PROCEEDINGS OF THE Iowa Academy of Sciences F"OI^ 18Q5. VOL III. PUBLISHED BY THE STATE. I I I I DES MOINES: F. B. CONAWAY, STATE PRINTER. ^Sr I LIBRARY OF I685-IQ56 PROCEEDINGS OF THR^L,;-^^^ ■• ^ ■>««* Jowa if idtiifftfrScienees F"OI^ 18Q5 VOLUME III. -:-J^v-- -- .'. . *» » PUBLISHED BY THE STATE. DES MOINES: F. R. CONAWAY, STATE PRINTER. LETTER OP TRANSMITTAL. Agricultural College, ) Ames, Iowa, February 15, 1896. \ To His Excellency, FRANCIS M. Drake, Governor of Iowa: Sir — In accordance with the provisions of chapter 86, laws of the Twenty- fifth General Assembly, I have the honor to transmit herewith the proceedings of the tenth annual session of the Iowa Academy of Sciences. With great respect, your obedient servant, Herbert Osborn, Secretary Iowa Academy of Sciences. OFFICERS OF THE ACADEMY. 189^. President.— U. W. NORRIS. First Vice-President.— CharTuES R. Keyes. Second Vice-President.— T. PROCTOR Hall. Secretary'- Treasurer.— Herbert Osborn. Librarian.— B.. FOSTER Bain. EXECUTIVE COMMITTEE. Ex-Officio.—B.. W. NoRRis, Charles R. Keyes, T. Proctor Hall,, Her- bert Osborn. Elective.— 'N . E. Hansen, W. H. Norton. T. H. Macbride. 1896. President.— T. PROCTOR Hall. First Vice-President— W. S. FRANKLIN. Second Vice-President— T. H. Macbride. Secretary- Treasurer.— Herbert Osborn. Librarian.— K. FOSTER Bain. EXECUTIVE COMMITTEE. Ex-Officio.—T. PROCTOR Hall, W. S. Franklin, T. H. Macbride, Her- bert Osborn. Elective.— W. S. Hendrixson, M. F. Arey, W. H. Norton. Constitution of the Iowa Academy of Sciences. Section. 1. This organization shall be known as the Iowa Academy of Sciences. Sec. 2. The object of the Academy shall be the encouragement of sci- entific work in the state of Iowa. Sec. 3. The membership of the Academy shall consist of (1), fellows who shall be elected from residents of the state of Iowa actively engaged in scientific work, of (2) associate members of the state of Iowa interested in the progress of science but not direct contributors to original research, and (3) corresponding fellows, to be elected by vote from original workers in science in other states; also, any fellow removing to another state from this may be classed as a corresponding fellow. Nomination by the council and assent of three-fourths of the fellows present at any annual meeting shall be necessary to election. Sec. 4. An entrance fee of $3 shall be required of each fellow, and an annual fee of $1, due at each annual meeting after his election. Fellows in arrears for two years, and failing to respond to notification from the secretary-treasurer, shall be dropped from the academy roll. Sec. 5. (a) The officers of the academy shall be a president, two vice- presidents and a secretary-treasurer, to be elected at the annual meeting. Their duties shall be such as ordinarily devolve upon these officers, (b) The charter members of the academy shall constitute the council, together with such other fellows as may be elected at an annual meeting of the council by it as members thereof, provided, that at any such election two or more negative votes shall constitute a rejection of the candidate, (c) The council shall have power to nominate fellows to elect members of the council, fix time and place of meetings, to select papers for publication in the proceed- ings, and have control of all meetings not provided for in general session. It may, by vote, delegate any or all these powers, except the election of members of the council, to an executive committee, consisting of the officers and of three other fellows, to be elected by the council. Sec. 6. The academy shall hold an annual meeting in Des Moines dur- ing the week that the State Teachers' association is in session. Other meetings may be called by the council at times and places deemed advisable. Sec. 7. All papers presented shall be the result of original investiga- tion, but the council may arrange for public lectures or addresses on scien- tific subjects. 8 IOWA ACADEMY OP SCIENCES. Sec. 8. The secretary-treasurer shall each year publish the proceed- ings of the academy In pamphlet (octavo) form, giving- author's abstract of papers, and, if published elsewhere, a reference to the place and date of publication; also the full text of such papers as may be designated by the council. If published elsewhere the author shall, if practicable, publish in octavo form and deposit separates with the secretary-treasurer, to be per- manently preserved for the academy. Sec. 9. This constitution may be amended at any annual meeting by assent of a majority of the fellows voting, and a majority of the council; provided, notice of proposed amendment has been sent to all fellows at least one month previous to the meeting, and provided that absent fellows may deposit their votes, sealed, with the secretary-treasurer. ARTICLES OF INCORPORATION OF THE IOWA ACADEMY OF SCIENCES. ARTICLE I. We, the undersigned, hereby associate ourselves with the intention to constitute a corporation to be known as the Iowa Academy of Sciences, the purpose of which is to hold periodical meetings for the presentation and discussion of scientific papers, to publish proceedings, to collect such litera- ture, specimens, records and other property as may serve to advance the interests of the organization, and to transact all such business as may be necessary in the accomplishment of these objects. ARTICLE II. The membership of the corporation shall consist of the incorporators, and such other residents of the state of Iowa as may be duly elected fellows of the Academy. ARTICLE III. The duly elected officers of the Academy shall be the officers of the corporation. ARTICLE IV. The principal place of business of the Academy shall be the city of Des Moines, in the state of Iowa. The capital stock of the corporation is none. The par value of its shares is none. The number of its shares is none. ARTICLE V. The Academy shall hold an annual meeting in the last week of Decem- ber, of each year, or upon call of the executive committee, and such other meetings as may be arranged for. IOWA ACADEMY OF SCIENCES. ARTICLE VI. This corporation shall have the right to acquire property, real and per- sonal, by purchase, gift or exchange, and such property shall be held sub- ject to the action of the majority of its fellows, or the council, the execu- tive committee, or such parties as it may by vote direct to transact such business in accordance with the constitution. All deeds, leases, contracts, conveyances and agreements, and all releases of mortgages, satisfactions of judgment, and other obligations, shall be signed by the president or vice-president and the secretary, and the signa- ture of these officers shall be conclusive evidence that the execution of the instrument was by authority of the corporation. ARTICLE VII. The private property of the members of this corporation shall not be liable for any of its debts or obligations. ARTICLE VIII. By-laws, rules and regulations, not inconsistent with these articles, may be enacted by the Academy. ARTICLE IX. These articles may be amended at any meeting of the Academy called for the purpose by assenting vote of two-thirds of the members present. 10 IOWA ACADEMY OP SCIENCES. MEMBERSHIP OF THE ACADEMY. FELLOWS. Almy, F. F Iowa College, Grinnell Andrews. L. W ..State University, Iowa City Arey, M. F - State Normal School, Cedar Falls Bain, H. P Geological Survey, Des Moines Barris, W. H Griswold College, Davenport Bates, C. O ...Coe College, Cedar Rapids Beach, Alice M ..Agricultural College, Ames Bennett, A. A Agricultural College, Ames Beyer, S. W ..Agricultural College, Ames BissELL, G. W Agricultural College, Ames Calvin, S.. State University, Iowa City Chappel, George M Signal Service, Des Moines Combs, Robert... Conrad, A. H. Parsons College, Fairfield Cratty, R. I. Armstrong CURTISS, C. P Agricultural College, Ames Davis, Floyd ..Des Moines Drew, Oilman Newton Ende, C. L Burlington Fink, B Upper Iowa University, Fayette FiTZPATRiCK, T. J Lamoni Franklin, W. S Agricultural College, Ames PULTZ, P. M Burlington Gossard, H. a Ames Hall, T. P Tabor College, Tabor Hansen, N. E Brookings, South Dakota Hazen, E. H ...Des Moines Hendrixson, W. S Iowa College, Grinnell Heileman, W. H Ames Holway, E. W. D_ Decorah Houser, G. L State University, Iowa City Jackson, J. A Des Moines Kelly, H. V ..Mount Vernon Leonard, A. G... Western College, Toledo Leverett, Frank Denmark Mally, C. W.. Agricultural College, Ames Marston, a Agricultural College, Ames IOWA ACADEMY OF SCIENCES. 11 Macbride, T. H State University, Iowa City NiLES, W. B Agricultural College, Ames NORRIS, H. W Iowa College, Grinnell Norton, W. H.. Cornell College, Mount Vernon Nutting, C. C State University, Iowa City OSBORN, Herbert Agricultural College, Ames Page, A. C State Normal School, Cedar Falls Pammel, L. H Agricultural College, Ames Reppert, F ...Muscatine Rigker, Maurice Marshalltown Ross, L. S Drake University Des Moines Sage, J. R State Weather and Crop Service, Des Moines SCHAEPFER, C. A State University, Iowa City SCHLABACH, Carl High School, Clinton Shimek, B State University, Iowa City Stanton, E, W Agricultural College, Ames Stookey, Stephen W Coe College, Cedar Rapids TiLTON, J. L Simpson College, Indianola Veblen, A. A State University, Iowa City Wachsmuth, Charles*.-. Burlington Walker, Percy H State University, Iowa City Weems, J. B Agricultui"al College, Ames Windle, Williams Penn College, Oskaloosa Witter, F. M Muscatine YOUTZ, L. A Simpson College, Indianola ASSOCIATE members. Ball, E. D.. Little Rock Bartsch, Paul j Burlington Beardshear, W. M Agricultural College, Ames Blakeslee Des Moines Brown, Eugene Mason City Carter, Charles Fairfield Carver, G. W Ames GiFFORD, E. H.. Oskaloosa Miller, G. P. . Des Moines Mills, J. S.. Eugene, Oregon Osborn, B. F .-Rippey Owens, Eliza. Ames Pammel, Emma Ames Reed, C. D... Ames Rolfs, J. A Le Claire SiRRiNE, Emma Ames Weaver, C. B Ames corresponding members. Arthur, J. C Lafayette, Indiana Barbour, E. H State University, Lincoln, Nebraska Beach, S. A Geneva New York Bessey, C. E State University, Lincoln, Nebraska Bruner, H. L Irvington, Indiana * Deceased. 12 IOWA ACADEMY OF SCIENCES. Call, R. E Louisville, Kentucky COLTON, G. H. ...Virginia City, Montana Crozier, a. a Ann Arbor, Michigan Gillette, C. P Agricultural College, Ft. Collins, Colorado Halsted, B. D... New Brunswick, New Jersey Haworth, Erasmus State University, Lawrence, Kansas Hitchcock, A. S .Agricultural College, Manhattan, Kansas Jameson, C. D Keyes, C. R State Geologist, Jefferson City, Missouri Lonsdale, E. H Missouri Geological Survey, Jefferson City, Missouri Mally, F. W -- Hulen, Texas McGee, W. J Bureau Ethnology, Washington, D. C. Meek, S. E State University, Fayetteville, Arkansas Newton, Geo... Grand Island, Nebraska Parker, H. W New York City, New York Patrick, G. E... Hopedale, Massachusetts Rolfs, P. H Lake City, Florida SiRRlNE, F. Atwood Jamaica, New York Spencer, A. C ...Johns Hopkins University, Baltimore, Maryland Stewart, F. C ..Jamaica, New York Todd, J. E State University, Vermillion, South Dakota WiNSLOW, Arthur St. Louis, Missouri Proceedings of the Tenth Annual Session IOWA ACADEMY OF SCIENCES The tenth annual meeting of the Iowa Academy of Sciences was held in the horticultural rooms at the capitol buildiog in Des Moines, January 1, 2 and 3, 1896. During the business sessions the following matters of general interest were acted upon: REPORT OF THE SECRETARY-TREASURER. Gentlemen — lb is a gratification at this our decennial meeting to report a flourishing condition of the academy. Comparison with our modest beginning, and with our struggles in earlier years to secure a solid foundation and to provide for the publication of results, warrants us in a feeling of satisfaction and of encouragement for renewed effort for the future. Our membership, which now numbers over 100, includes in its list sixty- three fellows, fifteen associates and twenty-three corresponding members. It represents nearly all the active scientific workers of the state, and also many whDse interest and cordial support of such work is of great value. Four of the fellows have removed from the state, and, according to our custom, may be transferred to the list of corresponding members. Four others have, at their own request, or on account of arrearages in dues, been dropped from the academy roll. Accounts and vouchers submitted herewith show receipts amounting to $153.21 and disbursements of $97.22, leaving a balance charged to the treasurer of $55.99. 14 IOWA ACADEMY OF SCIENCES. SUMMARY OF RECEIPTS AND EXPENDITURES. Receipts. Balance from last year $ 63.16 Ten membership fees at $3 30.00 Annual dues from members 58.00 Proceedings sold 2.05 Total $ 153.21 Disbursements. Expenses of ninth annual meeting $ 6.43 Stationery and stamps,, collecting dues 3.41 Printing programs, circulars, etc... 16.25 Author's reprints Vol. II 50.00 Express and postage on proceedings 19.25 Clerk hire, exchange and miscellaneous expenses... 1.88 Balance 55.99 Total - $ 153.21 Respectfully submitted. Herbert Osborn. The committee appointed to examine the accounts of the secretary- treasurer reported as follows: The committee finds the accounts of the secretary to be correct. 1 C. C. Nutting, Signed - C. O. Bates, A. C. Page. REPORT OP THE LIBRARIAN. Des Moines, Iowa, December 31, 1895. Gentlemen — I have the honor to submit the following report of my work as librarian of the academy for the year past. The academy is now receiving regularly forty-three serial publications, including the reports of the most important American and some of the foreign societies. In addi- tion, the reports of a considerable number of state and government bureaus are received. The papers are catalogued and placed in the alcove assigned to the academy by the state librarian. Within the past year exchanges have been effected whereby all, or a considerable number, of the back numbers of the following s>eries have been placed upon our shelves: Transactions Connecticut Academy of Science. Bulletin New Brunswick Natural History Association. Proceedings Colorado Scientific Society. Transactions St. Louis Academy of Science. Tufts College Studies. Proceedings Natural Science Association, Staten Island. Colorado College Studies. In two other cases exchanges were effected by the combined efforts of the Academy of Sciences and the Geological survey. In these cases it was IOWA ACADEMY OF SCIENCES. 15 thought better to place the books received in the regular collections of the state library. It is proposed to continue the exchange of back sets wherever it can be done to advantage; and for this purpose, as well as to provide for exchanges already made, it is recommended that the academy purchase at least fifteen copies of part one of the proceedings. Several copies of the back numbers of the academy have been sold and the money forwarded to the treasurer. It is recommended that some more systematic rules regarding the distribution and sale of the proceedings be adopted. Respectfully, H. Foster Bain, Librarian. Professor Hendrixson, for the library committee, made a statement of the work of the committee with reference to sci- entific books for the state library and the valuable additions that had been made as a result. The following motion was adopted that a vote of thanks be tendered the librarian and board of trustees of the state library for their courtesies in hearing the requests of the academy and the purchases of scientific works. A motion that a committee of three be appointed by the chair to petition the legislature regarding the preservation of forest and lake areas of Iowa and to present a memorial to con- gress through Senator Gear, regarding forest preservation. The committee appointed consists of Professors Macbride, Pammel and Fink. The following was adopted: Des Moines, Iowa, January 2, 1896. The Iowa Academy of Sciences, in regular session assembled, begs leave to call the attention of the Twenty-sixth General Assembly of the State of Iowa to the preservation and protection of our lakes in order to maintain some of the original conditions of the state. They should be made pleasure resorts where our citizens may spend a few days for recreation, and where possible the borders of the lakes should be planted with forest trees. These lakes contain large numbers of fish which alone would pay for their mainte- nance. They are frequented by many birds which, without them, will be driven from our state. Your honorable body can leave no richer legacy to future generations than the lakes that dot the northern part of our state surrounded with timber. We earnestly hope the Twenty-sixth General Assembly will pass some measure to preserve them. (Signed) T. H. Macdride. L. H. Pammel. B. Fink. Des Moines, Iowa, January 2, 1896. The Iowa Academy of Sciences, in regular session assembled, begs leave to call the attention of the United States congress to the absolute necessity of further legislation looking to the preservation and rational use of the remaining forest resources of our country. The academy petitions for 16 IOWA ACADEMY OF SCIENCES. larger and better guarded reservations, for the enactment of the McRae bill, H. R. 119, or of some similar measure which will yet more stringently guard our forests. (Signed) T. H. Macbride. L. H. Pammel. B. Fink. The following resolution was adopted: Resolved, By the Iowa Academy of Sciences, that we view with pleasure the efforts toward providing a state building for the preservation of material of historical and scientific value and would heartily endorse the movement for a " memorial, historical and art building." The following resolutions in regard to papers were adopted: That hereafter no papers will be published in the proceedings of this academy which are not placed in the hands of the secretary in full, or in a written abstract, before the adjournment of the annual meeting. That no paper shall be placed upon the printed program of the academy unless the title, when handed to the secretary, be accompanied by a brief abstract and that these abstracts be printed with the program. The thanks of the academy to the State Horticultural soci- ety for the use of their room were by motion tendered. In the sessions for the reading and discussion of papers the academy listened to the annual address of the president and papers giving results of investigations. These papers read in full or by title were referred by the council to the secretary for publication and follow herewith: IOWA ACADEMY OF SCIENCES. 