th in sandy humus in the greenhouse and covered with sphagnum; other acorns were placed in damp sphagnum moss. On October 8 many of these were split at the apical end. On October 25 the hypocotyl was more than five times as long as the acorn. The plumule made its way out near the upper end of the hypocotyl which at this 374 IOWA ACADEMY OF SCIENCE Vol. XXIV, 1917 stage was brownish and woody in texture, The first scalelike leaves on the stem were pubescent and alternately arranged. The young stem also was pubescent. The trichomes of the stem are long, slender and pointed, straight or curved, mostly singly, walls white, contents brown. The trichomes of the leaves are like those on the stem generally, only one, though sometimes grouped in twos or threes, not strictly stellate. The later and upper leaves were penni-nerved and sharply dentate, the teeth becom- ing gradually larger toward the base, pubescent on upper and lower surface, scattered, simple, general form somewhat spatu- late. The leaves below are glaucous. During the month of January the leaves dropped and the young twigs remained in this condition for eight weeks, when leaves again began to ap- Fig. 62. — Germinating acorns of Quercus acuminata. 1. On October 25. 2. On November 7. .3. On November 13. 4. Twisted roots and young lateral roots. 5. Trichomes on stem. Drawn by C. M. King. pear. The first leaves were penni-nerved, green on both sides, somewhat more shiny on the upper surface, pubescent on promi- nent veins and midribs, stipules soon falling. On May tenth these seedlings had reached a height of five to six inches. The acorns of this species germinate in about the same per- centage that those of the white oak do. On April 13 the total germination was 75 per cent. There is probably little reger- mination in any of the oaks. When the hypocotyl and radicle do not penetrate the soil drying will destroy the plumule. We received from Mr. J. H. Frazier some acorns with the hypocotyl two inches long. These acorns were placed in damp sphagnum GERMINATION AND JUVENILE FORMS OF SOME OAKS 375 moss. No further growth could be observed. On opening the acorns in February the cotyledons in part were still fresh, but the portion next to the hypocotyl was decayed. The hypocotyl also had decayed. 3Ug. 63. — 1. Germination of Q. acuminata acorns planted on October 8. 2, 3 and 4, condition on October 23 and 31. 5. Trichomes of stem. Dra'»'n by C. M. King-. Valley Oak ' (Quercus lobata Nee.) . Mr. George H. Kimball of T aba City, California, sent in some fresh acorns of this 376 IOWA ACADEMY OF SCIENCE Vol. XXIV, 1917 species. They were planted early in October in sandy humus in the greenhouse, receiving an abundance of water. The sur- Fig. 64. — The upper figure seedling bur-oak with expanded leaves and very young leaves, stipules, also scales on stem. The lower figure chestnut oak ( Q . acuminata), scales below on stem, full expahilod leaves and unfolding leaves. Photographed May 1, by Colburn. face was kept moist with sphagnum moss. In the course of a few days the acorns split near the upper apical end and the hypo- GERMINATION AND JUVENILE FORMS OF SOME OAKS 377 cotyl appeared. A single stem was produced that soon devel- oped lateral branches. The stem was pubescent. The straight or slightly curved trichomes have a thick colorless wall and brown contents and occur generally singly. The lower leaves consist of scales. The upper leaves are larger penni-nerved with numerous teeth, with small points, the upper surface darker, than the lower; the veins are light colored, prominent, mature leaves only slightly pubescent on the upper surface, especially on the midrib, lower surface of leaf pubescent with hairs om midrib and veins, trichomes .on lower surface of leaf mostly occur singly, sometimes two or three in a cluster, long .pointed, straight or slightly curved, walls thick, colorless, contents Fig 65. — Trichomes of valleyVoak (' Quercus lob at a) ; 1, from stem ; 2, from leaf. Drawn by C. M. King. brownish, the upper surface of leaf less pubescent than the lower. On May tenth these oak seedlings had reached a height of eighteen and one-half inches to twenty-two and one-half inches, a few smaller. The main root was twenty-four inches long. George B. Sudworth10 states that the species is a prolific seeder at intervals of about two years ; reproduction exceedingly scanty because the tree grows on grass covered pasture or wheat land the surface of which is rarely broken when the seed falls. The seed germinates readily when well covered with fresh litter or soil, but it is seldom so covered by natural means. 10Forest Trees of Pacific Slope; IT. S. Dept, of Agr., Forest Service, 19 08. 37S IOWA ACADEMY OF SCIENCE Vol. XXIV, 1917 Russian Ooak ( Quercus Bobur var. pedunculata) . The acorns were gathered on September 20, planted in the greenhouse in sandy humus, covered with sphagnum and kept moist. Many of the acorns were split at the apical end on October 4. The hypo- Fig. 66. — Right hand figure valley oak ( Quercus lob at a) , fully expanded leaves and unfolding leaves, both branches from the same acorn. The left hand figure, Russian oak ( Q . Robur var. pedunculata), showing stipules, scales and fully formed leaves. Photographed May 1, by Colburn. cotyl pushed its vray down into the soil, increasing in length very rapidly. On October 18 it was two inches in length, at first whitish in color, becoming brownish. GERMINATION AND JUVENILE FORMS OF SOME OAKS 379 Germination of Q. Rob ur var. pedunculata, according to obser- vations of H. Marshall Ward,11 occurs in the spring. Sooner or later as the temperature rises in the spring, the embryo in the acorn absorbs water and oxygen and swells, and the little radicle elongates and drives its tip through the ruptured investments at the thin end of the acorn and at once turns downward and forces itself slowly into the soil. With us the acorn germinates abundantly in the fall soon after it falls to the ground, in September or October, vary- ing with the season. In the greenhouse it tested 90 per cent Fig'. 67. — Germinating Russian oak ( Quercus Robur var. pedunculata ) ; 1, condition on October 4 ; 2, condition on October 20 ; 3, condition on October 30 ; 4, trichomes of stem ; 5, triehomes of leaf. Drawn by C. M. King. germination. The plumule pushed out near the upper end, the young stem was slightly pubescent, the trichomes of the stem generally occurring singly, long pointed, straight or slightly curved, cell wall -colorless, thick, contents brown, the lower leaves were scalelike, these successively larger, the fully formed penni-nerved leaves with margins of rounded teeth, upper sur- face of leaf shining, lower surface paler in color ; midrib promi- nH. Marshall Ward. The Oak, 19. 380 IOWA ACADEMY OP SCIENCE Vol. XXIV, 1917 nent, trichomes few on upper and lower surface of leaf, on very young leaves more numerous than when fully formed, singly or bunched, in some cases as many as live trichomes in a cluster, long pointed, cell walls thick, white, upper surface with similar trichomes^ but less in number, either singly or from two to four cells in a group. By May 10 these oak seedlings were from four to seven inches in height, averaging three and one-fourth inches. Post Oak ( Quercus stellata Wang.). The acorns were sent to us from Johnson City, Tennessee, by J. PI. Frazier. They were planted in the greenhouse on October 29 in sandy humus, . cov- Fig. 68. — Germinating post oak ( Quercus stellata), planted in October; 1, condition on November 10 ; 2, condition on December 5 ; 3, trichomes of stem ; 4, trichomes of leaf. Drawn by C. M. King. ered with damp sphagnum. The germination is hypogaeous and occurs soon after the acorns fall from the tree. The hyipocotyl pushes its way through the acorn at the apical end. The hypo- cotyl is strong; it soon becomes thickened and is woody. On December 5 it was somewhat longer than the acorn. Growth was much slower than in the white oak. The plumule emerges near the basal end of the hypocotyl. The young stem is pu- bescent, trichomes occurring singly or in (dusters of two, straight GERMINATION AND JUVENILE FORMS OF SOME OAKS 381 or slightly curved, variable in length, cell- wall white, thick, contents brown, The first leaves consist of scales, the upper larger, wide at the middle, with rounded lobes, pubescence scat- tered and abundant below, smooth above, trichomes on lower surface of the leaf. On May tenth seedlings of Quercus stellata were two inches in height. Swamp White Oak ( Quercus plcitanoides Lam.) Sudw. The acorns were gathered near Centerville, Iowa, on October 16. Fig. 69. — Upper left hand figure post oak ( Quercus stellata). Upper right hand figure Q. aquatica, scalelike leaves on stem below, stipules and fully formed leaves. Middle figure Q. velutina with scales and stipules, younger and older leaves. Photographed May 1, by Colburn. They were planted on sandy humus covered with sphagnum and kept moist. These acorns did not germinate until February. Lenticels are conspicuous on young branches, trichomes of stem long pointed, straight or slightly curved, walls thick, contents brown. The first leaves are somewhat pubescent. The leaves become successively larger, woolly 'pubescent, the upper leaves 382 IOWA ACADEMY OF SCIENCE Vol. XXIV, 1917 all penni-nerved, narrowed at the base, broader toward the middle, somewhat undulated, lower surface of leaf with scattered Pig'. 70. — Trichomes from young plant of swamp white oak ( Quercus platanoides ) ; 1, from stem ; 2, from leaf. Drawn by C. M. King. pubescence, persistent on the veins, scattered, occurring singly or in clusters of two or three, trichomes long pointed, straight Fig. 7i. — Swamp white oak ( Q. platanoides), scales on stem below leaf, early and late, fully formed leaf. Photographed May 1, 1917, by Colburn. or curved, cell walls thick, contents brown, upper surface with trichomes scattered and on midrib, singly or clustered, soon be- GERMINATION AND JUVENILE FORMS OF SOME OAKS 38: coming smooth, margin of leaf undulate with a few hairs. On May 10 the height of this seedling was from six and one-half to eight and one-half inches. Fig. 72. — The bur oak (Qiiercus macrccarpa ) ; 1, germinating acorn in cup ; 2, tri chorhes of stem ; 3, trichomes of leaf. Drawn by C. M. King. Bur Oak ( Quercus macrocarpa Michx.) . Acorns planted on October 2 in sandy humus covered with sphagnum moss were kept moist. Germination did not occur until April. However all 384 IOWA ACADEMY OF SCIENCE Vol. XXIV, 1917 the acorns did not germinate at one time. The total germina- tion was 65 per cent. In germination the strong hypocotyl pushed out from the apical end, soon becoming woody and dark in color, showing lenticels, trichomes singly or in some instances in groups of two, long pointed, straight or curved, cell walls thick, white, cell contents bro wn. The "first leaves scalelike, pu- bescent, becoming successively larger, petioles and young leaves pubescent on both surfaces, the larger leaves ipenni-nerved, of firm texture, margin scalloped with simple hairs, trichomes on upper surface and on midrib, thick walled, light colored, long pointed, singly or in groups of two or three, cell-walls light col- ored, cell contents brown, leaves of lower surface pale in color, similar to the upper, pubescent on midrib and veins, also with scattered hairs. On May 10 seedlings of the oak were from four and one-half to eight inches in height. Red Oak (Quercus rubra L.). -4corns from St. Charles, Mis- souri, were planted on October 21 and from Ames, Iowa, on September 24, in sandy humus covered with sphagnum moss and kept moist. Germination did not oeeur until March. They did not, however, all germinate at the same time, but continued to germinate until April 23. Thirty-nine and four-tenths per cent of the St. Charles acorns had germinated. Of the Ames material 34.96 per cent germinated. The hypocotyl pushed its way out through the apical end, at once producing a strong woody hypocotyl, the plumule coming out near the basal part. The lower part of the stem is somewhat pubescent. The tri- chomes slender, pointed, colorless, simple. The scales became successively larger, leaves penni-nerved, bright green above, lower surface paler in color, midrib above in some cases reddish, in others greenish. Pubescence on mid- rib and veins on lower surface sparse, very young leaves pu- bescent above and below. The trichomes on lower surface clus- tered in groups of generally four or more cells, with stellate appearance, usually straight, shorter than in the white oak group, pointed, walls colorless, contents of cell brown, upper surface with few trichomes. Teeth widely sep- arated, each tipped with a prominent bristle. On May 10 the seedlings averaged five and one-fourth inches in height. Acorns of Q. rubra gathered in the fall and left in the labora- tory all winter were placed in damp moss in May. At the close Fig. 73. — 1. Germination of red oak ( Quercus rubra), leaves and stipules; 2, as the stem emerges from the ground ; 3, trichomes from stem ; 4, trichomes from leaf. Drawn by C. M. King. 25 386 IOWA ACADEMY OP SCIENCE Vol. XXIV, 1917 of three weeks’ time, none had germinated. The acorns were sound when planted, upon being cut open the acorns were found to be brown, indicating that life was destroyed during the long period of drying out. Fig. 74. — Young red oak (Q. rubra ) stipules, scales below and fully formed leaves. Photographed May 1, 1917, by Colburn. Quercitron Oak ( Quercus velutina Lam.). Acorns gathered on September 23 were planted in greenhouse on September 24, in sandy humus, covered with sphagnum. The acorns did not Fig. 75. — Trichomes of Quercus velutina-, 1, from stem; 2, from leaf. Drawn by C. M. King. germinate until April. Although only sound acorns were planted the germination was only 25 per cent. GERMINATION AND JUVENILE FORMS OF SOME OAKS 387 The strong hypocotyl pushed out from the apical end and soon became woody. The plumule emerged near the basal por- tion of the hypocotyl. The young stem was covered with yellow- ish hairs, trichomes occurring singly or in clusters, or more correctly, a group of trichomes formed small cells at the base, giving it a stellate appearance, the individual hairs variable in length, thick colorless walls and brown contents, the first leaves of small pubescent scales, leaves becoming successively larger, penni-nerved, pubescent on midrib, veins and scattered, tri- chomes of two kinds on lower surface of leaf, the clustered tri- chomes with stellate appearance numerous, five or more cells with small basal cells; straight or slightly curved, wall thick, colorless, the simple trichomes woolly, brownish in color, upper surface of leaf similar but less pubescent, the veins conspicuously anastomosing, young buds in seedlings conspicuously pubescent, Fig. 76. — Trichomes of Quercus imbricaria; 1, from stem; 2, from leaf. Drawn by C. M. King. wholly unlike the red and shingle oaks. On May 10 these oak seedlings were from two to three and one-half inches high. Shingle Oak ( Quercus imbricaria Miclix.) . Seeds planted in sandy humus, kept moist by placing sphagnum moss on the soil. Seeds germinated in March. Produced strong hypocotyl, young stem smooth at first and lower leaves scalelike, upper suc- cessively larger, elongated penni-nerved margin with a few broad dentations ; first leaves not dentate, marginal bristles short, mid- rib much more prominent than the lateral, margin wavy smooth, upper surface nearly smooth, except a few hairs on midrib, tri- chomes occur singly or in fewer cases in groups of two or three, long pointed, straight or slightly curved, cell-wall thick, light colored, cell contents brown, midrib or lower surface with a few scattered hairs. On May 10 this oak seedling was six inches in height. S88 IOWA ACADEMY OF SCIENCE Vol. XXIV, 1917 AVater Oak ( Querciis aquatica .Walt.). Acorns came from Win. Diehl of Clemson College, South Carolina. They were placed in damp sphagnum moss immediately upon arrival here, about November first. They were left for a few weeks but no changes occurred. They were then transferred to sandy llU- Drawn by C. M. King-. liras, covered with sphagnum and placed in the greenhouse where they were watered every day. The seeds did not germinate until April 18, when the plumule appeared above the ground. A sec- ond seed pushed through the soil on April 24. The hypoeotyl GERMINATION AND JUVENILE FORMS OF SOME OAKS 389 pushed its way through the apical end of the acorn. It grew rapidly in length, soon becoming woody and brownish in color, carpet; 3, Quercus aquatica ; 4, Quercus platanoides ; 5, Quercus stellata. Drawn by C. M. King-. with lateral roots, the plumule coming from near the base. Stem slightly pubescent, trichomes in most plants singly or in 39C IOWA ACADEMY OF SCIENCE Vol. XXIV, 1917 some cases of two or three cells, long pointed, straight or slightly curved, cell-walls thick, contents brown. First leaves of scales Fig. 79. — Young leaves of oaks: 1, Quercus imbricaria; 2, Quercus rubra; 3, Quercus Robur var . _ pedunculata : 4, Quercus alba; 5, Quercus acuminata; 6, Quercus lobata. Drawn by C. M. King. reddish, becoming green ; the scale pointed, pubescent, larger leaves on midrib and pubescent on margin with GERMINATION AND JUVENILE FORMS OF SOME OAKS 391 stipules oblique, small reddish petiole slightly pubescent, promi- nently penni-nerved, veins anastomosing, margin wavy, entire, slightly revolute, midrib below and above smooth. On May 10 this seedling was three and one-half inches in height. REFERENCES. Ward, H. Marshall, The Oaks, 1892. Tubeuf, K. Samen, Friichte u Keimlinge, EeFin, 1891. Engelmann, G., Acorns and their Germination: Trans. Acad. Sci., St. Louis, 4, 190-192, 1880. Meehan, T. L., On the Cotyledons of Quercus: Proc. Acad. Natl. Sci. Philadelphia, 155, 1871. and Mazyck, W., Germination in Acorns: Ibid, 29, 1880. Stenzel, Zwei Nachtrage - sur Keimung der Eichel: Jahresh. Schles Cesell, veterland, Kultur, 54, 105, Breslau, 1877. Samenformen tei der Eiche: Biblioth, Botan., Heft 21, Cassel, 1890. Tubeuf, Die Buchenkeimlinge von Sommer 1889: Bot. Centralblatt, 41, 374, 1890. ■V PLANT STUDIES IN LYON COUNTY, IOWA. D. H. BOOT. The subject of this paper is one of a series of ecological studies carried on by the author during the last few years, and is a study of a part of the region, consisting chiefly of high prairie, in the northwestern part of the state, the tract considered cov- ering a part of the southwest corner of Lyon county, which is the northwesternmost county in Iowa. The region for many miles in every direction is dominantly prairie, although there , are isolated groves, and fringes of tim- ber are found along the streams and in sheltered parts of the rougher portions of the territory. The relation of such scat- tered groves and timbered tracts to one another, and to their prairie surroundings is always of interest, and presents ecologi- cal problems as yet only in part solved. It is very desirable that detailed local study of the prairie flora be carried on in order to determine the many problems regard- ing its distribution and development, and the relations existing between the prairie plants and those of forested areas. The nu- merous environmental factors entering into these problems are a source of great interest, and a very inviting field of research. This work should be done while undisturbed tracts of prairie and forest are still to be found. Such an area was selected for consideration in this paper because it is one that shows very sharply the transition from forest to prairie; because it is located ill the heart of the prairie region ; because it is far removed from larger forest areas, and is on the very edge of the great plains, there being no forest of any size west of it until one comes to the foot hills of the mountains; and because it has been but little disturbed by man. The locality chosen is in Lyon township, Lyon county, Iowa, along the state line. Here the Big Sioux river flows nearly due west for several miles, and the hills on the south side of the stream rise to a height of 180 feet above the water. In the part studied there is a level flood plain about 100 yards in width next the river, and then the bluff rises in a timbered slope ex- tending south about one-fifth of a mile, to the exposed summit, ;94 IOWA ACADEMY OF SCIENCE Vol. XXIV, 1917 which is bare of trees, and carries only prairie plants. The variety of plant habitats to be fonnd in close proximity to each other here varies from high, dry, exposed prairie, through scrubby bur oak woods, to heavy forest, as one descends the north face of the bluff. The bluffs along the river have deep ravines running back several hundred yards to the south in various places, and at certain points in these, small bogs appear about springs, while high, bare-topped ridges separate them. Photo- graphs of the bluff from various points of view are given in Plates XI and XII. The profile of the hill is shown in figure 80. St *ri on JJ/_ nUT StatioYvJl If ft ajkn>4, AJsmfu. ‘/-OO ft. S. AasiMA, 8 ft A X.H- ft' 5. f TA'M j ~r /TS-eAsttjCL^L^- Figure 80 This region has been worked over by the glaciers several times. Bed rock outcrops a few miles to the north, where ledges of the well-known Sioux quartzite appear along the river, and about a mile northeast of the area studied, on the north side of ihe river, are ledges of Cretaceous rock. Over the wooded bluffs we have a thin humus which becomes thicker in the wooded areas, and on the river bottom. Beneath the humus on the bluffs is a moderate amount of wind-blown loess, in no case observed to be more than four feet thick. Below this is a very extensive bed of yellow Kansan drift, at Syverud Bluff not less than sixty feet in thickness. Next below this come several feet of water bearing Aftonian gravels of an interglacial period, and then come great deposits of the earliest glacial drift that covered Iowa Academy of Science. Plate XI. PLANT STUDIES IN LYON COUNTY 397 this region, the so-called Nebraskan drift, here composed of a dark bluish jointclay, with small angular rock fragments, very impervious to water, and very tough and glutinous when it is wet. Many springs come out of the Aftonian gravel at the upper edge of the Nebraskan drift. They are fed by the rains soaking through the permeable Kansan drift sheet. Some of these springs are large, one such, a little farther along the river, flowing a constant stream easily large enough to fill a six inch pipe. In the area selected slumping of soils had occurred great enough to cause some general mingling of the various elements mentioned above as composing the geological formation. The river bottom is quite sandy. On these bluffs we have the high upper hill tops exposed to all the winds, that blow, and not sheltered in any way. Going down the bluff face we pass through zones of greater and greater protection from the southerly winds, and in the forest the trees shelter the herbaceous plants, and to a considerable degree1 one another, from the northerly winds, and from the sunlight. On t lie river bottom the shelter from prevailing winds is also as- sisted by heavy woods on the north of the river, and by the woodland up and clown stream. The particular tract selected for this study is in section 20. township 98 north, range 48 west, in Lyon township, at a point that I call Syverud Bluff, from the ' gentlemanly farmer who owned it. Man has exerted a minor influence on the flora of this tract. Some of the largest of the trees have been cut clown, and the bottom land and the forested bluff face have been very lightly pastured. The prairie hill top was not pastured, nor had it been culti- vated in the part belonging to this study. A few stray clover plants only have come in from a near-by field. We have here, therefore, an almost pure native flora. Such a pure native flora is a rarity in any part of Iowa, or of the states near to Lyon county, because the great value of the agricultural lands has led to the cultivation of almost all the prairie tracts, and the scarcity of timber has led to the destruction in large part of the native forest. On this bluff a. tract 145 feet wide from east to west, and running from the river south to the hill top, and extending 398 IOWA ACADEMY OF SCIENCE Vol. XXIV, 1917 over the hill top and down the south side, was selected for de- tailed observation as to soil, atmosphere, and other conditions affecting plant growth. Typical stations were selected as follows : Station I on the river flat, 8 feet above the river, in ordinary season, and 24 feet south of it. Station II near the foot of the bluff, 44 feet above the river, and 400 feet south of it. Station III in the timber, half way up the bluff side, 820 feet south of, and 119 feet above, the river. Station IV, 1,230 feet south of the river, 164 feet above it, located on the open prairie. The total area in forest on this tract studied was about 160,000 square feet. The area in pra’rie was about 100,000 square feet. It will be seen by the plant lists of the several stations that the flora of this locality does not comprise a large number oi species of flowering plants. The number of flowering plants native to the upper Mississippi yalley is considerably more than a thousand, and our list here is limited to 162 species. The lo- cality is so far west and north that, for Iowa, it has severe conditions. The plants of the prairie are largely plants of the western plains, while the flora of the forests has more the appear- ance of the forests farther east. In accordance with the prairie conditions we find that 62 per cent of the dry prairie plants of station IV are of a type unsuited for the more protected tracts of stations I, II, or III, and do not occur at these stations at all. Typical of these plants are Andropogan scoparms and Andropogan fur cat us, Anemone patens var. Wolfgangiang, Aster sericeus and Aster oblongifolius, Bouteloua curtipendula and Bouteloua hirsuia, Grindellia squarrqsa, Helianthus scab err imus, Kuhnia eupatorioides var. corymbulosa, Petalostemum candidum and Petalostemum purpureum,- Soli dago missouriensis and Solidago nem oralis, and Vida pedatifida. These plants are characterized by devices for protection from the drying effects of the hot southwest summer winds, and the scorching effects of the blazing summer sun. In some the leaves are markedly firm and rigid ( Solidago missouriensis and Helianthus seaber- rimus), or are clothed with hairy coverings ( Solidago nemoralis, Kuhnia eupatorioides var. corymbulosa, Aster sericeus and Anemone patens var. Wolf gam gi ana). In others the leaves are PLANT STUDIES IN LYON COUNTY 399 much dissected, in strong contrast to related species growing in sheltered localities ( Viola pedatifida, Petalostemum candidum, Petalostemum purpureum and Anemone patens var. Wolfgangi- ana), or they have very well developed root systems ( Petaloste- mum candidum, Petalostemum purpurcum, Aster sericeus, Kuhnia eupatorioides var. corymbulosa, and Andropogon sco- parius) . Gummy secretions protect some, as in Grindellia squamosa and Helianthus scaberrimus , while others protect themselves by very narrow and convolute leaves ( Bouteloua cur- tipendula, Bouteloua hirsute, Andropogon scoparius and Andro- pogan fur cat us) . Of the plants found at Station IV, the high prairie, 19 per cent are found at Station I, the river flat. Thirty-two ‘per cent of the plants of the dry prairie, Station IV, extend down the upper north face of the bluff to Station III, and, 12 per cent get to Station II, the lower forest level on the north bluff face. Some of these are strays, as in the case of Cirsium iowense, and Oxalis stricta, whose home is on the high prairie, but a few speci- mens of which occur, perhaps accidentally introduced; others, as Melilotus alba, are naturalized plants found at all stations, though growing much more vigorously in the damp river-bottom soil than in the dry soil of the high prairie, while there are hardy natives, as Euphorbia marginata, which can endure the dry upland, but also flourish more luxuriantly on the river flat. Rudbeckia laciniata, found at all stations, we would expect at the protected stations, and look upon it as a stray on the high dry prairies. This plant, is unusual in Northwest Iowa. Fift}^ per cent of the flora of Station I is not found at any other station, and 83 per cent of it does not appear at Station IV, which is its greatest extreme as respects conditions in this local- ity. Seventy-six per cent of the plants found at Station I (river flat) do not appear at Station II (lower timbered bluff face), and seventy per cent of them at Station III (upper timbered bluff face). The difference between II and III in favor of III is to be accounted for by carriage of seeds by birds in the case of such plants as Vitis vulpina, Symphoricarpos occidentals, Sambucus canadensis, and Ribes Cynosbati, and to other accidents of local distribution in the case of Agastache nepet aides , Chenopodium hybridum, Euporbia marginata, Laportea canadensis, Polanasia trachysperma, TJlmus americana, and Vernon' a fasciculata. In the 400 IOWA ACADEMY OF SCIENCE Vol. XXIV, 1917 case of such plants as Vernonia fasWkulata. in particular, whose home here is on the prairie, and which produces a large crop of easily distributed seed, the only reason for it not being found at Station II just as at Stations I, III and IV, is chance seed dis- persal, as it is well able to endure the conditions. Because of the accidents of chance seed dispersal in so narrow a strip as the tract under consideration many plants that are native to the scattered groves of this region are missed. Of the plants found at Station II, the lower part of the bluff face, 14 per cent are not found elsewhere. The total flora of this station is the smallest of all, being only forty-three species, or twenty-six per cent of the total number as compared with sixty- five species or forty per cent for Station I, seventy-five species, or forty-six per cent, for Station III, and fifty-six s'peoies, or thirty- four per cent, for Station IV. Of the plants not found elsewhere 1 tubus idaeus var. acideatissirniis would be expected at least in Stations I and III, but for the chance work of birds in distribut- ing seed, Verbena angustijolia is certainly a stray and should appear higher upon the hill, or on the sandy bottom, Phleum pratense, which is probably introduced, must be classed as a stray that could flourish at any station, though poorly at Station IV. Gymnocladus dioica appears to belong properly in the rich woods of Station II, near the foot of the bluff, where protection is good, both from drouth and from flood. Aster muliifloris var. exiguus, found only at this station, is perhaps a stray, for it frequents the sandbanks on the flat and the hills elsewhere. Of the plants found at Station II, thirty-seven per cent occur at Station I. sixty-five per cent of them at Station II, and sixteen per cent of them at Station IV. Station III has thirty-seven per cent of species not found elsewhere. It has the greatest total number of species of all the stations, namely, seventy-five per cent, due to its being located between the high prairie and the lower bluff woodland. It has eighteen species found also at Station IV, and twenty-eight species found also at Station II. Singularly, it has twenty species found on the river flat at Station I. Typical of the hardy plants that extend down to it from Station IV we have Solidago rigida, Rosa pratincola, Monarda mollis , Aster ptarmicoides, and Am- brosia .p silo st achy a. These, while at home on the dry prairie, are able to extend their range down the wooded bluff face as far as PLANT STUDIES IN LYON COUNTY 401 Station III. Elymus st rictus is an example of a plant more at home in the woods of Station III, as shown by the number of specimens, but able to extend its range upward to the dry prai- ries, where a few appear. Anemone cyUndrica is an illustration of a plant at home on the dry prairie, but able to accommodate itself to the drier parts of the woods, so that a few specimens appear at Station III. Of the plants at Station III, which appear abundantly at Station II, Quercus macrocarpa, TJlmus fulvci, S'ilene st elicit a, Ostrya virginiana, Frag aria vesca var. americana, and Aquilegia canadensis illustrate those which must have some protection, and flourish best where the shelter is good. Quercus macrocarpa illustrates well the effect on the hardiest trees of the difference in the conditions for growth due to variation in shel- ter. The 190 specimens found on the tract studied are all grouped in Stations II and II T, with the taller, thicker trees almost in- variably lower down, and those near the upper tree limit low, small in diameter, and gnarled and stunted in every way (see Plate. XI, I and II) . Station III marks the upper tree limit for a number of the hardier trees as well as the limit for a number of the hardier herbaceous plants which extend up through all the stations until they come to the extreme conditions of the dry prairie. Examples of these are Acer N eg undo, which shows regu- lar diminution in size from Station I to Station II, Ribes gracile, also much more vigorous and numerous at Station I than at Station II and Station III, Fraxinus pennsylvanica var. lanceo- lata, Tilia americana, and Arctium, minus, all showing the same traits as to size and vigor. Of plants found only in the upper woods typical examples are Monarda fistulosa, Primus virginiana, Rosa blanda, Liatris scariosa, Lepacliys pinnata, Heliopsis scabra, and Cary a glabra. Strays able to hold their own are illustrated at this station by Celastrus scandens, Juniperus virginiana, Lac- tuca scariola , and Trifolium pratense. The extent of variation in conditions at the several stations is indicated by the variation in flora, 20 per cent of the entire number of species being found at Station I, and nowhere else, 3 per cent of the entire flora appearing only at Station II, 17 per cent of it growing only at Station III, and 21 per cent of it only at Station IV. Only 1.8 per cent of the entire flora is able to adapt itself to the conditions found at all of the stations, 8 26 402 IOWA ACADEMY OF SCIENCE Vol. XXIV, 1917 per cent appears at three stations, 28 per cent appear at two stations, and 63 per cent at a single station. The very distinct division of the flora into prairie and forest, with the great differences between their floras, naturally lead to attempts to explain their clcse proximity. Lists of plants have been made by various botanists within the territory surround- ing Lyon county on the north, the east and the south. In Mc- Millan 7s “Metaspermae of the Minnesota Valley”, we have listed, among other things, the trees of that nearby tract. None of the trees in the Lyon county area are absent from these lists, nor from the lists in Shimek’s report on territory east of this, as given in “The Plant Geography of 'the Okoboji Region”. This Lake Okoboji region is in the valley of the Little Sioux river, and between that valley and the valley of the Big Sioux river intervene long stretches of open prairie without trees. If the forest trees of the Big Sioux valley had come from tho east across the country it would be reasonable to expect trees to be found on the intervening prairie. The same may be said con- cerning the introduction of forest trees from the Minnesota for- est to the northeast, A glance, however, at the map of Iowa makes clear a highway the trees could follow, viz. : up the valley of the Missouri river, and along the Big Sioux river to the region. All along this course the protection of bluffs and broken ground, the presence of water nearby, and the transporting agencies of animal life that would follow the stream, would be present to aid in the gradual advance of the trees into a region dominantly xerophytic prairie. Local conditions make it pos- sible for the trees of protected places to survive the generally harsh conditions that prevent the presence of a general forest. The prairie plants, in turn, are almost all found outside of Lyon county, and most of their names are reported from Har- rison and Monona counties. All of them occur in Woodbury county, about Sioux City. They extend north into Minnesota, as shown by the reports of Upham, and sixteen of them reach the Red river valley, as shown by the same author. Lyon county is near the eastern edge of the great plains and the plants are those of the dry prairies. They could be brought to this area in many cases by wind transportation of seeds, by seeds being car- ried by birds and animals, and by gradual advance by growth. Not needing the protection of a rhrer bank, the greater amount Iowa Academy of Science. Plate XI T. r PLANT STUDIES IN LYON COUNTY 405 of soil moisture, nor the high relative humidity demanded by the mesophytic or by the hydrophytie plants, they could travel directly over the prairie, and because of these qualities continue there. Birds flying over the prairie will drop such seeds of trees as they carry, any where, but the greater part, falling in un- suitable places perish. The less hardy vegetation survives only when it has a favored location. After obtaining a. footing in a stream valley the forest also may spread down stream by* the waters transporting the seed. STATISTICS OF FLOWERING PLANTS OF SYVERUD BLUFF. Sta. I Sta. II Sta. Ill Sta. V 6 er Cent o' er Cent o er Cent o' er Cent £ PS £ PS !? PS J25 j PS Number of species and per cent of grand total at each station Number of species and per cent of 65 40 43 26 75 46 56 34 Station I’s total found in other stations 16 24 20 30 11 17 The same in per cent of grand total of sppcips 16 10 20 12 11 7 4 Number of species and per cent of Station II’s total found in other stations 16 • 37 28 65 7 16 The same in per cent of grand total of sp^cios 16 10 28 17 T 4 Number of species and per cent of Station Ill’s total found in other stations 20 26 28 37 18 24 The same in per cent of grand total of sppcips 20 12 28 17 18 11 Number of species and per cent of Station IV’s total found in other stations 11 19 | 7 12 18 32 The same in per cent of grand total of species 11 7 7 4 18 11 Total number of species not found in other stations _ 33 6 28 35 zq Per cent of entire flora not found in other stations 20 3 17 21 Per cent of flora of separate sta- tion not found elsewhere 50 1 14 37 62 Total number of species collected 162 Per cent of entire flora growing at all stations l.S Per cent of entire flora growing at three stations 8. Per cent of entire flora growing at two stations 26. Per cent of entire flora growing at only one station 63. 