17 ANNUAL ADDRESS OB^ THE PRESIDENT. NEEDED CHANGES IN SCIENTIFIC METHODS.^ BY H. W. NORRIS. We live in a period that sees wonderful attainments in sci- ence and art, so that in theory and practice many think the summum bonum has been reached. It is pre-eminently the age of science and the application of scientific methods to all phases of human activity. The forces of nature have been made sub- ject to the wiU of man. The relations of man to his surround- ings have been carefully considered. The province oi human intellect has been made the ground of scientitic investigations. We now see scientific methods foremost and uppermost, and all human thought is more or less permeated and even molded by the new ways of looking at the lacts of our experience and rea- son. But with ail our enlightenment no other age has equaled ours in the prevalence of unblushing fraud and boasting duplicity. For every skilled specialist in surgery we have a dozen quacks, whose outrageous pretensions are only equaled by the astonishingly large patronage of the over- credulous. The rep- utable physician struggles along in his attempts to right the wrongs of the human body according to the best api)roved methcds, and too frequently receives as his reward only non- bankable prortiises, while Dr. Humbug puts up at the best hotels, advertises to cure all the ills human fiesh is heir to. and reaps a harvest of shekels. The name of Dr. X's sarsaparilla is emblazoned along every thoroughfare in the country, and the * \Mieu this address was nearly completed a copy of a recent lecture by President J. IVI. Coulter, of Lake Forest University, was received, in which were expressed many ideas quite similar to some contained in this paper. Wherein the writer has inten- tionally borrowed from President Coulter, due credit has been given. The Botanical Outlook. An address delivered before the Botanical Seminary of the University of Nebraska, May 27, 1895. 18 IOWA ACADEMY OF SCIENCES. merits of the Whoop up Indian Bitters have even been drama- tized for the stage. But the "regular" physician is held responsible for the final taking off of the poor dupes who have resorted to all the patent medicines before consulting the proper authorities. The discoveries of Edison and other investigators of nature's forces are quietly revolutionizing our industrial methods, and we think little of it. But the praises of electric belts, electric bitters and magnetic oils are sounded in every hamlet where the public press finds expression. We have seen in this generation the revival of an old imposture, that travesty on religion and science, the so-called Christian science. Occa- sionally a new messiah makes his appearance, drawing after him such throngs as to make the possibility of another Joseph Smith not an incredible idea. A visit to one of our interstate or international exhibitions fills us with wonder amounting almost to awe at the marvelous products of genius, a wonder exceeded only by that aroused by a perusal of the advertising columns of our daily papers. That advertising pays cannot be disputed, but the fact that it does pay is often a serious reflec- tion upon the methods of our mental training. Fence corners full of abandoned machinery show, among other things, an unfortunate ignorance of physical laws, and a too ready accept- ance of golden promises. In spite of our bureaus of animal industry, the stock raiser still resorts to patent condition pow- ders and hog cholera cures instead of managing his establish- ment on a sanitary basis. We are too much under the impres- sion that everything — life, health and happiness, can be pur- chased with the almighty dollar. So we throw discretion to the wind and leave the results to the Lord and the doctors. To-day, as it has always been, empiricism is a great hindrance to progress. A specific remedy for a specific evil, a lucky dis- covery of certain correlated phenomena, a haphazard experi- menting with fortunate results, have been all too frequently characteristic of scientific achievements. Great as are the vic- tories science has won in the domains of medicine and the applied arts, they have not been presented to the great public as having a rational basis. In fact the leaders in science see only too dimly the underlying meaning. To many the sole purpose of research is to turn up to view new facts. Facts are presented as interesting, or as having a practical bearing, or as having no bearing at all. The prosaic, dull drudgery of tracing relationship is omitted. Yet nothing exists out of relationship. IOWA ACADEMY OP SCIENCES. 19 In the inductive sciences that deal with facts of most obvious bearings we are magnifying the importance of isolated details and largely ignoriDg the idea of relationship. As long as people fail to understand that nothing is superior to law, so long may we expect the search for perpetual motion, the elixir of life and the fabled pot of gold. Metaphysicians tell us that the idea of cause is intuitive, yet vast numbers of people act as though cause and effect had no relations whatever in some realms of human experience. The extraordinary success attained by many investigators and inventors has produced a widespread notion that these successful ones are creators rather than discoverers, and that their genius (so-called) tran- scends common laws. The spirit of speculation so rife in soci- ety at present seems to subsist largely on the idea that the common laws of experience are often inoperative. Can we wonder at the enormous sales of patent nostrums as long as there is a widespread opinion that medical science has no rational basis? Can we wonder at the successful impositions of faith-healers and medicine-men when each holder of a phy- sician's diploma is considered a law unto himself, entitled to experiment at his own sweet will on suffering humanity ? Is it strange that people fail to be guided by reason when the mate- rials of experience are like so much wind-blown chaff? Says the worldly-wise man of to-day: "My son, be a freak, an hon- est freak if convenient, but by all means be a freak, for in freak-ism is success." I therefore make no apology for presuming to make a plea for scientific thought. We may indeed be proud of our achieve- ments in science. In this, the latter part of the nineteenth century, the age of Edison, Pasteur and a host of other inves- tigators, we need make no defense of the position science occu- pies in human thought and action. The air ship, the electric engine, the dynamite gun, are but faint indications of what is yet to be accomplished. The triumphs of surgical skill are just begun. We see the forces of nature arrayed against each other to give a purer atmosphere, a richer soil, a freer life to mankind. Material considerations outweigh all others in the arena of public opinion. Some say the world has gone mad with science. Scientific studies have crowded themselves into the public schools, colleges and universities in spite of the opposition of the classics. The children lisp in scientific phrases, and the old men sigh lor the good old times when ignorance was bliss. 20 IOWA ACADEMY OF SCIENCES. I am neither a prophet nor the son of a prophet, nor am I related by blool or marriage to any prophet or son of a prophet. This age may be as badly ia need of prophets as any other age, but what it needs most of all is common sense methods of deal- ing with the problems that confront it. It seems to me we may profitably spend a little time in the consideration of some of the bearings of scientific methods on current thought and action. What is the scientific spirit? Some would say it is the spirit of the age. But it may well be doubted whether there is such a thing as a spirit of the age. With people and their wants so diverse, the general iastability of chaaging institutions make a universal animating spirit well nigh impossible. Bat the sci- entific spirit is something definite and characteristic. We may notice some of the things it is not. Ih is not the mere seeking for truth, for many who seek the truth are content with half truths. It is not enthusiasm, fcr the enthusiast too often stands in his own light. It is not the mere collecting of data, for facts and the records of facts in themselves are well nigh worthless. The scitntific spirit seeks to demonstrate no proposition; it is not partisan. In short, the man imbued with the scientific spirit seeks the whole truth in all its relations, and accepts its teach- ings rc-girdless of consequences. We need to scrutinize very carefully a large amount of the so called science aad scieatific methods of to day. The word scientist, has become a sort of abrakadabra, by means of which men hope to conjure up the objects of their hopes and desires. Science is too often interpreted as the triumph of shrewdness over simplicity, tne hoodwinking of the ignorant and innocent by the irgenious sharper, or the successful defeat of an opponent through chicanery. So far is this carrie d sometimes that we are ready to parajihrase that famous expression of Madame Roland and exclaim, "O, science what crimes have been committed in thy name." Any addition to our knowledge that does not afl:ect and improve all classes orAy lov-ers relatively the under strata of society; any advance in science which does not adapt itself to the masses only renders Ihem more helpless in the hands of the unprincipled but more intelligent. Science and scientific meth- ods are not for the few, but for the many. We must not assume that scientific methods have no place in common affairs. The scientific spirit is not a new but an old factor in human pro- gress. Bat we are too much inclined to relegate science and scientific procedures to the specialist, the scientist, and as the IOWA x\CADEMY OF SCIENCES. 21 specialist and the quack are not distinguishable by the masses the results are often lamentable. It is said that the crank^i and irrational enthusiasts initiate all reform, not the sober, scientific minds; that the scientific mind is conservative and never leads a reform. If this were true, nevertheless it is always the sober, common- sense ideas that really accomplish the final good. Reformers are too often impracticable men. It requires all the best scientific methods combined with the best judgoaent to achieve the final results and eradicate the evils that follow in the wake of every reformer. We need not so much reformers, for there are plenty of them, but rather the application of scientific meth- ods to the solving cf human problems. The charge is often made that the theoretical sciences are not practical; that they have no direct bearing on the pursuit of health, wealth, and happiness; that they yield no results of value adequate to the time and labor spent on them. Not long ago a bright young scientist lamented to me the fact that bis chosen line of work, systematic botany, was so useless, and that biologists in general contributed nothing to the welfare of 1he human race. It is said that Louis Agassiz made the pro- fession of naturalist respectable in America. Before his time it had been barely tolerated. While scientists of to-day are con- sidered equally worthy with other citizens, jet if their libors do nob directly materialize in glittering gold they are evv3ry- where confronted with the question, "Of what good is it?" And. owing to the peculiarities of the questioner, very frequsntly no satisfactory answer can be given. But an answer is needed. The teaching of that only which is directly practical tends to swamp ail progressive ideas. To restrict our energies to the already known is to degenerate. The cry, " Give us prac- tical Studies" is a note of warniog. It means stagnatiEg ten- dencies. To concentrate our energies on practical details 1oo often mearjs to ignore broader relations. We see a wonderful development of technical schools and appliances for the study of the applied arts. To many th^s seems the scientific goal. Many believe that all our energies should be directed to the promoting of the applied sciences, and that the day of theoret- ical science is past. So we heiir demands for manual training departments of our public schools; demands that the literary and general culture of school life shall be minimized for the enlargement of the practical sciences. We see the young being 22 IOWA ACADEMY OF SCIENCES. hurried into the trades and specialists sent out who know nothing but their little tread-mill round of practice. Is it true that botany, zoology, astronomy, and theoretical chemistry and physics have no great value, and that aside from their purely disciplinary effects they might as well be consigned to the rubbish heap? By many the field of the natural sciences is regarded as a playground where the mind majT- relax itself in intellectual somersaults. I would not be understood as antagonizing technical schools, or as depreciating the value of a technical education, but I do say that a general demand for the practical shows something wrong in our educational system. Either we are failicg to render the general culture effect of our teaching of much value or we are holding out false notions as to the practical value of our studies. I believe the former to be the true cause. We are not seeking to discipline the mind in proper chaonels so much as to fill up the cup of mental capacity with scholastic hodge- podge. The great fault of science in our educational scheme is not that it is not practical, but that too often it is not much of anything. We are loading our courses of study with a great bulk of interesting things, "such as every one ought to know something about." Look at the program of studies of the average high school: a term each of botany, zoology, geology, astronomy, physiology, physics, chemistry, etc. What knowl- edge does the student gain of the inductive methods of study? Occasionally a little, usually none. What practical ideas does he acquire? Some, no doubt, yet in the text- books ordinarily used error is about as conspicuous as truth. If we could con- fine our science teaching in 'the public schools to a year of physics and an equal amount of some other one science, and concentrate our energies on quality instead of quantity, method instead of matter, the good results would be ten- fold what they are at present. I am confident that in proportion to the time spent upon it our science teaching yields fewer results than any other line of public school work. The same criticism may be applied to many of our higher institutions of learning. It is no wonder the public calls for something practical. When the inductive sciences were given such a conspicuous position in our educational sysLem as they occupy to-day, it was thought society was in a fair way to free itself from many errors. But we have too often gone merely from an error to a blunder. Our college and university training has too often IOWA ACADEMY OF SCIENCES. 