406 IOWA ACADEMY OF SCIENCE Vol. XXIV, 1917 PLANT LIST. SPERMATOPHYTA. Sta. I Sta. II Sta. Ill Sta. IV SUBDIVISION I. Gymnospermsc Family Pinacese Juniperus virginiana L SUBDIVISION II. Angiospermre Class I. MONOCOTYLEDONE^ Family Alismacere Sagittaria latifolia Willd Family Graminesc Andropogon scoparius MicTx Andropogon furcatus Mulil Bouteloua curtipendula (Michx.) Torn Bouteloua hirsuta Lag Setaria glauca (L.) Beauv. Elymus striatus Willd Hystrix patuia Mcench Plileum pratense L Foa pratensis L . Eragr'ostis megastac.iiya (Koeler) Link Eragrostis pectinacca par. special) ilia g7 Muhlenbergia teimiflora (Wil.)oBSP Fanicum capillare L. . . . Family Aracece Arisaema triphyllum (L.) Schott Family Liliacex Allium stellatum Ker. . . . Class IT. DIC3TYLEDONE/E SUBCLASS I. Archichlamydese Family Salicacece Populus deltoides Marsh. Salix nigra Marsh Family Juglandacese Ca.ya glabra (Mill) Spach Juglans nigra L Family Betuiacece Alnus sp , Ostrya virginiana (Mill.) Koch.,... Family Fagac'ex Quercus macrocarpa Michx Tamily Urticacese Laportea canadensis (L.) Gaud Ulmus amerkana L Ulmus fulva Michx Uitica gracilis Ait Family Fo'ygon acese Polygonum Hydropiper L Polygonum virginianum L Family Chenopodiacese Chenopodium album L Salsola Kali var. tenuifolia Mey. ... Chenopodium hybridum L Family Amaranthacese Acnida tuberculata Moq Amaranthus retroflexus L + + + + + + + m + + + + -f- t ~r + + + + + + + + + + + + + + + + + + + PLANT STUDIES IN LYON COUNTY 407 PLANT LIST— Continued Sta. I Sta. II Sta. Ill Sta. IV Family Caryophyllacese Silene stellata (L.) Ait. f + + Family Ranunculaceas Clematis virginiana L Aquilegia canadensis L + + Anemone cylindrica L + + Anemone patens var. Wolfgangiana (Bess.) Koch + Family Menispermacese Menispermum canadensis L + Family Cruciferae Erysimum cheiranthoides L + Radicula palustris var. hispida (Des.) Robin + Family Capparidacese Folanisia graveolens Raf + Polanisia trachvsperma T. & G + + Family Saxifragaceae Ribes gracile Michx + + 4- Ribes Cynosbati L + 4- Family Rosacese Geum virginianum L T Crataegus mollis (T. & G.) Scheele + Geum canadense Jacq + Prunus virginiana L .+ Rosa Blanda Ait .+ Rosa pratincola Greene + T Fragaria vesca var. americana Port. + Rubus idaeus aculeatissimus (Mey) Reg. & Til + Potentilla monspeliensis L + Prunus americana Marsh + + Family Leguminosse Gymnocladus dioica (L.) Koch..... Melilotus officinalis (L.) Lam + + + Trifolium repens L + + ! Melilotus alba Desr + + + + Astragalus caryocarpus Ker + Oxytropis Lambert! Pursh + Petalostemum candidum Michx + Petalostemum purpureum (Vent.) Rydb. + Trifolium pratense L + Amorpha canadense L + Strophostyles helvola (L.) Brit.... + Apios Tuberosa Moench + Astragalus canadensis L + Family Linaceas Linum usitatissimum L + Family Oxalidacese Oxalis stricta L + + + + Family Rutaceae Zanthoxylum americanum Mill + + Family Euphorbiacese Euphorbia marginata Pursh + + + Euphorbia petaloidea Engelm + 408 IOWA ACADEMY OF SCIENCE Vol. XXIV, 1917 PLANT LIST— Continued Sta. I Sta. II Euphorbia Preslii Guss Family Celastraceae Celastrus scandens L Family Aceracese Acer Negundo L Acer saccharinum L Family Rhamnaceae Ceanothus americanus L Family Vitaceae Vitis vulpina. L | Family Tiliaceag j Tilia americana L Family Violaceae Viola pedatifida G. Don I Viola cucullata Ait j Family Onagraceao Circaea lutetiana L Oenothera muricata L Oenothera serrulata Nutt j Family Umbelliferae Thaspium aureum Nutt j Zizia aurea (L.) Koch j SUBCLASS II. Metachlamydeae Family Oleaceae Fraxinus pennsylvanica var. lance- olata (Bor.) Sar Family Convolvulacese Cuscuta arvensis Bevr Family Boraginaceae Lithospermum canescens (Michx.) ! Lehm Lappula virginiana (L.) Greene. . . . Lithospermum Gmelini (Michx.) Hitchc Lithospermum Latifolium (Michx.) . Lappula Redowskii var. occidentalis (Wats.) Rvdh Family Verbenaceae Verbena bracteosa Michx Verbena hastata L Verbena stricta Vent.. Verbena urticaefolia L Verbena angustifolia Michx Family Labiatae Agastache nepetoides (L.) Ktz Monarda fistulosa L Monarda Mollis L Scutellaria lateriflora L. Teucrium canadense L Lycopus virginicus L Mentha arvensis var. canadensis (L.) Briq Physostegia virginiana (L.) Benth. Family Solanaceae Physalis pubescens L Solanum Nigrum L + + + + + + + + + + + + + -f + + + + + + + + + Sta. IlljSta. IV + + + + + + + + + + + + + I + ! + + ++ ++ PLANT STUDIES IN LYON COUNTY 409 PLANT LIST— Continued Family Serophulariacese Gerardia tenuifolia Vahl Pentstemon gracilis Nutt Verbascum Thapsus Family Phrymaceae Phryma leptostachya L Family Plantaginaceae Plantago major L Family Rubiaceae Galium Aparine L Family C'aprifoliaceae Sambucus canadensis L Symphoricarpos occidentals Hook.. Viburnum Lentago L Family Cucurbitaceae Echinocystis lobata (Michx.) T. & G. Family Campanulaceae Campanula americana L Family Compo sitae Aster laevis L Aster multiflorus var. exiguus Fern. E.upatorium urticaefolium Reich. . . Lactuca floridana (L.) Gaertn Solidago latifolia L Taraxacum officinale Weber Ambrosia artemisiifolia L Ambrosia psilostachya DC Aster ptarmicoides T. & G. ....... , Antennaria plantaginifolia (L.) Rich Artemisia ludoviciana Nutt Aster oblongifolius Nutt. . . . Aster sericeus Vent Brauneria angustifolia (DC.) Heller Grindellia squarrosa (Pursli.) Dunal Helianthus scaberrimus Ell Kulinia eupatorioides var. corym- bulosa T. & G Lactuca canadensis L Liatris punctata Hook Lygodesmia juncea (Pursh.) D. Don.. Solidago missouriensis Nutt Rudbeckia laciniata L Vernonia fasciculata Michx Solidago nemoralis Ait Arctium minus Bernh Helianthus decapetalus L Heliopsis scabra Dunal Lactuca scariola L Lepachys pinnata (Vent.) T. & G. Liatris scariosa Willd. . ; Solidago rigida L Aster lateriflorus var. thyrsoideus (GR.) Sheld Sta. I + Sta. II Sta. Ill Sta. I\ + + + f- + + + + + + + + + + + + + + + + + + + + + H- •f + + + + I + + + + + +-f + +++++ ++ 4*-f +*+.+4:4-4" •410 IOWA ACADEMY OP SCIENCE Vol. XXIV, 1917 PLANT LIST— Continued Sta. I Sta. II Sta. Ill Sta. IV Aster paniculatus var. lanatus F'er- nald Bidens frondosa L. '+ Bidens laevis (L.) BSP + Cirsium iowense (Pammel) Fernald + + Eupatorium perfoliatum L + Erigeron canadensis L + + Erigeron ramosus (Walt.) BSP + Cirsium canescens Nutt + THE FLORA. I ( SECOND ARRANGEMENT OF LIST.) The sharp transition in floras from one station to another is shown by the following list of the same plants as given in the preceding list, but arranged by. stations instead of in the order of plant relationship. The 4- indicates the presence of the plant at any station, and the continuous line of +?s gives a regular curve of transition from Station I to Station IV. Station I is river bottom, Station II is lower forest level of north face of bluff, Station III is upper forest level of north face of bluff, Station IV is bare prairie of hill top and south- west slope of hill. Sta. I Sta. II Sta. Ill Sta, IV Acer Negundo L + + + Acer saccharinum L + Acnida tuberculata . Moq + Agastache nepetoides (L.) Ktz + + Alnus sp + Amaranthus retroflexus L + Arctium minus Bernh + + + Aster lateriflorus var. thyrsoideus (Gr.) Sheld + + Aster paniculatus var. lanatus Fernald + Bidens frondosa L. . + Bidens laevis (L.) BSP + Campanula americana L + + Chenopodium hybridum L + + Circaea lutetiana L + Cirsium canescens Nutt + Cirsium iowense (Pammel) Fernald + • + Echinocystis lobata (Michx.) T. & G + Eupatorium perfoliatum L T- Euphorbia marginata Pursh + + Euphorbia petaloidea Engelm + Euphorbia Preslii Guss + PLANT STUDIES IN LYON COUNTY 411 PLANT LIST— Continued Eragrostis megastachya (Koeler) Link Eragrostis pectinacea var. spectabilis Gray. Erigeron canadensis L Erigeron ramosus (Walt.) BSP Fraxinus pennsylvanica var. lanceolata (Bor.) Sar Geum virginianum L Juglans nigra L. Laportea canadensis (L.) Gaud Lappula Redowskii var. oceidentalis (Wats.) Rydb L.ycopus virginicus L. . Melilotus alba Desr ■ . . Mentha arvensis var. canadensis (L.) Br'iq. Muhlenbergia tenuiflora (Wil.) BSP Oxalis stricta L Panicum capillare L Physostegia virginiana (L.) Benth Polanisia graveolens Raf Polanisia trachysperma T. & G Polygonum Hydropiper L. Populus deltoides Marsh Potentilla monspeliensis L. . . Prunus americana Marsh '. Radicula palustris (Des.) Rob Ribes Cynosbati L Rudbeckia laciniata L Sagittaria latifolia Willd Salix nigra Marsh Salsola Kali var. tenuifolia G. F. W. Mey. .. Sambucus canadensis L y Scutellaria lateriflora L Solanum nigrum L Strophostyles helvola (L. ) Brit Symphoricarpos oceidentalis Hook Teucrium canadense L Tilia americana L Ulmus americana L. Urtica gracilis Ait Verbascum Thapsus L. Verbena bracteosa Michx Verbena hastata L Verbena stricta Vent Verbena urticaefolia L Vernonia fasciculata Michx Vitis vulpina L Apios tuberosa Moench Aquilegia canadensis L Arisaema triphyllum (L.) Schott.. Aster laevis L Aster multiflorus var. exiguus Fern Cuscuta arvensis Beyr Eupatorium urticaefolium Reich Fragaria vesca var. americana Port. Galium Aparine L . Gymnocladus dioica (L.) Koch : . ! Sta. I Sta. II Sta. Ill Sta. IV + + + + + + + + + + + + + + + ~r + + + + + + + + + + + + + + +• + + + + + + + + + + + + + + + + + + + + + + .+ + + + + + + + + + + + + + + + + + 4- + + + + + + + + + + + + + + + ++ IOWA ACADEMY OF SCIENCE Vol. XXIV, 1917 412 PLANT LIST— Continued Lactiica floridana (L.) Gaertn Lappula virginiana (L.) Greene Melilotus officinalis (L.) Lam Ostrya virginiana (Mill.) K. Koch Phleum pratense L Poa pratensis L Polygonum virginanum L Quercus macrocarpa Michx. Rubus idaeus var. aculeatissimus (Mey) Reg. & Til Silene stellata, (L.) Ait. f Solidago latifolia L Taraxacum officinale Weber Trifolium repens L Ulmus fulva Michx Verbena angustifolia Michx Zizia aurea (L.) Koch Zanthoxylum americanum Mill Ambrosia artemisiifolia L Ambrosia psilostachya DC . Anemone eylindrica Gray Aster ptarmicoides T. & G As.tragalus canadensis L Carya glabra (Mill) Spach • Celastrus scandens L Chenopodium album L Clematis virginiana L Crataegus mollis (T. & G.) Scheele Elymus striatus Willd Erysimum cheiranthoides L Geum canadense Jacq Helianthus decapetalus L Heliopsis scabra Dunal Hystrix patula Moench Juniper us virginiana L Lactuca scariola L Lepachys pinnata (Vent.) T. & G Liatris scariosa Willd Menispermum canadensis L Monarda fistulosa L Monarda mollis L Oenothera muricata L Phryma leptostachya L Plantago major L Prunus virginiana L Ribes gracile Michx Rosa blanda Ait Rosa pratincola Greene Solidago rigida L Thaspium aureum Nutt Trifolium pratense L Viburnum Lentago L Viola cucullata Ait Allium stellatum Ker Amorpha canescens L Andropogon scoparius Michx Sta. I Sta. II Sta. Ill H “b + + + + 4: .+ + + Sta. IV + + + + + + + + + + + + + + + + + + + + + + + 4- + + + + + + + + + + + -f + I T + + + + + + + + + + + + + .+ + + + + + + . + + + + + + + + + + + PLANT STUDIES IN LYON COUNTY 413 PLANT LIST— Continued Sta. I Sta. II Sta. til Sta. IV Andropogon furcatus Muhl + Anemone patens var. Wolfgangiana (Bess.) Koch + Antennaria plantaginifolia (L.) Rich + Artemesia ludoviciana Nutt -p Aster oblongifolius Nutt 1 + Aster sericeus Vent + Astragalus carvocarpus Ker + Bouteloua curtipendula (Michx.) Torr + Brauneria angustifolia (DC.) Heller + Ceanothus americanus L + Gerardia tenuifolia Vahl 4- Grindellia squarrosa (Pursh.) Dunal + Helianthus scaberrimus Ell + Kuhnia eupatorioides var. corymbulosa T. & G -P Lactuca canadensis L + Liatris punctata Hook + Linum usitatissimum L + Lithospermuni canescens (Michx.) Lehm... + Lithospermum Gmelini (Michx.) Hitchc. ... + Lithospermuni latifolium Michx + Lygodesmia juncea (Pursh.) P. D. Don + Oenothera serrulata Nutt + Oxytropis Lamberti Pursh + Pentstemon gracilis Nutt + Petalostemum candidum Michx + Petalostemum purpureum (Vent.) Rydb.... + Physalis pubescens L + Setaria glauca (L.) Beauv + Solidago missouriensis Nutt + Solidago nemoralis Ait + Viola pedatifida G. Don + SUMMARY. The northwest portion of Iowa, because of the nature of its topography and its dry climate, is almost destitute of woodland, and its flora is characterized by a large percentage of plants specially adapted to withstand severe drought. The forests of this region are very similar in make-up and appearance to the forests farther east, while th$ upland flora is made up of dry-prairie species. In a particular representative locality in this region the plants group themselves in very definite fashion as is shown in the tabular summary of the flora for the several stations studied and summarized in percentages at the end of the list. The marked variations in lists correspond well with the marked changes in conditions found at the several stations. 414 IOWA ACADEMY OF SCIENCE Vol. XXIV, 1917 \ The upper limit of tree growth is a transition area from the bare prairie to the wooded forest characterized by stunted trees and hardy shrubs able to endure almost as severe drought as the highly xerophytic plants cf the open prairie. A variation in conditions, due to exposure, sufficient to cause only a few degrees of difference in relative humidity, is enough to cause striking variation in forest covering, if the critical point for the plants struggling to find foothold is not passed. The variation in soil is not of itself to be charged with the variation in flora because the same soil carries all the different floras within a few hundred yards cf eacli oilier, the plants vary- ing according to the exposure. Department of Botany, State University. WALTER E. ROGERS. During recent years the legumes have not only become of firs^ importance as hay and forage crops but they have been found to be of even more importance as restorers, of soil fertility. The amount of interest and attention given to the group by working botanists has been large and ever increasing. It would seem that we ought to know as much as possible about our economic plants. It is with this in mind that the present paper is sub- mitted. Mel Hot us alba (Desr.), once a despised roadside weed, is now recognized as a valuable crop plant and is grown over thousands of acres of our soil. A brief report is here made of a study of the stem, flower, and pollen. ANATOMY OF THE STEM. Stems a millimeter in diameter were the youngest which were sectioned. At this stage the vascular bundles are still separate. The pith is wide and the stem is much fluted (1, figure 81). At a diameter of two millimeters a wide continuous ring of wood has formed and a narrow zone of phloem, while in the cortex the bast has developed (2, figure 81) . In the mature sj^m (3, figure 82) which may attain a basal diameter of over two and a half centimeters, the bast becomes quite prominent on account of the thickening of the walls of its cells (4, figure 82). In radial thickness the bast columns vary from three to five cells. Isolated fibers measure 5.65 by 0.033 millimeters. The wood fibers are very short compared with the bast, measuring only 0.75 by 0.02 milli- meters. The medullary rays are generally one cell in width, some- times two, and rarely three. In tangential and radial sections they appear several to many cells in vertical height and their cells are peculiar in having their long axes parallel with the length of the stem. The bast and wood combine to give to the stem great stiffness, a quality of considerable importance in a hay or pasture plant, but also open to some objections since the older stems become exceedingly hard and unfit for feeding. ORGANOGRAPHY OF THE FLOWER. The inflorescence is a spikelike raceme and contains forty to sixty flowers, which are white and strongly zygomorph jc. The 416 IOWA ACADEMY OF SCIENCE Vol. XXIV, 1917 five green sepals of, the calyx are united somewhat unequally so that the teeth at the top of the tube are thrown into two sets, the anterior containing three and the posterior two. The corolla has five petals, the posterior (standard or vexillum) being larger and enclosing the others in the bud, but expanding and turning back at maturity. Interior to the two lateral petals lie the two lower ones and these last cohere along their anterior edges form- Fig. .81. — 1, Cross section of young stem at time of beginning of cambial activity, p, pith ; x, xylem ; pin, phloem ; c, cambium. 2, Portion of cross section of older stem, rb, region of bast. ing the carina which encloses the stamens and pistil (5, figure 83). The stamens, ten in number, are diadelphous, the one next the vexillum being free to the base while the rest are united for three-fifths of their length. In the bud the anthers occur in two sets or cycles, one above the other (6, figure 83), but at maturity the lengthening of the filaments has brought them to NOTES ON MELILOTUS ALBA 417 approximately the same level. The anthers are versatile and introrse. The pistil is elongate, oval in cross section and is pro- longed above into a filiform style which curves over slightly toward the standard and terminates in a globose papillate stigma. An extremely narrow stylar canal is present. Fig. .82. — 3, Portion from cross section of mature stem; showing frequency of tracheae in the wood and amount of hasti in the cortex. b, hast ; tr, tracheae. 4, Portion of cortex in cross section showing bast. MICROSPORANGIUM AND POLLEN DEVELOPMENT. The anther first appears as an oval mass of meristematic cells which very soon become four lobed in cross section. It flattens along the sides through pressure of the surrounding parts and the outer side becomes slightly wider than the inner. The radially elongated cells of the hypodermal layer divide by periclinal walls and the outer cells develop into the parietal layers while the inner develop the sporogenous tissue. 27 418 IOWA ACADEMY OF SCIENCE Vol. XXIV, 1917 Of the three parietal layers the outer becomes the endothecium and the inner the tapetum. The middle layer consists of tabular cells which, as development proceeds, become more and more compressed and finally disappear, probably being absorbed by the tapetum. The tapetal cells reach their greatest development at the time of tetrad formation, when they are large with heavily staining contents. Subsequently they undergo disorganization and disappear altogether during the growth of the microspores. Fig. 83. — 5, Cross section through the upper end of a mature flower, sep. sepals; pt, petals. 6, Longitudinal section of a younger flower showing a stamen of each of the two sets. The outer parietal layer in becoming the endothecium grows considerably in thickness and its cells develop on their radial walls riblike thickenings which unite into a plate on the inner wall. At the time of dehiscence the anther wall consists of only the endothecium and the epidermis. Dehiscence is by means of a longitudinal slit. NOTES ON MELILOTUS ALBA 419 The primary sporogenous cells become differentiated in each lobe of the anther as a single row (7, Plate XIII), probably five cells long. Both cross and longitudinal divisions follow rapidly and the result is a column of spore mother cells, four to six in number in cross section (8, Plate XIII) and ten in longitudinal section. The cells average ten to twelve microns in diameter but during the ensuing growth period increase in size until at the time of synapsis the diameter is fourteen to fifteen microns (9, Plate XIII). As the synaptic stage is initiated the mother cells begin to round off and to thicken their walls (10, Plate XIII). By the time that the heterotypic and homotypic divisions have given rise to four nuclei the wall thickening has become very pro- nounced and ridgelike ingrowths are produced midway between the nuclei (14, Plate XIII). Either these thickenings' grow inward, meeting in the center and cutting off the protoplasts from one another, or plates of material similar in staining reaction to the outer wall form between the nuclei and growing out- ward attach themselves to the projecting ridges (15, Plate XIII). The newly formed cells measure ten microns in diameter. The whole tetrad is now encased in the thickened wall of the mother cell and each member is individually enclosed in a layer which appears to be a condensation of the material of the mother cell wall (16, Plate XIII). This is the “special wall”, of Stras- burger. Inside this the microspore wall now forms, first as a delicate layer, but rapidly thickening (17, Plate XIII). The spores are at first spherical but soon elongate and when mature measure twenty-three by fifteen microns (18, Plate XIII). A characteristic feature of the wall is the possession of three longi- tudinal grooves or folds symmetrically disposed along the sides of the spore (19, Plate XIII). Each groove has at its middle point a thin spot in the wall, the exit pore. The division of the nucleus into tube and generative nuclei takes place some little time before dehiscence of the anther, and the generative cell when formed lies in the end of the grain (20, Plate XIII). Most of the pollen grains in the older anthers sectioned were as if turgid and did not show the wall foldings, but in grains which were taken from ripe anthers and examined, in air the wall folds were present. This pollen instantly became turgid 420 IOWA ACADEMY OP SCIENCE Vol. XXIV, 1917 when water was added to the mount. The turgid grains measured twenty-three by nineteen microns. ABNORMAL POLLEN. Certain of the. mother cells in the collections of September 16, 1914, developed abnormally. Usually each of these produced a single giant pollen grain. The anlage of the abnormal grains could usually not be de- tected until after the heterotypic and liomotypic divisions. The four nuclei resulting from these divisions take the usual arrange- ment. But instead of forming into a tetrad of spores the whole group with the surrounding cytoplasm becomes enclosed by a new wall which begins to form inside the wall of mother cell (21, Plate XIV). One of the nuclei now increases in size while the other three degenerate. The latter generally lie at one side and in late stages are crowded out against the wall. They often fuse together (22 and 23, Plate XIY). Meanwhile the dominant nucleus has enlarged until it has attained a diameter of twelve microns. The normal spore nucleus at first measures four and five-tenths microns. The increase in the case of the normal nu- cleus is four-tenths the original while in the abnormal grains the increase is sixteen-tenths. The wall of the giant microspore is of about the same thickness as the wall of the normal pollen but no exit pore is visible. The shapes of the giant grains vary from spherical to irregularly lobed (23, 26, 27 and 28, Plate XIY). The ultimate fate of the persistent nucleus was not deter- mined. One giant grain was found in which two nuclei much re- sembling the tube and generative nuclei of the normal pollen occurred (24, Plate XIY). A dark crescent at one side may have represented the three degenerating spore nuclei. The largest of the grains was thirty-five microns in diameter. The volume was therefore five and five-tenths times that of the ordinary pollen grain. Whether or not the giant grains are capable of germinating is of course unsettled since none were found except in the fixed material. Some of the variations from the above procedure in the devel- opment of the abnormal pollen were the following. In some cases the nuclear divisions of the mother cell were delayed for some time as evidenced by the thickened wall and the presence NOTES ON MELILOTUS ALBA 421 of an individual nucleus (25, Plate XIV). In many instances the formation of cross walls was initiated but suppressed at various stages. In some specimens the rudiment of a cross wall formed only a narrow trabecula (26, Plate XIV), while in others the trabecula extended almost across the cell width (28, Plate XIV). Several cases were found where septation had actu- ally taken place resulting in the formation of two grains from one mother cell (29, Plate XIV), and a few cases showed a di- vision wall cutting off one member of a tetrad (30, Plate XIV). Another case of occasional occurrence was that of mother cells which appeared to have passed through division normally but whose resulting pollen grains remained clinging tenaciously to- gether. To summarize, there were found all stages of gradation between pollen formed from mother cells without cleavage to pollen formed normally through mitosis and cleavage. DISCUSSION. There is a possibility that the giant grains were produced by hybrid plants. According to Jeffrey, giant grains have been of frequent occurrence in hybrid pollens examined in his labora- tory. Professor Jeffrey has no data on the nature and formation of these giant microspores. The collection of Melilotus flowers, which showed the aberrant- structures was taken from a number of plants and as the giant grains were found all through the collection it is probable that they were produced from a number of plants. If such were the case and if we are to assume that the large grains are in some way related to hybridism, then there must have been a number of hybrid plants growing in the same small area from which the collection was taken. Taking all the facts into consideration it does not seem probable that the giant grains can be safely as- cribed to hybridism. Cases somewhat similar to that found in Melilotus have been known for a long time in some of the Cyperaceae. Elving (1), Wille (8), and Strasburger (7) studied the pollen development in Eleocharis and later Juel (3) repeated the work very care- fully in Car ex acuta. In these forms the pollen mother cell passes through the tetrad divisions but three of the nuclei de- generate while the fourth persists and later divides into tube and generative nuclei. In these forms, however, the production of one pollen grain by a mother cell is the normal procedure. 422 IOWA ACADEMY OF SCIENCE Vol. XXIV, 1917 In Melilotus the giant grains are obviously abnormal. Moreover the development differs from that described by Juel and others in that the wall of the giant grain forms inside the old mother cell wall, while in the Cyperaceae the wall of the pollen grain is the modified mother cell wall. Miss Lyon (4) in her study of Selaginella found that in certain cases the megaspore mother cells formed spores without dividing or by dividing only once. Shattuck (6) working oil Marsilia, induced microspores from mother cells without the formation of cross walls. The abnormal- ities were brought about by' exposing the plants to a spray of cold water for several days. The formation of the giant grains in Melilotus resembles in some respects the formation of some of the giant microspores of Marsilia. In both cases the growth of the mother cell continues past the normal point of mitosis while cleavage takes place not at all or only incompletely. The variations from the normal in the case of Marsilia can be deafly correlated with certain envir- onmental factors. Any correlation in the case of Melilotus is very difficult since there appeared in the same flower and even in the same anther both normal and abnormal pollen. All of the flowers must have been subject to practically the same temperature and moisture conditions, as they were collected at points within a few feet of one another. As pointed out by Juel, the development of the giant grains is of some theoretical interest, for the facts show a striking re- semblance on the one hand with the development of the mega- spores of the heterosporous ferns and on the other hand with the formation of the embryo-sac of the Phanerogams. The de- velopment of these abnormal microspores indicates the homology of microspores and megaspores of higher plants as strikingly as does the abnormal germination of microspores as described by Nemec (5). In the one case the microspores resemble mega- spores in their formation and in the other case in their germina- tion. Perhaps the point of chief interest in connection with the giant grains is the variation in the extent of internal wall di- vision and the possible bearing of this upon the cpiestion of the formation of cell plates in the tetrad divisions. Since the divi- sions of pollen mother cells began to be carefully investigated NOTES ON MELILOTUS ALBA 423 it has been generally accepted that in the Dicotyledons, plates are formed and divide the mother cells into tetrads. The re- cent work of Farr (2), however, shows rather conclusively that in certain Dicotyledons the divisions take place without the formation of cell plates and by constriction of the walls. The appearance of the giant grains which have partly di- vided renders it probable that Melilotus is one of the plants whose pollen mother cells divide by ingrowth of the walls. In the study of the sections a complete series of stages in the cut- ting off of one or more members of a tetrad can be found. Figures 26, 27, 28 and 30, Plate XIY, represent such a series. It is hard to conceive of a method by which a partial or com- plete formation of cell plates would give rise to the appearances found when all partly formed division walls arise very evidently through the ingrowth of ridges from the enclosing wall. The problems of the chromosome behavior in these abnormal grains and of the possible connection with hybridism remain yet open and as the structures are being found in other genera it is hoped that a comparative study may be undertaken. Department of Botany, State University of Iowa. LITERATURE CITED. 1. Elving, F., Studien iiber die Pollenkorner der Angiospermen: Jenaische Zeitschrift Naturw., B. XIII, Jena, 1878. 2. Farr, C. H., Cytokinesis in the Pollen-Mother Cells of Certain Dicotyledons: Memoirs of the New York Botanical Garden, 6, 253- 317, 1916. 3. Juel, H. 0., Beitrage zur Kentniss der Tetradenbildung: Jalir. Wiss. Bot., 35, 1900. 4. Lyon, Florence May, A Study of the Sporangia and Gametopliytes of Selaginella apus and Sclaginella rupestris : Bot. Gaz., 31, 124-141, 170-187, 1901. 5. Nemec, B., Ueber den Pollen der petaloiden Antheren von Hya- cinthus orientalis : Bull. Int. Acad. Sci. Boheme, 1898. 6. ShattucTc, Charles H., The' Origin of Heterospory in Marsilia: Bot. Gaz., 49, 19-40. 7. Strasburger, E., Neue Untersuchunge uber den Befruchtungs- vorgang bie den Phanerogamen als Grundlage fur eine Tlieori der Zeugung, Jena, 1884. 8. Wille, N., Uber die Entwickelungschichte der Pollenkorner der Angiospermen und das Wachstum der Membranen durch Intussuscep- tion, Christiana, 1886. PLATE XIII. Fig. 7. One lobe of an anther1 in cross section showing a primary sporogenous cell. Fig. 8. Fig. 9. Fig. 10. Fig. 11. Fig. 12. Fig. 13. Spore mother cells in anther lobe. Microspore mother cell previous to synapsis. Mother cell in synapsis. Wall thickening at the corners. Metaphase. Completion of the heterotypic division. Metaphase of homotypic division. One spindle in cross sec- tion; the other in longitudinal section. Fig. 14. Completion of homotypic division. Mother cell wall con- stricting along the lines midway between the nuclei. Fig. 15. Three nuclei of the tetrad. The fourth lies below the plane of focus. Fig. 16. Thickening of the “special wall” completed. Microspore walls beginning to thicken. Fig. 17. Fig. 18. Fig. 19. Fig. 20. Spores at time of disintegration of the mother cell wall. Mature microspore. Cross section of microspore showing the grooves in the wall. Pollen grain with tube and generative nucleus. / ) Iowa Academy of Science. Plate XIII. PLATE XIV. Fig. 21. Fig. 22. Fig. 23. Fig. 24. Fig. 25. Fig. 26. Fig. 27. Fig. 28. Fig. 29. Fig. 30. Fig. 31. Mother cell forming single pollen grain. Microspore wall slightly thickened; four nuclei; no dividifig walls. Early stage in the fusion of the degenerating nuclei. Later stage; degenerating nuclei crowded out toward tlio outer wall. Giant pollen grain showing two nuclei; at the left the re- mains of the degenerating nuclei. Giant microspore in which the tetrad division has not yet occurred. Wall thickened; nucleus in resting phase. Wall cleavage initiated but suppressed early. Cleavage suppressed at a later stage. A case in which cleavage is almost complete. Two cells resulting from cleavage. One member of a tetrad cut off by cleavage. Outline of normal pollen grain, showing relative size. Iowa Academy of Science. Plate XIV. THE MORPHOLOGY OF THE TH ALEXIS AND CUPULES OF BLASIA PUSILLA. MARGUERITE B. ROHRET. HISTORICAL. First mention of the genus Blasia was made by Micheli Nov. PI. Gen. 1729. Linnaeus recognized the genus and added the specific name pusilla in his Species Plantarum 1753 p. 1138. In 1759 Schmidel wrote his ‘ 1 Dissertatio de Blasia.’’ Hooker 1816 called the plant J ungermaunia blasia but as this classification is much too broad it is not used today. Gottsche8 1828 published an account of the germination of the spores of Blasia pusilla. Later Gronland published his investigations of spore germina- tion in the leafy Jungermanniae, including Blasia in his discus- sion. In 1833, Nees von Esenbeek12 made some investigations on vegetative propagation and erroneously stated that the bud- receptacles (cupules) of Blasia are closed when young and open at the top at a later period. An incorrect figure of Hedwig’s had probably given rise to this error. Hofmeister9 included in his work on The Higher Crytogamia, a short sketch of vegeta- tive reproduction in Blasia, but some of his views are probably as faulty as those of Nees von Esenbeek.12 The most comprehensive study of Blasia pusilla was the classi- cal work of Leitgeb10 1874. His work was mainly on the gen- eral characters of the thallus, and on gemma formation. The development of the gemmae was treated in detail, following closely the work previously done by Hofmeister. He also fig- ured a few antheridia, several archegonia, and stages in the development of the sporophyte. Further work on the species was not reported until 1913 when W. E. Woodburn published his paper on the spermatogenesis of Blasia pusilla. THE THALLUS. Blasia pusilla is a temperate zone liverwort of wide distribu- tion. The species belongs to the Jungermanniales, which includes about 135 genera and over 3,500 species. This order of Hepatics is divided into the two sections Jungermanniaeeae Acrogynae and J ungerm an ni aceae Anacrogynae. In the first group the apical 430 IOWA ACADEMY OF SCIENCE Vol. XXIV, 1917 cell is given over to the formation of archegonia, which are ter- minal, while in the second group, to which Blasia belongs, the archegonia are formed on the dorsal side of the thallus from segments cut off from the apical cell, so that apical growth is not hindered. The subfamily Codonioideae includes eight genera, of widely divergent variations, namely Pellia, Calyeularia, Treubia, Fossombronia, Noteroclada, Petalphyllum, Siniodon, and Blasia. The genus Blasia, according to Sehiffner5 includes but one species B. pusilla. It is distinctly transitional between thallose and foliose forms of Hepatics, having a flattened, elongate thallus, which lies prostrate and firmly anchored to the substratum by rhizoids for about three-fourths of its length. The apical regions are free and grow somewhat inclined although the plants almost always point down the slope. The thallus is characterized by dich- otomous branching and has a broad midrib extending through- out its entire length on the underside. Along the midrib the thallus lobes are inserted horizontally and laterally. They re- semble leaves but are termed thallus lobes, not being separated from the midrib and from each other. This dorsi-ventral thallus is relatively simple, the tissue be- ing for the most part composed of uniform cells with thin walls. Chloroplasts are numerous in all the cells with possibly a few more in the top layer than in the lower ones. No air-chambers or pores were found. In cross section the thallus shows wing- like extensions projecting out from the midrib, which is found on the underside. This midrib, slightly depressed on the dorsal surface, and bowed out on the ventral side, is eight to twelve cells* in thickness and from the midrib to the point of lobe in- sertion, the thallus narrows gradually to the margin of the wings, which are one cell in thickness (1, figure 84). The only differentiation in the structure of the thallus tissue was first noticed in cross section, where groups of cells vary- ing from nine to thirty-six in number stained more deeply than the surrounding tissue. This differentiation suggested a strand of cells set apart for some special purpose, probably to function in conduction. Conducting tissue has been reported in three of the Ana (irogv nous Jungermanniales and nowhere else in the Liverworts. Sir William Hooker 1816 discovered the strands in Juogermannia now Pallavicinia Lyellii. Gottsche in 1864 de- MORPHOLOGY OP BLASIA PUSILLA 431 scribes a similar strand in Symphyogyna sinnuata and Leitgeb describes the cells of this strand in Symphyogyna and states that Blyttia (Pallavicinia) and Umbracnlnm (Hymenophyton) have similar strands. In fresh young plants of Blasia the strands can barely be dis- tinguished but in the old dead thalli they stand out on the sur- face as white threads. This would indicate that the cell walls are more resistant in the strand than in the surrounding tissue and the few experiments tried only serve to emphasize this fact. Upon the decay of the spongy thallus tissue these strands still hold their shape and can easily be picked from the soil surface. Drying has the same effect, entirely destroying the soft portion but leaving the threads unaffected. 432 IOWA ACADEMY OF SCIENCE Vol. XXIV, 1917 A weak eosin solution was used to test the conducting power of these cells, but the experiments were not wholly satisfactory as the whole thallus took the stain. There was a marked dif- ference in the degree to which the strand stained, as they be- came much darker than the surrounding cells. But even this would seem to indicate that more of the fluid was retained in the strands than in the remainder of the thallus. Generally, only two strands were found in a single thallus but the number varies from, two to five, depending on the amount of branching. They are found laterally in the thickened midrib of Blasia about equidistant between the dorsal and ven- tral surfaces. Where the thallus branched the strand divided giving off branches to each newly formed division. The angles of the cell walls were quite sharp in the transverse section but other markings were not found here (2, figure 84). In the longitudinal section (3, figure 85) a greater difference was noticeable. The conducting cells, averaging the same in width as those of the thallus, had a length three to five times greater and tapered to a point at each end. Cross Avails in some speci- mens run obliquely through these long tubes. The most strik- ing characteristic Avas the peculiar markings of the cell walls. The pits or depressions arranged irregularly along the walls are thin at the center and bordered by heavy darkly staining thickenings, giving the external appearance shown in 4, figure 85. These thickenings sIioav at fairly regular intervals along the wall in the prepared sections. Where the strands join the spongy tissue on either side, only the inside walls bear the mark- ings. The strands undoubtedly serve in a mechanical capacity, being provided with such strong Avails, but it is doubtful if this is their most important function. It does not seem consistent, that a tlialloid liverwort, attached by rhizoids for three-fourths its length, would need such strengthening as the strands might give. HoAvever, it is possible in the case of Blasia pusilla , that the resistant cells aid in giving body to the thallus upon which are found the gemmae receptacles and large sporophytes. Gottsche found that in Symphyogyna they had no connection with the “receptacles” on which the sexual organs were seated. These strand cells do not show nuclei, but simply a disinteg- rated substance, probably protoplasm, as it took the stain as readily and to about the same degree as the protoplasm in the surrounding cells. MORPHOLOGY OF BLASrA PUSILLA 433 In testing the plants in concentrated sulphuric acid, the thal- lus was found to melt away quite readily in from one to three hours, leaving the strands seemingly unaffected by the acid. At IT. Fig-. 85. — 3, “Longitudinal section through conducting strand. 4, Enlarged strand showing external markings. 28 434 IOWA ACADEMY OF SCIENCE Vol. XXIV, 1917 first the tissues of the thallus swelled considerably but soon broke down and the residue assumed the consistency of jelly. The strands, freed from the acid, were stained and mounted in balsam. They did not break down during the process but remained rigid and resistant. The mounts showed the identical markings seen in the prepared longitudinal sections. As most liverworts thrive only in moist habitats, the whole surface, if close enough to the sub-stratum, might absorb all the water needed or the thallus might be provided with rhizoids which perform the same function. With an increase in speciali- zation in these forms, as erect branches or parts raised above the thallus surface, it would seem almost necessary to have some sort of conducting system, more or less complex. Chick and Tansley14 say the following in regard to the three liverworts having conducting tissue : ' ‘ The three genera Palla- vicinia, Steph., Symphogyna, Nees et Mont., and Hymenophyton, Steph., differ in well-marked characters connected with the po- sition and investment of the sporogonium, and it is perhaps most probable that the striking character they have in common — the possession of an axial strand — has developed independently in each genus. The strand cells are formed, as might be expected, by longitudinal division of the inner cells cut off from the seg- ment of the apical cell and are differentiated very close to the apex. 7 7 The Growth of the Thallus. — The growth of the thallus pro- ceeds by means of a wedgeshaped apical cell. This type seems characteristic of the dichotomously branching forms, for the cell can be divided into two segments alike in size and shape and like the original apical cell. As each segment cuts off seg- ments from its inner face the two apical cells are pushed farther apart, and the dichotomous branching results. Leitgeb10 says, “The growth of the shoot results through the division of the 'vertex cell, 7 which forms a four sided segment, cutting off to right and left and dorsal and ventral sides. We find the same method of growth in the segments of Aneura and Pellia and the leaf-building segments of Fossombronia and Frullania, The segments cut off from the right and left sides of the apical cell develop the side leaves, while those cut from the dorsal and ventral sides take part in developing the branches. Those on the ventral side form hair papillae and scales.77 Some from the dorsal side form the sex organs. MORPHOLOGY OF BLASIA PUSILLA 435 Ventral Differentiations. — The two-celled mucilage hairs, found on both sides of the th alius, originate from a superficial cell which pushes out from the surface. This cell divides once and the basal cell retains its nucleus and chloroplasts while the outer one breaks down into a mucilaginous substance which stains very deeply. These hairs usually turn inward toward the apical cell, and form a protection for the growing point and for the younger sex organs which are found near the apex. The mucilage hairs do not seem to be deciduous, for old ones are found far back on the thallus after the growing shoot has elongated and formed new hairs at its tip. The ventral side of the thallus develops smooth, unicellular, colorless rhizoids. These hairlike structures are merely out- pushings of the epidermal cells along the midrib, which function both as anchorage organs and water absorbers. They are often so numerous that they form thick mats along the midrib, and the plants can be lifted from the soil only with difficulty. The under leaves are scalelike appendages called amphigastria. They are usually several cells in thickness at the center and one cell thick at the margin. These scales have denticulate margins in contrast to the entire margin of the thallus. They are easily detached and may give rise to new plants. No doubt the amphi- gastria are rudiments of the ventral row of leaves commonly found in the leafy liverworts, and may assist in holding water. We have a final ventral differentiation in the leaf auricles. These appendages begin as plates of cells pushed out from the lower epidermis of the thallus. Their marked incurving pro- duces a hollow, globular structure which becomes filled with Nostoc. As the cells are pushed out a mucilage papilla is formed at the outer margin which gradually curves inward. Another mucilage papilla pushes out from an epidermal cell into the hollow already formed. After the formation of the leaf auricle, it is infected with Nostoc which finds entrance at the point where the mucilage hair touches the thallus. In the young stages we find an aperture here but later the auricle is completely closed. Seen from the top of the thallus the .Nostoc colonies ap- pear as tiny black spots imbedded in the tissue. At the time Schmidel13 studied Blasia there was some uncer- tainty as to what the Nostoc might be. Schmidel in his “Dis- sertatio cle Blasia” considered the auricles as antheridia and the individual cells as sperms. 436 IOWA ACADEMY OF SCIENCE Vol. XXIV, 1917 Bischoff (1835) called the Nostoc colonies antheridia but a few years later Nees von Esenbeck found the real antheridia and called the Nostoc “ Keimkornerknotchen. ” Hofmeister9 held that the organs were reproductive buds, basing his idea on their analogy with what he called “the undoubted buds of An- thoceros” developing in the same manner. He says, “It is well known that numerous reproductive buds are formed on the under side of the stem of Blasia. The contents of one of the inner cells of the tissue of the stem (which cells are only separated from the under side by a single cellular layer) become trans- formed into a cell occupying the whole cavity of the mother- cell. This daughter cell changes into a roundish body, composed of small cubical cells which contain numerous very small chlor- ophyll bodies of a dark bluish-green color. The cellular layer of the under surface of the stem which covers the reproductive buds becomes swollen to a hemispherical shape by the increase in size of the latter. 1 have not seen these reproductive buds develop into young plants.” Corda4 figures the germination of the Nostoc cells and calls them new plants of Blasia. These erroneous ideas were not cor- rected until Leitgeb’s work was published 1874. He gave a good description of the structure and origin of the peculiar chambers, but failed to show the fully developed auricle. Coker3 says, “By pressing out the Nostoc he (Leitgeb) found that the colony was penetrated by clear cells, which he correctly deduces to be branches of the Blasia thallus that have arisen from the slime- secreting hair that was present in the young stages. There grows up from the. floor of the chamber a treelike structure with a single trunk, and from the repeated ramifications of this tree the whole colony becomes interwoven with cells which doubtless serve to abstract nourishment from the algae. This whole rami- fying structure has in all probability come, as Leitgeb thought, from the subsequent growth of the slime-secreting cell. In other cases of such symbiotic relationships, as Anthoceros, there are, likewise, cells growing in from the host plant ; but in all such cases, so far as I know, these outgrowths originate, not from a common base, but separately and at many points. The striking arrangement of Blasia seems to be confined to it alone.” The host plant cells no doubt take nourishment from the colonies of algae and they may also serve as water reservoirs as MORPHOLOGY OP BLASIA PUSILLA 437 do the mucilage hairs. That Nostoc is absolutely necessary to the growth of Blasia, has not been ascertained, but it is true that small colonies are found in the young tlialli very soon after the germination of the gemmae. The dorsal differentiations include the sex organs, the calyptra, and the cupules, in which the asexual reproductive bodies are produced. CUPULES. VEGETATUVE PROPAGATION. Asexual or vegetative reproduction in Blasia pusilla is accom- plished in two different ways. The amphigastria or underleaves may become detached from the lower surface of the thallus and give rise to new plants. These scales are loosely attached, easily removed and well prepared to launch new thalli. The second method is by means of asexual bodies called gemmae, which grow in special receptacles on the thallus and upon being expelled give rise to new plants. The development of the cupule in which these gemmae are formed is extremely interesting. The initial of the cupule is a dorsal segment of the apical cell and the mature cupule is located rather near the apex of the plant. By repeated divisions vertical to the plane of the thallus, the dorsal segment gives rise to a com- pact cluster of cells just back of the growing point (5, figure 86). Activity appears then to be retarded in this region and increased in the surrounding cells for they soon bulge up around the compact region, forming a rim (6, figure 86). Cell division is more rapid in the posterior part of the depression. The development of the cupule of Blasia follows closely the first few stages in the development of the Marchantia cupule as given by Barnes and Land.1 Here is the same compact tissue whose cells fail to divide and thus allow the surrounding cells to outgrow them. According to Barnes and Land,1 “In Mar- chantia the upgrowth of cells at the rim of the depression be- gins on the posterior margin but later extends completely around the depression, so that at maturity the cup is circular and of almost equal height on all sides. The origin of the cupule of Lunularia, has been shown to be the same as that of Marchantia, except that the development of the rim takes place only on the posterior side of the gemmiparous region, which is also more extensive. In some cases late in the development, a slight an- terior elevation continues the line of the posterior rim and so 438 IOWA ACADEMY OF SCIENCE Vol. XXIV, 1917 suggests the circular cup of Marchantia. The superficial origin of the gemmae is thus perfectly clear.” At the point where the posterior part of the Blasia cupule begins to increase all resemblance to Marchantia ceases (7, 8, 9, figure 86). The tissue resulting from the accelerated growth in Blasia covers the depression completely leaving only a small opening at the anterior end (10 and 11, figure 86). Because of this method of growth the resulting cavity is elongate and flask- shaped. Papillate cells are now found pushing out from all sides of the cavity and are soon cut off by transverse walls. These are differentiated either into mucilage hairs, similar to those' on the thallus, or into the initials of the gemmae (12, fig- ure 87). Further division of the gemma initials is carried on first by transverse walls and later by vertical walls, so that the mature gemma is composed of a mass of from four to twelve cells, resembling the anther idium in its younger stages. When the first gemmae are mature, accelerated growth in the margin cells of the walls about the opening, forces the edges upward forming a chimney-like tube at the anterior end of the cavity (13, figure 87). This tube attains a length of 1 to 2 mm. and varies from two to four cells in thickness. At the apex the edges flare outward slightly, giving the tube a bell- shaped opening. Most of the cupules were found on antheridial plants, although in several instances they were found on archegonial plants, where the arehegonia had not been fertilized. The cupules ap- pear later in the life cycle than do the sex organs. Leitgeb10 held that they were antheridial pockets, for in one instance he found a half grown anther idium at the posterior end of the cupule. He tried to find other stages but was not successful. Cavers2 thought the gemma receptacles were modified archegonial receptacles since arehegonia. were sometimes found in them. The writer is inclined to think that the cupules are especially formed for gemma production and are not modified sex organ receptacles. It is true that the development of thallus tissue is parallel to the development of the sex-organ covering, but if these cupules were degenerate antheridial receptacles it seems that the tissue development would cease when it had enclosed the depression, instead of elongating to form the long necklike extension. MORPHOLOGY OP BLASIA PUSILLA 439 Leitgeb10 says, ‘ ‘ Gemmas grow into male plants and those bear- ing flasks.” The writer is not prepared to dispute this idea, nz- cupules. 10-11, Early stages in formation of cupule neck. until further investigation has been made, but is doubtful if such is the case. The occurrence of flasks on the archegonial 440 IOWA ACADEMY OF SCIENCE Vol. XXIV, 1917 plants would probably be the best argument against his theory. In cultures which he made, gemmae develop eel no further than a vegetative body about six cells long and two to four cells wide, in which instance it would be impossible to tell whether the plants were male or female. The Gemmae. — The multicellular gemmae are ovoid in form, about .14 mm. at the greatest diameter. They are held in the receptacle upon hy aline stalks, one cell in thickness, and in some cases twice the length of the gemma. Throughout the period of gemma development the mucilage papillae have been secreting a slimy substance which is poured out into the flask cavity. The mature gemmae, breaking from their stalks, become imbedded in this viscid substance and are ready for expulsion from the flask. Just how this is accom- plished has not been fully proven. Hofmeister9 says, “The es- cape of the buds is doubtless caused by the pressure which the numerous rapidly growing young buds necessarily exert upon the mucilaginous contents of their receptacle, which contents are thereby in constant motion toward the opening in the neck.’7 Beside the pressure of the growing gemmae it is possible that the entrance of water into the flask causes the swelling of the muci- lage forcing it from the flask neck. This conclusion is supported by the observation of drops of the exuded mucilage standing at the tops of the necks, especially when the atmosphere was moist, or when the dew was still upon the plants. After the expulsion of the mucilage drop with its load of gemmae, they can easily be scattered. It is probable that insects or snails might be responsible for distribution of some of the gemmae through contact with these slime globules filled with mature brood bodies. But doubtless water splashing on the plant is the more efficient agency for gemma dispersal, as the slime dissolves quickly in water. These little asexual bodies grow very rapidly and produce .juvenile plants one to two mm. long in a few days. Their growth is extremely interesting and takes place while they are still sticking to the dorsal side of the old thallus. Leitgeb10 was prob- ably referring to these new plants, which are sometimes star- shaped in their earlier stages, when he described the “stern- schuppen” of Blasia. Goebel7 says the following in regard to the asexual reproduction of Blasia: “Blasia has two kinds of MORPHOLOGY OF BLASIA PUSILLA 441 gemmae : the one is a nearly spherical cell-mass produced in a flasklike receptacle with a long neck; the other is a gemma- rf pulsion. scale at the base of which there is to be seen at a very early period of development the cell from which the new thallus pro- 442 IOWA ACADEMY OF SCIENCE Vol. XXIV, 1917 ceeds, — this gemma-scale arises upon the upper side of the thal- lus, especially upon shoots which hear neither sexual organs nor receptacles for gemmas. These gemma-scales require investiga- tion especially in their biological relationships.” No trace of these scalelike appendages showed on the dorsal surface of the specimens studied. In only one case were the gemmae found germinating in the flask, and in this instance only a single protuberance was pushed out at the side. This flask was an old thallus and the gemmae probably had been developed the fall before. This is an exception to the usual procedure, however, for the gemmae are expelled at maturity, while young buds are forming at the base of the flask. Conditions for germination are not likely to be favorable when the biood-buds are tightly crowded together in the flask and surrounded by the viscid gel- atinous substance produced by the mucilage papillae. When gemmae are placed in a favorable situation, growth pro- ceeds by means of the end cell which develops into the regular wedge-shaped apical cell already described for this plant. In the earlier stages of the thallus, the apical cell builds up a broad flat stem and the leaf-like lobes appear on opposite sides of this expanded portion. In very early stages the plant looks like a leafy liverwort having distinctly separated lobes set on the stemlike midrib apparently like leaves. The lobes must in- crease in bulk laterally for in the mature thallus they are closely set together forming a more nearly thalloid plant. At the apex of the young plant, the lobes form a rosette around the growing point. This arrangement is advantageous, as it affords protec- tion for the bud. Nostoc appears in the plant very soon after the gemmae ger- minate. Often two or three distinct colonies may be formed on plants .25 mm. in length. It is possible that the Nostoc finds en- trance into the flask and adheres to the gemmae before they are shed. Rhizoids develop early on these little plants and soon be- come long and much entangled. It would seem that the young plants could not long thrive perched on the dorsal surface of the thallus but they do grow for a time, probably upon nourishment stored in the gemma which persists at the base of each new plant. As the old thalli die these new shoots are allowed to rest on the soil where they ma- ture into vigorous well-developed plants. Further study will MORPHOLOGY OF BLASIA PUSILLA 44: probably throw light on the question as to whether these plants are fertile or sterile. Material kept in the laboratory did not prove very satisfactory for this study as conditions were not fa- vorable for plant growth. The branches of the thallus had a tendency to grow erect and spindling, with much smaller and widely separated lobes. Advantages of Asexual Reproduction. Cavers2 says, “It seems probable that in both Blasia and Cavicularia we have an example of the replacement of spore production by asexual re- production. Blasia is found more often with gemma flasks than with fruits.’7 In the recent observations of Blasia, fruits wTere found quite as abundant as flasks. This problem will make an interesting study in connection with seasonal changes and the va- riations in environmental factors operating during these seasons. Evans6 has found in species of Metzgeria that gemmae are not likely to appear when the plant is growing luxuriantly. However, it is the writer ’s theory that vegetative reproduction is a safeguard in tiding the plant over unfavorable periods. In times of stress for the plant sexual reproduction would be a much longer and more uncertain mode of propagation, than that of asexual gemmae. Sex organs are formed in the summer but spores are not shed until the following spring, while gemmae may be fully developed and shed during most months of one growing season. In the second place it seems likely that gemmae are better pre- pared to produce a plant body quickly, than are the spores, be- ing so much larger and so abundantly supplied with food. Mac- vicar11 says, “When a plant cannot obtain its normal amount of nourishment and especially moisture, it will be smaller and weak- er than the type, the stems being shorter and the leaves fre- quently deformed. Fruit is not uncommon in this form. The other deviation is when the plant has a deficiency of light. Under this condition it is generally green or pale green, the stems are elongate and thin, the leaves distant and smaller, and if it be a thallose species the branches have a tendency to grow erect. In such plants fruit rarely occurs but gemmae are often abundant, ’ ’ In this case also it would seem that gemma production is more abundant under unfavorable conditions. 444 IOWA ACADEMY OF SCIENCE Vol. XXIV, 1917 SUMMARY. 1. Blasia pusilla is a relatively simple liverwort having a dorsi-ventral thallus with laterally inserted leaf-like lobes. 2. The growth of the thallus proceeds by means of the wedge- shaped apical cell, characteristic of the dichotomously branched forms. 3. The thallus shows distinct strands of thick-walled cells functioning as mechanical and conducting tissue. 4. The conducting strand is composed of elongate cells, ta- pering to a point at each end, and having pits scattered irregu- larly in the thick walls. 5. Mucilage hairs are found on both sides of the thallus massed at the apex for the protection of the growing region. 6. Rhizoids and scalelike amphigastria are found on the ven- tral surface of the thalli. 7. The leaf auricles also found on the ventral surface are filled with Nostoc colonies. 8. Blasia is dioecious, the antheridial plants being more slen- der and more deeply lobed than the archegpnial plants. 9. Antheridia are found in two rows, one on either side of the midrib. 10. Ten or twelve archegonia are formed near the apex of the plant, the group surrounded by the upstanding side leaves. 11. Both archegonia and antheridia arise from dorsal seg- ments of the apical cell, and the initials are similar. 12. Vegetative reproductive bodies or gemmae are developed in cupules on the dorsal surface of the thallus. 13. These cupules have long tubelike necks from which the gemmae are forced by the swelling of mucilage in the base of the flask. 14. The gemmae of Blasia are multicellular, each cell contain- ing a large nucleus and many oil globules. 15. The gametophyte of Blasia pusilla occupies an interme- diate position between the thallose and foliose forms of liver- worts. 16. This study shows that the cupules of Blasia, which are the most complex of the liverworts, are comparable to the simpler ones of Marchantia and Lunularia. Department of Botany, The State University. MORPHOLOGY OP BLASIA PUSILLA 445 LITERATURE CITED. 1. Barnes, G. R., and Land, W. r J. G., Origin of Cupules in Marchan- tia: Bot. Gaz., 46, 401, 1908. 2. Cavers, F., On Saprophytism and Mycorhiza in Hepaticae: New Phytol., 2, 30, 1903. 3. Coker, W. C., Abnormalities in Liverworts: Bryologist, 12, 104, 1907. 4. Corda, Deutschlands Jungermannieen in Sturm’s Flora, H. 26, 27, S. 137. 5. Engler and Prantl. (Schiffnen) , Die Natiirlichen Pflanzenfamilien, I. Teil III, Abteilung I, Halfte 1895. 6. Evans, A. W., Vegetative Reproduction in Metzgeria,: Ann. Bot., 24, 271, 1910. 7. Goebel, K., Asexual Propagation of Hepaticae, Organography of Plants, 1905. 8. Gottsche., Uebersicht der Leistungen in der Hepaticologie: Beilage zur botan., Zeit., 1828. 9. Hofmeister, W., Germination, Development and Fructification of the Higher Cryptogamia, 1851. 10. Leitgeb, H., Untersuchungen fiber die Lebermoose, Jena, 1874- 1882. Dis frondosen Jungermannien, Vol. III. ■ 11. Mamiear, 8. M., The Students’ Handbook of British Hepatics, 1912. 12. Jsfees von Esenbeclc, Naturgesch. d’ Europ. Lebermoose, 1833. 13. Schmidel., Dissertatio de Blasia, 1759. 14. Tansley , A. G., and Chick, Miss E., Notes on the Conducting Tissue System in Bryophyta: Ann. Bot., 15, 1901. INFLUENCE OF ORCHARD SOIL MANAGEMENT ON FRUIT BUD DEVELOPMENT AND FORMA- TION AS FOUND IN THE APPLE. R. S. KIRBY. Since this is merely a progress report on fruit bnd develop- ment, it is impossible to draw definite conclusions, as insufficient data have been compiled. The chief object of orcharding is the production of the largest possible amount of high class fruit. Since the development of fruit really starts with the development of the fruit bud, the production of' high grade fruit depends on the development of the fruit buds. Therefore it would be important to determine what influence the different methods of soil management would have on fruit bud formation and development. This problem deals with the morphological structure of the apple fruit bud as found in its development from the time of the leaf and flower bud differentiation until the opening of the flowers. The buds studied were from six trees each, of two varieties; Grimes Golden and Jonathan, which are located in the state Experiment Orchard at Council Bluffs, Iowa, These trees were grown under four orchard cultural condi- tions, namely white sweet clover sod, cover crop, blue grass sod, and clean tillage, with two trees of each variety serving as checks in the two first named conditions. The methods followed included taking ten buds from each tree at intervals of about two weeks from July 6, 1916, till blossoming time in 1917. The buds were fixed and imbedded according to the recommendations of A. W. Drinkard, Jr.,1 ex- cept for a few minor changes. It was found that collodion could be eliminated and the buds successfully sectioned when imbedded in hard paraffin by keeping the buds in a ten per cent alcoholic glycerine solution for twenty-four hours to soften the tissue and infiltrating in an oven in which the temperature was not allowed to rise over two degrees C. above the tempera- ture of the paraffin used. 1Drinkard, A. W., Jr., Fruit Bud Formation and Development: Annual Report Va. Polytechnic Institute Agr. Exp. Sta., 1909. 