23 concentrated itself on less important details and ignored broader principles. While it can not be said of many of our colleges, as was recently said of a leading American univer- sity, that its zoological department had all run to scales and tail feathers, yet it is true that we are burying relationships under a bewildering mass of details. It must be confessed that some of our latest and most improved methods, notably of those biological studies included under the term morphology, have a tendency to increase rather than diminish this evil. There is always the danger of mistaking the means for the end. The fault of science teaching in our public schools lies in the fact that the student gains little or no conception of the bear- ing of scientific study on his life. The facts of science are pre- sented as so many isolated entities, interesting or uninteresting as the case may be. The high school must not be looked at and judged as a preparatory school for college training, but as a finishing school for a large part of our school population. The studies should be arranged not as leading to a college cur- riculum, but as preparing pupils for active lite, not by loading their brains with facts, but by training their mental activities. In this latter respect high school science makes a lamentabJe failure. I make no tirade against public schools. The fault lies largely and chiefly with the schools that prepare our teachers for science teaching, i. e. , our colleges and universities. We may say the public schools are behind the times in this respect, and they are merely following the lead of publishers of anti- quated text-books. This may be true, but nevertheless the evils of science teaching in our high schools are only minia- tures of those that exist so frequently in our colleges. What do I consider the pre eminent good to be obtained from the study of the inductive sciences? To enable the mind to detect the living truths; to perceive that every effect may be referred to an appropriate cause; to see that nothing is inde- pendent of relationships; to see that human activities are inti- mately bound up with other activities; and that the individual is but part of a whole. In other words, to adjust the mind to the sum total of its environment. When we can once establish our scientific ti-ainiugonsucha basis, empiricism, charlatanism, and all the frauds that prey on human credulity must beat a retreat. 24 IOWA ACADEMY OF SCIENCES. Fellow laborers, we are not doing our duty. We are too often content with quantity instead of quality. We cover too much ground and look for premature results. We fail to keep in mind the great idea, that method is more than matter, that the result we seek is not accumulation but power, not acquisi- tion but capacity, not bulk but strength. And we also forget that every scientist is a teacher, whether officially so or not. I believe that science and scientific study have a direct bearing on human existence. I believe that the sciences are not merely interesting, disciplinary as studies, practical when applied in the industrial arts, but that the more scientific people are the happier they are, not that they are warmer, or less hungry, or more intellectual, but that they are better adapted to their sur- roundings. In other words life ought to mean more than strug- gle, acquisition and success, it should mean better relation- ships. I do not believe that the chief end of scientific training is skill in invention. I do not think the chief business of the scientist is to produce something practical. This age is pre- eminently practical, and in so far as it is so it depends largely on scientific methods in vogue. But the satisfaction of bodily wants and natural ambitions is not the goal of scientific research. We need not less but more theory with our practice. The man without a theory is as unbalanced as one with nothing but a theory. The aim of scientific research is to find the ideal adju&tment of man to his enviroum;ent, and that relation will never be attained by purely practical means. We see to-day an immense number of so-called investigators engaged in original research. Probably one-half of these know little or rothing beyond their specialties. Many of them are engaged in matters of little general import, and see only a very circumscribed horizon. Many of them are unable to see the relations of their special studies to anything else. So they drift into empiricism, narrowness, and dogmatic assertions. We are leaching men to specialize before they can generalize, and the results must be unfortunate. A large part of these investigators are entirely out of place. To become a specialist in science one must be more than merely able to manipulate a microscope, or to set up a dynamo, or to mix chemicals without a disastrous explosion. Whatever may be said pro and con regarding the old system of industrial apprenticeship, this is certain, that no one can become a reliable investigator without a long and laborious service of preparation. We are putting IOWA ACADEMY OP SCIENCES. 25 "the label, investigator, upon too much crude material. To quote President Coulter: "Teachers assume a serious respon- sibility in urging born hod carriers to become architects." I do not wish to be understood as decrying original research or specialization of studies. On the contrary, I believe every earnest thinker needs to concentrate his energies now and then on special investigation, but every act in specialization should rest on a foundation of broad culture. No scientist should be content to pass off the field of adivity without leaving the store of human knowledge richer for his having lived. If we consult the life records of those who have done most to put the various branches of science on a broad rational basis, we see that they have been men who have got at the heart of nature through special investigations. Only those who have labored them- selves can rightly interpret the labors of others. Knowledge is not the goal. Truth for truth's sake may be good, but not h>est. Unrelated ideas are as valueless as mummies buried beyond all discovery. We are making an egregious mistake when in our teaching or researches we emphasize a detail here and a detail there and utterly fail to find any relationships. Yet this is just what is done over and over again by our so-called investigators. Year after year they extol their special hobbies and lament that the world calls them visionary. I believe in the popularization of science. lb would be entirely out of place for me to assume that any member of this academy believed in what is known as popular science, which in fact is usually no science at all. I believe that science should be made popular, not by prostituting its aims and methods to the pleas- ing of public fancy, but by educating the masses in the methods and applications of science. Correct thinking is prerequisite to correct acting. Yet how often do we labor simply to reform the acting! Comparatively speaking, of what lasting good can be the triumphs of science of our day if only the purely practi- cal results impress themselves on the public mind? If our dis- coveries, little and big, are to be applied as so many patent nostrums how meager the results! If the rationale of science is to be restricted to the sphere of the highly educated classes and the wonderful results of research are to be regarded as empirical by the masses, how discouraging the prospect to one who has at heart the welfare of the whole race! Pasteur and others have well nigh succeeded in placing medical science on a rational basis, yet how few comprehend the actual state of 26 IOWA ACADEMY OP SCIENCES. matters! How many physicians themselves look upon their profession as founded on empirical data! The failure of the public to recognize fundamental principles accounts largely for the success of many of the frauds of our day. We look upon professional and technical schools as places where the student gains skill in manipulating and proficiency in experimenting, and too often that is all they are. The scientist is often justly accused of isolating himself and his work from the sphere of human activity, of seeking his little bit of truth merely for the truth's sake, never dreamicg that his greater duty is to relate himself and his work to the great body of truth. No one has a natural monopoly on truth any more than on any other reality. I do not believe in a scientific Olympus where above the clouds and turmoil of the common place, far from the maddening crowd, can dwell the votaries of science indifferent to the prob- lems that perplex the masses. If the true aim of scientific study is to find the ideal adjustment of man to his environment our present progress in reahzlrig that aim is altogether too slow arid uncertain in comparison with our pretensions. We must make radical changes in the ways we are presenting the facts and methods of science to the public. The observing minds of to-day cannot fail to see that modern civilization is on the point of some great changes. The first half of the twentieth century will see enacted what would now seem subversive of the present best order of things. The wisdom and folly, success and disaster, attending these changes will depend largely on the scientific or unscientific means employed in attaining desired ends. It is basest folly to attempt to solve society's problems with leaving out of sight fundamental human laws. There is no true science of sociology yet formulated. The dictum of the social reformer is the baldest empiricism. We can never get anywhere by Bellamy colonies and Brook Farm experiments. Why then advocate social schemes to which not even the angels in heaven could conform much less men of tlesh and blood? If sociology is. ever to be established on a rational basis it must take man as he is, and as he has been, a creature of bone and sinew, ever striving for better conditions and never presenting phenomena that are independent of natural laws. Sociology can be made a science only by laborious patient endeavor. Humanity's problems cannot be solved in a day, nor a year, nor a lifetime- No one man can solve them. The chemist, the biologist, the IOWA ACADEMY OF SCIENCES. 27 physicist, the ethnologist, the mechanic, must assist. What a pathetic spectacle is presented iu the charitable and mission work man is doing for his fellow man. It is the old story of eradicating one evil and sowing the seeds of a dozen more. How little of philanthropic work aims at more than alleviating present conditions! Were it not for the fact that in some instances, and they are all too few, the highest of scientific attain- ments are being directed toward studying and correlating the fundamental laws of society for the purpose of establishing abid- ing criteria of action I should deem the field of social reform utterly hoj)eless. We evidently need not so much a change of method here as a change from no method at all to a scientific method. The scientific world stacds committed to the theory of evolution, for by no other can the existing order of things be explained, even though much is as yet unexplained. It is the only thiog that can bind our scientific knowledge into a coher- ing whole. Any ignoring of it plunges into deepest empiri- cism. The ideas of growth, development, change from simple to complex, and resultiag inter-relationships are extremely vague in popular thought. Particular modes of procedure are often mistaken for general principles, this or that theory for a law. One of the greatest obstacles that the theory of evolution, the only real interpreter of lacts, has had to contend with has been and is now the widespread belief in infallibility — infallibility of all knowledge. Yet no more important truth needs to be learned than that the wisdom of to-day may become the folly of to-morrow. A change in belief is too often mistaken for an exchange of an old for a new dogma. The fact that scientific theories and knowledge in the year lb96 are not like those in the year 1859 constrains many, particularly those of a theolog- ical bias, to deny any truth in either. Nor do many scientists place themselves in any more commendable attitude. Some of our scientists give evidence of as intolerant a dogmatism as ever disgraced ecclesiastical history. The man who assumes infallibility of scientific knowledge, in whole or in part, thereby puts himself beyond the pale of truth seeking. President Coulter notices among botanists of to-day several bad tendencies. Some of them have so wide an application that I may use them in recapitulating my preceding statements: 1. The tendency to narrowness. This is shown in the magnifica- tion of details, and minimizing of relationships; in the failure 28 IOWA ACADEMY OF SCIENCES. to recognize the applications of science in whole or in part. 2. The tendency to certainty — dogmatism, infallibility. This reaches its culmination in the balancing of a scientific chip on the shoulder. 3. The tendency to mistake acquisition for the power to do something. This is profoundly characteristic of science teaching in our educational system. 4. The tendency to immature research — dilettantism. To which I would add: 5. The tendency to Phariseeism; the scorning of all not scientists; a holier-tha,n- thou attitude that puts the possessor out of touch with human struggle; the despisicg of all efforts that are not of a certain superfine order; lack of charity for fellov/ scientists; criticism of every man's honest endeavor. 6. The tendency to minimize theoretical considerations; the cry for the practical. It is obvious that these tendencies cannot fail to create a feeling in popular thought of distrust, contempt, and disregard of science aud scientific methods. The effect on the scientist is stultifying, narrowing, dogmatizing. The worst result will be that progress in solving humanity's problems will be retarded. Every tendency to restrict the application of scientific methods is detrimental to progress. I believe that science and the methods of science must take in the future a greater share in shaping the destiny of the race than they have in the past, not so conspicuous perhaps, but none the less real. I believe most profoundly in an earthly order founded on a scientific basis. I see no other hope for society. I am not visionary. Hence I can make no forecast of a rainbow- tinted land of promise, wherein the plutocratic lion deals with the democratic lamb on a strictly scientific basis. Scientific method is not a universal panacea. But the problems that perplex humanity will be settled justly only as they are approached from a rational standpoint, I am not pessimistic as to the future of science. But the best results will not be achieved unless some of our methods are radically changed. Materialism and philosophic nihilism are no bugbears to me. Though science and scientific methods cannot make a perfect humanity, any attempt to solve the problem by ignoring science is basest folly. I believe the day will come when empiricism and its twin brother dogmatism will yield the field to the scientific spirit. Speed the day ! IOWA ACADEMY OF SCIENCES. HOMOLOGIES OP THE CYCLOSTOME EAR. BY H. W. NORRIS. The ear of the Cycles tomata has until recently been consid- ered so peculiar as to render it difficult to explain its relations to the typical Vertebrate ear. Then again, the diversity of structure in the auditory orga,n of the Cyclostomes themselves renders the task of homologizing the various parts somewhat uninviting. Our exact knowledge of the structure and relations of the ear of the Cyclostomata begins with the researches of KeieP, in 1872. His predecessors had assumed that the auditory organ of the Cyclostomata was a thing sui generis, hence most of their observations were defective. Ketel was the first to attempt to find a fundamental type of the vertebrate ear. While the results of his studies in that direction did not find ready accept- ance, nevertheless, in the light of most recent investigations, we see that his conclusions were essentialiy correct. In the light of zoological knowledge tAventy years later, his opinions would have seemed not only reasonable, but they would have been considerably modified from their original form. Johannes Miiller" in 1836 discovered the semicircular canals in the ear of Petromy zon, and that they were only two in number. DameriP in 1800 claimed to have found the canals, but his statements are extremely vague. Other observers, PohP, Weber\ Blain- ville^ Rathke' and Breschet^ had denied the existence of the 1 Ueber das Geliorogan der Cyclostomen— Basse Anat. Studien, 1872. 2 Ueber den cigeiithumlichen Ban des Gehororgans bei den Cyclostomen. Fortsctz d Vergl. Anat. d. Myxinoiden in Ahli d. K. Akad. d Wissen. Berlin, 1836. 3 Anatomie des Lamproies Memoires d anatomic comparee. Paris, 1800. ^Expositis generalis anatomica organ! auditus per classes animalium. Vindo- bonae, 1818. SDe aure et auditu hominis et animalium. Leipzig, 1820. 6De I'organisation des animaux ou Principes d'anatomie comparee. Paris, 1822. 7 Bemerkungen uber den inneren Bau der Pricke. Danzig, 1826. SRecherches anatomiques et physiologiques sur I'organe de I'ouie des poissons.. Acad, des Sci Sava7is Eirangers. 1838. 30 IOWA ACADEMY OF SCIENCES. canals, or at least any more than as rudiments. It was very early recognized that two distinct forms of ear were to be found in the group of Cyclostomata, the one found in the Myxine and the other in the Lampreys. MtiUer'-' first gave any adequate description of the ear of Myxine. Previously Anders Retzius^" had given a very meager description. Ketel attempted to show that the ear of Myxine is genetically related to that of higher vertebrates through the ear of Petromyzon as a connecting link. Unfortunately he failed to recognize the existence of semicircular canals in the ear of Myxine, considering the mem- branous vestibule as merely a ring. Ibsen" had in 1816 recog- nized a semicircular canal in Myxine and two ampullae. Ketel considered the Cyclostome ear as in an arrested stage of evolution, and that it really represented an ancestral condi- tion of the Vertebrate ear. He sought for traces of the third or horizontal canal in Petromyzon, and believed he found it in a sense organ connected with the crista acustica of the anterior canal. The cochlea he found represented in the " sackartiger Anhang" of the membranous labyrinth. Ketel failed to com- pletely homologize the Cyclostome ear with that of the Verte- brate type, because he did not recognize the existence of semicircular canals in Myxine, and further, because, working from the higher types downward, he had not grasped the idea of the fundamental form of the auditory organ. Gustav Eetzius^^ in 1881 recognized the existence of a single semi- circular canal in Myxine; but he did not agree with Ketel as to the relationships of the ear of the Cyclostomata. It remained for Ayers'^ in 1892 to establish beyond question the rank of the Cyclostome ear. Starting with the idea that the Vertebrate auditory organ is composed of modified sense organs of the lateral line system, he shows almost beyond question that the Cyclostome ear is not a degenerate structure, but rather repre- sents an ancestral type. According to this interpretation, we recognize in the Vertebrate ear iwo originally distinct parts, an anterior utriculus and a posterior sacculus, with which, and forming a part of, are a nuaiber of canals. The ear of Myxine 9Loc. cit. lOYtterligare Bidrag till anatomien af Myxine glutinosa. Kongl. Vct.-Almd. Ilandl. Stockholm, 1824. 11 Anatomiske Undersogelser over Orets Labyrinth, afsluttet af Forgattern i 1846. i2Das Gehororgan der Wirbelthiere I, Stockholm, 1881. iSVertebrate Cephalogenesls, II. A Contribution to the Morphology of the Verte- brate Ear, with a Reconsideration of its Functions. Journal of Morphology, Vol. VI, Nos. 1 and 2. 1893. IOWA ACADEMY OF SCIENCES. 31 is seen to consist of a utriculo-sacculus, imperfectly divided into two parts, into which open two canals, each with an ampulla containing a sense organ. Unlike the condition in the Lampreys, or higher Vertebrates, the two canals unite with each other without an unpaired connection, or commissure, with the vestibule. Hence the failure heretofore to recognize more than one canal. The ear of Petromyzon differs from that of Myxine chiefly in the fact that the two canals are connected with the membranous labyrinth at their point of union by an unpaired commissure. The two semicircular canals of the Cyclostome ear correspond to the anterior and posterior canals of higher Vertebrates. The anterior is connected with the utriculus, and the pos- terior with the sacculus, at their ampullar ends. In other vertebrates the connection of the posterior canal with the sac- culus is lost at an early stage of development, so that the three canals in the adult are connected only with the utriculus. This, however, is not the ancestral nor the early embryonic condition. Embryology" indicates that the vertebrate ear early consists of two parts, an anterior utricular and a posterior saccular region. This is the adult condition in the cyclostomes. Ayers calls particular attention to the fa^jt, which Ketel, Hasse, and Retzius had already noticed, that in Petromyzon there are two distinct endolymphatic ducts, a further striking indication that the vertebrate ear is a two fold structure in origin. Ayers, however, gave the first explanation of their presence. That the existence of these two ducts is a funda- mental characteristic, is indicated by the fact that they are distinct from a very e?.rly stage of development. Unfortunately the material at my disposal does not give a complete series of the development of the ear, but the stages studied by me indicate that Ayers is correct ia his interpreta- tion of their presence. Thus we see that recent investigation confirms the opinion of Ketel that the auditory organ of the Cyclostomata is not an aberrant structure. Ayers may be said to be the first and only one who has given a coherent explana- tion of the structure and origin of the Vertebrate ear. "H. W. Norris. Studies on the ear of Amblystoma. Part I. Journal of Morphology, 32 IOWA xVCADEMY OF SCIENCES. ORIGIN AND SIGNIFICANCE OF SEX. BY C. C. NUTTING. This paper is not presented as a contribution to our knowl- edge of the subject of the origin of sex, so much as an attempt to express concisely a theory of sex drawn from various sources, but pdncipally from a work on the "Evolution of Sex" by Geddes & Tnomson, a work which seems to me to mark an epoch in the science of philosophical biology. My excuse for presenting this subject before you to-night lies in the fact that it has been my fortune within the past year to persoaaliy investigate the origin of the sex-elements in one group of animals, the hydroids, and to follow in the footsteps of that great master August Weismann, whose studies have given such an impetus to the search for truth in the realm of sex and heredity. My own studies have resulted in a conviction that there is truth in the theory advanced by Geddes & Thomson, and my effort this evening will be to state this theory, in a slightly modified form, in a series of definite propositions, each one of which I believe to be defensible, if not invulnerable. First, however, it will be necessary to call to your minds the most important facts concerning reproduction among the one- celled animals, or Protozoa. The simplest form of reproduction is that of the amoeba, in which there is a simple division of the body mass of the parent cell into two portions, each of which becomes an independent organism. This is known as the process of reproduction by fission. Turning to a somewhat higher group of Protozoa we find another step introduced in the reproductive process. If we study the Paramecium, for instance, we will find that it multi- plies by fission, as does the amoeba, but that at intervals IOWA ACADEMY OF SCIENCES. 33 another process takes place, two individuals becoming adher- ent, the cell walls in the region of contact being dissolved as punctured, and an interchange of the protoplasm taking place. After this the individuals separate and the process of fission is renewed, and goes on for many generations. Ultimately, how- ever, the process of conjugation is again resorted to. In certain of the Vorticellidce the reproductive process is still further complicated by the fact that the fission is not simple but multiple, one of the halves resulting from simple fission again dividing into a number of small ciliated bodies, each of which is capable of uniting with a normal vorticella ia the pro- cess of conjugation. In certain Acinetans the multiple fission is internal, the parent cell having its contents broken up into a number of ciliated bodies, which escape through the ectosarc. We thus see that in going from the lower to the higher Pro- tozoa we find the reproductive process growing more and more complicated. First in the amoeba we find simple fission, then in the Paramecium we find simple fission plus conjugation. In the vorticella we have simple fission plus multiple fission plus conjugation. In the aciuetan we find simple fission plus inter- nal multiple fission plus conjugation. Such, then, are the facts. We now turn to seek an^ explanation. Anabolism is the constructive, conservative, potential energy of the cell. Katabolism is expressed in the destructive expenditure of this energy in active or kinetic processes. The growth of any normal cell has a necessary limit due io a purely physical cause. The mass increases as the cube ot the diameter, while the surface increases only as the square:- The surface performs the function of respiration, but it cannot perform this function for an unlimited mass any more than a cubic inch of lung can perform respiration for a full grown, man. As a cell increases in size its mass increases more rapidly than its surface, until a point is reached beyond which it can not grow, because the surface can supply no more oxygen. It is worked to its limit, and can not respond to increased demands. At this stage there are three possibilities: First. — Death, which would end the question. Second. — Stationary balance, which is impossible. 3 84 IOWA ACADEMY OP SCIENCES. Third. — Katabolism, which would cause the cell to disappear, or auabolism would recur at a certain point, and we would thus have an alternation or rhythm of katabolic and anabolic states. This is logically conceivable, but it would debar the possibil- ity of reproduction, and the individual cell would be theoret- ically immortal, but as a matter of fact would be destroyed ultimately by accidental means. If, when the cell had reached the limit of size, it should divide, either accidentally or otherwise, there would result two individuals, both small enough to admit of an expression of anabolism in growth. There would thus be two organisms to hold the fact of spe- cific existence instead of one. Therefore, any cell which would divide would have double the chance of perpetuation that a single cell would. In other words, cells capable of spontaneous or mechanical fission would be selected and preserved by natural selection. Let 1,000 generations proceed thus by simple division or fission. By this time considerable differences would exhibit themselves in the descendants of our original cell, owing to dif- ferences in environment and food supply. One line of cells would be abundantly fed, would grow large, inactive, anabolic. Another line would be insufficiently nour- ished, and would grow smaller, more active, katabolic. Taking the large anabolic cells, we find: First. — They tend to become more and more inactive. (Activ- ity may express itself either in motion or cell division.) Second — The anabolic cells accordingly tend to become quies- cent on the one hand, and to cease dividing on the other. Third. — This tendency would ultimately result in death, if not in some way counteracted. Taking the smaller katabolic cells, we find: First. — They tend to decrease in size. Second. — They tend to become more and more active. Third. — Their expenditures would eventually bankrupt them, they would be worn out, would die of exhaustion. Taking the two kinds of cells we find: First. — One needs something that can express itself in cell division, Katabolism. Second. — The other needs nourishment which would express itself in growth, Anabolism. IOWA ACADEMY OF SCIENCES. 35 In other words: One is full and dying of plethora. The other is hungry and dying of excessive expenditure of energy. It would evidently be a good thing for them to pool their issues. This is effected by the process of conjugation, whereby: First. — The small, active, katabolic cell imparts its energy (kinetic) to the large passive cell, and that energy expresses itself in cell division. Second.— The large, passive, anabolic cell imparts to the daughter cells its anabolic propensities which express them- selves in groivth. la other words: The anabolic cell receives the impetus necessary to cell division or fission, and the katabolic cell receives nourishment and the tendency to grow. What brings them together? Hunger, or its equivalent. Hunger is a fundamental property of all things that need nourishment. It is therefore a property of katabolic cells. The small, active cells need nourishment. The large, anabolic cells are packed full of nourishment. Example — Acinetan. An intensification of this process would be brought about in time by natural selection and would result in multiple fission, external and internal, which is the highest expression of sex found among the Protozoa. SEX IN THE METAZOA. Eydroid as a Type. — The male cells originate from amoeboid endodermal cells which differentiate along the line of katabo- iism. They divide repeatedly and eventually become the smallest and most active cells in the colony. The female cells originate from amoeboid endodermal cells which differentiate along the line of anabolism. They grow excessively and become passive and circular in outline. They eventually become the largest and least active cells in the body. These two cells unite, or the smaller seeks the larger and is absorbed in it. As a result: 36 IOWA ACADEMY OP SCIENCES. First. — The small, active cell imparts its kinetic energy to the large, passive cell, and that energy expresses itself in cell division. Second. — The large, passive, anabolic cell imparts to the daughter cells its anabolic propensities, which express them- selves m growth. By the growth and division of cells every organism, from the hydroid to man himself, attains its perfection. It will be seen from what has been said that there is no fundamental difference between the reproductive processes in the Protozoa and Metazoa. Ail of the complicated machinery associated with sex in the higher forms are merely accessory to the fundamental fact of the meeting of two cells, an inter- mingling of protoplasm and a subseqiient cell division, all of which phenomena are essentially present in the conjugation and fusion of the Paramecium for instance. As to the significance of sex, it is not sufficient to say that it serves to perpetuate the species. It does much more. It serves to improve species in that the commingling of the char- acteristics of two parents furnishes the main potentiality for individual variation among the offspring. Indeed, Weismann stoutly maintains that we have here the only cause for indi- vidual variation upon which natural selection can act, and he believes that evolution would be impossible among sexless animals. However this may be, it is clearly true that progress is much more rapid and certain by virtue of the fact that most individuals animals have a> father and a mother. It would be impossible in the limits of this paper to discuss the tremendous ethical, social and moral significance of sex. It must suffice to suggest that altruism had its birth in the world when brutes first cared for and protected their helpless young, and that through the social relations of parent and child, hus- band and wife, all that is purest and best in human affairs found its inception and its impetus. IOWA ACADEMY OF SCIENCES. 37 THE REDUCTION OF SULPHURIC ACID BY COPPER AS A FUNCTION OF THE TEMPERATURE. LAUNCELOT W. ANDREWS. The object of the experiments described in this paper was to determine whether the reduction of sulphuric to sulphurous acid by copper takes place at a lower or at a higher temper- ature than the incipient dissociation of the former compound into water and the acid anhydride. The sulphuric aci4 employed was the ordinary pure product, containing 98.4 per cent of Hg SO^. The apparatus illustrated in the figure was used. The method employed was to heat the copper with the sul- phuric acid (in flask B) gradually in a sulphuric acid bath while 38 IOWA ACADEMY OP SCIENCES. passing a dry current of air or of carbonic anhydride through it. The escaping gas was then tested (in flask C) by suitable reagents, to be described, for sulphuric and sulphurous anhy- drides respectively. Flask A contained concentrated sulphuric acid of the ordinary temperature (25°C) to dry the gas, which was usually passed at the rate of about eighty bubbles per min- ute. The importance of securing absence of dust from the acid being recognized, the interior of the whole apparatus was washed with boiling concentrated sulphuric acid and dried in dustless air. Experiment I. — Flasks A and B were charged with concen- trated sulphuric acid and C with a solution of barium chloride. Air was drawn through the whole in a. slow current for fifteen minutes. The solution in C remained clear. B was now very slowly heated while the current of air was maintained. Before the bath reached 70°C there appeared in C a faint tur- bidity of barium sulphate, which at the temperature named became distinct. At 60°C the solution 'remained unchanged, even after passing the air for a long time. Hence sulphuric acid of the given concentration begins to give up sulphuric anhydrides, that is, it begins to dissociate at a temperature lying between 60° and 70°C. Experiment II. — The apparatus charged as before, with the addition of pure bright copper wire in B, and with highly dilute iodide of starch instead of barium chloride in C. After passing air for several hours at the ordinary temperature, much of the copper had gone into solution and anhydrous copper sulphate had begun to crystallize out, but the iodide of starch, made originally very pale blue, retained its color. This shows that in the presence of air, sulphuric acid is attacked by copper at ordinary temperatures, but without reduction of the acid. The reaction must take place in accord- ance with the equation: 2Cii+0, 2H,SO,=2Cu S0,+2H,0. Experiment III. — This was like the last, except that the appa- ratus was filled with carbonic anhydride, and a current of this gas was substituted for air. The copper was not attacked, and the starch iodide was not decolorized. The temperature of B was now slowly raised, and when it reached 90° the solution in C was bleached. In a sim- ilar experiment a solution of dilute sulphuric acid, colored pale straw with potassium bichromate, was used as an indicator for IOWA ACADEMY OF SCIENCES. 