448 IOWA ACADEMY OF SCIENCE Vol. XXIV, 1917 Over one thousand permanent slides have been prepared which contain only longitudinal median sections of as many terminal buds of the apple cyme. To date, the results are rather indefinite, as all material and data have not been' studied. A few of the most important facts follow. Flower and leaf buds started to differentiate as early as July 1 and continued to differentiate till September 15, but by far the largest percentage started to form between July 20 and August 10. The fruit bud formation is closely correlated with the growth of the trees. This showed up strongly in the Jonathan, for flower buds became differentiated on July 1 on a tree that had a diam- eter increase of .218 inch while on the tree of the largest growth with .517 inch diameter increase the flowers did not form till September 8. Buds from the same type of spurs were found to show over a month difference in time of development and those borne terminally on long wood growth were found in some cases to be two months behind the flowers on the spurs of the same tree. From the material so far studied the order of the time of flower bud differentiation or start of formation is as follows: Jonathan : Clover sod. Blue grass sod. Clover sod. Cover crop. Clean tillage. . Cover crop. Grimes Golden: Clover sod. Blue grass sod, Clover sod. Cover crop. Clean tillage. The clover sod plot at the top of the Jonathan list was far ahead of the next four plots and the last cover crop was a month behind the clean tillage. In the Grimes Golden the time of the flower formation was much shorter. The clover sod and blue grass sod were very close together while the next two, namely the cover crop and clover sod, were almost even. The clean tillage was about a week behind. Department of Botany, State College. THE WHITE WATER LILY OF CLEAR LAKE, IOWA. HENRY S. CONARD. Opportunity was made last summer (1916) for examining the Avater lilies (Nymphaea) growing in the west end of Clear Lake, near Ventura, Iowa. An attempt was made to study the specific characteristics as outlined before this Academy a year ago,1 and* to seek for correlation of characters. The results are tabulated below. The day of my observations was partly cloudy and cool in the morning, clear and warm after midday. The earliest floAvers opened from 7 :30 to 8 a. m., all being open by 8 :30. The earliest closure (first day flowers) was at 3 p. m. ; many flowers Avere scarcely beginning to close at that hour, when I had to close my observations. The floAA-ers were all sweet scented, though not so richly as those of N. odorata of New Jersey and eastern Pennsylvania, There was, hoAvever, considerable difference in the richness of the odor of individual blossoms. The floAvers were of rather large size, the length of outermost petals rang- ing from 6.6 cm. to 7.7 cm. The peduncles were smooth or rarely villous, pure green, dull purplish green or strongly brown striped, and from 0.6 cm. to 1.0 cm. in diameter. No fruits were found. The sepals were uniformly green on the outside, without purple coloring. Petals 29 to 39, mostly 31, spatula te to elliptic- lanceolate (See Table 1, and figure 88). Stamens 82 to 105, the innermost filaments more slender than their anthers (Table 1)., The leaves Avere usually pure green above and beloAv, but sometimes bright red-purple beneath, especially those in shallow water. The angle of the sinus lobes was short and obtuse or acuminate. The petioles were pure green, faintly striped, or very strongly brown striped, usually smooth but occasionally hairy. Rhizomes were collected up to a meter in length and 1.3 to 4.0 cm. in diameter, finely pubescent, with few stoutly attached branches, or with many slenderly attached tubers, or both. iProc. Ia. Acad. Sci., Vol. 23, p. 621. Pub. 1917. 29 450 IOWA ACADEMY OF SCIENCE Vol. XXIV, 1917 From these data it appears that this group of plants shows morphological characters which have hitherto been thought characteristic of both Nymphaea odorata and N. tuberosa. All of the Cleark Lake plants are stouter in petiole and peduncle, and larger in flower than any form of N. odorata , except the var. gigantea. And they do not ever show the upturned leaf margin which is so characteristic of that variety. In the time of open- ing and closing of flowers the Clear Lake plants agree with N. tuberosa. That we are not dealing with a mixed stand of the two species is shown by frequent mingling of characters in one plant. One noted as having very sweet-scented flowers had strongly striped petioles, and leaves bright red-purple beneath. Another, with water only 50 cm. deep, had many typical tubers, strongly striped petioles, and leaves bright red-purple beneath. Another, with large rhizome and distinct tubers in addition to branches, had petioles pure green. One with stout, striped peduncle, had a flower whose outer petals were 7.5 cm. long and elliptic-lanceolate (Table 2). And- so on, as shown by the subjoined tables. It is possible that this is a group of hybrids, but there is no way of being certain of it. It seems more probable that we have to do with a form of N. tuberosa. In this case the diagnostic characters would be reduced to the generally larger size of the plant in all its parts, the formation of tubers under suitable con- ditions, and the hours of opening and closing of the flowers. Doubtless the seed character would also remain distinctive. Further detailed records of the Clear Lake plants are ap- pended. It is hoped that similar and more critical observations can be made in other localities in Iowa and neighboring states. The writer will be glad to assist observers in any way possible. TABLE 1— NUMBER OF FLORAL ORGANS. * Flower No. 1 l 2 3 l 4 5 6t Average Sepals—, 4 4 4 4 4 4 4 4 4 Petals—, 34 31 31 39 31 39; ±spatulate 29; ± spatulate 33; spatulate 32+ Stamens 51 92 82 .104 85 105 105 72 92+ Carpels.. . 2i 13 16 17 15 15 16 13 15 * Abnormal not averaged. fPeduncle not striped. ^Peduncle striped. 3 4 Fig. 88. — Nj^mphaea tuberosa of Clear Lake, Iowa. Parts of the water lily flower; 1-7 from flower No. 1; 1, lateral sepal; 2, outermost petal; 3, petal of third row; 4, petal of inner row; 5, vertical section of ovary showing carpellary style, stigmatic half way up the inner face, stigmatic basin, and spherical axile process ; 6, outer stamen ; 7, innermost stamen ; 8-11 from flower No. 2; 8, lateral sepal; 9, outermost petal; 10, petal of third row; 11, petal of inner row. All natural size. Collected at Clear Lake, Iowa, August 15, 1916. No. of Flower 452 IOWA ACADEMY OF SCIENCE Vol. XXIV, 1917 TABLE 2— SIZE OF FLORAL ORGANS. Organ Shape Dimen- sions, cm. Breadth: Length= Lateral sepal 7.8x2. Outermost petal. lanceolate 7.5x2.3 1:3.26 Peduncle stout, striped Petal of 3d row.., spatulate 7.2X2.5 1:2.88 Inner petal spatulate 5.5x2.0 1:2.75 Innermost petal-. acute 4.6xl.5 Outer stamen 41x0.7 Anther 1.2 cm. long Innermost st 0.9x0.05 Anther 0.4 cm. long x 0.1 cm. Lateral sepal elliptic 6.5x2.3 Outermost petal. spatulate 6.6x2 .4 1:2.75 Petal of 3d row__ 6.0x2. 2 1:2.72 Inner petal rounded- spatulate 4.8x2.0 1:2.4 Innermost petal- 3.3X1.5 Peduncle stout, striped Outer stamen 3.4x0. 8 Anther 0.7 cm long Lateral sepal , elliptic 8.0x2.7 Outermost petal- elliptic 7.7x2. 5 1:3,08 Petal of 2d row— spatulate 7.8x2.9 1:2.69 Petal ob. lanceolate 7.0x2. 6 Petal ob. lanceolate 5.9x2.3 Petal- spatulate 4.9x1. 9 Innermost petal-. ob. lanceolate 4.2xl.3 Outermost stamen 41x0.8 Anther 1.0 cm. long Outer stamen 4.0x0. 5 Anther 1.3 cm. long Sepal 6.7x2, 2 Petal elliptic 6.7x2.2 1:3.05 Petal obovate 6.4x24 1:2.66 Petal spatulate 5.2x20 1:2.6 Petal _ elliptic 4.1x11 Stamen _ elliptic 3.8x0,9 Peduncle stout, striped Stamen elliptic 3.6x0.6 Sepal 61x1.9 Outermost petal- elliptic 6.3x2.4 1:2,625 Petal spatulate 6.6x2.2 1:3.0 Petal spatulate 4.9X2.4 1:2.0 Petal spatulate 4.4x1. 7 Petal spatulate 41x1.4 Peduncle striped Outer stamen 3. 6x0.6 Outer stamen 3.2x0. 3 Anther 1.4 cm. long Width of outermost petal: length=l: 2.625 to 1:3.26 (extremes). 1: 2.96 average of 5. Width of second row petal: length=l:2.66 to 1:3.0 (extremes). 1:2.76 average of 5. TABLE 3— DETAILS OF LEAF AND FLOWER. WHITE WATERLILY OF CLEAR LAKE •n ° O) d d d d §§ S3 <-H S3 pH P PH S3 pH CD 3 a a a a CO CO © co .2 Pm Q cn £ £ £ o o o 73 Ph PH pH 53 Ph PH Ph o Oh 03 03 c3 ?H a S3 S3 GO 03 03 03 03 03 4P HHH ■+H 02 03 C3 c3 c3 c3 o p P P P S3 OQ 2 43 S3 PH ^ a ass a jo pH S3 C3 S C3 S3 o rg ftl a « 03 03 03 03 P O 02 GO 03 03 03 c3 c3 'on m bn > fl .a ©a b/) bdQ bJO bfl fl a a P P 33 ft £ « a a ft ft a S3 ft ^ ^ S3 4-> a a 03 03 a ft 2 ,a O 03 ft O 0) 03 a) 03 03 03 03 03 •P-P+J -f-i HHp 4H o3 c3 c3 c3 53 ft 53 53 « a a p .a .a .a a .a a bn bn bn 2 bjQ ’bio bJ3 bo So <1 ^ fH p -a ^ ?H pH ?H pH 03 03 c3 2 03 53 c3 c3 53 s s s o a ass a 03 0) 03 S3 03 03 03 03 03 03 03 03 ft ft ft o> *s 'a *a o T3 ^ 7ft 73 73 •P+3-P co m co 73 03 03 03 03 03 03 o Oh ft ft ft ft ft •+H +3 +3> S3 S3 S3 ft *s 'a *g *Ph *Ph •rH «rH *rH ppp -+H -f-» 53 53 03 H-H 02 OQ CO CO CO «H «H «+H CO oS i. » CO 04 HP CO CO OO CO cd tH i — 1 r—i r—i rH 1— i H rH rH as 2 i-l .g i-H rH tH r- i HHH rH £ jo -on tH 04 CO TP Leaves all green beneath. TABLE 4— DETAILS OF RHIZOMES AND LEAVES. 454 IOWA ACADEMY OF SCIENCE Vol. XXIV, 1917 P °N a 5 a a P* a © H ^ O O 03 03 03 5 03 pH r— | PH pH ft P-l Ctf+J &J0 bJ3 feuo E- &0 ? ft'aQ ft ft O) 0^3 u P-i OP P-i ft! 4-> c3 03 03 ft o> ft s s a g ft a 03 ft rrt 'ft ft! ^ <-! 'i r ■> 'ft GJ , 2 ft.: o o a a •jrj a ft *r| •£ *£ -4^> fft ft h 4-> -+-> H-3 * 5 5q «2 CQ GO >> a * >> >» >J HjC+jiyqHan O fl pj O O «r7 O 4-> 2 03 ■lfl£m-iVlV2WU2W. a a a © m ® ® o o o a 5q a oc aj ^ o £ £ ■§iff ft ^ ft ft K'j'0 Q$ oT a ft ft ft ft £ £ £ £ « a io 5s +3 +S a a a> as G 13 W 03 03 ^ Jh ^ 03 a 2 a ft«H a a i-i &§ o a 03 1ft CO GO CO C3 GO ftOOOOO c4 co co co i-4 oo ft ft co fti ft t I CO 03 a 03 ft o ift c6 CO 03 HNa^iftat>ooao > a 03 w £ s o *H w o w ft 03 OF 0 o a EH £ W a -M 02 w 03 £ 03 Eh a g ft 03 w o P4 O A PICE A FROM THE GLACIAL DRIFT. WILBUR A. THOMAS. Early this year (1917) we received at our laboratory a piece of fossil wood from Mr. B. 0. Walden of Wallingford, Iowa. Wall- ingford is in the northern part of the state, about thirty miles southeast of Spirit Lake. Mr. Wolden secured this wood from a farmer near Wallingford. It was taken up with an eighteen inch auger drilling machine from a depth of eighty feet. Along with this wood, were found some well preserved bits of moss, some leaves or needles which resembled spruce needles, and a very small, immature cone. The glacial drift which held this material is estimated to be at least 10,000 years old. In general appearance the wood is coated with claylike soil, and is light, much as old drift wood. It is in an excellent state of preservation. Under the microscope it may be noticed that the large cells at the beginning of the annual growth are in some cases broken in, or caved in, as though from pressure of the earth. The following things may be seen in the sections. There are no tertiary spiral markings on the trachejds. The resin canals, pitting, and bars of Sanio prove it to be Abietinean ; the normal resin canals put it in the Pineae. It is differentiated from Pinus by the thick walled secretory cells. The tangential pitting is well marked, the rays are thick walled and Abietinean ; the marginal trachieds are smooth walled, and in some cases there are masses of carbon in the pits. According to Mr. Torrey of Harvard University, the intergla- cial wood is a Piceoxylon. It cannot be a Pseudotsuga for there is no evidence of spiral markings. Neither can it be a Larix for there is no dark colored heart wood. It can safely be placed as a Picea. The very interesting fact may be noted here that the White Spruce, or Picea alba, is not found growing in Iowa, nor closer than the Black Hills of Dakota. The range of the Picea alba is Newfoundland, Nova Scotia, and New Bruns- wick, westward through Quebec and Ontario to the forest limit of Manitoba. In the prairie region it is found in the sand hills bordering the first prairie steppe. Occasionally it is found in 456 IOWA ACADEMY OP SCIENCE Vol. XXIV, 1917 the valley of the Saskatchewan and on the Bow river from Cal- gary where it is mixed with P. Engelmanni. It is found also on the coast of Maine, through northeastern Vermont and westward through northern Michigan and Minnesota to the Black Hills of Dakota, .where it is known as the Black Hill Spruce. In Mon- tana, along the Rocky mountains, it reaches its greatest develop- ment along streams and lakes in the Flathead region, at an ele- vation of 2,500 to 3,500 feet. Picea alba , to which this fossil wood is probably nearly re- lated, is characterized by thin summer wood, rather prominent, upwards of one-fourth the spring wood, from which the trans- ition is gradual, rarely abrupt; the structure rather dense and the tracheids squarish. The spring wood is open.; the tracheids are squarish-hexagonal, uniform in very regular rowTs, and the walls thin. The resin canals are scattering, and the rays are not very numerous. The bordered pits are found in one row, are numerous, and are round or elliptical. The orifice is usually large. In the summer wood the pits become remote or obscure, and the orifice usually becomes a prolonged slit. In the fossil wood we find a number of these points present, especially in the shape of the tracheids, the open spring wood with its thin walls, which failed to withstand pressure. The tangential pitting of the fossil wood is better marked than that of Picea alba. These and other similarities give us sufficient grounds to place them in close relation to each other. Department of Botany, Grinnell College. PIONEER PLANTS ON A NEW LEVEE. III. FRANK E. A. THONE. The present paper is the third of a series of brief notes on the yearly changes in the re-vegetation of a soil area exposed by the building of a new levee in Des Moines in the spring of 1914.1 In the first paper the general character of the plant pioneers during the season of 1914 was discussed/ with speculations as to their probable modes of travel. In the second, note was made of the replacement of the first year ’s dominating plant, Amaran- thus retroflexiis, by Chenopodium album, which gained the leadership through its earlier germination, and of the threatened overthrow of the latter by Lactuca scariola. The writer regrets that the hasty survey lie was able to give the place during the past summer (1916), together with his in- ability to visit it at all during the present spring, do not make possible anything like a comprehensive summary of conditions now prevailing on this strip of ground. However, one or two of the more marked changes seem to be worth recording. In the first place, the statement made in the spring of 1916 that the goosefoot would probably hold its place as dominant that summer, but have to fight for it with the wdld lettuce the following year, proved to be too conservative. The lettuce was overwhelmingly the dominant, crowding the goosefoot practically to extinction, just as the latter had in its day crowded the pigweed. It was also holding its own against the invasion of Ambrosia trifida, which during the two previous seasons had been spreading up the levee from its original re- stricted territory on the lower end. The two previous domi- nants had failed to prevent this weed from encroaching on their territory. Scattered among the wild lettuce was a good deal of Erigeron canadense, which formed dense clumps here and there. This plant was a newcomer, having appeared for the first time during the preceding season. It may. possibly be- come a contender for first place. Proceedings Iowa Academy of Science, Vol. XXII, pp. 135-142, and Vol XXIII, pp. 423-426. 458 IOWA ACADEMY OF SCIENCE Vol. XXIV, 1917 The most interesting thing about the conditions on the levee last summer, however, was the start that was being made toward a second re-vegetation of the upper end of the levee, which had been denuded by grading operations early in the year. Only a scattering stand of plants made their appearance during the summer. Of these, the dominant was not the lettuce, which held first place elsewhere on the area, but Amaranthus retro- flexus, the dethroned and exiled monarch of the first season ! It would rather seem as though the whole cycle were about to repeat itself. Scripps Institution for Biological Research, La Jolla, California. CHLOROTIC CORN. (A PROGRESS REPORT.) W. H. DAVilS. During the last few years, much attention has been given to a plant disease known as chlorosis. This disease has been de- scribed in many plants, the most which are of economical im- portance, as Mosaic of Tobacco (6) “White Pickle,” Peach yel- lows, etc. Chlorotic corn plantlets have been noticed by growers for a number of years but very little work if any has been published, concerning this disease in corn. Kernels from an ear of Reid’s yellow dent corn were planted, and about one-third of the plantlets were chlorotic either throughout the whole plant or some of the lower leaves. This observation led to a second planting from the same ear. On December 13, 1916, fifty ker- nels from this ear were planted in compost soil in the green- house. Eleven plantlets out of thirty-eight were chlorotic ; four had no chlorophyll; three had the first leaf (above the sheathing leaf) chlorotic ; the other four varied, having two to three chlorotic leaves. The following questions now arise. Is this disease transferable wdien other plants come in contact with diseased leaves ? Can it be transferred by aphids through trans- ferring quantities of sap? How serious is this disease to corn plantlets ? On January 14, 1917, the plantlets that -were chlorotic were loosely bound in contact with chlorotics. Proper care was taken against transferring the organism by aid of a string or by per- sonal contact. Marked surfaces of leaves on chlorotic plants were washed with sterile water then pierced with a sterilized needle. This needle was then used to transfer the supposed or- ganism and the fluid by piercing a washed surface on a marked leaf of a non-chlorotie plant. Five of such transfers were made on each of five non-chlorotic leaves on five plantlets. Proper pre- cautions were observed in flaming the needles, tweezers and not handling with hands. In six weeks and two days after planting, all four of the chlorotic plants had died and wilted to the ground. 460 IOWA ACADEMY OF SCIENCE Vol. XXIV, 1917 The roots appeared to be normal. All other plants and checks seemed healthy. On March 20, all the living plants possessed no visible symptoms of chlorosis. The chlorotic leaves had withered and died after living about two weeks. But one case was noticed where new leaves seemed to contract the disease from the chlor- otic leaves or stem below. Each leaf that appeared possessed less of the disease until finally it showed only in the midrib. A more intensive field study on a more extensive scale will be made this year to ascertain how prevalent this disease is and its economic status, if any. Conclusions seemingly warranted : 1. Corn embryos may be chlorotic. 2. Chlorosis in corn plants may not be transferred to other corn plants by contact or by sap. 3. When corn plantlets are entirely chlorotic, they will not mature. THE AECIAL STAGE OF ALSIKE CLOVER RUST. W. H. DAVIS. A rust belonging to the genus Uromyces is rather prevalent in this latitude on the common clovers, white (. Trifolium repens L.), red ( Tri folium pratense L.) and alsike ( Trifolium hybri- dum L.). The rusts on clovers were formerly classified as a single species or one rust until the work of Liro separated them into two species, one on red and one on white clover. The dis- position of the rust on alsike clover is not clear. Liro (9), in his inoculations 93-94, tried to inoculate alsike with uredinio- spores of white clover rust, but the results were negative. Ac- cording to Sydow (6, p. 133) Alsike clover is a host for the rust on red clover ( T . pratense ) while Arthur (2, p. 225) gives Alsike as a host for the same rust as found on white clover. There seems to be a general belief that the rust of white and of alsike clover are of the same species. This belief is confirmed by the fact that they are morphologically similar in two respects ; the sizes of the urediniospores and telispores are similar and the urediniospores of each have two to three germspores equatorially placed. They differ in the number of known spore forms — • white clover has all five spore forms, while alsike has no pycnia and aecia. Rostrup (6, p. 134) reported aecia on alsike in Ger- manjr (1886) but the correct determination of the host is cnies- tioned. It is not generally accepted that alsike rust has a pyc- nian and an aecial stage. On April 25, 1916, several out of door clover plats were under careful observation for the aecial stage of rusts when golden swellings were noticed on the midribs of the leaves on an alsike clover plant. The Alsike plants had been left uncut during the summer and fall of 1915, so the old rusted leaves and stems remained intact. On April 27, 1916, specimens of aecia were picked and used for inoculating purposes. As aecia and pycnia were abundant during the month of May, material was killed, imbedded for sectioning and pressed for herbarium specimens. The aecial stage continued to develop until June 7 when none could be lo- cated. The aecial stage of this rust could not be located around 462 IOWA ACADEMY OF SCIENCE Vol. XXIV, 1917 Cedar Falls, Iowa, during the dry summer and fall of 1916. Pycnia — Occurrence — Mostly in groups, 1 mm. to 10 mm. long, numerous, mostly along the midrib of the leaflet on the under side. Often found on the upper side, on petioles and stipules, near or remote from aecia. Appearance — Noticeable on account of the swollen areas on the leaf and the striking golden color of the aecia with which they are associated; generally on the smaller leaves covered by a canopy of larger and more vig- orous leaves. Color — First white water soaked areas, later, a dirty brown. Shape — Flasked with a globose base. Size — Height 118 Mu. (Aver, of 10) ; width 118 Mu. (Aver, of 10) • osteole 25.4 Mu. ; hymenial surface 30 Mu. ; paraphyses, length 65 Mu., wddth 2-4 Mu.; pycnospores 2-3x4-5 (Standard 3x4). Twenty measured. See figure 94. Aecia — Numerous, scattered with pycnia which appear three to five days before aecia open. In mass, color a striking golden ; leaf appears swollen and puffed at this point or in some cases the entire length. More striking than the aecial stages of red and of white clover rust. More like the white because the symp- toms show better on the upper leaf surface. The first aecia ap- Fig. 89. — An Aecium on Red Clover. AECIAL STAGE OF ALSIKE CLOVER RUST 46: peared April 26, 1916, and the aeciospores proved viable. When on the petiole, they were located at or below the lower half. Size — the patches vary from 0.1 mm. to 150 mm. in length and tend to the elliptical, near or remote from pycnia; height, 182 Mu. (20 measured), width, 172 Mu.; peridial cells length, outer Fig. 90. — An Aecium on Alsike Clover. For measurements see Tables I and II. 22 Mu. (10 averaged), inner 15 Mu. (10 averaged), width, 14 Mu. (10 averaged). Lumen, length 12.5 Mu., width, 10 Mu., outer wall, transversely striated 2. 5-3. 5 Mu. thick ; inner wTall minutely verrucose, 0.7-1. 5 Mu. thick. The cups present a white 464 IOWA ACADEMY OF SCIENCE Vol. XXIV, 1917 waxy appearance when emptied of aeciospores. The peridial wall is not recurve as in white and red clover rust but more flask shaped. See figure 90; figure 92 (1, 2, 3) ; Plate XV, A; Plate XVI, A. Aeciospores- — Shape — Globose, subglobose, to ellipsoid-angular ; wall color, starchy white, less than 1 Mu. thick; surface mi- nutely verrueose; sizes 10-22x15-26 Mu.; standard 17-20x20-24 Mu. (54 measured) ; germination, Minimum, 4° C., Optimum, 14° C., Maximum, 22° C. The first spores emitted from an aecium are more viable, more active and have a quicker pene- Fig. 91. — Tracing from a camera lucida drawing. 1, Teliospore of Alsike Clover rust germinating: Spore collected October 31, 1916. Set to germinate December 19, 1916. . Drawn December 22, 1916. Spore 20.4x27.2 Mu'. Pro- mycelium 6.8x170 Mu. Sterigmata 2x4 Mu. (average). S'poridia 14x17 Mu. (average). 2, A sporidium of 1 germinating while on the sterigma. Germ tube 3.4x34 Mu. long. 3, An average sized sporidium 7x14 Mu. tration than later ones. These aecia differ in that about twenty- four hours after opening, the spores seem mostly lifeless. The most successful time to inoculate with these spores is just as they come from the aecial cup. Viability one to three hours. Period of noted infection nine to fourteen days. See figure 90. The following tables show the relative measurements of spores and peridial cells from the rusts on three clovers. All measure- ments are in microns, the width being first indicated. AECIAL STAGE OF ALSIKE CLOVER RUST 463 TABLE I. Stage I Aeciospores Host Arthur o' 'O as Sydow Howell Davis o a> a VI Size Temp. Temp. Size Stand 'rd l| No T. repens — 15- 17 x 16- 21 14x23 14-18 x 17-21 14x22 15-18 26°0 3 20 .6-24 X 16-30 18-22 x 22-26 50 T. pratense . T. hybridum — — 27 3 12 25-35 4 14 Ll. '8-24 x 20-29 10-22 x 15-26 18-22 x 22-24 17-20 x 21-24 73 54 Fig. 92. — Peridial cells of Aecia from Alsike Clover rust. Camera lucida drawings from prepared slides of material collected out of doors May 13, 1916. 1, A shows the inner surface of a peridial cell; C, The striated outer wall ; E, The large lumen of the cell. Note the overlapping of the outer walls, also the thickness compared with the inner wall. For measurements see table II. 2 and 3, Other peridial cells of the same rust. The proper names used as headings signify the authors whose reports are used. The germinating temperatures are given in degrees centigrade, beginning at the top, minimum, optimum and maximum in order. ‘ ‘ Number ’ ; in the last column refers to the number of spores measured. The measurements given 30 466 IOWA ACADEMY OF SCIENCE Vol. XXIV, 1917 under T. pratense are those of Davis and Johnson, who connected this stage with the life cycle of rust on red clover. See report of the National Association for the Advancement of Science, De- cember, 1916 : The Aecial Stage of Red Clover Rust by Davis and Johnson. TABLE II. Peridial Cells— Stage 1 Aecia Hosts Sydow .8, p.161 1 Ivanhoff Davis High Wide Open- ing No Wall Wall Lumen Wall Lumen 2* 1.5 1.7-3 8-12 x T. repens 4-5 1 4.5 13.5 5 20-22 308 230 310 10 23-3.5 8-10 x T. pratense 5-6.8 12-16 189 178 224 5 . /-1.5 8-12 x T. hybridum 2.5-35 10-14 182 172 140 10 *Thickness of the inner wall of the peridial cells. tThickness of the outer wall of the peridial cells. The heading “number” refers to the number of aecial cups measured. The measurements were made from stained slides. AECIAL STAGE OF ALSIKE CLOVER RUST 467 TABLE III. Stage O— Pycnia Host Spores High Wide Osteole Paraphyses Hymenial Surface T. repens 1. 7x2.4 150 120 17 Numerous 2.5x40 35 T. pratense— 2-3.5 x 3.5-5 100 100 25 Numerous to 25 2-5 x 25 T. hybridum. 2-3 x 34-40 4-5 119 119 26 Numerous 9 /1 v QA The above numbers are averages of measurements and counts of ten pycnia, killed, sectioned serially and stained. Summary of the tables comparing the aecia and pycnia of the rust on T. hybridium with that on T. repens and T. pratense. 1. The aeciospores on alsike clover rust are smaller than those of red and of white clover rust. 2. The range of temperature for germination is much nar- rower than that of the other aeciospores. 468 IOWA ACADEMY OF SCIENCE Vol. XXIV, 1917 3. The inner and the outer walls of the peridial cells are much thinner than the corresponding peridial walls of the other rusts. The outer peridial wall of each clover rust is trans- versely striated while the inner wall is minutely papillose. 4. The lumen in the cells of the peridium averages smaller. 5. The openings of the aecia are smaller, the edges do not. recurve but incurve while those on T. repens recurve consid- erably, on T. pratense slightly or are straight. 6. The paraphyses are longer, hymenial surface of the pycnia deeper than that of T. repens. 7. The pycnia are taller and the osteoles wider than those of T. pratense, smaller than those of T. repens. 8. There are as many morphological differences between the aecial and pycnial stages of the rust on T. hybridium and T. repens (also T. pratense) as between that on T . repens and T. pratense, which are regarded as two separate rusts. Inoculations AECIAL STAGE OF ALSIKE CLOVER RUST 469 § ® pu .j'p o 2 c3 o Qqq O 3 S ^ a CD TH cd 2P §.£? rC >J|— I 73 PH hH bn bfl >» a> TP 5 w> oa ^ -m o o '23 -*-* rQ O r-H ^ ^ P2 ^ =+H cst,x>oon~-t^-oo NO O O OO OOO CO CO co CO CO t-H T—l HHH 4* 1 Cvj Tji eo ell Ojl Ol lA rH Cjl OJ 4) XO 4) CO CO CO CO CO 1—1 H rt i— I i— i CO t>- If!) iA CO 2 Sci ci2 CO t>. CO CO t>- 5> rC 4J a o Kfl 03 c3 u o a-* m 6 ,Q fl o » c3 pH a 0D co © «h 03 Cl C C g ° OS ° ° C© CO CO CO CO ro 'V'O ® c3 03 03 J? a> o> a> s Ph Ph Ph h— ' a a a cd OP QQGCpQ Inoculations Results 470 IOWA ACADEMY OF SCIENCE Vol. XXIV, 1917 Ph~ g o a 'u 5 p> «» ® T3 03 §s *0 O O O CO o fONO 1-10 0 1 OOWO 30 CO CD t'- ’l1 T7 tH tH rH tH t>- 1>- OO o ci o tH 1-H rH 1 T— 1 rH co tH H 1—1 CM CM H H yH co oo co co co co CO CO lO UOUOUOOOCOCOUOlO a> a? £ M 2 ]» 1 £- t>- tH tH T— i CD CO 1 CD CO ti. ti 9? 04 CM CM Cjl CM 2 s T— I CM CM ©+s jh a «H 03 03 bo - a s ip ft C8 hh I g I— I 'O 03 a -S m g <1 2^ O I*4 . ■s s^1 g.2 g «jro£ O ^ j fl g 03 ,rt M M sap 3 p too • rH .,-1 Cj o 0.2 «H «w Mi $ -t— ++ AECIAL STAGE OF ALSIKE CLOVER RUST 471 Conclusions from the above spore sowings : 1. The aecial stage of 'alsike clover will not inoculate red clover, white clover, mammoth clover, crimson clover, alfalfa and white melilot. 2. The aeciospores of alsike clover will inoculate alsike clover and produce the characteristic urediniospores. 3. The urediniospores of alsike clover rust fail to inoculate the same plants that the aeciospores fail to inoculate. 4. The urediniospores will inoculate alsike and produce the characteristic uredinia and telia. 5. The teliospores germinate and produce the characteristic sporidia (which were observed in spore sowings on water) which produce the aecia on alsike clover only, following the aeciospores and urediniospores in this respect. 6. The rust on alsike clover is a long cycled, autoecious rust with all spore forms w7hich have not been transferred to the other clovers. The Synonomy of Clover Rusts. Host, undetermined species of Trifolium. 1. Puccinia trifolii (“Puceinia des trefles”), Hedw. f., 1805 (PLe trefles rampant, le trefle filiforme et le trefle hybride”) (alsike). See Ref. 5, p. 5. 2. Uredo fabae trifolii, Alb. and Sclrw., 1805. 3. Uredo trifolii D. C., 1808. 4. Aecidium trifolii-repentis Cast., 1842. 5. Uredo fallens. Desm. (“in follis trifoliorum”), 1843, 6. Aecidium trifolii (Hedw. f.) Liro, 1847. 7. Trichobasis fallens, Cooke, 1870. 8. Uromyces trifolii (Hedw. f.) Liro (4, p. 534). On- red clover T . pretense L. 9. LTromyces trifolii (Hedw. f.) Liro, 1906. (The rust on Alsike clover is placed here by Sy dow. ) 10. Uromyces fallens (Desm.) Nov. Comb. Kern, 1911. 11. Nigredo fallens (Desm.) Arthur, 1912 On white clover T. repens. L. Uromyces trifolii-repentis. (Cast) Liro, 1906. 6, p. 131- 132. Uromyces trifolii (Hedw. f.) Liro, 1911, p, p. 6. Nigredo trifolii (Hedw. f.) (2, p. 219.) Arthur, 1912. Res. Sci. Con. Bot. Yien., 344. 1906. (The rust on alsike clover is assigned to this species by Arthur. ) 472 IOWA ACADEMY OF SCIENCE Vol. XXIV, 1917 The causal organism for rust on alsike clover has been given as Uromyces trifolii (Hedw. f.) Liro and Nigredo trifolii (Hedw. f.) Arthur, thus placing it with the rust on red clover in the former case and with that on white clover in the latter. The question which naturally arose as to its disposition can now be answered in a more satisfactory manner. As the aecial stage has been definitely located and connected in the life cycle by inoculations, it shows the rust to be long cycled, autoecious, with all spore forms. Inoculations show that none of the spore forms have been transferred to the other clovers. The measure- ments show many morphological differences, at least as many as exist between the rust on white and on red clover. Nigredo fallens (De.s.) Arthur, is the rust on red clover; Nigredo trifolii (Hedw. f.) Arthur, the rust on white clover. If the rust is to be named, probably Nigredo hybridi Davis would be in best keeping with Arthur’s classification, which transfers the rust from the genus Uromyces to that of Nigredo. Otherwise Uromyces hybridi Davis. Department of Agriculture, State Teachers College. LilTERATURE ClTED. 1. Davis , J. J., A Provisional List of the Parasitic Fungi of Wis- consin, Part II, 17, 984, 1914. 2. Arthur , North American Flora (Urediniales) , 3, 219, 1912. 3. Saccardo, Sylloge Fungorum, 21, 542, 1912. 4. Saccardo , Sylloge Fungorum, 7, 534, 1888. 5. Kern, F. D., Rusts of White and Red Clover: Phytopath, 1, 3-6, 1911. 6. Sydow, Monographia Uredinearum, 2, 131-133, 1910. 7. Duggar, Fungous Diseases of Plants, p. 395, 1909. 8. Ivanoff, Untersuchunger liber den Einfluss des Standortes auf den Entwickelingsgang und den Peridenbau den Uredineen: Centralblat fiir Bakter und Parasitet, 18, 265-470-655-661, Fig. 33, 1909. 9. Liro, Acta Societatis pro Fauna et Flora Fennica, 29, 11, 1906. 10. Howell, J. K., Bui. Cornell Univ. Ag. Exp. Sta.,. 24, 129-139, 1890. U. Trifolii-Bot. Gaz., 15:228, 1890. 11. Pammei, L. H., Bui. Ia. Ag. Exp. Sta., 13, 51-55, May, 1891. 12. Pammei, L. H., Bui. Ia. Ag. Exp. Sta., 61, 141, July, 1902. Iowa Academy of Science. Plate XV. A. Aecia on Red Clover; B, Aecia on Alsike Clover ; C, Aecia and Fycnia on White Clover. Iowa Academy of Science. Plate XVI. A, Aecia on a leaf of Alsike Clover ; B, Aecia on a leaf of Red Clover. I ■ ■ THE USE OF IRON IN NUTRIENT SOLUTION FOR PLANTS. G. E. CORSON AND A. L. BAKKE. Nutrient solutions have been made use of to a considerable extent in endeavoring to determine the specific role of certain nutrients as well as questions of nutrition in general. It is known that iron, although used in small quantities, is essential for chlorophyll production. The present work is a study for the purpose of ascertaining the value of different amounts of iron to an otherwise balanced solution. This feature has sug- gested itself in that the majority of such Solutions do not con- tain definite amounts of iron, but are simply designated by a ‘ ‘ trace. ? ’ This amount will naturally vary with different work- ers. The relative value of iron in the ferrous and in the ferric condition was tested out. The present study does not present any evidence as to the respective merits' of various solutions that have been previously used. This has been done by Totting- ham1 and Shive2 and so is not within, the province of this in- vestigation. Tottingham and Shive have introduced a measure- ment that is based on total atmospheric pressure. The concen- tration of each salt is measured according to its molecular weight. Gram molecular concentrations are used. Shive ’s solution con- taining three salts3 is an improvement over Tottingham ’s. It is natural then that Shive ’s solution should lie the more popular of the two. This solution consists of the following compounds : potassium phosphate (KH2 P04|§ 0.0180 m; calcium nitrate (Ca.