39 sulphurous acid in C. In this case the change of color did not occur until the temperature had risen to 108°, the indicator being, as might be expected, less sensitive than the other. Experiment IV. — Same as III, except that a reagent for both sulphuric and sulphurous acid was used in C. This reagent was prepared by slightly acidifying a solution of barium chloride with hydrochloric acid and then adding enough potassium permanganate to render the solution pale rose color. This indicator is capable of showing the presence of consid- erably less than do m. g. of sulphurous acid. When the temperature of the bath had reached 70 °C the solution in C was distinctly turbid with barium sulphate, but its color was unaltered. At 86° it began rather suddenly to bleach, and at 87° it was colorless. Special care was taken in filling B not to get any sulphuric acid on the neck or sides of the flask. A repetition of this experiment gave identical results, the gas being passed at the rate of two to three bubbles per second. The conclusions to be drawn from this investigation are: First. — That the dissociation of sulphuric acid of 98.4 per cent, begins to be appreciable at a temperature somewhat below 70°, which may be estimated at about 67°. Second. — The reduction of sulphuric acid by copper does not begin below 86°, that is, not until the acid contains free anhydride. The assertion made by Baskerville,^ that sulphuric acid is reduced by copper at 0° is, therefore, incorrect. He appears to have based the statement, not on any demonstration of the formation of sulphurous acid, but solely on the formation of copper sulphate, which occurs, as I have shown, ^ in conse- quence of the presence of air. A more careful repetition of his experiments under condi- tions securing entire exclusion of air can but lead him to a different conclusion from that he obtained at first. The fact adduced by him that under certain conditions cuprous sulphide may be formed by the action of the metal upon sulphuric acid does not allow any conclusions to be drawn respecting the presence of "nascent" hydrogen, since it may be explained perfectly well either by the direct reducing action ijournal of the Am. Ohem. Soc, 1895, 908. 2Traube has shown the same thing for dilute sulphuric acid. Ber: 18, 1888. 40 IOWA ACADEMY OF SCIENCES. of the copper or by Traube's theory which is backed up by almost convincing evidenced Stannous chloride will reduce sulphuric acid with formation of hydrogen sulphide and free sulphur, an analogous reaction in which the assumption of "nascent" hydrogen is inadmissible. 3Moritz Traube, loc. cit. and Bcr., 18, 1877, etc. €LAYS OF THE INDIANOLA BRICK, TILE AND POT- TERY WORKS L. A. YOUTZ, INDIANOLA. Analyses of several clays from a brickyard at Indianola have recently been made by me to go into a report of the Geological Survey of Warren county. Though it has been said that a knowledge of the constituents of a clay, determined by a purely chemical analysis, is of very little value to a practical brick- maker, yet in comparing the analyses of these clays and those from other vicinities, it seems that points of great value to the m.anufacturer are made plain, and points that can be derived from no other source. So I wish to give a few ideas which came to me as I made the comparison, as points, of local inter- est at least, were, it seems to me, clearly brought out. In order to get an intelligent idea of the value of this clay for brick and tile it may be helpful to give a short outline of some of the qualities of clay for the various kinds of brick. The quality and character of brick depends, of course, pri- marily upon the kinds of earth used; the mechanical mixing, drying and burning being important items, however. The varieties of clay most frequently used for common bricks are three. The so-called blue clays, hydrated aluminum silicates, combined with small quantities of iron, calcium, mag- nesium and alkalis; sandy clays or loams, and marls which con- tain a large proportion of lime and magnesium. In addition to these are the clays for special kinds of brick, as fire-brick, pottery, terra cotta, etc. Hydrated silicate of aluminum is infusible even at the most intense furnace heat, but if these be jnixed with alkalis, or alkali earths, it becomes fusible, and in IOWA ACADEMY OF SCIENCES. 41 about the proportion of the admixture. So that clays con- taining more than about 3 per cent of lime can not be made into good brick from this fact, and that the calcium carbonate being reduced to calcium oxide by heat will slack by moisture and the brick then crumble. However, by burning at a higher temperature than is usual the injurious effect of lime can be greatly overcome unless it is in so great quantity as to lower the fusing point too much. The amount of combined water in a clay is a very important item in determining its adaptability for good brick. In a pure hydrated silicate of aluminum so much water will be given off by burning that the brick in going through the sweating process become too soft and run together, or else crack so as to be made much inferior. So all pure clays for brick must be mixed with sand, powdered quartz, powdered brick, gangue, or some such material, in order to alleviate this difficulty. In loams a certain per cent, of lime or similar material needs to be added to act as a flux, as too much sandy material makes the brick brittle. Marls in this country have been, it appears, but little used for brick making, as the lime is supposed to be detrimental. Yet in Europe a very fine malm is made from marls having as high as 40 per cent or more of calcium carbonate. They simply heat the brick probably 200 degrees higher than the ordinary brick. This gives the brick a white color instead of red, the iron and calcium being united with the aluminum as a ferric- aluminum calcic silicate. Of the Indianola brick clays, analyses of two samples will be sufficient for our purpose of comparison. The brick are made from a certain small deposit of blue clay, taken probably twenty feet below the surface, mixed with a much larger pro- portion of a darker colored clay immediately above this blue layer. The lower strata gave the following analysis from the air dried samples: Si O2... 66.779 AljOg. 19.525 Fe^ O3 - 72 Ca O trace Loss dried at 100° 8.08 Loss by ignition 5.48 Total 100.584 42 IOWA ACADEMY OF SCIENCES. The sample above this as follows: SiOj.... 67.85 Al^Og+FejOg 20 45 CaO 1.19 Md O trace K2 O... trace Loss dried at 100°.. 3.47 Loss by ignition 7.12 Total... 100.08 It will be seen that in each there is a large per cent, of silica and alumina. The upper containing more free silica, conse- quently gave a higher per cent of silica and alumina, but con- tained a considerably smaller per cent, of hygroscopic moisture, The higher loss by ignition in the upper stratum being due doubtless, to a larger amount of organic matter near the sur- face. Lime was present in the upper stratum in appreciable quantity, and iron in small quantity in each. A trace of man- ganese oxide in the upper stratum. From Crossley's " Table of Analyses of Clays " for common brick we take three average samples, which are as follows: Common brick clay: Si O2 49.44 Alj O3... 34.26 Fcj O3 7.74 CaO 1.48 Mg 0-... 5.14 Water and loss 1.94 Total 100 00 Sandy clay: Si Oj 66.68 AI2 O3 26.08 Fe^ O3 1.26 Mg O trace Ca O 84 Water and loss 5.14 Total 100.00 Marl. — London "Malms."' Si02+Al2 03 43.00 Fej O3- 3.00 CaO... 46.50 Mg O 3.50 Water 4.00 Total 100.00 IOWA ACADEMY OF SCIENCES. 43 Comparing the Indianola clay with these, with the first it is at variance especially in silica, alumina, and oxide of iron. With the second it corresponds very well except in A]., O3 and in hav- ing more water. But we could not call it a sandy clay. The upper layer contains a little sand, but the lower practically none. To the third there is no comparison. It seems then as these clays represent the three common classes of brick, that this clay at Indianola must represent a kind which though it may make, as it has proven itself to do, good common building brick, yet it may be adapted to other kinds of brick. The Stourbridge, England, clays, from which the world- famed fire brick are made, yield, by averaging the analyses of four different clays, the following proportion of materials: No. 1. Si O2 64.95 Alj O3..-. 2292 Fe2 O3 1.90 Ca O+Mg O .64 Kj 0+Na2 O 37 Hj Oloss.- 9.60 Total... - 100.38 Woodbridge fire clay bed, New Jersey, also famous for its- quality of refractory clays, as follows: No. 2. Si O2 combined 40.50 Si ©2 free (quartz sand) 6.40 46.90 AI2 O3.-. 35.90 35.90 TiO^ 1.30 1.30 KjO+NajO. .44 Fe2 O3 1.10 154 H2 O combined 12.80 Ha O hygroscopic 1.50 14.30 Total... 99.94 99.94 From Trenton, New Jersey: No. 3. Si O2 combined 17.50 Si O2 free (quartz sand) 56.80 74.30 AI2 O3 18.11 18.11 K2 0+Na2 0+CaO 1.07 1.07 FejOg+HzO 6.99 6.99 Total.... 100.47 100.47 44 IOWA ACADEMY OF SCIENCES. These three samples of fire brick clays are selected from a list of about 100 analyses of clays taken from various parts of the United States and Europe, and, I think, represent a fair average as to composition. From these it may be seen that in general a large amount of Alg O3 and Si O^, with small amounts of alkali, or alkali earths, or iron oxide, is characteristic of these highly refractible clays. Further, it seems that a large per cent, of Alg O3 over Si O^ increases the inf usibility. However, there seem to be two varieties of fire clay, varying considerably in composition, which make equally good fire brick. One is where the silica is nearly all combined with a percentage of about 40 to 50 per cent, and a large amount of aluminum oxide — probably 25 to 35 per cent. — and water making up the greater amount of the remaining 100 per cent. This clay, of course, as the per cent, of the alumina over the silica and these two over other metallic oxides increases, finally runs into kaolin. The other kind is one where the combined silica is small and the alumina less than in the first case, the combined silica prob- ably not having a much higher percentage than the alumina, the remaining part being made up almost entirely of free silica (quartz sand) and water. No. 2 above illustrates the first and No. 8 the second class. By comparing the Indianola clays with these it will be seen that the average is essentially the same as No. 1. This being an average of several samples of each of the two classes referred to above, i. e. , No. 2 and No. 3. But in the Indianola clays there is but small amount of free silica. This being the case, and from the fact that it is so free from magnesia, lime, potash, and iron oxide, it would seem that this clay would be well adapted to be used as the clay basis of fire brick, and then the necessary amount of free silica (either powdered quartz, glass, or silicious brick dust) be added. By a very careful com- parison of all the clays the analyses of which I have, and the qualities of brick made from these, theoretically it seems to me by this means very superior fire brick could be made. The fusibility of bricks made by this method with this clay as far as I know has not been determined. Yet it seems it would be an experiment worth trying, and one which we may attempt at a later date. I am informed that the pottery made at this plant is not made from the clay at Indianola, but is made from clay taken just above the upper vein of coal at Carlisle, Iowa. I have not analyzed this clay and cannot at present make a comparison. IOWA ACADEMY OF SCIENCES. 45 UNIT SYSTEMS AND DIMENSIONS. T. PROCTOR HALL. (Abstract.) [Published in full in Electrical World February 7, 1896.] The three fundamental units of the C. G. S. system are reduced to two when the unit of mass is defined as the quantity of matter which, by its gravitational force, produces at unit distance unit acceleration; and these two to one when the unit of time is defined as the time taken by an ether wave one cen- timeter long to advance one centimeter. A table is given show- ing the dimensions of units in each of these three systems, and the advantages of the latter are pointed out. A MAD STONE. BY T. PROCTOR HALL AND ERNEST E. FRISK. Here and there is found a man possessing a pebble for which he claims the remarkable power of preventing hydrophobia when applied to the wound made by a mad dog. We have been unable to find any record of a scientific examination of a mad stone or a scientific test of its properties. This may be partly accounted for by the rarity of the stone, and the high esteem in which they are held by their owners. A popular idea is that they are formed by accretion in a deer's stomach. Last summer while visiting the Mammoth Chimney mine, eighteen miles south of Gunnison, Col., a prospector called attention to some small pieces of light- colored rock from the mine, which adhered very strongly to the tongue. Some 46 IOWA ACADEMY OF SCIENCES. specimens were secured as a curiosity, and after being properly- rounded, to obscure their origin, were recognized by some of the "old inhabitants" as genuine mad stones. Their curative power has yet to be tested, but in all other respects, apparently, their identification is complete. The fragments removed from the larger specimen were pre- served for examination and analysis. The specimen itself is larger than a hen's egg, light gray in color, with darker specks of iron scattered through; distinctly stratified; with no cleavage planes. The luster on a broken surface is resinous, on a worn surface more earthy. Its hardness, considered as a rock is 2^, but the fine powder scratches glass. It is infusible in an ordi- nary blowpipe flame, and powders easily after ignition. Under the microscope it appears to be made of flat and irreg- ular transparent granules about 1-500 millimeter tnick, some of which are ten times that width, fitted loosely together so as to leave irregular cavities everywhere in communication with each other. The fragments resemble fragments of silicious infuso- rial shells which are found in large quantities in some parts of the Rocky mountains. The specimen after remaining some weeks in the air of a dry room (heated by hot air) weighed 70.77 grams. It was placed in distilled water, in which it floated for two or three minutes, boiled for some hours, and allowed to cool. After weighing it was hastily dried with a piece of filter paper and weighed again. Lastly it was dried some hours in an oven at a temper- ature of 100° to 150° C, cooled in a desiccator, and weighed. Weight in ordinary dry air. 70 77 grams. Weight in water, saturated 39.14 grams. Weight in air, saturated 115.00 grams. Weight in air, dry.. 69.15 s:rams. From this data we get: Volume of rock in the specimen 30 01 cc. Volume of cavities in the specimen 45.85 cc. Total volume 75.86 cc. Specific gravity of rock 2.304 Specific gravity of. the whole 912 Volume of water held in ordinary dry air 1 62 cc. Some fragments of the stone were pulverized in an agate mortar, fused with sodium and potassium carbonates, and analyzed in the ordinary way. Before fusion the powder was dried at about 150°C. The results are as follows: IOWA ACADEMY OF SCIENCES. 47 No. 1. No. 2. Weight of powder... 