(N03)2 0.0052 m ; magnesium sulphate (Mg S04) 0.0150 m; iron phosphate (Fe P04) 0.0044 grams per liter. The pressure in atmospheres of this solution is 1.75. This medium has proven to be 27 per cent better than the old solution of Knop which has been looked upon as more or less of a standard. In the present study, wheat and Canada field pea plants were used. The wheat was germinated in clean quartz sand. When Nottingham, W. E., A quantitative chemical and physiological study of nutrient solutions for plant cultures: Physiol* Res., 1 , 133-245, 1914. 2Shive, J. W., A study of physiological balance in nutrient media: Physiol. Res., 1, 327-397, 1916. 3 , A three salt nutrient solution for plants: Amer. Jour. Bot., 2, 157-160, 1915. 478 IOWA ACADEMY OF SCIENCE Vol. XXIV, 1917 the seedlings were sufficiently large, so as to be readily handled they were first carefully washed in tap water and later in dis- tilled water. They were then ready to be placed in the solu- Weight of total crop in grams (36 pl- ants.) .THE .EFFECT OF FERRIC PHOSPHATE UPON THE GROWTH OF WHBfil SEEDLINGS . (TOTAL CROP.) » ^ r * * c to o f-< O o *H rH CJ \r\ o o o o ■U O O O Q n • • • ♦ .c ♦ c U.O <1) -M B- - O T t; U) I CM CO 't Figure 95 tions. Six seedlings were inserted into a flat cork stopper of sufficient size to fit a Mason fruit jar, according to the method of Totttingham. The Canada field peas were germinated upon galvanized iron wire screen ; otherwise, the methods of procedure USB OF IRON IN NUTRIENT SOLUTION 479 were the same. On account of the presence of a fungus on the pea seeds, it was necessary to sterilize the seeds again by using mercuric chloride. In both the wheat and Canada field pea, the plants were allowed to grow for twenty-four days. The solu- Weight of total crop in grams (36 pl- ants] . THE 3JFP33T J3E JjgBHQBjj. _THE GROWTH. -Off. migAT SEEDLINGS „ (TOTAL CROP.) l-t • &I1 C O O o ^ H OJ . IA ■ri O O O O OOOO •t5 3 rH o * Z S T ■xs c/i o r-\ a tit I i t CM r'A ■'t W0 4 5 Figure 96 tions were changed every fifth day. At the end of that period, dry weight determinations were made of roots and tops. In the first series, the effect of varying amounts of ferric phosphate in the nutrient solution containing the three salts upon wheat, is presented in figure 95. 480 IOWA ACADEMY OF SCIENCE Vol. XXIV, 1917 The various culture solutions contain: (1) distilled water, (2) Shive’s solution without iron, (3) Shive’s solution having 0.0010 gms. ferric phosphate per liter of the solution, (4) Shive’s solution having 0.0025 gms., (5) Shive’s solution having .0044 Weight of crop in grams (36 Pl- ants.) 7.0000 6.0000 5.0000 4.0000 3.0000 .THE EFFECT _0_F FERRIC PHOSPHATE UPON JHE GROWTH OF CANADA FIELD PEA SEEDLINGS . (TOTAL CROP j O * — I CM ^ VTN O O O O O O O O •w ; II) -HJ O to r-l rn t* lrs\0 gms., (6) Shive’s solution having .0050 gms. per liter. For each culture 36 plants were used. The total crop in dry weight is given. No. 5 gives the greatest dry weight, producing 2.700 grams. This then agrees with Shive ’s results. USE OF IRON IN NUTRIENT SOLUTION 481 The next series have the same concentrations of iron, ex- cept that the iron is in the ferrous form. The results presented graphically in figure 96 show that No. 4, with .0025 grams of Weight of crop ^ in grans' (36 pi- 1 ants ) THE EFFECT OF FERROUS PHOSPHATE JT^ONJTIffl' 'GROWTH OF CANADA FIELD' PEA SEEDLINGS . (TOTAI, SHOP) 7.0000 6.0000 5.0000 4.0000 3.0000 g .? = p * • u a M- ^ oArv <-* CM 1CM>- O O O O .+> ,.o o. o I 04 ro^t ITVC 4 5 Figure 98 ferrous phosphate (Fe2(P04)3, is the best in the series. The total yield is only 2.1778 grams (dry weight). This is much less than in the previous case. Solutions Nos. 5 and 6 give yields that are still smaller in amount. 31 482 IOWA ACADEMY OF SCIENCE Vol. XXIV, 1917 The graph (figure 97) shows the comparative merits of ferric phosphate for the Canada field pea. All the cultures of the series, except No. 4, give an increase in yield on the addition of iron. Where 0.0050 grams of ferric phosphate are added to a liter of the solution the total dry weight amounts to 7.2132 grams. Whether or not this is the upper limit of ferric phos- phate cannot be stated at this time. In the series (figure 98) where ferrous phosphate is used, the behavior is somewhat different. Here No. 4 gives the highest yield, producing 7.1146 grams. Number 5 in the ferric phos- phate has the same amount of iron, but the total yield is only 6.2774 grams. In comparing the two series further it is noted that there is not a great deal of difference between the total yield (7.1146 grams) of No. 4 of this series and the total yield (7.2132 grams) of No. 6 in the ferric phosphate series. The results obtained in this study show that the amount of iron is probably of more importance than is generally supposed. The yield of the two kinds of plants, varying widely in mor- phological character, and growing in water cultures, is depen- dent- upon iron. Ferrous phosphate is less efficient than the ferric form, yet in the case of the Canada field pea, the varia- tions are not nearly as well marked as for wheat. Iron in the form of ferric phosphate to an amount equal to 0.0044 grams to a liter of the solution (as used by Shive) gives the greatest yield for wheat. The series with wheat show that this plant is more suitable for experiments of this kind. Iowa State College. THE CUTINIZATION OF APPLE SKINS IN RELATION TO THEIR KEEPING QUALITIES AND THEIR ENVIRONMENT. (ABSTRACT) WINIFRED PERRY. The apples were obtained from Iowa, New York, Arkansas and Washington, so as to present different growing conditions. The following varieties were prepared by the paraffine method, sectioned and drawn with the camera lucida : Jonathan from Iowa, Washington and New York; Gano from Iowa; Grimes from Arkansas, Washington and Iowa; Winesap from Iowa and Washington; Ben Davis from Arkansas and New York; Salome from Iowa and Washington; ITubbardston from New York; Black Twig and Willow Twig from Iowa; Fallawater, Twenty Ounce, Wealthy, Baldwin, Greening, Fameuse, and Maiden Blush from New York; Collins Red from Arkansas; and the Delicious from Iowa. For convenience the work was divided into four divisions, as follows : 1. The correlation of the amount of cutinization with the keeping quality. — There is a relation between the thickness of the cutinized area and the records of the keeping qualities of the different varieties of apples studied. 2. The correlation of the cutinization with the moisture in the different states during the growing period, or April to October inclusive. — ‘'Perhaps the most important factor to which life is subjected is the moisture relation,” says Prof. W. J. Young in his article on Variation in the Apple. And there is undoubtedly a relationship between the amount of cutinization and the moisture during the growing period. 3. The correlation of the cutinization and the mean temper- ature of the different states during the growing period. — A high temperature is not always followed by a thickly cutinized por- tion, so the statement that there is a correlation between the cutinization and the temperature cannot be made at this time. 4. The correlation of the cutinization with the percentage of clear, partly cloudy and cloudy days in the different states 484 IOWA ACADEMY OF SCIENCE Vol. XXIV, 1917 during the growing period. — The sun does not seem to be an important factor in the cutinization of apple skins, while it is in the color development of the fruit. Department of Botany, State College. SOME NATURAL WATERS OF CENTRAL NEW YORK. NICHOLAS KNIGHT AND VERNON C. SHUPPEE. The little stream from which the City of Oneida, New York, receives its water supply, and also the reservoir, are located in the midst of the Salina shales. In some places these shales con- tain notable quantities of gypsum, many times quite large masses of selenite. The soil survey of Madison county, New York, issued by the government printing office at Washington in 1907, contains an account of the geology of the region. It is there stated that the ravine occupied by the city reservoir is Upshar clay, the sides of the surrounding slope are Allis clay and the higher portion of the watershed Miami stony loam. The Upshar clay is derived directly from the disintegration and weathering in place of the red Salina shales of Silurian age. The Allis clay is formed by the weathering in place of the light colored Salina shales. The Miami stony loam is derived from the weathering in place of a comparatively heavy mantle of glacial material deposited as a terminal moraine by one of the later advances of the ice- sheet at about the close of the glacial epoch in this section. It is not likely that the hard local limestones have contributed any considerable amount of material to the formation of the till, but that the soft red shales along the, foot-hills have contributed to it is evident from its color. It is, however, quite probable that the limestone now contributes to the soil or soil solution. The character of the soil in which the reservoir is located as well as that of the watershed itself accounts for the large amounts of hardness in the form of calcium sulphate and calcium and magnesium carbonates. It is necessary to employ water soften- ing plants in order to use the water in the manufacturing in- dustries of the city, and also in the engine boilers of the different railway lines. The analysis of the water is given in Table I. 486 IOWA ACADEMY OP SCIENCE Vol. XXIV, 1917 TABLE I. Parts P£r Million Total solids 1029.0 CaS04 561.3 GaCOg 305.8 MgCOs - 134.5 Pe203 and ALO. 1.6 SiO, ’ 5.0 Nad 20.0 C02 91.5 Free ammonia 0.048 Albuminoid ammonia 0.072 Nitrates 0.34 . While unusually hard, the water shows rather unusual free- dom from organic contamination. The proposed supply for the city, the water from Florence creek, is of a very different quality. It lies about twenty miles north of the city of Oneida. The stream is fourteen miles long and the watershed averages one and a fourth miles in width, comprising an area of seventeen square miles. In the locality of the stream is the greatest amount of precipitation to be found in New York state. The streams in that section receive an average flaw of one million gallons daily for each square mile of watershed, so the daily average for Florence creek would be seventeen millions of gallons. The main reservoir to hold two hundred millions of gallons will be located at the hamlet of Glenmore, and if necessary to meet the needs - of the growing city, another reservoir to hold five hundred millions of gallons can be constructed farther up the stream. The watershed is very sparsely settled, containing scarcely one residence per square mile, and the danger of con- tamination is accordingly very slight. The sides of the valley are steep and wooded, about a hundred feet in height, and the bed of the stream is rocky for the most part and the current is quite swift. The stream is several hundred feet higher than Oneida, so the water can easily be delivered by the gravity sys- tem. An analysis of the water gave the result shown in Table II. SOME NATURAL WATERS OF CENTRAL NEW YORK 487 TABLE II. Total solids CaS04 CaCCX MgC03 Fe.O, . . SiOL. NaCl Free Ammonia Albuminoid Ammonia . . . Nitrogen in Nitrates Nitrogen in Nitrites COo Parts Per Million 71.6 12.8 28.77 14.98 1.16 ...... 2.20 .11.80 0.04 0.07 . . . . . 1.19 0.00 25. 001 The water is unusually soft and in marked contrast to the present supply. An analysis of the rock taken from the bed of the stream at the hamlet of Glenmore gave the results shown •in Table III. TABLE I'll. SiCC A1A Fe2Os CaO MgO K20 Na.0 Total Per Cent . . .79.94 . . . 4.75 . . . 8.24 . . . 4.89 . . . 1.91 . . . 0.04 . .. 0.48 . .100.25 The rock is quite a pure sandstone, with very little calcium and magnesium, which accounts in a measure at least for the softness of the water. It is a sandstone of the Medina forma- tion which at Glenmore borders closely on the Hudson river shales. Department of Chemistry, Cornell College. X THE DISSOCIATION OF DOUBLE SALTS. HAROLD L. MAXWELL AND NICHOLAS KNIGHT. The 'purpose of this work is to study the condition of double salts in aqueous solutions. Graham1 was the first to show that the double sulphates of the alums could be separated by diffu- sion. Marignac confirmed this work soon after and reached the conclusion “That double salts are found as such only at the moment of crystallization.” Later in 1882, Riidorff made a study of the diffusion of some of the double bromides and chlor- ides. He diffused the double salt solutions, using gold beater’s skin for a membrane,2 and then analyzed the diffusate and in this way determined the proportion in wdiich the double salts came through. If the diffusate contained the various elements in the same proportion that they would be found in the double salt, it would be evident that the double salt did not dissociate in the solution, but if the diffusate contained the elements in a different proportion from that found in the double salt it would be plain that the salt had dissociated in the solution. From these determinations it is possible to classify double salts in two general classes. First, those which suffer decom- position in aqueous solution and second, those which are not broken down when in a water solution. To the first class be- long : Copper Potassium Chloride 2KC1. CuCl2+2PI20. Magnesium Potassium Chloride KC1. MgCl2+6H20. Copper Ammonium Chloride 2NH4C1. CuC12+2H20. Sodium Cadmium Chloride 2NaCl. CdCL-f 3H20. Zinc Potassium Chloride 2KC1. ZnCl2+H20. Barium Cadmium Chloride BaCL. C'dCl2+4H20. The following three double chlorides are not decomposed in the presence of water: Sodium Platini! Chloride 2NaCl. PtCl4. 8PLO. Potassium Platinie Chloride 2KC1. PtCL. Mercuric Ammonium Chloride 2NH4C1. HgCl2. iChem. Pharm. In, 56. 1851. eBer., 21, 4. 1888. 490 IOWA ACADEMY OF SCIENCE Vol. XXIV, 1917 Later some important work was done on these compounds and others by Kremers,3 Grotian4 and Berthelot.5 The latter gave us the general proposition founded upon his thermochemical studies: “Double salts formed with the liberation of a small amount of heat are to be regarded as separated, for the most part, into their constituents, by water.” In 1910 Parsons and Evans6 made a thorough- study of the alums, including in their investigations : Ammonium Chrome Alum. Potassium Chrome Alum. Potassium Aluminium Alum. Ammonium Aluminium Alum. Ferric Ammonium Alum. In summing up the results obtained from their study, the authors said, in a paper presented before the American Chem- ical Society: “When alums are dissolved in water they are decomposed into the simple sulphates which can be separated from each other by diffusion. The Chrome Alums separate more readily than the Aluminium Alums,” Jones and Ota7 used the conductivity method in determining the presence of double salts and by increasing the dilution they were able to determine the rate of dissociation. The work in- cluded the study of four double chlorides and those at only a small range of dilution. The same method was employed by Jones and Knight8 in a comprehensive study of the double bro- mides and chlorides. This work included many more double salts than had been studied before and each one was measured over a much wider range of dilution. In several salts the dilution ranged from the molecular weight in two litres to the same in seventeen thousand litres. An important part of this work was the dis- covery of two new double bromides : sodium cadmium bromide and ammonium zinc bromide. These new salts were analyzed and found to have the composition : 2NaBr. 3CdBr2-|-6fLO and 3NH4Br. ZnBr2. 3Ann. Fhys. (Pogg), 98, 58. 4Ann. Phys. (Wied), 18, 177. 5 Ann. Chim. Phys. (5), 29, 198. eJournal of the Amer. Chem. Soc., Vol. 32, page 1383, 1910. 7Amer. Chem. Journal, 22, 5. 8Amer. Chem. Journal, Vol. 21, No. 2, August, 1899. THE DISSOCIATION OF DOUBLE SALTS 491 This work of Jones and Knight included the following four double chlorides and as many double bromides. Sodium Zinc Chloride. Strontium Cadmium Chloride. Ammonium Magnesium Chloride. Potassium Magnesium Chloride. Barium Cadmium Bromide. Potassium Cadmium Bromide. Sodium Cadmium Bromide. Ammonium Zinc Bromide. CONDUCT OF DOUBLE SALTS IN AQUEOUS SOLUTIONS. The compounds which we have studied are • Sodium Cadmium Bromide 2NaBr. 3CdBr2-|-6H20. Ammonium Zinc Bromide 3NPI4Br. ZnBr2. Copper Ammonium Chloride CuCl2. 2NH4C1+2IT20. Iron Ammonium Sulphate FeNH4 (S04)2. In the study of these compounds we used the diffusion method. We obtained the porous cups from Carl Schleicher and Sell till and found that the size, 45 mm. wide and 100 mm. high, gave the best results. This article is listed as Diffusions — Hiilsen No. 597. These cups are Compact enough to permit diffusion only slowly, yet porous enough to pass enough material to admit of accurate analysis. They are placed in 200 cc, beakers and 50 cc. of the five per cent solution of the double salt is placed in each one. Then distilled water is placed in the beaker until it reaches the same level in the beaker that the salt solution has in the diffusion cup. These beakers must be kept at a constant temperature as this factor plays an important part in determining the amount of material to pass through the walls of .the cup. By varying the temperature at one concentration of the salt solution and then by varying the concentration of the salt soltition at each temperature, it is possible to secure an endless list of data showing the effect of temperature and dilution upon the rate of dissociation of the salts. 492 IOWA ACADEMY OF SCIENCE Vol. XXIV, 1917 THE DOUBLE BROMIDE OF SODIUM AND CADMIUM. 2 NaBr, 3CdBr2+ 6H2O. We brought together the constituent bromides in the propor- tion two to three to form the salt 2NaBr. 3CdBr2-j-6H20 which was first made by Jones and Knight and described in “ Aqueous Solutions of Double Salts.”9 The salt crystallized out in long narrow plates with tapering mitre-like ends. We dried the salt and made two analyses of it with the following results : Cd. Per Cent 32.60 32.77 Br. E'er Cent 46.51 46.50 H20 Per, Cent 21.00 20.90 Total Per Cent 100.11 100.17 Since the total per cent of the elements of this salt is 100 it is evident that no sodium salt was present in the compound. By calculation we found that the result from the above salt corre- sponds to the formula CdBr2-f-4H20 which has the composi- tion : Cd. Br. H20 Total Per Cent Per Cent Per Cent Per Cent 32.56 46.51 20.93 100.00 The cadmium bromide which crystallized out of this mixture of salts resembled the original cadmium bromide very closely and when a microscopic examination was made of the two salts it was noted that the two were identical in crystalline form. The cadmium bromide which we had obtained was returned and redissolved in the mother solution. More of the sodium bromide was added until the amount of the two bromides was proportional to their molecular weights. From this mixture there separated out a salt made up of small six sided plates about the thickness of a ten cent coin. Analysis of this salt gave the following results: Cd. H20 Br. Per Cent Per Cent Per Cent 30.00 10.09 56.47 This corresponds to the formula 2NaBr. 3CdBr2+6H20 which has the percentage composition : Cd. H20 Br. 29.80 9.55 56.59 9American Chemical Journal, Vol. XXII, No. 2, August, 1899. THE DISSOCIATION OF DOUBLE SALTS 493 With this assurance that we had the right salt we proceeded with the diffusion tests using the method outlined in the fore- going. We made these tests at several temperatures and also at different concentrations and time intervals. Concentration Temperature Duration of Test 5 Per Cent 13°C 45 Minutes We found on the analysis of the diffusate, the following amounts of the salts in solution: (Weight in grams.) Test No. 1 Test No. 2 CdBr2 .04009 .04131 NaBr .02290 .02320 In the double salt crystals, the proportional parts of the various elements may be represented by the formula : 2NaBr. 3CdBr2. Since the molecular weights of these are 206 and 810 respectively, it is evident that, if this salt does not dis- sociate in a water solution, the two salts found in the diffusate will bear the same ratio to each other. Prom the above mole- cular weights it is seen that the cadmium bromide should be 3.9 times heavier than the sodium bromide, if the double salt has not dissociated. We find from the analysis of the diffusate that the sodium bromide is a little more than half the weight of the cadmium bromide that diffused through the walls of the porous cup. Concentration 5 Per Cent CdBr2 NaBr Temperature 46°C Test No. 1 .10045 .04953 Duration of Test 45 Minutes Test No. 2 .10915 .05244 In this we have less than half as much of the sodium bromide as of the cadmium bromide. It seems that less of the salt has dissociated since the ratio is more nearly 1 to 3.9. This may not necessarily point to the fact that the salts break down more easily in cold than in warm water. It may be that the heat has so lessened the internal friction of the solvent that it passes through the walls more easily and in carrying a larger amount of the salt through in the same time, the more cadmium bromide is taken through. This is only a supposition, however. 494 IOWA ACADEMY OF SCIENCE Vol. XXIV, 1917 Concentration 25 Per Cent CdBr2 NaBr Temperature 13° C Test No. 1 .12916 .07610 Duration of Test 45 Minutes Test No. 2 .12480 .07052 It is readily noted that the 25 per cent solution with the same time duration and the same temperature has diffused a much larger amount of the salt. We found this true in each case with this salt. Concentration 25 Per Cent CdBr2 NaBr Temperature 13 °C Test No. 1 .13094 .08861 Duration of Test 45 Minutes Test No. 2 .14458 .08690 This test serves only to verify the foregoing one. Concentration 2U Per Cent CdBr, NaBr Temperature Room Temp. Test No. 1 .40921 .19392 Duration of Test 24 Hours Test No. 2 .36731 .17313 We made an analysis of the contents of the cup also and found that even in the twenty-four hours the solution had not reached its equilibrium, that is, the solution within the cup con- tained more of the salt per cc. than did the solution surround- ing the cup within the beaker. Conclusions : sodium cadmium bromide dissociates when dis- solved in water. Sodium bromide diffuses faster than cadmium bromide. THE DOUBLE BROMIDE OF AMMONIUM AND ZINC. 3NH4Br. ZnBr,. We added the ammonium bromide to the zinc bromide in the proportion of three to one, multiplied by 'their molecular weights, to form the salt : 3NH4Br. ZnBr2. There separated out a large amount of the salt which we analyzed with the following re- sults : Br. Zn. Ammonium Total P'er Cent P*er Cent P*er Cent P*er Cent 77.19 12.60 10.40 100.19 THE DISSOCIATION OF DOUBLE SALTS 495 This compares favorably with the calculated results which are : Br. Per Cent 77.07 Zn. Per Cent 12.52 Ammonium F’er Cent 10.40 Total P*er Cent 99.99 With the use of the same method employed in the examina- tion of the preceding salt, we diffused the salt and found the following results : Concentration 5 Per Cent ZnBr2 NH4Br Temperature Room Temp. Test No. 1 .43537 .78583 Duration of Test 24 Hours Test No. 2 .42142 .77359 In the double bromide the ratio between the constituent bro- mides is one of the zinc to 1.3 of the ammonium bromide. Un- less it is dissociated by water the diffusate should contain these elements in the same ratio one to the other. We find, however, on analysis that the ammonium bromide is much in excess of this ratio. The results show that the ammonium bromide is to zinc bromide as 1 :1.8. Concentration 2 % Per Cent ZnBr2 NH4Br 5 Per Cent ZnBr2 NHJBr Temperature Room Temp. Test No. 1 .30132 .35455 Room Temp. Test No. 1 .2856'8 .83258 Duration of Test 24 Hours Test No. 2 .32412 .37241 12 Hours Test No. 2 .31271 .84781 It appears from the results that during the first twelve hours the ammonium bromide goes through the porous cup much faster than during the second twelve hours. In the twenty-four hour test the ammonium was not present in large excess but in this analysis of the twelve hour test we find that the ammonium bromide is. present in much larger proportions. Concentration 5 Per Cent ZnBr, NHJ3r Temperature 55°C Test No. 1 .04428 .26310 Duration of Test 1 Hour Test No. 2 .04947 .29190 496 IOWA ACADEMY OF SCIENCE Vol. XXIV, 1917 This test also shows a larger proportion of the ammonium bromide. The raising from “Room Temperature” to 55° C. has also been an active agent of dissociation. Concentration 5 Per Cent ZnBr, NHJBr Temperature 55 °C Test No. 1 .02518 .08336 Duration of Test 15 Minutes Test No. 2 .01972 .08059 The data here recorded in connection with the preceding tests, give an excellent example which shows how the amount of solid matter that diffuses through the cup per unit of time, is greatest for the first unit of time. and becomes smaller and smaller as the solutions become more nearly in an equilibrium. It is noted that half as much of the zinc bromide was diffused in the first fifteen minutes as was diffused during the full hour test. This rate of decrease for each succeeding period diminishes until with long duration of time tests, when the solutions become nearly saturated, the difference or the rate of decrease is very small. C O N CENTR ATION 5 Per Cent ZnBr NH4Br Temperature Room Temp. Test No. 1 .27178 .80585 Duration of Test 12 Hours Test No. 2 .33168 .832206 This test was made under the same condition as one of the foregoing and similar results were obtained, each serving to check the other. Concentration 5 Per Cent ZnBr2 NHJBr Temperature Room Temp. Test No. 1 .12064 .46180 Duration of Test 6 Hours Test No. 2 .10240 .47242 It may be noted when comparing this six hour test with the twelve hour tests, that less than half as much of the zinc bro- mide was diffused, while more than half as much of the am- monium came through the walls. Conclusions — (1) Zinc ammonium bromide dissociates in water solution. (2) Ammonium bromide passes through a membrane faster than ZnBr2. (3) Ammonium bromide dializes much faster than ZnBr2 at the beginning of the test, but the amount dialized, per unit time, decreases more rapidly when the time is lengthened. THE DISSOCIATION OF DOUBLE SALTS 497 THE DOUBLE CHLORIDE OF COPPER AND AMMONIUM. C11CL. 2XH.C1 + 2H20. For these tests we used the salt crystals furnished by the Baker Adamson Company. The analysis of this salt compared favorably with the calculated composition which is: Per, Cent Cu 22.89 NH, Per Cent 12.97 Cl Per Cent 51.16 H20 Per Cent 12.97 Concentration CuCl2 NHjCl TEMPERATURE Teist No. 1 .10365 .40470 Duration of Test Test No. 2 .08954 .37995 From the formula of the double chloride of copper and am- monium, it is plain that the two salts have combined in such a way that the relative molecular weight is 134 of. the copper chloride to 107 of the ammonium chloride. If the salt does not dissociate we will expect then to find the salts in the diffusate in the proportion of (1) one of the ammonium chloride to 1.25 of the copper chloride. The analysis, however, shows the pres- ence of about four times as much ammonium chloride as of the copper chloride. Concentration 5 Per Cent CuClo NH4C1 Temperature Room Temp. Test No. 1 .07820 .23149 Duration of Test 2 Hours Test No. 2 .06680 .20469 The ammonium chloride is still present in an excess but not so much as in the first instance. Concentration 5 Per Cent CuCl2 NH4C1 Temperature Room Temp. Test No. 1 .05428 .10626 Duration of Test 1 Hour Test No. 2 .05015 .10690 It is readily seen, from the results of the five, two, and one hour tests, that the difference is less in the shorter time tests. It is to be expected then that since the CuCl2 diffuses at a more even-, rate, the ammonium chloride comes through very much faster during the first part of the test and decreases rap- idly until the weight of the copper chloride seems to approxi- mate the weight of the ammonium salt. 32 498 IOWA ACADEMY OF SCIENCE Vol. XXIV, 1917 Concentration 5 Per Cent CuCl2 NH4C1 Temperature 63°C Test No. 1 .16231 .35727 Duration of Test 2% Hours Test No. 2 .15929 .34984 With the rise of temperature it is noticed that the two salts are approaching’ a different ratio and that the ammonium chlor- ide has taken another marked increase. Instead of the ratio of 1 to 1.25 we have the ratio of 1 to 2.25. Concentration 5 Per Cent CuCl2 NH4C1 Temperature 63°C Test No. 1 .07259 .20596 Duration of Test 1 Hour Test No. 2 .08508 .20188 This test serves to verify the statement made above concern- ing the rapid diffusion of the ammonium salt during the first part of the tests. We have in these data more evidence to prove that the decrease of the ammonium chloride is more rapid than the decrease of the copper chloride, for each additional time unit. The ratio between the two salts for the shorter periods is higher than for the longer periods. Concentration 5 Per Cent CuCl2 NH4C1 Temperature Room Temp. Test No. 1 .24141 .53293 Duration of Test 10 Hours Test No. 2 .26204 .51076 THE DOUBLE SULPHATE OF IRON AND AMMONIUM. FeNH4(SG4)2. Concentration 5 Per Cent FeS04 (NH4);S04 Temperature Room Temp. Test No. 1 .01039 .03608 Duration of Test 2 Hours Test No. 2 .01249 .04312 From the above formula we computed the ratio of the two constituent salts and found that they were present in the ratio of 100 of the iron to 33 of the ammonium sulphate. If then the salt does not dissociate we would expect to find three times the weight of the iron sulphate as of the ammonium sulphate, in the diffusate. But from the above data it is evident that the ammonium is much in excess and that the double sulphate dis- sociates when in a water solution. THE DISSOCIATION OF DOUBLE SALTS 499 Concentration 5 Per Cent FeS04 (NHJoSO, Temperature Room Temp. Test No. 1 .02548 .05709 Duration of Test ' 3 Hours Test No. 2 .01824 .04244 We find here an example of how the ammonium salt decreases at a more rapid rate than iron salt for the longer periods. Concentration 5 Per Cent FeS04 (NH4)2S04 Temperature Room Temp. Test No. 1 .03998 .07799 Duration of Test 5 Hours Test No. 2 .04623 .09438 The ammonium sulphate is still on the ratio decrease and now for the five hour test it is less than twice the weight of the iron, while for the two hour period it was three times greater. Co n cen tr atio n 5 Per Cent Temperature Room Temp. Test No. 1 Duration of Test 10 Hours Test No. 2 FeS04 .08621 (NH4)2S04 .15411 .09196 .16478 The total weight of the salts which came through the walls during the ten hour test is less than twice the weight of the salts which came through during the five hour test. This is another example of how the total amount of salt which passes through a dializer during any period of time, is greatest for the first period and decreases for each additional period. This is only to be expected for as the solutions within and without the porous cup come to approximate an equilibrium, there is less pressure and consequently less force to urge the salts through the membrane. GENERAL CONCLUSIONS FROM DATA SECURED. The double salts studied do not exist as such in aqueous solu- tions, but dissociate into simpler salts. The rate at which the dissociated ions of a salt pass through a porous membrane is inversely proportional to the size of the ions of that salt. Some ions, which are of themselves small, hydrate and thus become large and because of this they pass through the more slowly. This is in accordance with the “Hydrate Theory” of Jones and Knight. Department of Chemistry, Cornell College. WATERWORKS LABORATORIES. JACK J. HINMAN, JR. The material which I have put into this paper is a part of the data which I hav^ been gathering for an article on the con- trol of waterworks plants by laboratory methods. The audi- ence which I am considering in the preparation of that paper is one which is interested specifically in the problems and tech- nique of the waterworks plant. Numerical results of operation, and quantity weights are naturally of greater interest to them than they are to you. Indeed, the tabulations and deductions which I have to offer to you today are of a rather special in- terest. My hope is that my data on the laboratories themselves may not prove uninteresting to you, although they are based almost entirely upon the figures upon a single chart. To begin with, I sent out a very comprehensive questionnaire to every town in the United States and Canada that had a pop- ulation of 25,000 or more at the time of the 1910 census. A few additional questionnaires were sent to a number of other towns in adjoining states. These towns were selected on ac- count of the method of water purification employed. My percentage of replies has been excellent. I have data on an average daily pumpage of more than 3;000 million gallons of water of which more than 2,800 million gallons, supplying a population of nearly 17 million people, on the basis of the 1910 report, is protected by laboratories directly under the con- trol of the waterworks officials or their superior officers. Plants which are more or less completely controlled by contract chemists or special arrangements with local concerns or institutions are, for the time being, omitted. In the control of the 90 plants which supply the 2,800 million gallons of water daily, 195 laboratory workers are employed. Of these, 91 have the title of chemist or assistant chemist. Many of the others have the title superintendent of filtration or lab- oratory director, and so on. Some of these men I know have had chemical training. Some are engineers who have picked up the rudiments of water examination and carry on such de- terminations as are necessary for their plants. The preponder- ance of one-man laboratories is significant and the variety of 502 IOWA ACADEMY OF SCIENCE Vol. XXIV, 1917 the work which must he performed is worthy of notice. In ad- dition to