5882 gram. .4559 gram. Si O2 found 95.53% 96.14% Al 2 O3 plus traces of Fea O3- 4 59% 4.01% Total 100.12 100 15 The force of adhesion to a wet surface was estimated at 200 grams per square centimeter, or about one -fifth of an atmos- phere, but it may be much greater. If applied to a poisoned wound at once it would undoubtedly absorb some of the poison and so assist in the cure. The popular belief in its efficacy has therefore, some foundation in fact. If more of this rock can be secured it is our intention to test the rapidity of its absorption of moisture from the air when cut in thin slices, with a view to its use as a hygrometer. The vein in which the specimen was found is twenty feet wide, nearly vertical, and strikes westward. The contents of the vein are chiefly light and dark blue translucent quartzite, mixed with amorphous clay and iron oxide, and bordered by a thin blanket of limestone. Some of the translucent quartzite is mixed with light gray mad stone, as if the firmer portions were formed by fusion of the light gray material. The latter agrees very closely in composition, as well as in appearance, with the silicious shells already mentioned, and was probably formed from them by the internal heat of the vein. PHYSICAL THEORIES OP GRAVITATION. T. PROCTOR HALL. A force which belongs to individual atoms, is independent of chemical and physical conditions, and cannot be altered or destroyed by any known means, must be closely related to the fundamental nature of the atoms. One of the most essential parts in our concept of matter is mass, and the force of gravi- tation of an atom is proportional to its mass. Mass and gravi- tation stand, therefore, either as co-effects of the same cause or as cause and effect. The force exerted by each atom at any point decreases in proportion to the increase of the expanding 48 IOWA ACADEMY OP SCIENCES. spherical surface containing the point; following the law of all forces expanding in three- fold space, which may be stated thus: Force x area of distribution=a constant. From this fact it is evident that the distribution of the force of gravitation is conj&ned to threefold space; for, since the boundary of a fourfold sphere is a solid, a force expanding in all directions from a point in fourfold space decreases in inten- sity in proportion to the increase of the boundary, that is to say, in proportion to the cube of the radius, instead of follow- ing Newton's law. Newton's law has been experimentally proved for distances that are very great compared with the diameter of an atom, and to a degree of accuracy limited by errors of experiment. It does not necessarily follow that the law holds with absolute accuracy, or that it holds at all for distances comparable with atomic dimensions. All that we can say is that for distances moderate and great the law expresses the facts as accurately as they have been experimentally determined. Gravitation is not, like magnetism, polar. In crystals atoms have an orderly arrangement, yet no difference has been found in the weight of any crystal when it is set on end or laid on its side. This fact, along with the complete independence of elec- tric conditions, show that gravitation is neither an electric nor a magnetic phenomenon. The ether, so far as our knowledge goes, is a homogeneous isotropic continuum. In the conveyance of light and of elec- tric strain it shows the properties of an elastic solid. To plane- tary motions and to ordinary motions on the earth it offers no appreciable resistance, and may therefore be called a fluid. Michelson and Morley have shown that the ether close to and in the earth moves with the earth, which indicates that the ether does not move among atoms without some resistance cor- responding to friction. The existence of an ether strain such as that in a leyden jar also shows that there is a resistance on the part of the ether to the kind of motion that takes place in the electric discharge. Ether has mass, since it conveys energy by waves which have a finite velocity. Lord Kelvin has pointed out that the apparently inconsistent properties of the fluid-solid ether are analogous with the properties of ordinary matter. Pitch or taffy, either of which can be bent or moulded easily by a steady pressure, is shattered like glass by a quick blow from a hammer. The ether in like manner yields easily before IOWA ACADEMY OF SCIENCES. 49 moving bodies whose velocity is relatively small, not exceed- ing a few hundred kilometers per second, but acts as a solid toward such high velocities as that of light, which is nearly 800,000 kilometers per second. Copper, again, is a familiar example of a metal having nearly perfect elasticity within a certain limit of straiD. Beyond that limit it yields to pressure like a fluid. The ether shows the same combination of proper- ties with a wider limit of strain. Ether in a vacuum will bear a very great electrical strain without yielding; so that the most perfect vacuum attainable is an all but perfect non conductor; but if atoms be present the ether gives way to the stress and a current passes very much more readily. This indicates that there is some sort of discontinuity at or near the surface of the atoms. One of the oldest theories of gravitation was proposed by Le Sage and elaborated by him for a lifetime. He supposed the atoms to have an open structure, something like wire models of solid figures, and to be exposed to a continuous storm of exceedingly minute "ultramurdane corpuscles" which he assumed to be flying about in all directions with inconceivable velocity. Two atoms shelter each other from this storm in direct proportion to the quantity of matter in each and inversely as the square of their distance apart, and are therefore driven together in accordance with Newton's law. The ultramundane corpuscles are supposed so small that no atomic vibrations cor- responding to heat or light are caused by their impact. Le Sage's theory is unsatisfactory because it takes no> account of the ether, which for such high velocities acts as a> solid and would bring the little flying corpuscles to compara- tive rest in a small fraction of a second. Kelvin has proposed a modification of Le Sage's theory in order to accommodate it to the existence of the ether. He first showed that vortex rings have some of the properties of elastic solids, and in a perfect fluid would be indestructible; then sug- gested that atoms may be vortex rings of ether, and the ultra- mundane corpuscles very much smaller vortex rings having high velocities of translation. In order to account for the permanence of atoms and corpuscles, this view prt supposes a practically frictionless fluid ether, which does not at all corre- spond with the actual ether. Maxwell, after deducing the mathematical theory of elec- tricity from the hypothesis of ether strain, showed that gravi- 4 50 IOWA ACADEMY OF SCIENCES. tation also could be accounted for on a similar hypothesis, and that the properties required for the propagation of gravitation are similar to those exhibited by the ether in the phenomena of light and electricity. This theory is the only one that is in harmony with what is known of both gravitation and the ether. It is simple, and makes no assumptions whatever regarding the nature of matter or of atoms. It is incomplete in that it leaves the nature of the strain undetermined. The non-polar character of gravitation, its symmetry in every way about the atom, reduces to two the possible kinds of strain required by Maxwell's hypothesis. These are displace- ments of ether radially (1) outward from or (2) inward toward the atom. Assuming, as is customary, that the ether is incom- pressible, the radial displacement over a spherical surface about the atom is constant; and therefore the displacement and the intensity of the stress at any point varies inversely as the square of its distance from the atom. It is not necessary to suppose, either, that the atom itself is spherical or that the dis- placements in its immediate vicinity are directed toward or from a single point; for at the distance of a single centimeter from the atom the surface of equal displacement must be so nearly spherical that the most accurate observation now possi- ble would fail to detect any irregularity. Possibly variations in the form of the atom or in the direction of displacement immediately around it may be the cause of the chemical proper- ties of the atom, since these are apparent only at very small distances from it. For the sake of clearness let us suppose that outward dis- placement of the ether is caused by the insertion of a quantity of matter, an atom, at any point. Draw a cone having the cen- ter of displacement for its vertex. Any small element in this cone is by its outward displacement shortened and widened; so that there is on each end of the conical element a pressure, and in all directions perpendicular to the pressure a tension due to the stretching of the expanded spherical shell containing the element. Suppose, also, for the sake of clearness, that inward dis- placement is produced either by cutting out small portions of the ether and leaving holes (atoms) toward which the strain is directed, or by condensing small portions of the ether into atoms. An element of the cone is by its inward displacement lengthened and made narrower, and has a tension on each end and a pressure in all directions perpendicular to the tensions. IOWA ACADEMY OF SCIENCES. 51 The strain in each case extends to infinity, or as far as the ether extends. If the displacement of ether were prevented from extending on one side by a rigid imaginary wall, the whole strain on that side would take place between the atom and the wall, and would be more intense than on the opposite side. The atom would tend to move in such direction as to decrease the intensity of the strain, namely, from the wall if the displacement were outward, toward the wall if the displace- ment were inward. By the same reasoning two atoms repel each other if the displacement is outward, and attract if it is inward. The law of gravitation is thus explained on the hypothesis that each atom is accompanied by an inward dis- placement of the surroucding ether, proportional in amount to the mass of the atom. Minchin (Statics, fourth edition, vdI. 2, p. 475,) by a course of mathematical reasoning has reached the same conclusion. If the atoms be regarded as cavities, the mass of an atom is represented by the quantity of ether removed, which repre- sents also the volume of the atom. Since atomic volume is not proportioned to atomic weight, the cavity-atom hypothesis must be abandoned. On the condensation hypothesis the mass of an atom is the quantity of ether condensed, its volume the space occupied on the average hy the condensed mass which may have any kind of irregularity of form. This hypothesis implies that all atoms are built out of the same original stuff, and is in this respect similar to but not identical with Front's hypothesis. The fact that all atoms attract with forces proportional to their masses shows that all atoms possess the same kind of mass, and are therefore likely to consist of the same sort of stuff. Valence, selective affinity, electric and other peculiarities of atoms, must, if this hypothesis of gravitation be correct, find their explanation in the form and density of the atom, the dis- tribution of its stuff in space, which can be expressed as a function of the three space co ordinates; together with the laws of energy, which express the relations of the atom to the ether. The field of force about an atom is also capable of representa tion by a function of the space co- ordinates such that when the distance r from the atom is relatively great the equipotential surfaces are very nearly spheres. 52 IOWA ACADEMY OP SCIENCES. Stress in its ultimate analysis is probably dynamic. If so, the maintenance of the field of strain about an atom as it moves presents no greater difficulty than the maintenance of the field of light about a moving candle, or of the field of sound about a moving bell. The propagation of such ether strains as occur in light, elec- tricity and magnetism is very greatly influenced by thematerial substai.ces present in the strained medium. It is not probable that the gravitatiorai strain differs from others in this respect, and we may reasonably hope to find some inductive phenomena in connection with gravitation. A feasible plan is to surround a delicately poised mass by a thick pair of hemispheres (which may be hollow for liquids), and note with a refractometer any change of position, which, since the attraction of a sphere at a point within it is zero, will be due either to induction or to irregularities of the sphere. Errors due to irregularities may be readily eliminated by rotating the sphere. THE LE CLAIRE LIMESTONE. BY SAMUEL, CALVIN. The Le Claire limestone constitutes the second stage of the Niagara formation as it is developed in Iowa. The first or lower stage has been called the Delaware, from the fact that all its varying characteristics are well exhibited in Delaware county. The Delaware stage embraces many barren beds and presents a very great number of phases, but at certain horizons it abounds in characteristic fossils. The typical faunas of this lower stage embrace such forms as Pentamerus oblongus Sow- erby, Halysites catenulatus Linn93us, Favosites favosus Goldfuss, Strombodes gigas Owen, Strombodes iJentago^ius Goldfuss, Ptycho- phyllum expansum Owen, and DiphTjjjliyllum multicaulellaAl. The beds of the Delaware stage furthermore contain large quanti- ties of chert. The Le Claire stage of the Niagara follows the Delaware. The exact line of separation between the two stages has not been, and probably cannot be, definitely drawn. There are IOWA ACADEMY OF SCIENCES. 53 massive, barren, highly dolomitized aspects of both stages that, taken by themselves, cannot be differentiated in the field. Under such circumstances the observer must work out the strati- graphic relations of the particular group of strata under con- sideration before referring it to its place in the geological col- umn. In general the Le Claire limestone is a heavy bedded highly crystalline dolomite. It contains scarcely any chert, and m the lower part there are very few fossils. There are occa- sionally a few specimens of Pentamerus, of the form described as Pentamerus occidentalis Hall, and the principal coral is a long, slender, tortuous Amplexus which is represented only by casts of the vacant or hollow parts of the original corallum On account of the complete solution of the original structure the spaces occupied by the solid parts of the corallum are now mere cavities in the limestone. In the upper part of the Le Claire stage small brachiopods abound. They belong to the genera Hameospira, Trematospira, Nucleospira, Rhynchonella Rhynchotrepa, Atripa, Spirifer, and probably others. Inmost cases the fossils have been dissolved out, leaving numerous cavities. The calcareous brachial apparatus of the spire bear- ing genera is often the only part of the original structure rep- resented. No statement can well give any idea of the numbers of the small shells that crowded the sea bottom near the close of the Le Claire stage, nor of the corresponding number of the minute cavities that are now so characteristic a feature of this portion of the L3 Claire limestone. In some localities in Cedar county the small brachiopods of this horizon are repre- sented by very perfect casts that were formed by a secondary filling of the cavities left by solution of the original shell. The external characters are thus fairly well reproduced. Compared with the beds of the Delaware stage, the Le Claire limestone as a rule lies ia more massive ledges, it is more com- pletely dolomitized, and its fracture surfaces exhibit a more perfect crystalline structure. It contains an entirely different fauna, a fauna ia which small rhynchonelloid-and spire-bearing brachiopods are conspicuous. Its fossils are never silicified and, m marked contrast with some portions of the Delaware' Its upper part at least is notably free from chert The Le Claire limestone is the lime burning rock of Sugar Creek, Cedar Valley, Port Byron, and Le Claire. Wherever it occurs it fur- nishes material for the manufacture of the highest quality of 54 IOWA ACADEMY OP SCIENCES. With respect to their distribution the strata of this stage are well developed at Le Claire in Scott county. They are seen in the same stratigraphic relation at the lime kilns on Sugar creek and at Cedar Valley in Cedar county. They occur beneath the quarry stone at and near Stone City, Olin, and Hale in Jones county. They are again seen at numerous points west of the Jones county line in Linn. Indeed they are somewhat gen- erally, though by no means universally, distributed in the east central part of Scott, southwestern parts of Clinton, western Cedar, and the southern parts of Jones and Linn. They seem to be limited to the southwestern corner of the Niagara area. A line drawn from the mouth of the Wapsipinicon through Anamosa would mark approximately their northeastern limits. The Le Claire limestone is in some respects unique among the geological formations of Iowa. In the lirst place it varies locally in thickness, so much so that its upper surface is exceed- ingly undulating, the curves in some places being very sharp and abrupt. In the second place it differs from every other limestone of Iowa in frequently exhibiting the peculiarity of being obliquely bedded on a large scale, the oblique bedding often affecting a thickness of fifteen or twenty feet. The phe- nomena suggests that during the deposition of the Le Claire limestone the sea covered only the southwestern part of the Niagara area, that at times the waters were comparatively shallow, and that strong currents, acting sometimes in one direction and sometimes in another, swept the calcareous mud back and forth, piling it up in the eddies in lenticular heaps or building it up in obliqely bedded masses over areas of consid- erable extent. The oblique beds observe no regularity with respect to either the angle or direction of dip. Within com- paratively short distances they may be found inclining to all points of the compass. Again the waters at times were quiet, and ordinary processes of deposition went on over the irregular sea bottom, the beds produced under such circumstances con- forming to the undulating surface on which they were laid down. In some cases these beds were horizontal as in the upper part of the section illstrated in plate 1, while in other cases they were more or less llexuous and tilted as seen in the left bank of the Wapsipinicon above Newport. (Figure 2.) Professor Hall accurately describes some of the variatiocs in the inclination and direction of dip in the Le Claire limestone IOWA ACADEMy OF SCIENCES, VOL. III. Figure 1. Exposure of LeClaire limestone at the Sugar creek lime quarries. Cedar county. Iowa. Tlie limestone is obliquely bedded in the lower part of the section and horizontally bedded above. The same fauna occurs in both sets of beds. Oblique beds dip southeast. Figure 3 Oblique beds of LeClaire limestone, dipping northeast, in west bank of Mississippi river, one-half mile below LeClaire. Iowa. IOWA ACADEMY OF SCIENCES. 