the widely differing subjects of bacteriology, microbi- ology and chemistry of water, miscellaneous chemical and bac- teriological work must be entered into. If the laboratory man is also an engineer, so much the better. I was surprised on first preparing my chart to see how re- cently the laboratories listed had been installed. Beginning with the one maintained by the city of New York since 1897 and that of Utica, New York, established in the same year, we have a rapidly increasing number of laboratories established during the succeeding nineteen years. Six plants with a com- bined average pumpage of 32.5 millions gallons per day are now installing laboratories. Twelve plants with a combined pumpage of 45 million gal- lons per day have daily examinations made at outside labora- tories. The Metropolitan Water District which supplies Boston and some neighboring communities is a State Commission. It maintains its own laboratory and supplies a little more than 100 millions of gallons of water daily. Of the plants reporting twenty-one are owned privately, sixty- eight municipally and one by the United States Government. The employees of twenty-eight of the municipally owned plants and those of the Government plant are selected by civil service methods. Rivers and streams form the direct source of sixty-two plants out of the ninety that have their own laboratories, the remain- ing sources are lakes, impounded waters from more or less satis- factorily protected watersheds and in a few instances wells and infiltration galleries. Those plants which do not maintain lab- oratories are nearly all using the water of wells, or impounding reservoirs. None of them supplies more than an average pump- age of 16 million gallons per day. One or two pump direct from streams without treatment. Artesian waters and the waters of great impounding reservoirs are to be expected to be of uniform composition and quite con- stant in their bacterial contents. Occasional growth of algae may require copper treatment to avoid odors and tastes, but otherwise the water should be very uniform. Rivers, small reser- voirs and lakes and shallow wells are very likely to be incon- stant. Raw water from such sources is subject to very sudden alteration with consequent need for an immediate readjustment WATERWORKS LABORATORIES 50: of the treatment. In small plants and those using water from unchanging sources laboratory control has, for the most part received little attention. Reliance has been placed upon the examinations made by the state laboratories at irregular inter- vals. For constant supplies this will probably continue to be sufficient. But plants of all sizes which treat the water of rivers and the other variable waters will have increasing difficulty in keeping the water supplied for their consumers satisfactory ac- cording to the accepted standards of efficiency. That these standards, are constantly becoming more rigid can easily be shown. To be sure, when bacterial standards came into vogue, the old arbitrary standard of 100 bacteria per ec. was almost universally used for all supplies, treated and un- treated. Then it became customary to set a certain per cent removal of bacteria when treating water. Then it was said that in addition, the colon bacillus should be constantly absent in one cc. of the treated water. A few years ago the Treasury Department issued a bacterial standard for water supplied to passengers in interstate traffic. The standard which was adopted — not by the unanimous consent of the committee appointed to draft the standard — is now regarded as a very rigid one. The 504 IOWA ACADEMY OF SCIENCE Vol. XXIV, 1917 Department held that inasmuch as the quantity of water re- quired by the passengers is small the railroad companies could afford to furnish a better water than a city water plant. As a matter of fact the Treasury Department Standard is rapidly becoming the working standard of the waterworks operators in this country. In effect it requires a maximum count of 100 bacteria per cc. on agar at 37° and not more than one positive tube out of five ten cc. plantings into lactose broth for the colon group. Acid colonies on Litmus lactose agar of typical colonies on Endo’s medium are given as authorized confirmatory tests for the colon bacillus. Of the ninety plants listed in the chart fourteen already claim this standard for the water they supply. Many of the others use a standard differing only slightly. The percentage standard of plant efficiency is not satisfactory because as the raw water becomes higher in bacteria the number of bacteria in a water which is up to the standard, may become very large. For instance 99 per cent efficiency at one time dur- ing the past winter (1916-17) when the raw water of our local plant showed 880,000 bacteria per cc. would have allowed a bacterial count of 8,800. Wohlman has recently proposed a standard based upon the ratio of the logarithms of the numbers of bacteria in the raw and treated water. It requires higher bacterial-removal efficiency. There are very few plants in my list which are content to wmrk merely with a view to the removal of the turbidity and color. It is very necessary, especially in connection with the chlorination treatment, to have as much as possible of the color and turbidity removed, but that is not the aim of the water treatment. The waterworks superintendent who “ didn’t be- lieves in these here bacteria, anyway” is almost extinct. A glance at the table will show you that in spite of the ex- cellent work which has been done in the preparation of our Standard Methods of Water Analysis, the bacteriological pro- cedure of the water plants is far from uniform. This is due in part to the changes recommended in the 2d Edition of the Standard Methods. It was recommended that the bacterial counts be made on agar at 37°, dropping the gelatine count at 20°. In view of the great amount of work which had already been done on gelatine, this was objected to quite strenuously and gelatine has been officially reinstated in the 3d Edition which has just come from the press. The Confirmatory tests WATERWORKS LABORATORIES 505 for B. coli have been confused. The new Edition of the Stand- ard Methods provides a uniform scheme which will doubtless be extensively followed. Chemical standards based upon the ordinary factors of a sanitary analysis often mean very little when applied to a treated water in routine examination. This is due to the fact that there is usually very little oxidation in passing; through a filter and a purified water will still show evidence of its former pol- lution and unsafe condition. With a stored water there is greater oxidation and therefore the individual determinations of the sanitary analysis probably mean more. There are a num- ber of papers which have been written upon the amount of use- less work which has been done on the routine water samples from a single plant. In connection with the operation of the plant a very few factors are usually sufficient. Alkalinity is probably of the greatest importance because it sets a limit upon the amount of alum or iron sulphate which can be added to a water. Free carbon dioxide is especially important in iron re- moval plants. An iron determination can show at once whether the iron is being removed. Where waters are softened the total hardness, erythrosine or methyl orange and phenolphthalein al- kalinities, magnesium, etc., may be determined advantageously every day. Most of us, however, run a few thousand nitrite and nitrate determinations on the product of a water, plant be- fore we realize that the numerical variation throughout the year is too small to give important information from day to day. It is understood, of course, that the really important factor is the bacterial data which on account of cultural methods must of necessity be one or two days behind at all times. In work with a treated water the chemical substances present which are determined in a sanitary analysis usually are of little im- portance. It may be, however, that bog water and the colored water of the early spring may contain some toxic substances. Occasionally the plumbosolvency of a. water will be important in soft water districts. A weekly or monthly sanitary water anal- ysis in the complete form ought to satisfy any demands. Quar- terly minerals analyses ought to meet industrial conditions as a rule. Laboratories for the State Board of Health, The State LIniversity. THE ELECTROMOTIVE FORCE AND FREE ENERGY OF DILUTION OF LITHIUM CHLORIDE IN AQUEOUS AND ALCOHOLIC SOLUTIONS. J. N. PEARCE AND F. S. MORTIMER. Various experimental methods may be employed for compar- ing the activities of solutions of electrolytes, viz., freezing point, boiling point, vapor pressure, osmotic pressure, electrical con- ductivity and electromotive force. Of these, the latter is gen- erally more convenient of application ; it has the advantage in that measurements are more easily made and its use is not re- stricted to any particular temperature interval. In solutions ranging from the moderately dilute to the very concentrated it may be applied more accurately than the conductivity method. The electromotive force method, however, has its limitations. It shares with all of the other methods the disadvantage of be- ing inapplicable for solutions other than those, of the uni-univa- lent electrolytes. This, coupled with the troublesome factor of the boundary potential, has limited its usefulness. Many attempts have been made to eliminate this boundary potential. Some, following the lead of Ostwold,1 have interposed solutions of an inert salt between the electrode vessels. Unfor- tunately, the electromotive forces thus measured vary consid- erably not only with the concentration of the interposed solution, but also with the nature of the electrolyte used. Consecpiently such measurements are of doubtful value. Nernst,2 Planck,3 Henderson,4 Cumming,5 and others have sought to overcome the effect due to boundary potential by in- troducing formulae involving the relative mobilities of the ions. A few cells have been set up which do not involve the trans- ference of ions from one electrode vessel to the other. Cells of this type are limited to those electrolytes for which it is pos- sible to find electrodes reversible to both of the ions in the so- lution. So far the only cells thus investigated from which cal- iMessungen, 3d ed., p. 448. theoretical Chemistry, Nernst, Translation of 6th German ed., p. 370. 3Wied. Ann., 40, 561, 1890. *Zeit. phys. Chem., 59, 118, 1907. 5Trans. Faraday Soc., 8, 86, 1912. 508 IOWA ACADEMY OF SCIENCE Vol. XXIV, 1917 dilations of free energy may be made are those containing so- lutions of the alkali halides or of the halogen acids. From the electromotive forces of such cells it has been found possible to calculate the free energy of dilution with a high degree of accuracy. Using potassium chloride as the electrolyte, Maclnnes and Parker6, determined the electromotive forces of concentration cells both with and without transference. From the data thus obtained they calculated the transport numbers and the activity ratios of the ions. They found that the concentration ratios calculated from the conductivity data are invariably higher than the activity ratios determined by the electromotive force method. As the dilution increases the value of the activity ratio ap- proaches that of the concentration ratio. Ferguson7 has measured the electromotive forces of concen- tration cells of hydrochloric acid using electrodes reversible to both ions, in cells without transference as well as in cells directly connected. He also found that the observed activity ratios are less than the concentration ratios calculated from the conductiv- ity data. The transport numbers for the ions of hydrogen chlor- ide are constant in dilutions greater than thirty liters. He con- cludes, therefore, that conductivity measurements do give us an accurate method for calculating relative ion concentrations in the more dilute aqueous solutions of hydrogen chloride. Ferguson and Tolman8 and later Ellis9 measured the free energy of dilution of hydrogen chloride solutions over a wide range of concentrations. The object of the present investigation was to determine the effect of solvent on the free energy of dilution, the transport numbers of the ions and the activity ratios of lithium chloride in aqueous and alcoholic solutions. THEORETICAL. In his treatment of the free energy of chemical substances Lewis10 has introduced the terms activity and fugacity. Activity has the dimensions of concentration and is defined as “Such a property of a .given substance that, (1) if the activity, a , for a substance is the same in any two phases, the substance will not 6Jour. Am. Chem. Soc., 37, 1445, 1915. 7 Jour. Physical Chem., 20, 326, 1916. 8Jour. Am. Chem. Soc., 34, 232, 1912. 9Proc. Nat. Acad., 83, 1916. 10Jour. Am. Chem. Soc., 35, 1, 1913. DILUTION OF LITHIUM CHLORIDE 509 pass from one phase to the other when the two phases are brought together; (2) if a is greater in one phase than in another, the substance will tend to pass from the first phase to the second; (3) the activity of a perfect gas is equal to its concentration; (4) the activity of a solute in a perfect solution is equal to its con- centration.” When two phases of the same system, but of different concentrations or activities are brought together, the material in the phase of high activity will tend to escape over into the phase of lower activity. This escaping tendency Lewis called by the term fugacity, /. It has the dimension of pressure. Activity is defined in terms of the fugacity by the equation, a=f/ RT where R is the gas constant and T the absolute temperature. In applying this conception of activity to a working cell, let us consider first the cell involving transference, e. g. A g - AgCl j LiCl - LiCl | AgCl - A g. a" a' (a'^a') During the passage of one faraday of electricity one equivalent of chloride-ion is formed on the dilute side from the silver chlor- ide electrode, while on the concentrated side one equivalent of chloride-ion is removed from the solution to the electrode. At the same time Nc equivalents of lithium-ion migrate into the dilute chamber and 1-Nc equivalents of chloride-ion migrate to the concentrated side. The total result is the transfer of Nc equivalents of lithium chloride from the concentrated to the dilute solution, or from the solution of activity a to that of activity a'. The free energy accompanying the transfer of one mole of the salt is given, therefore, by the relation : E\F Nc = RT loge S-- a' (1) where E is the electromotive force, F the faraday (96,494 coulombs), Nc the transport number of the cation, R the gas constant (8.3160 joules), T the absolute temperature (298.09°), and a" and a' are the activities of lithium chloride in the two solutions. The following cell does not involve transference: Ag - AgCl | LiCl - LiCl (LiHgx ) - (LiHgx ) LiCl - LiCl | AgCl - Ag. a" a” a' a1 an^>a The passage of one faraday of electricity involves on the dilute 510 IOWA ACADEMY OF SCIENCE Vol. XXIV, 1917 side only the formation of one equivalent of lithium chloride from the silver chloride and lithium amalgam electrodes. On the concentrated side there is transferred to the electrodes from the solution one equivalent of lithium chloride. The free energy accompanying this change is, E, F=RT loge— (2) a Combining equations (1) and (2) we arrive at an expression for calculating the transport number of the cation directly from the electromotive force measurements : Nc = E Ex (3) All cells on closed circuit tend to operate until the activities of the two solutions become equal. In cells without transference such an equalization by direct diffusion of the molecules and ions is impossible. The same result is obtained, however, by the formation of the salt from the electrodes on the dilute side and the simultaneous removal of the salt to the electrodes on the concentrated side. It is obvious, therefore, that the free energy of dilution of lithium chloride is equal to the sums of the free energies of dilution of the separate ions, i. e., ^ ^ a" (LiCl) a” Li + ' a” Cl" Er • F - RT loge (LiCl) ~ RTloge a< Li + • a> Cp Assuming that a'' li'A == o!’ ci- and that a! llA =a' ci‘, Then for the chloride ion, Er F = 2RT lo£ a Cl* a GI- RT logf a (LiCl) a’ (LiCl) (4) The well known relation of Nernst makes possible a calcula- tion of the electromotive force from electrical conductivity data. For cells involving transference, E = 2 N, RT *"N” c F loge a' N and for cells without transference. RT A N” E^a-jrloge yN, (5) (6) The ratios of the activities of the ions and of the undissociated molecules are readily obtained from equation (4). The con- DILUTION OF LITHIUM CHLORIDE 511 eentration ratios of the ions are calculated from the conductivity measurements by the following evident relations. ° C r _ a N" =A -N C cr a N' a’ N' ' { > For the undissociated salt, C C (LiCl) ( LiCl) ST ( 1— q ' ) = A °° - A ’ ' N' ‘ ( l-fly) N' ’A 00 - A ' (8) where C" and C' represent the concentrations of the appropriate ions or molecules, N" and 1ST the salt concentrations, x 00 , x" and x' the equivalent conductivities at infinite dilution and at the concentrations N" and N', respectively. The free energy of dilution in calories per equivalent is equal to Bj, the electromotive force, multiplied by the faraday (96,494 coulombs) and divided by the joule equivalent of the calorie, (4.182). Or, E(23073)=Cals. MATERIALS AND APPARATUS. Water. — The conductivity water was prepared according to the method of Jones and Mackay!1 Ethyl Alcohol, — Ordinary 95 per cent alcohol was allowed to stand over fresh quicklime for three w^eeks ; it was then de- canted and distilled. The distillate was allowed to stand over anhydrous copper sulphate for one week and then redistilled. This distillate was refluxed over metallic calcium for ten hours and again distilled. To the last distillate were added a few crystals of dry silver nitrate and it w^as refluxed for two hours to remove reducing agents. The distillate from this treatment was collected and preserved in dry glass-stoppered bottles, be- ing protected from the air during distillation by calcium chlor- ide tubes. In each distillation a fractionating column was used and only that middle portion which passed over between 77.9° and 78° (uneorr.) was used. Methyl Alcohol. — Kalilbaunvs best grade of alcohol was fur- ther purified in the same manner as the ethyl alcohol, except that the treatment with quicklime was omitted. Only that frac- uAm. Chem. Jour., 19, 83, 1897. 512 IOWA ACADEMY OF SCIENCE Vol. XXIV, 1917 tion of the distillate passing over between 64.9° and 65.1° (un- con*.) was retained. Lithium Chloride.— Kahlbaum’s best grade of lithium chloride was recrystallized four times by passing pure hydrogen chloride gas into a saturated solution of the salt in conductivity water. The crystals were filtered on a Buchner funnel and sucked dry. They were then heated in a platinum dish in an electric oven in which the temperature was gradually raised to 150c. Finally, the dry salt was finely powdered in an agate mortar and trans- ferred to porcelain boats; these were placed in a combustion tube and heated for several hours at 160° in a rapid stream of dry hydrogen chloride gas. All traces of the latter were then removed by a stream of dry hydrogen gas, after which the boats were quickly transferred to large glass-stoppered weighing tubes. Solutions. — All of the solutions used were prepared by first dissolving an amount of the salt in excess of that desired for the highest concentration. The chloride content was then de- termined in at least three separate samples by the Drechsel12 modification of the Yolharcl method. All of the various con- centrations in any given solvent were made by the proper dilu- tion of this solution. All measuring apparatus was certified and the solutions were made rip to Volume at 25°, care being taken to avoid undue exposure of the alcohols to the air. Lithium Amalgam, — This was prepared by the electrolysis of a saturated solution of lithium chloride in pyridine, usng pure redistilled mercury as cathode. It was then washed in absolute alcohol, quickly dried by reduced pressure, and then filtered through a capillary tube into a sealed, glass container from which the air had previously been displaced by dry hydrogen. Electrodes:- — The silver chloride electrodes consisted of short, thick pieces of pure silver wire fused into the ends of glass tubes. To the ends within the tubes were soldered long copper wires, which were of such length that they could be bent into small mercury cups, thus making contact with the wire leads. Twelve or fifteen of the electrodes thus prepared were first grouped as cathodes about a single pure silver anode immersed in a solution of potassium-silver-cyanide. After a dense, white coating of silver had been formed they were removed, rinsed, and then inserted as anodes in a 1.0 N hydrochloric acid solution 12Z. anal. Chem., 16, 351, 1877. DILUTION OF LITHIUM CHLORIDE 513 On -passing the current from a single lead accumulator for one to two minutes there is formed a closely adhering, reddish brown deposit of silver chloride. For any one series of measurements, the silver chloride electrodes were always first checked against each other. This was done by grouping them in a dilute solu- tion of hydrochloric acid and observing the potential differences between each electrode and another similar electrode taken as a standard. Only those varying by less than .05 millivolts were chosen. Two or three of these electrodes were then placed in each half-cell. After they had been in contact with their re- spective solutions for four or five hours, each electrode was re- eheeked against those in the other half-cell. Unless at least two electrodes in each half-cell differed by less than .02 millivolts, the cell was disconnected and the electrodes replated. Form of cell. — It was desired to measure the electromotive forces of two combinations, viz., one involving transference, Ag — AgCl j Li Cl n" j | LiCl n' | AgCl— Ag, the other without transference, Ag— AgCl | LiCl n' — LiCl n ' (LiHgx )- (LiHgx ) LiCl n'-LiCl ri | AgCl-Ag The form of cell adopted was such that both of these combina- tions could be obtained from a single set-up of the apparatus. Two half-cells, each having two side-tubes and containing solu- tions of the desired concentrations in contact with the silver chloride electrodes, were so arranged that from one set of side- tubes a. liquid junction could be made and the first combination thus obtained. The other set of side-tubes were thus left free for liquid connection with small cells', into which dipped the amalgam electrodes, thereby forming the cell without transfer- ence. Liquid contact between the half-cells was effected by means of an inverted T-tube fitted with a three-way stop-cock. To further prevent diffusion loose plugs of cotton were inserted into the bore of these stop-cocks. Fresh liquid contacts were readily made by drawing more of each solution into the free limb of the T-tube. For cells with transference it is essential that a sharp boundary be produced between the solutions im- mediately before measurements are made. It was found that the electromotive force of the cells directly connected remained constant for several days when this precaution was observed. 33 514 IOWA ACADEMY OF SCIENCE Vol. XXIV, 1917 The amalgam dropping-electrodes were similar to those used by Maclnnes and Parker13, The amalgam was allowed to drop slowly into two small half-cells through capillary tubes con- nected to a common container. These capillary tubes were about cne millimeter in diameter and were fitted with stop -cocks to regulate the flow. To insure good contact between the amalgam electrodes, platinum wires were fused into each of these capil- lary tubes just below the stop-cocks; these were then joined by a copper wire. Numerous experiments were made to determine the most suit- able concentration of the amalgam. A concentration of .002 per cent was observed to give the best results. It was found that by dropping from 20 to 30 drops per minute no appreciable bubbling occurred on the electrode. The voltage remained very constant for several minutes. The galvanometer would waver off slightly occasionally, but it would immediately return upon the formation of another drop of the amalgam. All measurements of electromotive force were made with a Wolff potentiometer in connection with a sensitive Leeds and Northrup, “Type H, ” wall galvanometer. Differences of po- tential of .01 millivolt were easily detected in the aqueous solu- tions, but owing to the greater resistance in the more dilute non- aqueous solutions it was sensitive only to .05 millivolt. A Cad- mium-Weston cell which had been recently standardized and occasionally rechecked against a similar element certified by the Bureau of 'Standards was used as the standard of reference. Al- though its temperature coefficient is practically negligible, this cell was kept in an insulated glass beaker, suspended in the constant temperature bath. All measurements were made at 25°. The constant temperature bath used was mechanically stirred, electrically heated and electrically controlled at 25° ± .01. In all cases at least four cells of each combination were meas- ured. This, together with the fact that more than one electrode was used in each solution certifies to the degree of accuracy ob- tained in this work. DISCUSSION. The experimental results obtained are to be found in the ac- companying tables. Table I contains the observed and calcu- lated electromotive forces and the transport number of the ca- 13Loe. cit. DILUTION OF LITHIUM CHLORIDE 515 tion in the solvents, — water, methyl alcohol and ethyl alcohol. A glance at these tables shows an absolute lack of agreement between the observed and calculated electromotive forces. Only in the more concentrated cells containing the aqueous solutions do the calculated results even approximate to those observed. Here the calculated values are slightly lower, while for all other cells they are higher than the observed electromotive forces, the difference between the two increasing with increasing dilution. For cells with transference both the calculated and observed electromotive forces increase with dilution, while for cells with- out transference the experimentally determined values decrease Avith increasing dilution in each of the three solvents. 516 IOWA ACADEMY OF SCIENCE Vol. XXIV, 1917 TABLE I. Electro .motive Forces and Transport Numbers. Water Electromotive Forces. Trans- Observed Calculated PORT With Without With Without Number Nr — N, Trans. TrxVns. Trans. Trans. •Cation 1.0 - -0.1 0.03192 0.11430 0.03081 0.11042 .279 0.03195 0.11435 0.03195 0.11435 0.5 - —0.05 ' 0.03501 0.10865 0.03505 0.10870 0.03589 0.11144 .322 0.03503 0.10870 0.1 - —0.01 0.03581 u. 10430 0.03584 0.10435 0.03886 0.11330 .343 0.03585 0.10435 0.05- —0.005 0.03640 0.09950 0.03640 0.09960 0.04152 0.11376 .365 0.03640 0.09960 0.01- —0.001 0.0391 0.0704 0.0391 0.0704 .555 0.0391 0.0704 Methyl Alcohol 0.5 - —0.05 0.03860 0.09390 0.03855 0.09385 .411 0.03857 0.09385 0.1 - -0.01 0.04005 0.07980 0.04002 0.07975 .502 0.04005 0.07980 0.05- —0.005 0.04105 0.07160 0.04103 0.07160 .573 0.04105 0.07165 Ethyl Alcohol 0.5 - —0.05 0.03322 0.08880 0.03322 0.08875 .374 0.03325 0.08875 0.1 - —0.01 0.03559 0.07170 0.03560 0.07170 0.04627 0.0.9310 .497 0.03560 0.07170 0.05- -0.005 0.03820 0.06140 0.03820 0.00145 0.05939 0.09549 .622 0.03820 0.06145 DILUTION OF LITHIUM CHLORIDE 517 The calculated electromotive forces of cells involving* trans- ference are obtained by making the proper substitutions in equa- tion (5) ; for cells without transference similar substitutions are made in equation (6). The molecular conductivities of lithium chloride which have been substituted in these equations are taken from the work of Greene14 for the aqueous solutions. Those for solutions in ethyl alcohol are taken from the work of Jones and Turner.15 No conductivity data for solutions of lithium chloride in methyl alcohol at this temperature are to be found in the literature. This is not essential, however, since the calculated electromotive forces in methyl alcohol would doubtless show results similar to those which have been found for solutions in water and ethyl alcohol. From theoretical considerations (Equation 6) it is evident that the magnitude of the calculated electromotive force for cells without transference is dependent solely upon the ratio of the ionic concentrations as calculated from electrical conductivity. On the other hand, the observed electromotive forces for cells without transference are determined by the ratio of the activity of the solutions, and more particularly the activity of the ions, about the electrodes. For cells with transference the value of the electromotive force measured is dependent not only upon the relative activity of the ions in the two solutions, but also upon the transport numbers of these ions. The electromotive force of cells with transference is useful in this investigation only as a factor for the determination of the transport number (Equation 3). All other calculations are made from the values of the electromotive forces without transference. The transport number of the lithium ion increases with in- , creasing dilution in each of the solvents studied. For a given change in dilution this increase is least in the aqueous solutions and greatest for solutions in ethyl alcohol. The values of the transport numbers determined by this method are the average values between the two concentrations of the electrolyte consti- tuting the cell. It is, therefore, difficult to make a direct com- parison with other published results. Table II gives the values obtained by Kohlraush and Holborn16 for the transport number of the cation of lithium chloride in aqueous solutions at 25°. “Trans. Chem. Soe., 93, (2) 2042, 1908. 15Am, Chem. Jour., 40, 558, 1908. lcLeitvermogen der Electrolyte, p. 201. 518 IOWA ACADEMY OF SCIENCE Vol. XXIV, 1917 The mean values of these have been calculated and are inserted for comparison. TABLE II. Transport Numbers of ttie Lithium Ion in Aqueous Solutions. Normality 1. — 0.1 0.5 — .05 0.1 — .01 .05 — .005 Kohlraush 261 .31 .27 .33 . .31 .37 .33 (.39) 17 Calc, mean .28^ .300 .340 .360 Obs. mean .279 .322 .343 .365 The agreement is as satisfactory as could be expected and confirms the applicability of this method of measuring the trans- port numbers of ions. The transport numbers of the ions in a solution are determined bv the relative mobility of these ions at the dilution in question. The mobility of an ion is in turn a function of its mass, the area and configuration of its surface and the viscosity of the solution. The variation of the transport number with the dilu- tion of the salt in lithium chloride solutions must be caused by a change in one or more of these properties of one or both of the ions. Jones and Getman18 have shown that, starting with a concen- tration of 0.24 N, the molecular lowering of the freezing-point, produced by lithium chloride in aqueous solutions increased both with the concentration and with the dilution. They have also found10 that the molecular elevation of the boiling-point prt^ duced by solutions of lithium chloride in ethyl alcohol is at all concentrations greater than the values calculated on the basis of dissociation. . They attribute these abnormal increases in the freezing-point lowering and boiling-point elevation with increas- ing concentration to “solvation.” The solvation of an ion undoubtedly increases both its mass and surface and probably also affects the viscosity of the solu- tion. If one of the ions of an electrolyte is more highly solvated than the other, dilution will affect the two ions to a different degree. Consequently, such an electrolyte should show a differ- ence in the relative mobility of the ions with varying dilution and therefore a corresponding change in the transport numbers. Conversely, a change in the transport numbers with dilution may be considered to be an indication of solvation. If this 17Extrapolated. 18Zeit. phys. Chem., 46, 261, 1903. 19 Am. Chem. Jour., 32, 338, 1904. DILUTION OF LITHIUM CHLORIDE 519 change in the transport numbers with the concentration of the salt indicates solvation, then it is evident that either the ions or the molecules, or both, are solvated in each- of these solvents. The solvation of the ions or molecules of lithium chloride in these solutions should affect to some extent the activity of the solutions. The activity ratios have been calculated (Equation 4) and are to be found in Table III. „ TABLE III. Activity Ratios and Free Energy of Dilution. Water Ni— N? Activity Ratio Ions Conc. Ratio Ions Activity Ratio Undiss. Conc. Free Energy Ratio of Dilution Undiss. Cals. L. —0.1 9.2-54 7.590 85.61 22.24 2638.0 .5 — .05 8.285 8.236 68.60 21.44 2506.4 .1 — .01 7.617 8.954 58.02 25.92 2407.2 .05— .005 6.942 9.049 48.18 31.43 2297.2 .01— .001 3.936 15.49 1624.4 .5 — .05 6.215 Methyl Alcohol 38.63 2166. .1 — 01 4.725 22.32 1840.8 .05— .005 4.031 16.25 1652.6 .5 — .05 5.626 Ethyl Alcohol 31.625 2047.8 .1 — .01 4.037 6.123 16.298 17.04 1654.4 .05— .005 3.305 6.415 10.923 19.7 . 1417.2 The concentration ratios calculated' from equation (7) have been inserted for comparison. All of these activity and concen- tration ratios are for solutions having a normality ratio of 10 to 1. It will be observed that the activity ratio decreases with increasing dilution in each of these solvents. Comparing similar cells in the different solvents, the activity ratio decreases as the molecular weight of the solvent increases. The activity ratio of the ions is less than the concentration ratio in all cells, ex- cept for the more concentrated aqueous solutions. With a normality ratio of 10 to 1 it would be expected that the activity ratio of the ions should gradually increase to the value of 10 at infinite- dilution. In order to determine whether the activity ratio reaches a minimum value, a cell containing aqueous solutions of higher dilutions (0.01-0.001) was measured. 520 IOWA ACADEMY OF SCIENCE Vol. XXIV, 1917 No minimum is to be observed. It is, therefore, evident that lithium chloride behaves abnormally in each of these solvents. Conductivity measurements indicate that the concentration ratio of the ions approaches the value 10. Electromotive force meas- urements, on the other hand, indicate that the activity ratio of the ions decreases as more dilute cells are measured. Assuming that solvation does exist in these solvents, then, ac- cording to the law of mass action, the amount of solvation per mole of solute will be greatest in the most dilute solutions. However, on account of the greater concentration of the salt, more of the active solvent will be rendered inactive in the higher concentrations. The concentration of the ions and molecules, measured on the basis of active solvent present, will be abnor- mally increased in the concentrated solutions. Tfiie activity of the more concentrated solution in each cell will be relatively in- creased and this increase will become progressively larger as more concentrated cells are used. Hence, the activity ratio should and does increase with increasing concentration. It does not appear that the activity ratio will approach the concentration ratio at any attainable dilutions. In the calcula- tion of the concentration ratio by the conductivity method, the assumption is made that the mobilities of the ions are the same at all concentrations, including infinite dilution. That this as- sumption is sometimes erroneous is shown by the results herein reported. The discrepancy between the activity and concentra- tion ratios and between the observed and calculated electro- motive forces is in all probability due to variations in the mo- bility of the ions. There is, perhaps, another reason for this increase in the activity ratio with increase in the concentration of the salt. Walden20 has found that the dielectric constant of salt solutions generally increases with increase in the concentration of the salt. According to the Nernst-Thompson rule this should mean a rela- tive increase in the ionizing power of the solvent, and hence in the number of the ions present. If this is true, we should ex- pect an increase in the activity of the ions in the more concen- trated solutions. As with solvation, so should this cause the activity ratio to become progressively larger with increasing concentration. 20Jour. Am. Chem. Soc., 35, 1649, 1913. DILUTION OF LITHIUM CHLORIDE 521 The free energy of dilution is by definition proportional to the logarithm of the activity ratio of the ions. Consequently, the free energy of dilution is found to decrease as the concen- tration of the salt is diminished. Comparing similar cells in the different solvents the free energy of dilution decreases as the molecular weight of the solvent increases. This work is being continued in the higher alcohols. SUMMARY. The electromotive force of concentration cells containing so- lutions of lithium chloride in the solvents, — water, methyl al- cohol and ethyl alcohol, have been measured in two combinations, viz., one involving transference of ions, the other without trans- ference. All of the cells measured contained solutions having a noramility ratio of 10 to 1. The electromotive force of cells with transference increases with the dilution, while for cells without transference it is found to decrease with increasing dilution. The transport numbers have been determined and it has been found that for all three solvents the transport number of the lithium ion increases as the concentration of the salt is dimin- ished. The activity ratio of the ions in two solutions having a nor- mality ratio of 10 to 1 decreases as more dilute solutions are used. The activity ratios of the ions have been compared with the concentration ratios calculated from electrical conductivity. The activity ratios are smaller than the concentration ratios in all cases, except in the cells containing the more concentrated aqueous solutions. The effect of solvation and the effect of a possible increase in the dielectric constant with increasing concentration of the salt have been advanced as possible causes for the increase in the activity ratio of the ions. The free energy of dilution decreases with increasing dilution in each of the three solvents studied. The effect of solvent has been studied in connection with the transport numbers of the ions, the activity ratios and the free energy of dilution. For similar concentrations of solute the transport number of the lithium ion is highest in methyl al- 522 IOWA ACADEMY OP SCIENCE Vol. XXIV, 1917 cohol, except in the dilute cell where it is highest in ethyl alcohol. The corresponding values in the aqueous solutions are lower than in either of the other solvents. Comparing the activity ratios and likewise the free energies of dilution for similar cells in the separate solvents, both are found to decrease as the mole- cular weight of the solvent increases. Physical Chemistry Laboratory, The State University of Iowa. THE SOLUBILITY AND HEAT OF SOLUTION OF SUC- CINIC ACID IN WATER. AND THE PARAFFIN ALCOHOLS. H. E. FOWLER AND J. N. PEARCE The following is the report of an investigation undertaken for the purpose of collecting further information concerning the influence of solvent upon certain specific properties of solu- tions. The solvents chosen, including water, represent the lower homologues of the paraffin alcohol series. MATERIALS AND APPARATUS. Ordinary 95 per cent ethyl alcohol which had been standing for several months over quicklime was decanted and distilled. The distillate was then allowed to stand .over anhydrous copper sulphate for several days, then decanted and again distilled. This distillate was. next refluxed over metallic calcium for sev- eral hours and again distilled into glass-stoppered bottles, being protected during the final distillation by a tube of phosphorus pentoxide. The remaining alcohols were of Kahlbaum’s “C. P.” grade. Except for the preliminary treatment with lime, they were sub- jected to exactly the same treatment as was the ethyl alcohol. In every distillation a Glinsky fractionating still-head was used and only the constant-boiling middle fraction1 was collected for use. The boiling points of the fractions taken were. Methyl Alcohol ..... 64°. 5 — 64°. 7 at 750.6 mm. Ethyl Alcohol 77.7 747.2 n— -Propyl Alcohol 96.0— 96.2 743.1 n — Butyl Alcohol 115. —115.2 745.6 iso — Butyl Alcohol 105.9—106. 733.1 ter— Butyl Alcohol 81.2— 81.5 741.7 Succinic Acid. — A high grade of the “C. P.” acid was further purified by the rapid cooling of a; hot saturated aqueous solu- tion. The fine white crystals were filtered on a Hirsch funnel, sucked dry, then allowed to dry on a porous plate and finally allowed to stand over phosphorus pentoxide in a desiccator for at least three weeks before being used. 524 IOWA ACADEMY OF SCIENCE Vol. XXIV, 1917 Benzoic Acid. — Kahlbaum’s “C. P.” acid was first fractionally resublimed, then fused and preserved in a desiccator until it was needed. Sodium Hydroxide Solutions. — The solubility was determined by titrating weighed portions of the saturated solutions with a standard solution of sodium hydroxide, using phenolphthalein as indicator. For this purpose two aqueous solutions of sodium hydroxide were prepared, approximately .5N and .ION, re- spectively. A slight excess of solid barium hydroxide was added to each to remove any carbonates present. After being allowed to stand for some time they were quickly filtered into ceresin- coated stock-bottles.. Each of these stock-bottles was connected with the upper end of a certified burette by means of a ceresin- coated glass tube, thus forming a single piece of apparatus. The burettes.' were filled by suction. Entrance of carbon dioxide into the apparatus was prevented by trains of test-tubes con- taining the respective standard solutions. The alkaline solutions were standardized (Morey’s Method1) by titrating against weighed portions of benzoic acid, care being taken to insure complete neutrality of the alcohol used. Here as elsewhere in the work only hot redistilled water was used. The saturation apparatus consisted of a large glass test-tube (22x150 mm.) provided with a tight-fitting, one-hole rubber stopper. Into this hole was pressed a metal sleeve through which passed the axle of the stirrer and to which was attached a stout spiral of heavy platinum wire. The only possible open- ing into the test-tube was kept effectually sealed by the flange of the axle which rotated upon the metal sleeve. The stirrer was driven at the rate of 1,200 to 1,600 revolutions per minute by means of a small electric motor. The saturation apparatus thus arranged was; immersed in the constant temperature bath which was electrically heated and electrically controlled at the desired temperature to within ±0.02°. While preliminary experiments showed that saturation is com- plete in two hours, the time allowed for saturation was rarely less than four hours. After saturation the stirrer was stopped, the crystals allowed to settle and several portions of the clear saturated solution were withdrawn by means of certified 5 cc. pipettes. To prevent the entrance of fine crystals into the ^Bureau of Standards, Scientific Paper, No. 183, 1912. SOLUTION OF SUCCINIC ACID IN WATER 525 pipettes the tips were protected by small muslin filters. These portions were transferred to tarred glass-stoppered weighing bottles and the weight of the solution was determined. The samples were then transferred to small Erlenmeyer flasks, boiled water added and then titrated to a faint pink color by means of the standard alkali. In every case the final titration was made with the dilute sodium hydroxide. From the data thus obtained were calculated the solubilities. The heats of solution of succinic acid in the solvents used have been calculated by means of the well-known van’t Hoff isoehore, InCg - InCi Q T2— Ti ~ RT2- Ti where R is the gas constant (1.985 cals.). C2 and Cx are the sol- ubilities at the absolute temperatures T2 and Tly respectively, and Q is the molar heat of solution produced by dissolving one gram-mole of the acid in one hundred grams of the solvent. By a mathematical rearrangement, 2.3026X1.985XT,XTI C, Q = y y logic. Q cals- Succinic acid is but slightly dissociated in water and practic- ally not at all in the alcohols. This relation will give, therefore, a close approximation to the heats of solution of the acid in the solvents under consideration.. The results obtained are given in the accompanying table. Each solubility value given is the mean of three or four separate values which do not differ by more than a few hundredths of a gram per one hundred grams of solvent. TABLE I. Solubility of Succinic Acid. Solvent In Grams Per 100 Grams of Solvent In Moles Per 100 Moles of Solvent Molar Heat of Solution 25° 30° 35° to Oi o 30° 35° Qi Q 2 Water - _ 8,368 10.295 12.821 1.277 1.571 1.956 7442.5 8142.6 Methyl Alcohol 20.460 23.076 26.260 5.552 6.262 7.125 4320.4 4796.9 Ethyl Alcohol 9.996 11.492 .’3.185 3.899 4.483 5.143 5230.7 5101.0 "—Propyl 4.806 5.665 6.664 2.445 2.882 3.391 5905,4 6027.4 " — Butyl 3.179 3.817- 4.464 1.995 2.395 2.801 6572.7 5804.4 tert — Butyl 8.504 9.687 10.949 5.336 6.079 6.871 4680.0 4542.1 Iso — Butyl 2.532 3.062 3.646 1.589 1.921 2.288 6825.7 6478.7 Iso — A.myl 2.146 2.570 3.133 1.601 1.918 2.338 6474.3 7352.0 526 IOWA ACADEMY OF SCIENCE Vol. XXIV, 1917 Qi and Qo represent the molar heats of solution calculated for the intervals (25°-30°) and (30°-35°), respectively. SUMMARY. As might be expected, the solubility of succinic acid-increases with rise in temperature in all of the solvents studied. Consid- ering the alcohols alone, the solubility at all temperatures is greatest in the methyl alcohol and decreases rapidly with the in- crease in the molecular weight of the alcohol. Methyl, ethyl, 71- propyl and n-butyl alcohols have the simple molecular chain structure. n-Butyl (CLI3CH2CH2CH2OH) , iso-butyl ((CH3)» CHCHoOH) and tert-butyl) ((CH3)3COH) are isomeric com- pounds whose molecular structures differ simply in the grouping of the atoms within the molecules. The effect of these structural differences upon the solubility of succinic acid is to be seen from the table, the solubility being greatest in the tertiary-butyl and least in the iso-butyl alcohol. The effect of solvent upon the heat of solution is apparently just the reverse of that upon the solubility. For the normal alcohols the heat of solution increases as the molecular weight of the alcohol increases. Likewise, for the isomeric butyl alcohols the heat of solution is greatest in the iso-butyl and least in the tertiary-butvl alcohol. For the temperature intervals studied the heat of solution shows a decided increase with rise in temperature for solutions in water, methyl alcohol and iso-amyl alcohol. The reverse is equally true for solutions in iso-butvl alcohol. For the other alcohols the heat of solution may be considered as practically independent of the temperature. Obviously, the heat of solution of a given substance is a specific property of the solvent. These deductions are based entirely upon the assumption of the validity of the van’t, IToff isochore when applied to solubility methods. Hints as to interesting relations between the solubility of the solute and the surface tension, compressibility and the association of the solvent have been observed. Before any generalizations can be made regarding these relations the work will have to be extended to higher alcohols and these we do not have. Physical Chemistry Laboratory, The State University of Iowa. THE PROTEIN CONTENT AND MICROCHEMICAL TESTS OF THE SEEDS OF SOME COMMON IOWA WEEDS. L. H. PAMMEL AND ARTHUR W. DOX. Weed seeds are recognized as an important factor in the dietary of our useful birds. Other things being equal, those seeds haying the highest nutritive value might be expected to figure more prominently in this regard than seeds less nutritious. In animal feeding, the protein content of the feed is taken as the measure of its nutritive value, and the cost of the feed is de- termined largely by the protein content as ascertained in the chemical laboratory. Hence the protein content of weed- seeds is of some economical importance as related both to the maintenance of our native birds and to the control of the weeds themselves. The list of species, the analyses of the seeds of which are here reported, comprise but a small part of the weed flora of the state. It is hoped, however, that the writers may have oppor- tunity to extend the list during the coming season. The seed samples were collected in the vicinity of the Iowa State College during the late summer and early fall of 1916. All chaff, hulls, appendages, etc., were removed by rubbing in a cloth, screening, and winnowing, until the seeds were practically clean. The samples thus obtained were spread out on watch glasses in a dust-proof cupboard for several weeks until they Avere air-dry. The determinations here recorded are all on the air-dry basis. As a matter of additional interest the weight of fifty seeds was determined in each case, and from this value the approximate number of seeds per gram was computed. Nitrogen was de- termined by the well known Kjeldahl-Gunning method and the value thus obtained was multiplied by the factor 6.25 to convert it into protein. For the purpose of ascertaining the microscopic characters of the weed seed investigation made chemically by Doctor Dox, a micro-chemical test also was made to determine the presence of starch, protein and fat. Microscopic tests have been made of the seeds of a great many weeds. A brief reference to some of the papers will not be amiss in this connection. One of us made a study of the anatomical characters of the seeds of Leguminosse, 528 IOWA ACADEMY OF SCIENCE Vol. XXIV, 1917 * chiefly genera of Gray’s Manual1, on the seed coats of the genus Euphorbia2, on the seeds and testa of some Cruciferae3, on the structure of the testa of several leguminous seeds,4 on some meth- ods in the study of mature seeds;5' on the seed coats of C rot alarm sagittal is and Astragalus mollissimiis6, on the histology of the caryopsis and endosperm of some grasses7, and on the char- acters of weed seeds8. P. II. Rolfs has reported on the seed coats of Malvaceae9, and the seeds of Berberidaceae have been studied by Pammel, Burn ip and Thomas.10 Winton and Moel- ler11 dircussed the microscopy of vegetable foods. Hanausek, Winton and Barber12 have a similar discussion in The Micro- scopy of Technical Products ; A. J. Pieters and V. K. Charles13 have reported on the seed coats of certain species of the genus Brassica. while Winton14 has discussed the anatomy of weed seeds. Emma Sirrine15 has worked on the structure of the seed coats of Polygonacese. Kramer’s Pharmacognosy10 is another textbook covering this subject. Three of the most important European treatises on the sub- ject are TIarz, Landwirtschaftliche Samenkunde ; Tschirch, A., and Oesterle,. Anatomischer Atlas der Pharmakognosie und Nahrungsmittel ; Wiesner, Die Rohstoffe des Pflanzenreiches. m. H. Pammel, Trans. Acad. Sci. St. Louis, 9, 90-273, pi. 7 -35. This paper gives an extensive literature. 2Trans. Acad. Sci. St. Louis, 5, 543-568, pi. 12-Uf. 3Am. Mo. Mic. Jour.. 18, 205., 269, 312, 2 pi., 2 figs.. Bull. Ia. Agrl. Exp. Sta, 4Bull. Torrey Lot. Club. 13, 17-24, pi. 52-53. 5Jour. Appl. Micro., /, 37-39, 6 figs. cThe Biennial Rep. Ia. State College and Farm, 13. 47-48. 7Trans. Acad. Sci., St. Louis, 8, 199-220, pi. 17-19. See also Bull. Iowa Geol. Survey, 1, 525. sCharlotte M. King and L. H. Pammel, Weed Flora of Iowa, Bull. la. Geol. Survey, 4, 505-587, figs. 383-442. This paper contains a bibliography. 9Bot. Gazette, 17, 33-39, pi. 3. 10Froc. Ia. Acad. Sci., 5, 209-223, pi. 12-16. nEnglish translation of Josef Moeller, Mikroskopie der Nahrugs u. Genuss- mittel aus dem Pflanzenreiche. 12John Wiley and Sons, New York, 1907. 13Bull. U. S. Dept. Agrl. (Bur. PI. Ind.), 29, 19. 14Rep. Conn. Agrl. Exp. Sta., 1902, 345-358. 15Proc. Ia. Acad. Sci., 2, 128-134, pi. 7-9. 16A text book of botany and Pharmacognosy, Lippincott, 190'7. TESTS OF IOWA WEED SEEDS 529 PROTEIN CONTENT CHEMICALLY CONSIDERED. The samples thus far examined are given below in the order of their protein content. Common Name Botanical Name Wt. of 50 No. seeds per gm. Per cent nitrogen Per cent protein j Sweet clover Melilotus alba .0882 567 5.61 35.05 Red clover . _ _ ___ Trifolium pratense — Yellow seed .0877 570 5.48 34.23 Purple seed .0834 600 5.37 33.54 Yellow sweet clover Melilotus officinalis .0832 601 5.35 33.44 Alsike clover Trifolium hybridum .0335 1490 5.24 32.72 Milkweed Asclepias syriaca .3214 156 5.00 31.25 White clover _ _ _ __ Trifolium repens .0270 1850 4.97 31.03 Greater ragweed Ambrosia trifida .8045 622 4.94 30.89 Rudbeckia hirta _ _ __ _ .0085 5880 4.92 30.73 Wild lettuce - jLactuca canadensis .0305 1640 2.72 29.45 Swamp milkweed Asclepias incarinata .0903 5540 4.69 29.33 Dandelion Taraxacum officinale .0160 3120 4.64 28.98 Dandelion _ erytbrospermum .0138 3620 Horse mint Monarda punctata .0241 2070 4.52 28.28 Vetch - Vicia fab a : 1.2174 41 4.46 27.87 Pepper grass __ Lepidium virginicum .0112 4460 4.27 26.70 'Pumbling mustard Sisymbrium altissimum .0077 6490 4.01 25.03 Sand bur _ Cenchrus tribuloides - .3619 138 3.86 24.14 Three -seeded' mercury Acalypha virgirmca .0366 1370 3.85 24.07 Wild mustard Brassica arvensis .0905 552 3.80 23.72 Small ragweed _ Ambrosia artemisiaefolia_ .2495 200 3.75 23.46 Five-finger Potentilla arguta .0065 7690 3.73 23.29 Wild four o'clock Oxybaphus nyctagineus .1262 396 3.64 22.77 Mallow Malva rotundifolia .0656 762 3.61 22.57 Homo Cannabis sativa .4524 111 3.59 22.47 P'rickly lettuc° Lactuca scariola _ _ _ .0222 2250 3.49 21.80 Velvet leaf • Abutilon theophrasti .5002 100 3.35 20.93 Sticktight Bidens frondosa .1740 287 3.25^ 20.30 Wild morning glory __ Convolvulus sepium 1.4340 35 3.23 20.20 Doorvard plantain Plantago major .0107 4670 3.05 19.09 Burdock Arctium lappa .3270 153 3.05 19.06 Heal-all Prunella vulgaris .0334 1500 3.03 18.91 Catnip Nepeta cataria .0289- 1850 3.00 18.75 Timothy Phleum pratense .0190 2630 2.89 18.04 Mullein Verbascmn thapsus .0034 14700 2.86 17.86 Spurge ______ Euphorbia Preslii . 0266 1880 2.85 17.81 Green cone flower _ ___ Lepaehys pinnata .0343 1460 2.80 17^52 Evening primrose Oenothera biennis .0147 3400 2.72 16.99 Yellow foxtail Setaria glauca _ .0549 811 2.65 16.92 Simpson honey plant Serophularia marila'ndica. .0055 9090 2.55 15.’ 93 Soap wort Saponaria officinalis .0836 598 2.55 15.92 Redroot _ Am a r a nth us ret r o f lexu s— .0166 3010 2.49 15.59 Bull thistle Cirsium lanceolatum .0923 5420 2.48 15.48 Pigweed Amaranthus graecizans __ .0176 2840 2.32 14.52 Wild parsnip Pastinaca sativa _ _ ___ .1080 463 2.30 14.36 Cinquefoil Potentilla inonspeliensis___ .0048 10400 2.27 14.15 Knot grass _ _ _ __ Polygonum aviculare .0423 1180 2.21 13.85 Yellow dock Rumex crisnus . 0678 737 2.14 13.14 False groin w7ell Lithospermum latifoliumJ .6S95 . 73 1.93 12.04 ITostrate pigweed Amaranthus blitoides .0441 1130 1.88 11.75 White vervain Verbena urticaefolia .0176 2840 1.78 11.12 Germander Teuerium canadense .0544 919 1.76 11.03 Hoary verain _ _ _ . Verbena stricta .0331 1510 1.63 10.16 Wild buckwheat __ Polygonum convolvulus __ '.2080 240 1.59 9.94 Erect knot weed. Polygonum erectum .0580 862 1.49 9.28 Lady’s thumb _ Polygonum Persicaria .0537 931 1.05 6.56 Smartweed Polygonum Pennsylvani- Horse gentian _ cum .1561 320 .91 5.69 Triosteum perfoliatum 2.3260 21 .88 5.51 Prairie rose Rosa pratincola .4825 104 .68 4.25 Sumach Rhus glabra _____ .2199 277 .52 3.24 34 530 IOWA ACADEMY OF SCIENCE Vol. XXIV, 1917 As might be expected, the legumes stand at the head of the list. The oil-bearing seeds, also, contain considerable amounts of protein. On the other hand, those that contain notable quantities of starch, as the Polygonaceac, are much lower in protein. Those at- the end of the list represent seeds with a thick woody coat .sufficient in amount to reduce greatly the protein percentage. On the whole, there is rather a close agreement in composition between related species of the same genus. The list, however, is as yet too incomplete to warrant discussion in greater detail. In the paper on the anatomy of the Leguminosae attention is called to the presence of fat when the carbohydrates are wanting. In such cases fat is present usually in greater amounts than where the starch occurs. The reserve food not only varies in the tribes but in related genera. In the Yiciese and Phaseolese the reserve food consists largely of carbohydrates in the form of starch and proteins, the latter in the form of aleurone grains. In the Caesalpinieac e. g., honey locust, the reserve food occurs in the form of proteins and fat. In the soy bean (Soja hispida) it occurs largely as fat and proteins, in clover as starch, protein and fat. The microchemical tests recorded in this paper consisted of the usual test for starch, namely, iodine in potassium iodide, iodine for protein, Sudan III for fat, ferric chloride for tannin. Many of the testa or pericarps have some tannin. Tannin was not, however, found in the endosperm of many seeds and for this reason the test is omitted from the table. The pericarps of many seeds, as well as the testa, contain some tannic acid, although the amount with some exceptions is very small. Most of the tests given in the table were made by us. Where the tests were made by others, they have been starred. Most of the starred tests were taken from Harz, Winton and Moeller. MICHROCHEMICAL TESTS FOR STARCH, PROTEIN AND FAT. Name Starch Protein Fat Graminese Agropyron repens _ abundant some little Aristida ramosissima - compound grain abundant some little Bromus ciliatus var. purgans simple abundant some little *Bromus secalinus simple grains some little Digitaria humifusa _ abundant small polygonal simple some little TESTS OF IOWA WEED SEEDS 531 MICROCHEMICAL TESTS FOR STARCH, PROTEIN AND FAT— Continued Name Starch Protein Fat Oenchrus tribuloides large and small some little abundant Echinochloa crus-galli abundant small polygonal simple some little Elymus canadensis simple abundant some little Hordeum jubatum simple abundant some little *Lolium temulentum small simple some little Setaria glauea __ abundant small polygonal simple some little Setaria viridis abundant small polygonal simple some little Setaria Italica abundant small polygonal simple some little Urticaceae Cannabis sativa none abundant abundant tjrtica gracilis - none abundant abundant Amaranthacese Amaranthus blitoides very small grain abundant some little Amaranthus graecizans very small grain abundant some little Amaranthus retroflexus . very small grain abundant some little Poiygonaceee Polygonum aviculare __ small starch grain abundant small little Polygonum convolvulus- grains variable in size small little Polygonum erectum _ _ _ - grains abundant small little Polygonum Persicaria __ _ — - apparently simple abundant small little Polygonum Pennsylvanieum compound and , abundant small little Rumex acetosella ___ __ - abundant simple some little Rum ex crisDus __ __ abundant simple some little ' Nyctaginacese Oxybaphus nyctagineus __ __ abundant simple abundant some -OaT-yophyllacese Saponaria officinalis compound abundant some little Silene antirhina _ _ - _ small some little Silene virginica _ _ small some little Agrostemma githago small some little Ranunculaeeee * Ranunculus arvensis _ none abundant some ^Ranunculus abortivus _ _ _ _ none abundant some Berberidacese Berberis vulgaris none abundant j some Chenopodiacese Salsola Kali var. tenuifolia _ _ none abundant j some Chenopodium album abundant small some little Cruciferse Brassica arvensis _ ___ _ none abundant abundant Brassica nigra _ _ none abundant | abundant Barbarea vulgaris __ _ none abundant abundant Camelina sativa __ _ none abundant abundant Capsella Bursa-pastoris none abundant abundant Lepidium apetalum none abundant abundant Lepidium virginicum __ _ __ none abundant abundant Sisymbrium officinale ___ __ ■ _ none abundant abundant Sisvmbrium altissimun none abundant abundant Oomnositse Ambrosia artemisiifolia. none abundant abundant Ambrosia trifida ___ none abundant some Arctium major none abundant some *Centaura Oyanus ___ _ . none abundant some Cirsium lanceolatum __ none some little Lactuca canadensis __ none some little Lactuca scariola 1 none some little Rudbeckia hirta _ none some little Taraxacum officinale none some little Scrophulariacese Scrophularia marilandica none abundant some Yerbascum Thapsus none . abundant some 532 IOWA ACADEMY OF SCIENCE Vol. XXIV, 1917 MICROCHEMICAL TESTS FOR STARCH, PROTEIN AND FAT— Continued Name Starch Protein Fat Plantaginacese PI ant ago major very few abundant some Caprifoliaceae Triosteum perfoliatum none abundant some Labiatse Nepeta cataria none abundant some Monarda fistulosa none abundant some Prunella vulgaris ___ __ none abundant some Teucrium canadense. _ _ _ . none abundant some Solanacese Datura Stramonium _ _ none abundant some Physalis pubeseens __ __. none abundant some Solanum carolinense none abundant some Oonvolvulacese Convolvulus sepium . __ __ none abundant some Cuscuta Epithymum _ __ ___ small grains some little Boraginacese C'vnoglossum virginianum ! none some little Lithospermum latifolium _ j abundant compound some little *Melampyrum arvense none some some Verbenacese Verbena stricta ___ _____ none abundant some Verbena urticaefolia none abundant some Onagraceae Oenothera biennis _ _ none abundant some Umbelliferse Daucus earota ______ none abundant some Heracleum lanatum none abundant some P'astinaca sativa _ none abundant some Ericaceae Waceinium Mvrtillus none abundant some Asclepidaceae Asclepias incarnata none abundant abundant Asclepias syriaca _ _ none abundant abundant Linaceae abundant Linum usitatissimum _ none some Malvaceae Abuliton Theophrasti none 1 abundant some Gossvpium herbaceum none abundant some Malva rotundifolia none abundant some Sida spinosa none abundant some Hibiscus Trionum none abundant some Leguminoseae Amorpha canescens small grains some some Amphicarpa monoica _ _. none abundant some Astragalus canadensis _ none abundant some Cassia Chamaecrista _ __ none abundant some C'rotalaria sagittalis _ _ __ none abundant some Dalea alopecuroidss____ _ . . none abundant some Desmodium canescens __ none abundant some Gleditsia triacanthos _ none abundant some Glycyrrhiza lepidota none abundant some Lathyrus venosus _ some large grains some little Lespedeza capitata _ _ __ none abundant some Medicago lupulina none abundant some Melilotus alba __ ___ small grains some little Melilotus officinalis __ __ small grains some little Trifolium pratense small grains some little Trifolium repens__ _ ___ _ __ small grains some little Vicia sativa abundant little Euphorbiacese Acalypha virginica ___ none abundant abundant Euphorbia corollata __ __ _ none abundant abundant Euphorbia maculata ___ _ _ _ _ none abundant abundant Euphorbia preslii _ none abundant \ abundant Rosacese Potentilla arguta __ _ present abundant some Potentilla monspeliensis __ present abundant some Grossulariaceae Ribes rubrum _ _ norje abundant some Iowa Agricultural Experiment Station, State College. SYNTHESIS OF A NAPHTHOTETRAZINE FROM DIE- THYL SUC CINYLO SUCCINATE AND DICYANDIAMIDE . ARTHUR W. DOX. On account of the ease with which dicyandiamide can he pre- pared in quantity and at very small cost from the crude calcium cyanamide of commerce, this substance is beginning to find numer- ous applications in organic syntheses. Among other properties, the amidine structure of dicyandiamide has been taken advan- tage of for the preparation of certain nitrogen heterocycles. For example, by condensation with such substances as a-ketone acid esters, various pyrimidine derivatives are obtained. Thus, dicy- andiamide condenses with amlonic ester derivatives1 and with acetoacetic2 ester to form substituted pyrimidines. It is not im- probable that dicyandiamide is capable of entering into the same condensation reactions and yielding cyanamino derivatives or ihe various heterocycles now prepared from guanidine. The readiness with which dicyandiamide yields pyrimidine derivatives suggested to the writer the possibility of preparing til, 8, 6, 8 — naphthotetrazine, or symmetrical benzodipyrimidine, by condensation with succinylosucciuic ester. Other amiclines have been condensed with succinylosuccinic ester, forming sub- stituted naphthotetrazines. Thus, benzamidine3 yielded 2, 7 — diphenyl — 4, 9 — diketotetrahydro — 1, 3, 6, 8 — naphthotetrazine, guanidine4 the corresponding 2-7 — diamino, and acetamidine5 the corresponding 2-7 — dimethyl derivatives. Other derivatives of this heterocycle have been prepared by Bogert and Nelson6 from p — diaminoterephthalic acid and its derivatives. They all appear to be characterized by insolubility, infusibility and general in- ertness. German Patent 165, 223, 1905. 2Soll & Stutzer, Ber. 42, 4534, 1910. 3Pinner, E'er. 22, 2609, 1889. 4Bogert and Dox. J. Amer. Chem. Soe., 27, 1127, 1905. 5Bogert & Dox, ibid., 27, 1136, 1905. 6Bogert & Nelson, ibid., 29, 729. 1907. 534 IOWA ACADEMY OF SCIENCE Vol. XXIV, 1917 EXPERIMENTAL. Dicyandiamide was prepared by the method of Soil & Stutzer7 from commercial calcium cyanamide supplied by the American Cyanamide Co., of Niagara Falls, Ontario. The product was ob- tained in large white crystals, melting at 209° (corr.). Succiny- losuccinic ester, prepared in the usual way from diethyl suc- cinate and sodium, was suspended in ten times its weight of water and an ecpial volume of 5 per cent sodium hydroxide so- lution was added. After the ester had dissolved to a bright yellow solution, dicyandiamide, equivalent in amount to two molecules for every molecule of succinylosuccinic ester, was added in the solid form, and the mixture was gradually warmed on an electric stove. As the temperature rose, the dicyandiamide went into solution and at about 50° a pale yellow granular precipi- tate began to form. Heating was continued until the mixture just began to boil. After cooling, the precipitate was filtered with suction, washed with water, dilute hydrochloric acid, alco- hol and finally ether, and dried in the oven at 100°. The yield was 37 per cent of the theory. In a second and third prepara- tion, equal weights of dicyandiamide and succinylosuccinic ester were used, and the yields on the basis of the latter substances were 72 per cent and 61 per cent respectively. The mother liquor was bright red, the color evidently being due to an oxidation process, since the red appeared first at the surface of the solution in contact with the air. This color turned yellow on acidifying and then back to the- original red on the addition of alkali. Like the other n a phthotetr azine derivatives described, this con- densation product is characterized by its insolubility in the neutral solvents and by its infusibility. At about 320° it dark- ens in color without melting. Analysis of the product gave the following results : The condensation consists in the elimination of two molecules of water and two of alcohol, between one of succinylosuccinic N C H Found 37.2 48.5 2.7 Calc, for Ck Hs Ns O, 37.8 48.6 3.0 7Soll & Stutzer, loc. cit. SYNTHESIS OF A NAPHTHOTETRAZINE 535 ester and two of dicyandiamide, yielding a substance of the fol- lowing structural formula : N II NCHN-C 0 H H /C\h/v"\. NHCN I I II nm^\c^S\cxm H H o Figure 100 The product is therefore 2, 7 — dicyanamino — 4, 9 — diketotetra- hydro — 1, 3, 6, 8 — naphthotetrazine. Chemistry Section, State College. THE BEHAVIOR OF BENZIDINE TOWARD SELENIC AND TELLURIC ACIDS. ARTHUR W. DOX. Within quite recent years benzidine ( p-diaminodiphenyt ) has come into use as a precipitant for the sulfate ion. It was first applied as a quantitative reagent for the determination of sul- fate by Rasehig1 in 1903. Other investigators subsequently in- troduced modifications in the original method of Rasehig and succeeded in obtaining very satisfactory analyses with this re- agent. For example, in the analysis of water samples which con- tain iron salts, hydroxylamine hydrochloride is added to prevent oxidation of the benzidine. The precipitated benzidine sulfate is collected in the usual way and is either weighed direct or titrated with sodium hydroxide, using phenolphthalein as an indicator. Titration is rendered possible by the very weak basic properties of benzidine. Bruckmiller2 states that the benzidine method for sulfates in water compares favorably with the time- honored barium chloride method in point of accuracy, and has the advantage of being more rapid. The writer undertook to determine whether the corresponding acids of selenium and tellurium, two elements closely analogous to sulfur and occurring in the same group of the periodic sys- tem, would react in the same manner, with benzidine. The benzidine reagent was prepared as follows : Two grams of Merck ’s benzidine were stirred to a paste with a little water, washed into a 250 cc. volumetric flask, 2.5 cc. concentrated hydro- chloric acid added, and the solution made up to the mark. A slight sediment was removed by filtration. Qualitative tests were first made with this reagent. When added to a solution of sodium sulfate, as was expected, a white granular crystalline precipitate began to form instantly. With a solution of Kahlbaum’s sodium selena’te the same phenomenon was observed, except that the precipitate was more granular and settled out more readily. However, a solution of Kahlbaum’s sodium tellurate gave no precipitate whatever with the benzi- dine reagent. 