55 as seen at Le Claire*, but he assumes that the inclination of the beds is due to folding and uplift subsequent to their deposition. On this assumption the Le Claire limestone would have a thick- ness of more than 600 feet, whereas the maximum thickness does not exceed 80 feet, and the average over the whole area is very much less. Prof. A. H. Worthenf studied this limestone at Port Byron, 111., and Le Claire, Iowa, and describes it as " presenting no regular lines of bedding or stratification, but showing lines of false bedding or cleavage at every conceivable angle to the horizon." He assigns to these beds a thickness of Figure 2. Inclined undulating beds o'^the Le Claire stage near Newport, Iowa. fifty feet, but he offers no explanation of what he calls ' ' false bedding or cleavage." In White's report on the geology of lowat the oblique bedding seems to have been taken as evi- dence that a line of disturbance crossed the Mississippi river at Le Claire with a direction nearly parallel to the Wapsipinicon valley. This apparent disturbance was last recognized about three miles west of Auamosa. The angle of dip it is said has reached in some places twenty-eight degrees with the horizon. McGee in discussing the Regular Deformations of Northeastern Iowa% quotes Dr. White on the Wapsipinicon line of disturbance * Kept, on the Geol. Surv. of the State of Iowa, Hall and Whitney, vol. I, part I, pp. 73-74. 1858. + Geol. Surv. of 111., vol. I, p. 130. 1865. * Kept, on the Geol. Surv. of the State of Iowa, Charles A. White, vol. I, p. 133. 1870. § Pleistocene history of Northeastern Iowa, p. 340. 1891. 56 IOWA ACADEMY OF SCIENCES. and accepts the observations on which the statement is based as evidence of a synclinal fold extending frooa Le Claire to Ana- mosa. White's observations appear to have been made only at the two points mentioned. At both places the strata seem to be inclined at a high angle. On the assumption that the incli- nation of the strata indicates orogenic disturbance, the con- clusion that the disturbed beds were parts of the same fold was very natural. There is, however, no fold, nor is there any line of disturbance. In the whole Niagara area southwest of the line which marks the limit of the Le Claire limestone the phe- nomena seen at Le Claire and west of Anamosa are repeated scores of times and in ways that defy systematic arrangement. The beds incline at all angles from zero to thirty degrees, and even within short distances they may be found dipping in every possible direction. Twenty miles southwest of the line sup- posed to be traversed by the synclinal fold, for example at the lime kiln on Sugar creek, along the Cedar river above Roches- ter, at Cedar Valley, as well as at many intermediate points distributed promiscuously throughout the area of the Le Claire limestone, the beds stand at a high angle, and the multiplicity of directions in which they are inclined, eve a in exposures that are relatively near together, is wholly inconsistent with the idea of orogenic deformation. The beds are now praciically in the position in which they were laid down in the tumultuous Niagara sea. The principal disturbances they have suffered have been the results of epeirogenic movements which affected equally the whole region over which these limestones are dis- tributed, as well as all the adjacent regions of the Mississippi valley. The exposures at Port Byron and Le Claire present some interesting features that are not saen so well at any of the exposures farther west. In the first place, the lime quarries at Port Byron show the characteristic oblique position of the strata, and at the same time they demonstrate that the oblique bedding is real and not a mere deceptive appearance due to cleavage of a mass of sediment that was originally built up regularly and evenly on a horizontal base. As in other groups of strata, there are faunal and lithological variations when the beds are compared one with another. These varying charac- teristics do not intersect the beds in horizontal planes as they would if the present bedding were due to cleavage of a mass that had risen vertically at a uniform rate, but they follow the IOWA ACADEMY OF SCIENCES, VOL. Ill TM» 1 - ' .^' T' t t Figure 1 Thin-bedded LeClaire limestone overlying the phase represented in Plate I, figure 2. as seen on west side of Main street, LeClaire, Iowa At this point sub-marine erosion removed portions of certain beds, and the space so formed was subsequently filled with a second set of beds which overlapped obliquely the eroded edges of the first. IOWA ACADEMY OF SCIENCES. 57 individual layers in their oblique course from top to bottom of the exposure. The facts confirm the statement that the beds were deposited one by one in the position in which we now find them. On the west side of the Mississippi, south of Le Claire, the usual oblique bedding is seen in the bank of the river, below the level of the plain on which the lower part of the town is built. The individual beds, as in all the characteristic expos- ures of this formation, range from eight to twelve inches in thickness. Above the level of the beds exposed in the river bank there is another series of Le Claire beds that depart some- what from the ordinary type. Near the base of this second series the layers are thick and the rock is a light gray, porous, soft, non- crystalline dolomite. These grade up into thinner and more compact beds, but the lithological characters are never quite the same as those of the more typical beds at a lower level. The soft, porous gray- colored beds contain casts of Dinobolus conradi (Hall). The same species ranges up into the harder beds, but the characteristic fossils above the soft, porous layers are casts of small individuals of Atrypa reticularis and a small, smooth- surfaced Spirifer. The layers become quite thin in the upper part of the Le Claire. They show many anomalies of dip, but, so far as observed, they do not as a rule stand at as high angles as do the harder and more perfectly crystalline beds of the lower series. The existence, however, of tumultuous seas is no less clearly indicated at this horizon than in the lower beds that pitch at greater angles. In the town of Le Claire, on the west side of the main street, there is evidence of the erosion of the sea bottom by currents, and sub- sequent filling of the resulting channels with material of the same kind as formed the original beds. In eroding the observed channel some of the previously formed layers were cut off abruptly, and in refilling the space that had been scooped out the new layers conformed to the concave surface and lapped obliquely over the eroded edges of the old ones. The angle at which the lower, more highly inclined beds stand never exceeds twenty-eight or thirty degrees; that is, it never exceeds the angle of stable slope for the fine, wet, cal- careous material of which the strata were originally composed. The Le Claire limestone is, as a whole, sharply set off from the deposits of the Delaware stage by its hard, highly crystal- line structure, its freedom from chert, its easily recognized 58 IOWA ACADEMY OF SCIENCES. fauna, and its record of anomalous conditions of deposition. In the field the distinction between the Le Claire and the Ana- mosa stages are even more easily recognized, though faunally the two stages are intimately related. In the Anamosa stage oblique bedding is unknown; liihologically the rock is an earthy, finely and perfectly laminated dolomite, not highly crystalline in its typical aspect, and too impure for the manu- facture of lime. It may be quarried in symmetrical blocks of any desired dimensions, "while the Le Claire limestone breaks into shapeless masses wholly unfit for building purposes. The quarry beds of the Anamosa stage are quite free from fossils, but along the Cedar river in Cedar county the brachiopod fauna of the upper part of the Le Claire reappears in great force in a stratum four feet in thickness, up near the top of the forma- tion. The beds of the Anamosa stage are very undulating, and dip in long, graceful, sweeping curves in every possible direc- tion. The knobs and bosses and irregular undulation devel- oped on the sea bottom as a result of the peculiar condition prevailing during the Le Claire age, persisted to a greater or less extent after the age came to an end, and it was upon this uneven floor that the Anamosa limestone was laid down. The puzzling flexures of the Anamosa limestone, and the puzzling variations in altitude at which it occurs, were largely deter- mined by irregularities in the upper surface of the Le Claire formation. THE BUCHANAN GRAVELS: AN INTERGLACIAL DEPOSIT IN BUCHANAN COUNTY, IOWA. BY SAMUEL CALVIN. About three miles east of Independence, Iowa, there are cross-bedded, water-laid deposits of sand and gravel of more than usual interest. The beds in question occur near the line of the Illinois Central railway. The railway company indeed has opened up the beds and developed a great gravel pit from which many thousands of carloads have been taken and used as ballast along the line. Overlying the gravel is a thin layer of lowan drift, not more than two or three feet in thickness, but charged with gray IOWA ACADEMY OP SCIENCES. 59 granite boulders of massive size. Some of these boulders may- be seen perched on the very margin of the pit, and some have been undermined in taking out the gravel and have fallen to the bottom. The surface of the whole surrounding region is thickly strewn with lowan boulders. It is evident that the lowan drift sheet was spread over northeastern Iowa after the gravels were in place. These sands and gravels are now so incoherent that they may be excavated easily with the shovel, and yet there is no evidence that the glaciers that transported the overlying boulders and distributed the lowan drift cut into them, or disturbed them, to any appreciable extent. The lowan ice sheet was probably thin , and all the loose surface materials in front of its advancing edge were frozen solid. The thickness of the gravels is some- what variable, owing to the uneven floor upon which they were deposited, but it ranges from fifteen to twenty feet. The beds have been worked out in places down to the blue clay of the Kansan drift. Throughout the gravel bed, but more particular y in the lower portion of it, there are numerous boulders that range in diameter up to ten or twelve inches. These boulders are all of the Kansan type. Fine grained greenstones predominate. Pro- portionally large numbers of them are planed and scored on one or two sides. Those that are too large to be used as ballast are thrown aside on the bottom of the excavation, and in the course of a few seasons many of the granites and other species crumble into sand. The contrast between the decayed granites of tha Kansan stage and the fresh, hard, undecayed lowan boulders in the drift sheet above the gravels, is very striking. Many of the boulders from the gravels are coated more or less with a secondary calcareous deposit, a feature not uncommon among boulders taken directiy from the Kansan drift sheet in other parts of Iowa. As to their origin the Buchanan gravels are made up of materials derived from the Kansan drift. As to age they must have been laid down in a body of water immediately behind the retreating edge of the Kansan ice. There are reasons for believing that the Kansan ice was vastly thicker than the lowan, but the temperature was milder, and so when the period of melting came enormous volumes of water were set free. That strong currents were developed is evidenced by the coarse char- acter of the material deposited as well as by the conspicuous 60 IOWA ACADEMY OF SCIENCES. cross bedding that characterizes the whole formation. Some of the larger boulders found at various levels throughout the beds were probably not directly transported by currents, but by float- ing masses of ice. While, therefore, the gravels lie between two sheets of drift, and for that reason may be called intergla- cial, probably Aftonian, they yet belong to the time of the first ice melting, and are related to the Kansan stage of the glacial series as the loess of northeastern Iowa is related to the lowan stage. While the Illinois Central gravel pit is the typical exposure of the Buchanan gravels, the same beds are found widely dis- tributed throughout Buchanan, Linn, Jones, Delaware and prob- ably other counties. One exposure that has been utilized for the improvement of the county roads occurs on the hilltop a mile east of Independence. Another, used for like purposes, is found a mile and a half west of Winthrop. The county line road northeast of Troy Mills cuts through the same deposit. Throughout the region already indicated there are many beds of similar gravels, but in general they are so situated as not to show their relations to the two beds of drift. The Buchanan gravels, it should be remembered, represent the coarse residue from a large body of till. The fine silt was carried away by the currents and dej:.osits of it should be found somewhere to the southward. It may possibly be represented, in part at least, by the fine loess- like silt that forms a top dressing to the plains of Kansan drift in southern Iowa and regions farther south. RECENT DISCOVERIES OP GLACIAL SCORINGS IN SOUTHEASTERN IOWA. BY FRANCIS M. FULTZ. The discoveries of localities showing glacial scoring in southeastern Iowa have been somewhat numerous during the last few years. In a paper presented before this body a year ago^ I called attention in detail to the different known exposures iGlacial Markings in Southeastern Iowa. Proc. la. Acad. Sci., Vol. II, p. 313. Des Moin es, 1895. IOWA ACADEMY OF SCtENCES, VOL. III. PLATE III. Figure 1. General view of the typical exposure of the Buchanan gravels. Figure 2. Near view of the Buchanan gravels. IOWA ACADEMY OF SCIENCES, VVJj III. Figure 1. Abandoned part of gravel pit. Figure 2. Field immediately north of the gravel pit showing large numbers of Iowa boulders. IOWA ACADEMY OP SCIENCES. 61 of glaciated rock in this region, and pointed out that the testi- mony they gave was unanimous as to the southeastern move- ment of the ice sheet. Since then another exposure has been located that seems to bring conflicting testimony. This locality is the joint discovery of Mr. Frank Leverett and myself. It is situated on the lot at the northeast corner of the intersection of Court and Prospect streets in the city of Burlington. Some quarrying had been done by blasting out the level rock aoor. Everywhere on the margin of the hole thus formed may be seen the finely striated and grooved sur- face. On the east side a patch, 6x8 feet, was cleaned off and a finely striated surface brought to view. The direction of the stri^, taken with compass and corrected, was S. 79° W. This would indicate an almost due westerly movement, which is in direct variance with that shown by all other discoveries of gla- ciated rock in this region. If direction of strice alone were taken into consideration, then it might be claimed that the ice move- ment in this case also was towards the east. But a close and critical examination shows that all the accompanying phe- nomena point to a westerly trend; e. g., the indicated move- ment of the ice around and over a prominence, and down into and out of a depression. This is new and important evidence that the Illinois lobe of the great ice sheet crossed the Mississippi river and invaded Iowa. It will be remembered that I presented a paper on this subject at our last meetitg.