1Raschig, Z. angew. Chem., 1908, 617, 81S. 2BruckmilIer, J. Ind. Eng. Chem., 7, 600, 1915. 538 IOIWA ACADEMY OF SCIENCE Vol. XXIV, 191' The two precipitates above mentioned were then prepared in larger quantities, and after careful washing and drying were further identified by analyses for nitrogen. Substance Nitrogen Found Calculated Benzidine sulfate 9.61 9.93 9.53 Benzidine selenate 8.40 8.51 8.34 In order to determine how nearly quantitative was the precipi- tation of selenic acid, a stock solution of the sodium selenate was prepared by dissolving one gram of the crystalline substance in 100 cc. water. Portions of 10 cc. each of this solution were used for the determinations given below, which were carried out in the usual way, using both the benzidine and the barium chloride methods. Parallel determinations were made with a similar so- lution of sodium sulfate. Sodium Sulfate Benzidine BaSO, SO, Sulfate so4 Found Calc. Found Calc. .1289 .0531 .1552 .0528 .1288 .0531 .1548 .0527 Sodium Selenate. Benzidine BaSe04 SeOj Selenate SeO, Found Calc. Found Calc. .0749 .0383 .0829 .0360 .0749 .0383 .0832 .0362 .0821 .0357 .0819 .0356 From the above data it will be seen that sulfate determined as benzidine sulfate agrees fairly well with that determined as barium sulfate, as has been claimed by other investigators. How- ever benzidine selenate, prepared here for the first time, is not precipitated as completely as the barium selenate. The average > of the four determinations shows that under the conditions of the experiment about 94 per cent of the selenate is precipitated by benzidine, assuming that the precipitation of barium selenate is quantitative. In the presence of dilute hydrochloric acid, tellurates give no precipitate with benzidine. Chemistry Section, State College. AMINO ACIDS AND MICRO-ORGANISMS. ARTHUR W. DOX. The study of amino acids has come to be recognized during re- cent years as a subject of tremendous importance, on account of its fundamental relation to the problems of human and animal nutrition. Not many years, since, all proteins were thought to be of equal nutritive value. Now we know that many of the proteins are deficient in one or more amino acids, and cannot support life and growth unless supplemented by other proteins which make up the deficiency. And from a study of the pro- teins with reference to their amino acid make-up, the study of the amino acids themselves began to occupy the attention of chemists. Thus after the chemist had taken the protein molecule apart and identified the various amino acids of which it was composed, he undertook to synthesize these amino acids from simple substances, to separate the synthetic products into their optically active components, prepare numerous derivatives, and finally to study their behavior toward biological processes of both animal and vegetable nature. The fact that amino acids play an important part in the phe- nomenon of alcoholic fermentation was not known in the time of Pasteur. It may safely be said, however, that Pasteur’s ob- servations regarding the constant occurrence of certain sub- stances in small amounts as by-products of fermentation was the incentive which prompted further research in this important field by subsequent investigators. The disintegration products of amino acids through the in- fluence of micro-organisms have an important relation to animal nutrition. Micro-organisms may produce profound changes in the protein constituents of food, either before or after ingestion. These changes have been variously termed ripening, fermenta- tion and putrefaction, according to their nature and extent. The ripening of cheese consists largely in the disintegration of the protein and of amino acids comprising it, and even here no sharp line of distinction can be drawn between ripening proper and putrefaction, the difference being mainly a matter of the olfac- tory and gustatory education of the individual. Fermentation 540 IOWA ACADEMY OF SCIENCE Vol. XXIV, 1917 is a term applied mainly to processes involving the formation of alcohol, though it has lately come to be used in a much broader sense. Putrefaction may be defined as that process of disinte- gration which results in the formation of poisonous products, as the so-called ptomaines, and products with offensive odors, such as the organic sulphur compounds and the indol derivatives. In general, fermentation is usually ascribed to yeast and putre- faction to anaerobic bacteria. In fermentation the part played by amino acids is more or less incidental, the main reaction hav- ing to do with the breaking down of carbohydrate. Putrefac- tion on the other hand, has to do directly with amino acids, and the disintegration of the latter may be retarded or even prevented by the presence of carbohydrate. Ackerman has proposed the term aporrhegmata to designate all those fragments of amino acids which can be formed from the latter by the vital functions of animals and plants. Many of these products have been determined in an experimental way, by adding an amino acid of known purity to a culture medium, inoculating with the desired organism, and after a sufficient time of incubation identifying the products. Prom such experiments a large number of data have already been secured, but as yet no attempt has been made to assemble and correlate them, with a view to determining the fundamental nature of the process. The following table was constructed by the writer after a careful search of the literature. It is based mainly upon the work of Ehrlich, Effront, Drechsel, Neuberg, Pringsheim and Ackermann. AMINO ACIDS AND MICRO-ORGANISMS 541 Amino Acid Decomposition Products Yeasts Bacteria glycine <3 — alanine d. — valine 1 — leucine d — isoieucine 1 — tyrosine 1 — phenylalanine 1 — cystine 1 — serine 1 — aspartic acid d — glutamic acid d — arginine 1 — histidine lysine 1— proline 1 — tryptophan phenylglycine isovaline methyl alcohol, acetic acid acetaldehyde, alcohol isobutyl alcohol isoamyl alcohol d — :amyl alcohol p — oxyphenylethyl alcohol (tyrosol) Phenylethyl alcohol ethylene glycol succinic acid succinic acid tetramethylene diamine, guanidine imidazolylethyl alcohol indolethylalcohol tryptophol benzylalcohol butvl alcohol acetic acid, CO., valeric acid, isobutylamine isoamylamine caproic acid, valeric acid d — caproic acid p — oxyphenylethylamine (tyramine) p — oxyphenylpropionic acid p — oxyphenylacetic acid p — cresol, phenol hydrocinnamic acid phenylacetic acid (C2Hr)2S, QH..SH, H2S propionic acid 3 — alanine succinic, propionic, formic acids y — amino butyric acid butyric, formic acids ornithine 8 — amino valeric acid tetramethylene diamine 3 — imidazolylethylamine I midazolpropionic acid pentamethylene diamine amino valeric n — valeric acid indolpropionic, indolacetic skatol, indol indol-ethylamine The products formed by yeasts and by bacteria are considered separately for purposes of comparison. Some gaps will be noted in the table, but the data are on the whole sufficiently com- plete to give an idea of the dominant reactions. Some anoma- lies will be found, but considering the fact that the data were secured by different investigators working with different or- ganisms and under varying conditions, the uniformity is really surprising. YEASTS. First let us consider the products formed by yeasts. Out of the fourteen amino acids on which data are available, eleven give rise to an alcohol with one less atom of carbon. The reac- tion probably proceeds in three stages, as follows: (1) hydrol- ysis of the amino acid into' ammonia and the corresponding hydroxy-acid, (2) cleavage of the hydroxv-acicl into the next lower aldehyde and formic acid, (3) reduction of the aldehyde to the corresponding alcohol. The fact that traces of the alde- hyde-and formic acid have in some cases been demonstrated as 542 IOiWA ACADEMY OF SCIENCE Vol. XXIV, 1917 transitional products serves to corroborate the above assumption. Taking alanine as a simple illustration, the reaction may be written as follows : ch3 ch .nh2 .cooh— >ch3 choh .cooh — > ch3cho — >CH3CH2OH alanine lactic acid acetaldehyde ethyl alcohol The aliphatic alcohols, isobutyl, d-amyl, and especially isoamyl, are constituents of the well known fusel oil of the distillery. Crude spirit contains an average of 0.4 per cent fusel oil, and never exceeds a maximum of 0.6 per cent. Yet in laboratory experiments it is possible to increase the yield of fusel oil up to 7.0 per cent by the simple addition of leucine to the fer- menting sugar. Fusel oil is, however, invariably produced in small amount when the fermenting medium contains no amino acids whatever. This is explained by the fact that some of the yeast itself undergoes autolysis, whereby the amino acids con- tained in the yeast protein are set free and then fermented into the higher alcohols. The relative amounts of isobutyl, cl-amyl and isoamyl alcohols of the fusel oil correspond very closely with those of the valine, isoleucine and leucine of the protein from which they are derived. The nitrogen liberated as am- monia during this reaction is then utilized for the growth of new yeast cells. This then explains the fact that the greatest yields of fusel oil are obtained when the fermenting medium is deficient in nitrogenous substances other than proteins or amino acids. In the case of the two dibasic acids, aspartic and glutamic, the reaction is somewhat different. I11 both cases the only prod- uct thus far identified seems to be succinic acid. If the reaction proceeded after the same fashion as with the monobasic amino acids, the products would be ^-lactic and 7-oxybutyric acids re- spectively. These substances have not yet been identified as fer- mentation products of aspartic and glutaminic acids, though future investigations may reveal their presence. Considering the abundance of leucine and glutaminic acid in plant proteins, it is not surprising that their fermentation products, isoamyl alcohol and succinic acid, were long ago iden- tified. Pasteur recognized the regularity with which these prod- ucts accompanied alcoholic fermentation, and even included them in his chemical ecpiations in which he attempted to balance the original sugar with the fermentation products. It did not occur AMINO ACIDS AND MICRO-ORGANISMS 543 to Pasteur that these by-products, amounting to only 5 per cent of the original sugar, might possibly not have their origin di- rectly in the sugar. It remained for Buchner nearly forty years later to prove that the fermentation of pure sugar by a cell-free extract of yeast gave rise to no succinic acid or fusel oil whatever. In general it may be said that the action of yeast upon a naturally occurring “-amino acid is to add a molecule of water, then remove a molecule each of ammonia and C02. The am- monia is then utilized for the building up of new protein and the remainder of the original molecule cast aside as useless in the form of an alcohol of the same chemical structure as the amino acid but with one less carbon atom. Many investigations dealing with bacterial decomposition of proteins are recorded in the literature. Although some of the end-products identified in such studies can be traced with more or less certainty to a particular amino acid, the problem is much more intricate, and therefore the present discussion will be confined to studies upon individual amino acids where the latter were introduced into a medium freh from other sources of nitrogen. BACTERIA. Turning now to the bacterial decomposition products of amino acids, we find the problem somewhat more complex. An examina- tion of the table will, however, reveal two predominating types of products, viz., amines and fatty acids, both retaining the cyclic nucleus of the original amino acid. Out of the fifteen amino acids on which data are available at least eight are known to give rise to amines, by the simple loss of C02 from the car- boxyl group. The two dibasic acids, aspartic and glutamic, lose the carboxyl adjacent to the amino group but retain the other carboxyl, the product being an ^-amino acid. This reaction is entirely analogous to that whereby the monobasic amino acids are converted into an alkylamine. Taking valine as an illustra- tion the reaction may be written (ch3)2 oh ch nh> cooh — > (ch2)2 ch cm nh2 + co2 isobutylamine Out of these same fifteen amino acids, twelve are known to give rise to fatty acids (or the corresponding aryl-substituted 544 IOWA ACADEMY OF SCIENCE Vol. XXIV, 1917 fatty acid). This reaction probably consists in the hydrolysis of the amino acid into a hydroxy acid and Nil,, then a reduction of the hydroxy acid to the fatty acid. The formation of valeric acid from valine may be written (CH.), ch choh COOH + NH:{ — > valine hydroxy isovaleric acid (CH3)2 CH CPE COOH isovaleric acid However, the bacterial action does not usually stop at this point. The acid may undergo oxidation to the next lower mem- ber of the series, and this in turn may meet the same fate, until finally only the cyclic nucleus is left, as in the ease of tyrosine and tryptophan. Tyrosine and tryptophan present a complete series of degradation products, all the intermediate stages hav- ing been identified. Thus, HO .C«H4 .CH2 CH .NHa .COOH > HO .C«H4 ,OH»CH2COOH — > tyrosine p-hydroxyphenylpropionic acid HO . Ci;H4 .CHo .COOH — > HO .CHECH, — > HO .C6H3 p-hydroxyphenylacetic acid p-cresol phenol The behavior of micro-organisms toward the optical isomers of amino acids is a problem of considerable interest. All of the amino acids under consideration, with the exception of glycine, contain at least one asymmetric carbon atom. They are, there- fore, capable of existing in an isomeric form with opposite op- tical properties. The naturally occurring form is readily at- tacked by micro-organisms, whereas its optical isomer remains unaltered. The racemic mixture of the two forms can therefore be sepa- rated, one form being destroyed and the other remaining in- tact. This specific behavior is made use of in preparing the isomer of an optically active substance, the latter being first racemized by heating with a base, and added to a suitable culture medium, upon which the desired organism is then inoculated. There are, however, three exceptions to the phenomenon of asymmet- ric utilization of amino acids by organisms. Aspartic acid, tyro- sine and proline are broken down with equal readiness when present in either optical form. The phenomenon of specific utili- zation by micro-organisms is manifested not only toward optical or geometrical isomerides but also toward isomerides charac- terized by the location of the amino group which must be attached AMINO ACIDS AND MICRO-ORGANISMS 545 to the alternately occurring carbon atoms, in order to be sub- ject to attack by .certain fungi. For example, a and 7 amino- butyric acids are utilized while Z3 amino butyric acid is not. The effect of saprophytic mold fungi upon amino acids is still more profound. In this case the products are chiefly C02 HoO, NH3 and oxalic acid. The commonly occurring species of Aspergillus and Penicillium are able to utilize the naturally occurring amino acids as sources of nitrogen, and as a rule the}^ carry oxidation practically to completion. Certain intermediary fungi, however, seem content with the initial hydrolysis whereby the nitrogen is liberated in a form that meets their require- ments, and the remaining hydroxy acid left to accumulate in the medium. Thus Oidium lactis converts tyrosine into p-oxy- phenyl lactic acid, phenyl-alanine into phenyl-lactic acid, and tryptophan into indollactic acid. But the oxidizing fungi are present in sufficient abundance in nature to account for the continual disappearance of recognizable protein decomposition products from such media as the soil where they would other- wise tend to accumulate. Chemistry Section, Iowa State College. 35 THE SEPARATION AND GRAVIMETRIC ESTIMATION OF POTASSIUM. S. B. KUZIRIAN. The market value of chloroplatinic acid, particularly under present conditions, is so high as to warrant a careful search for some cheaper reagent for the determination of potassium. Serullas1, as early as 1831, proposed taking advantage of the insolubility of potassium perchlorate in concentrated alcoholic solutions and applying it as a reagent for the estimation of potassium. Unfortunately his proposal did not receive the at- tention it deserved because a convenient method for the prepa- ration of perchloric acid had not at that time been worked out. Lately, Kreider2 elaborated a method for the preparation of perchloric acid in large enough quantities and in sufficient pur- ity to attempt its use as a precipitant for potassium. Follow- ing the treatment suggested by Caspari3 he obtained very satis- factory results.2 The method was improved and simplified by Willard4 in 1912, enabling one to obtain a very pure product in a comparatively short time. This revived old hopes and work was started by some of the Station chemists to study its merits as a substitute for chloroplatinic acid. T. D. Jarrell5 conducted some co-operative work in collabora- tion with other station chemists on some commercial products, the object being a comparison of results obtained by the official method and the perchlorate method. Ten investigators reported varying results on both methods, and the conclusion6 reached was that the perchlorate method in its present form for deter- mining potash in mixed fertilizers is very unsatisfactory, con- suming too much time, and demanding removal of sulfuric acid with barium chloride in case the former is present, and that unless sufficient perchloric acid is added to combine with barium chloride to form perchlorate, the barium is not washed out from the potassium perchlorate precipitate with the alcohol wash, and further that potassium perchlorate is somewhat soluble6 in the alcohol wash. 548 IOlWA ACADEMY OF SCIENCE Vol. XXIV, 1917 Baxter and Kobayashi7 on the other hand, have shown that by careful manipulation and on use of absolute alcohol at low temperature satisfactory results can be obtained. Hills has shown that aniline perchlorate, which is easily pre- pared from aniline oil and perchloric acid, has a definite com- position and contains no water of crystallization. A known amount of these crystals dissolved in a measured amount of absolute alcohol will, according1 to Hill, precipitate potassium quantitatively as perchlorate. His negative errors average 0.0004 grams K20. When, however, this is calculated into per cent error, it amounts to over 1.5 per cent. An explanation for the negative errors, according to Hill, is the incomplete conver- sion of KC1 into K'C104. As the writer recently had occasion to run a large number of potassium determinations on the ash of forage plants and animal carcasses, the use of aniline perchlorate was tried under varying conditions. According to the writer ’s experience, the results are the best when the following points are observed. The exact strength of the alcohol used must be known, and none used that runs below 99.5s per cent. For every 1.5 cc of water used for dissolving the mixed chlorides, 50 cc of absolute alcohpl should be added. A weighed amount of aniline per- chlorate dissolved in 50 cc of absolute alcohol must be added to the dissolved chlorides drop by drop with constant shaking and set aside for one hour before filtering. Under these condi- tions the writer succeeded in obtaining the following results. PRECIPITATION OF POTASSIUM* WITH ANILINE PERCHLORATE. No. of Expt. Wt. of KC1 taken Gms. Corresponding Wt. taken of O aj .6 S W 60 «_ TS o a . G Corresponding LWt. found of 1 Error in K20 Gms. KoO Gms. KC104 Gms. KC1 Gms. K>0 Gms. 1 0.2005 0.1267 0.3726 0.3670 0.1975 0.1247 0.0020 2 0.2005 0.1267 0.3726 0.3685 0.1983 0.1252 0.0015 3 . .. 0.2000 0.1264 0.3716 0.3675 0.1978 0.1250 0.0014 4 0.2000 0.1264 0.3716 0.3670 0.1975 0.1247 0.0017 5 0.2000 0.1264 0.3716 0.3677 0.1972 0.1250 0.0014 6 0.2000 0.1264 0.3716 0.3676 0.1979 0.1249 0.0015 7 0.2000 0.1264 0.3716 0.3690 0.1986 0.1254 0.0010 8 0.2000 0.1264 0.3716 0.3680 0.1981 0.1251 0.0013 9 0.1000 0.0632 0.1858 0.1844 0.0993 0.0627 0.0005 io _ ' 0.1000 0.0632 0.1856 0.1840 0.0991 0.0626 0.0006 11 0.1000 0.0632 0.1856 0.1845 0.0994 0.0628 0.0004 12 0.1000 0.0632 0.1856 0.1843 0.0993 0.0627 0.0005 ♦The potassium chloride used was recrystallized from the commercial c. p. product. When it was estimated as chloroplatinate, it showed a purity of 99.9 per cent KC1. GRAVIMETRIC ESTIMATION OF POTASSIUM 549 The main objections to the perchlorate method at present are the time8 required and the slight solubility of potassium perchlorate in 95 per cent alcohol. The use of aniline perchlorate in place of perchloric acid shortens the process to such an ex- tent as to make it decidedly advantageous over all the processes in use for the separation and estimation of potassium. More- over it affords the best means for direct quantitative separation and estimation of sodium in the alcoholic filtrate. As to the solubility of KC104 in 95 per cent alcohol, the writ- er’s experience, in applying’ this method to the estimation of sodium and potassum in the ash of forage plants and animal carcasses, has been that some potassium chloride is occluded in the perchlorate. This is shown by the fact that higher results are obtained if the precipitate is allowed to stand for about two hours before filtration. Three series of four experiments each were conducted to establish this point. When the precipitant, dissolved in the proper amount of alcohol, was added all at once and filtered within fifteen minutes, decidedly lower results were obtained, but when the precipitant was added drop by drop with constant shaking and allowed to stand about two hours before filtration, the results were decidedly better. If it were simply a matter of solubility, no better results could be expected under the latter conditions. The potassium chloride which seems to adhere persistently to the perchlorate, being soluble in alcohol, is of course washed off gradually with the alcohol wash. Jarrell, in summing up his. experience with regard to the solubility of potassium perchlorate, does not state whether he obtained the theoretical yield when he prepared the potassium perchlorate from potassium chloride. The writer is inclined to believe that under the conditions Jarrell’s precipitates were contaminated with potassium chlor- ide. A careful observation of the table shown in this paper will illustrate the fact more clearly. In experiments 9, 10, 11 and 12, 0.1 gram of KC1 was used instead of 0.2 gram. Exactly the same amount of water and alcohol were used and the same procedure followed, but the negative errors in this case are low enough to be within experimental error. These results clearly tend to show that when sufficient precautions are taken to pre- vent occlusion during the conversion of the chlorides into per- chlorate, a complete precipitation may be expected. 550 IOWA ACADEMY OF SCIENCE Vol. XXIV, 1917 Taking into consideration the fact sufficient chloroplatinic acid must be added to combine with all the bases present in order to be washable by the alcohol wash, the necessity of find- ing a cheaper substitute is at once appreciated. In the writer’s opinion, aniline perchlorate is the best reagent to replace the highly expensive platinic chloride for the separation and esti- mation of potassium. It is easily prepared, is much cheaper and is easy to handle. LITERATURE CITED. 1. Serullas, Ann. Clum. Phys., 46, 294, 1831. 2. Kreider, Am. Journ. Science (3), 49, 443. 3. Caspari, Z. Angew. Chem., 68, 1893. 4. Willard , J. Am. Chem. Soc., 34, 1480, 1912. 5. Jarrell , Journ. A. O. A. C., 1, 400, 1915. 6. lUd., 1, 29, 1915. 7. Journ. Am. Chem. Soc., 39, 249, 1917. 8. Hill, Am. Journ. Science, 40, 85, 1915. Chemistry Section, Agricultural Experiment Station. THE ACTION OF THE AMINO GROUP ON AMYLOLITIC ENZYMES. (ABSTRACT) ELBERT W. ROCKWOOD. The work is a continuation of that reported last year on the action of the auxoamylases, the accelerators of starch splitting enzymes. Anthranilic acid (orthoaminobenzoic acid) has been shown to increase the activity of the salivary starch-digesting enzyme. In a similar manner the isomers of the anthranilic acid were tested, the figures given below representing the relative amounts of digestive products formed. NO. 45. Time of Digestion. 1 hour 3 hrs. 5 hrs. 7 hrs. 24 hrs. Standard (no activator) . . . ... 3.6 6.0 10.8 11.5 20.9 Ortho acid 5.1 9.6 13.7 16.4 25.8 Meta acid 5.2 9.2 14.6 16.1 25.4 Para acid . ... 4.5 9.2 13.5 16.2 26.4 All the isomers are seen to be auxoamylases. That, is, the po- sition of the amino radical in the benzene ring with reference to the carboxyl is immaterial in modifying the activity of the compound. Inasmuch as the protein molecule is composed of a great com- plex of amino acids it might be surmised that upon hydrolysis it would become more active in its influence upon amylolytic fer- ments than is the original protein. Two proteins;, gelatine and serum albumin, were hydrolyzed by boiling with sulphuric acicl and parallel digestions were run, one containing no protein, for a standard, one 0.5 grm. of the original protein and the third the same amount of hydrolyzed protein. The results are shown, below : 552 IOiWA ACADEMY OF SCIENCE Vol. XXIV, 1917 NO. 47. Gelatine. 1 hour. 2 hrs. 4 hrs. 6 hrs. Standard 8.9 13.2 15.3 Gelatine 15.5 21.8 21.4 Hydrolyzed gelatine 16.0 18.1 22.2 As the number of free amino groups in the g elatine molecule becomes greater the stimulating power appears to increase. NO. 48. Serum Albumin. 1 hour. 2.5 hrs. 4.5 hrs. Standard 1.8 4.6 7.3 Albumin 16.1 21.8 24.7 Hydrolyzed albumin 19.2 24.1 27.8 This protein acts similarly to the gelatine and its decomposi- tion products. The amines of the methane series also have the power of stim- ulating the digestive power of ptyalin. Three were tried, methylamine, CH3NH2 ethylamine, CoH5NH0 and diethylamine, (CSH5-)SNH. NO. 143. 2 hrs. 4 hrs. 6 hrs. Standard 8.5 13.0 15.0 Methylamine 21.6 24.4 24.4 Ethylamine .21.1 23.8 24.4 Diethylamine 21.6 23.9 24.9 Hence the activating effect is due to the nitrogen and not to the NITo as a group, since the derivatives of the group act as powerfully as the group itself. Trials were made also with the pentavalent nitrogen of the ammonium radical. Both ammonium salts of strong and weak acids were employed. In all the experiments the reactions of the solutions were made neutral to litmus, with the amino compounds as well as with the ammonium salts. Inasmuch as different samples of saliva were used the results from one series cannot be exactly compared with those of an- other; consequently several must be given. ACTION OP AMINO GROUP ON AMYLOLITIC ENZYMES 55: NO. 138. 1 hour 2 hrs. 4 hrs. 6 hrs. Standard . 5.3 8.7 11.3 12.4 Ammonium sulphate 6.9 10.3 12.5 13.1 Ammonium thiocyanate . . 6.6 • 9.3 12.5 13.2 Ammonium acetate 4.6 6.2 9.8 10.2 NO. 140. 1 hour. 2 hrs. 4 hrs. 6 hrs. Standard .. 4.4 8.8 . 13.6 17.5. Ammonium nitrate 4.7 9.9 14.9 17.6 Ammonium oxalate 4.2 6.1 9.9 12.8 NO. 141. 1 hour. 2 hrs. 4 hrs. 6 hrs. Standard . 10.9 14.0 15.8 17.4 Ammonium acetate 8.0 10.7 12.6 15.4 Ammonium chloride ...15.7 17.8 18.9 20.0 Ammonium oxalate 8.3 11.5 15.7 18.7 NO. 142. 1 hour. 2 'hrs. 4 hrs. 6 hrs. Standard . 1.0 2.4 . 4.8 6.7 Ammonium malate 1.1 2.7 5.2 6.4 Ammonium tartrate ............ 1.4 2.8 5.8 7.5 From the above it is seen that the ammonium salts of the strong acids (nitric, sulphuric, hydrochloric and thiocyanic) have a more marked effect than those of the weak acids (acetic, malic and tartaric) ; oxalic acid does not conform to the rule. Department of Chemistry, State University. SUBJECT INDEX Page Alsike Clover Rust, Aecial Stage of, !W. H. Davis 461 Amino Acids and Micro-Organisms, Arthur W. Dox 530 Amino Group, Action of, on Amylolitic Enzymes, Elbert W. Rockwood 551 Apple Skins, Cutinization of, in Relation to Keeping Qualities and Environment, Winifred Perry 483 Bell’s Vireo Studies, Walter W. Bennett 285 Benzidine, Behaviour of, Toward Selenic and Telluric Acids, Arthur W. Dox . 537 Bermudas as a Type Collecting Ground for Invertebrates, H. A. Cross, Jr 301 Binaural Sound Localization, Influence of Intensity Ratio on, EL M. Berry and C. C. Bunch 203 Bird Records During Past Winter, 1916-1917, in Northwestern Iowa, T. C. Stephens 245 Birds Observed in Clay and O’Brien Counties, List of, Ira N. Gabriel son 259 Blasia Pusilla, Morphology of Thallus and Cupules of, Marguerite B. Ron ret 429 Blindworms, Eyeball and Associated Structures in, H. W. Norris.. 299 Buchanan Gravels of Calvin and Iowan Valley Trains, M. M. Leighton 86 Cap-Au-Gres Fault, Extent and Age of, Charles Keyes 61 Conduction Currents, Precontact, L. E. Dodd 231 Conservation, Geologic Aspects of, James H. Lees ...133 Coral, Fossil, Large Colony of, A. O. Thomas ...105 Corn, Chlorotic, W. H. Davis 459 Crustacean, Decapod, from Kinderhook Shale at Burlington, Otto Walter 119 Driftless Area, Bibliography of, W. D. Shipton 67 Earth History, Fundamental Concepts of, James H. Lees 155 Earthquake near Iowa City, April 9, 1917, Note regarding, George F. Kay 103 Entomostraca, List of, from Okoboji Region, Frank A. Stromsten. 309 Fruit or Nut, Supposed, from Tertiary of Alaska, A. O. Thomas. .. 113 Iowa Weeds, Protein Content and Microchemical Tests of Seeds of, L. H. Pammel and Arthur W. Dox . 527 Iowan Glaciation and So-called Iowan Loess Deposits, M. M. Leighton 87 Iron in Nutrient Solution for Plants, use of, G. E. Corson and A. L. Bakke 477 556 SUBJECT INDEX Page Lake Okoboji, Second Record of Oscillations in Level of, and of Temperature and Meteorology of, John L. Tilton 33 Lithium Chloride, Electromotive Force and Free Energy of Dilu- tion of, in Aqueous and Alcoholic Solutions, J. N, Pearce, and F. S. Mortimer 507 Loess and the Antiquity of Man, B. Sitimek 93 Loggerhead Turtle, Development of Musk Glands in, Frank A. Stromsten 311 Male, Influence of, on Litter Sizes, E. N. (Wentworth ..305 Mammals of Sac County, Annotated List of, J. A. Spurrell 273 Mound Groups in and near Proposed Government Park at Mc- Gregor, Ellison Orr 1 43 Naphthotetrazine, Synthesis of, from Diethyl Succinylosuccinate and Dicyanalamide, Arthur W. Dox 533 Natural Waters of Central New York, Nicholas Knight and Vernon C. Shippee 485 Oaks, Germination and Juvenile Forms of, L. H. Pammel and C. M. King 367 Ocheyedan Mound, Osceola County, George F. Kay 101 Odonata of Iowa, Lloyd Wells . . . . 327 Okanogan Valley, Washington, High Level Terraces of, Charles Keyes 47 Orchard Soil Management, Influence of, on Fruit Bud Development, R. S. Kirby 447 Picea from the Glacial Drift,. Wilbur A. Thomas 455 Pioneer Plants on a New Levee, III, Frank E. A. Thone 457 Plant Studies in Lyon County, D. H. Boot 393 Plates, Similar, Non-Farallel, Plane, Electrical Capacity of, L. E. Dodd 217 Pleistocene Deposits Between Manilla in Crawford County and Coon Rapids in Carroll County, George F. Kay 99 Poison Oak, Mites Affecting, H. E. Ewing 323 Post-Kansan Erosion, M. M. Leighton 83 Potassium, Separation and Gravimetric Estimation of, S. B. Kuzirian • 547 Prairie du Chien-St. Peter Unconformity in Iowa, Arthur C. Trowbridge 177 Pre-Cambrian Stratigraphy, Continental Perspective of, Charles Keyes 53 President’s Address, George W. Stewart 29 Protozoa, Observations on, Clementina S. Spencer 335 Rat, Common, Further Notes on Venous Connections of Lymphatic System in, Ttiesle T. Job. . 319 Red Clover, Additional Notes on Pollination of, L. H. Pammel and L. A. Kenoyer 357 Resonance in an Alternating Current Circuit, Interesting Case of, H. L. Dodge .189 Rheostat design, certain feature of, H. L. Dodge 183 SUBJECT INDEX 557 Page Rodents, Iowa, Notes on, Dayton Stoner 353 Salts, Double, Dissociation of, Harold L. Maxwell and Nicholas Knight 4S9 Snake, Some New Endoparasites- of, Ti-iesle T. Job 315 Squalus Acanthias , Analysis of Cranial Ganglia of, Sally P. Hughes 295 St. Peter Sandstone, Origin of, Arthur O'. Trowbridge 171 Stroboscopic Effect, the, L. E. Dodd 221 Succinic Acid, Solubility and Heat of Solution of, in Water and the Paraffine Alcohols, H. E. Fowler and J. N. Pearce 523 Tellurium, Thermal Conductivity of, Arthur R. Fortsch 213 Tungsten, Effect of Drawing on Density and Specific Resistance of, Wi. Scheiever ... 235 Tungsten, X-Ray K-Radiation of, Elmer Dershem 201 Tungsten Wires, Certain Elastic Properties of, L. P. Sieg 207 Waterworks Laboratories, Jack J. Hinman, Jr 501 White Sweet Clover, Melilotus alba, Notes on, Walter E. Rogers.. 415 White Water Lily of Clear Lake, Iowa, Henry S. Conard 449 Yangtze River, China, Observations on Erosion History of, C. L. Foster 127 Zincite-Copper Contacts, Effect of Hydrogen Sulphide on Unilateral Conductivity of, R. B. Dodson 241 AUTHOR INDEX Bakke. A. L., 477 Bennett. W. W., 285 Beery, E. M., 203 Boot, D. H., 393 Bunch, C. C., 203 Conard. Henry S., 449 Corson, G. E., 477 Cross, H. A., Jr., 301 Davis, W. H., 459, 461. Dershem, Elmer, 201 Dodd, L. E., 217, 221, 231 Dodge, H. L., 183, 189 Dodson, R. B., 241 Don, Arthur W., 527, 533, 537, Ewing, H. E., 323 Fortsch, Arthur R., 213 Foster, C. L., 127 Fowler, H. E., 523 Gabrielson, Ira N., 259 Htnman, Jack J., Jr., 501 Hughes, Sally P., 295 Job, Thesle T., 315, 319 Kay, George F., 99, 101, 103 Kenoyer, L. A., 357 Keyes, Charles, 47; 53, 61 King, C. M., 367 Kirby, R. S., 447 Knight, Nicholas, 485, 489 Kuzirian, S. B., 547 Lees, James H., 133, 155 Leighton, M. M., 83, 86, 87 Maxwell, Harold L., 489 Mortimer, F. S., 507 Norris, H. W., 299 Orr, Ellison, 43 Pammel, L. H., 357, 367, 527 Pearce, J. N., 507, 523 Perry, Winifred, 483 Rockwood, Elbert W., 551 Rogers, Walter E., 415 Rohret, Marguerite B., 429 Schriever, Wm., 235 Shimek, B., 93 Shippee, Vernon C., -485 Shipton, W. D., 67 Sieg, L. P., 207 Spencer, Clementina S., 335 Spurrell, J. A., 273 Stephens, T. C., 245 Stewart. G. W., 29 Stoner, Dayton, 353 Stromsten, F. A., 309, 311 Thomas, A. O., 105, 113 Thomas, Wilbur A., 455 Thone, Frank E. A., 457 Tilton, John L., 33 Trowbridge, Arthur C., 171, 177 Walter, Otto. 119 Wells, Lloyd, 327 Wentworth, E. N., 305 ' . SMITHSONIAN INSTITUTION LIBRARIES