^ The evidence on which the claim was based was the presence, on the Iowa side, of boulders of Huron conglomerates. I was convinced that this westward movement was not the latest in this region, but that the ice moving from the northeast was the last to hold possession of the west bluff of the Mississippi; and I so put forward in the paper. Mr. Frank Leverett, who has made an exhaustive study of this question, is of the opinion that the Illinois ice sheet was the last to invade this portion of Iowa, and that the movement extended to some twenty miles west of the river. This recent discovery of glacial scoring certainly strengthens his theory. For it is situated at such an elevation that any ice sheet passing over would be almost certain to leave its impress; and there- fore the strice we now find are very apt to be those made by the latest invasion. 2Extensiou of the lUinois Lobe of the Great Ice Sheet Into Iowa. Proc. la. Acad. Sci., Vol. II, p. 309. Des Moines, 1895. 62 IOWA ACADEMY OF SCIENCES. However, I am not yet fully convinced. Of the somewhat numerous discoveries of glacial scorings in this region, nearly all are on the very brow of the west bluff bordering the Mis- sissippi flood plain, where they wcuJd offer the best possible opportunity for erosion. It would therefore seem that they ought to be the records of the very latest invasion. And all these, without a single exception, show southwestward move- ment. SOME FACTS BROUGHT TO LIGHT BY DEEP WELLS IN DE3 MOINES COUNTY, IOWA. BY FRANCIS M. FULTZ. During the past year a number of deep wells were sunk in Des Moines county. Some of them reached such extraordinary depths before touching rock, or without touching rock at all, as would clearly show the presence of buried river channels. In a paper presented before this society a year ago I stated that the preglacial and present drainage systems in this region were practically the same. From facts recently brought to light I must necessarily change that opinion. To what extent remains yet to be seen. My attention was first called to the presence of buried water courses in this locality by Mr. Frank Leverett, of the United States Geological Survey, who has collected a large mass of data on the glacial phenomena of this region. He has already given us a general discussion of the preglacial conditions of the Mississipjoi basin^; and in the course of time we may hope for further and more detailed contributions along the same line. The deep wells in question are located some eight or nine miles north of Burlington. One is on the farm of L. Aspel- meier, near Latty station. It is 233 feet deep, and penetrates the rock but two feet. Unfortunately there was no record kept of the character of the deposits passed through, which is also true of the other wells to be mentioned further on. Therefore the details are somewhat meager. As nearly as could be deter- mined the till continued to a depth of 188 feet, where a gravel 1 Journal of Geology, p. 740, Vol. Ill, No. 7, 1895. IOWA ACADEMY OF SCIENCES. 63 bed of several feet in thickaess was passed through. In this gravel deposit well preserved bones were found. They were crushed into fragments by the drill, but a number of pieces, from one inch up to three inches long, were brought up in the wash. I saw these fragments about a week after they were discovered, and they had the appearance of having belonged to a living animal not longer ago than that time. Mr. Jennings, of New London, Iowa, who had charge of the drilling, told me that the bones had quite a fetid odor when first brought up. It was difficult to determine from what particular bones the fragments were, but I would place them as parts of the leg bones of some animal of slender build. Below the gravel bed the drill passed through a black deposit, which the well drillers call "sea mud," and which rests directly upon the blue shale of the Kinderhook, 231 feet below the surface. A quarter of a mile north of the Aspelmeier well the rock bed is reached at a depth of less than thirty feet. It is the hard, compact limestone of the Upper Barlington. This shows a drop of over 200 feet in within a distance of 80 rods. Half a mile south of the Aspelmeier well, on the farm of Fred Timmerman, there is another deep well which reaches a depth of 184 feet without striking rock. The bottom of the well is in a gravel deposit, which partakes of the nature of a forest bed. From it much woody matter was brought up. A half mile still further south, making a mile south from the Aspelmeier well there is still another deep well. It is on the place of H. C. Timmerman. It reaches a depth of 188 feet without striking rock. It likewise terminates in a gravel bed containing much woody matter. In the two Timmerman wells the water rises seventy- five feet. When last heard from the Aspelmeier well was not furnishing a satisfactory supply. These wells indicate an old channel of great depth, and of not less than a mile and a quarter in width. The width is probably much greater. Mr. Frank Leverett suggests that this ancient river bed was the water outlet of part of the ter- ritory now drained by the Skunk river. 64 IOWA ACADEMY OF SCIENCES. RECENT DEVELOPMENTS IN THE DUBUQUE LEAD AND ZINC MINES. BY A. G. LEONARD. During the past year or two there have been some important developments In the Dubuque district, New lead mines have been opened up, new ore bodies have been discovered, and the Durango zinc mine, the largest in the state, has been still further developed. About one mile west of the city is located the mine of the Dubuque Lead Mining company, which has been worked only about a year and a half. It is on the west end of the old level range which has been followed for nearly three miles and has yielded considerable ore from various points along its length. When the mine was visited in November, 1895, there were seventy -five men employed and the place presented a lively appearance. The three shafts are 210 feet deep with a steam hoist 'On one and gins on the other two. The company has just erected a concentrator at the mine for the purpose of crushing and cleaning the ore. This was made necessary by the fact that in this mine much of the Galena occurs scattered through the rock, sometimes in particles of considerable size. The limestone is crushed and the lead then separated from it by washing. The ore-bearing dolomite forms a zone from two to four feet wide and contains an abundance of iron pyrites. This latter mineral is often found here cr} stallized in beautiful octahedrons with a length of from one-fourth to three-fourths of an inch. Besides being disseminated through the rock the Galena occurs in large masses in what is probably the fourth opening, and it likewise fills the crevice above for some dis- tance. The ore body is apparently an extensive one; 700,000 pounds of lead have already been raised. Work in this mine is made possible only by the constant operation of a steam pump which keeps the water below the opening where the ore occurs and thus allows the miners to reach the deposits. IOWA ACADEMY OP SCIENCES. 65 The extensive zinc mine at Durango, five miles northwest of Dabuque, has several points of special interest. The timber range on which the diggings are located was once well known as a large lead producer. The range has a width of 100 feet, and is formed by three main crevices, with a general direction S. 80° E. The openings occur ninety feet below the crown of the hill, and where they are enlarged the three fissures unite in caverns of immense size. In these openings the lead occurred,. and above them, extending to the surface, the hill is filled with zinc carbonate. The zinc is known to extend also below the level of the lead. The mine is worked by means of an open cut extending through the hill, with a width of forty feet and a depth of about eighty feet. The crevices are more or less open up to the surface. Several can be seen in the face of the cut, and in them the ore is most abundant, though it is also found mixed all through the fractured limestone. The strata have been subjected to more or less strain, possibly owing to the large caves below, and are broken into fragments. The carbonate is found coating these pieces and filling the spaces between, occurring also, as stated, in the open crevices. The latter have a width of from one to two feet. In working the mine the larger masses are blasted and the smaller ones loosened with the pick. The ore is removed from the rock, the. latter is carted off to the dump, and the dry bone, mixed with more or less waste material, is carried to a neighboring stream. Here it is washed by an ingenious contrivance which thoroughly frees the ore from all sand and dirt. The method was invented, by Mr. Goldthorp, superintendent of the mine, and is quite extensively used about Dubuque. An Archimedes screw, turned by horse power, revolves in a trough through which a stream of water is kept flowing. As the screw revolves it gradually works the ore up the gentle incline, while the water runs dowu and carries with it all sand and dirt. Afterwards the dry bone is picked over by hand and the rock fragments thus separated. During the past season eighteen men were employed at the mine and the daily output was from fifteen to eighteen tons of ore. This would mean a yield of over 2,500 tons for six months, and is probably about the annual production of the mine during the last few years. Most of tne zinc mines have been closed for nearly two years on acount of the low price paid for the carbonate, the average being only $5 to $6 per ton the past year. About 800 tons 5 €6 IOWA ACA.DEMY OF SCIENCES. were, however, sold at these figures. There are very large quantities of ore in sight in these mines, as even a brief inspec- tion clearly shows, and they are capable of yielding thousands of tons for some years to come. The output of the mines for the past year can be given only approximately. They have produced about 750,000 pounds of lead and from 3,000 to 3,500 tons of zinc. But it must be remembered that, as already stated, most of the zinc mines were closed during the past season. They are easily capable of yielding from 8,000 to 10,000 tons of ore annually. THE AREA OF SLATE NEAR NASHUA, N. H. BY J. L. TILTON. Maps of Crosby and Hitchcock. The area briefly outlined. Description of the slate area. Description of the rocks. Section from Nashua northward. Section along the Massachusetts line. Section west of Hollis Center. Section east from Runnells Bridge, and southeast from Nashua. Attempt to harmonize descriptions of Crosby and Hitchcock. .Structure. Dip, strike, general section. Evidences of faults. Cause of metamorphism. Maps of Crosby and Hitchcock. — Crosby's map of eastern Massachusetts represents an area of slate, or argillite, as it is termed, running from Worcester through Lancaster and Pep- perell^^to the New Hampshire state line. The eastern part of this argillite, two and one-fourth miles wide on the map, but four miles wide according to the text,* continues north into New Hampshire just west of the Nashua river. On the east of the argillite lies mica schist in an area very narrow (three- fourths of a mile) near the state line, but much wider toward the southern part of the township of Dunstable. On the west *Crosby's "Geology of Eastern Massachusetts," p. 137. IOWA ACADEMY OP SCIENCES. 67 of the argillite lies gneiss close to the state line, but mica schist a little farther southwest (in Townsend). Hitchcock's geological map of New Hampshire (Rockingham Sheet) represents an island of gneiss extending from Mine Falls to a mile south of the Massachusetts line near Hollis Station (occupyicg a part of the area where Crosby locates argillite). This island lies in "Rockingham Mica Schist," extending along the northwest side as an area three and three- fourths miles wide, on the average, and along the southeast side as an area two and a half miles wide. Both these areas of mica schist are represented as continued toward the north- east across the Merrimac river and southwest into Massa- chusetts. It is the object of this paper to mark out and describe the slate rock in the vicinity of Nashua (Crosby's argillite, or the north- ern of the two areas marked by Hitchcock as mica schist). The Area Briefly Defl^ned. — Tte slate rock is found to lie in an area six miles wide extending northeast- southwest, just north- west of the Nashua river. Along the southeast of this area the contact between the slate and the adjacent schist and gneiss extends from Runnells' bridge in a northeasterly direction parallel with the general course of the Nashua river as far as Nashua, where the river leaves the vicinity of the contact. In the city of Nashua the contact extends northwestward in a line between Shattuck's ledge and the reservoir. Along the northwest of this slate area the boundary-line extends from where Gulf brook crosses the slate line, north- eastward through the valley just east of Proctor Hill, near Long pond, Pennichuck pond and Spaulding's pond (or Reed's pond, as it is called locally) and crosses the Merrimac river a mile below Thornton's ferry. This line is not perfectly straight but curved slightly with the convex side to the northwest. Just north of Gulf brook the line curves somewhat suddenly toward the southwest, passing between the two exposures half a mile northeast of the mouth of Gulf brook. Southeast of Nashua no slate was found in the area repre- sented on Hitchcock's map as a branch of this slate there marked "Rockingham Mica, Schist." General Description of the Slate Area. — The area of slate is marked by an extent of lowland occupied partly by swamps 68 IOWA ACADEMY OF SCIENCES. and ponds.* It contains the Nissitisset river, Flint pond, Long pond, Parker's pond, Pennichuck pond, Round pond and Spaulding's pond, besides a large area of swamp. The southeastern part of the slate area is largely occupied by the present valley of the Nashua. Within this area the hills of slate rise in ridges to a height of one hundred feel above the adjacent lowland. They do ngt form continuous ridges, nor does their general direction con- form to the direction of strike. This general direction is N. 70° E., while the strike is on the average N. 57° E., though the strike varies a few degrees even in strata but a few feet apart, as the rock is much contorted. These hills are low in contrast with the hills in the gneiss and schist area adjoining. From the top of Long Hill, a hill of the Monadnock type just south of Nashua, these slate hills appear below the Cretaceous peneplain. The valleys between tbese hills, even the hills themselves, are mantled with drift, and the river valleys deeply covered with washed drift; but further reference to this important feature is here omitted as not a part of the problem under consideration. Description of the Rocks — The character of the rocks and the relation of them one to another is perhaps best seen along a line from Shattuck's ledge, Nashua, northwestward. At Shat- tuck's ledge, the rock is gneiss in part heavy, in part quite schistose. At the reservoir, three quarters of a mile west, occurs slate with bands of graphite. Northwest for three miles the rock is a slate very much crushed and crumpled, and in the northern part of this area, a shaly slate interbedded with gneiss. The dividing lines, then between the slate and the schist, and between the schist and the gneiss, are not definitely marked lines, but are intermediate places in a series of gradations. Similar gradations from slate through schist to gneiss are to be found in the southwestern part of the area near the conflu- ence of Gulf brook and Nissitisset river. Here, south of the Massachusetts line, the slate is both shaly and quartzose. Just north of the Massachusetts line quartz veins are very marked in a dark schistose rock. This same structure is found in a railroad cutting near by, revealing in an -excellent manner *The contour lines of the accompanying map are as given on the New Hampshire State geological atlas. IOWA ACADEMY OF SCIENCES. 69 the schistose structure with quartz veins. A little farther northwest gneiss appears instead of schist. Here, then, there is a passage from slate through gchist to gceiss. Just west of Hollis Center is still another opportunity to observe an approach to the dividing line between the slate and the schist, though not so good as eiiher of the two already- described. Just west of Hollis Center there is slate. This grades through schist to the gneiss quarried at Proctor Hill. Southeast of the slate area are several outcrops of gneiss: one at Shattuck's ledge in the northeastern part of the city of Nashua, another in the western part of the city, where it is quarried in one place, a third on the Nashua river, five miles above Nashua, a fourth at Flat Rock quarry, and again at Long Hill, south of the city. The sudden transition from slate to gneiss close to the Nashua river will be referred to urder the heading "Faults." Eastward from Runnells' bridge, near Hollis, there is a gra- dation from the slate through schist to the gneiss at Flat Rock quarry, and a similar gradation from schist to gneiss between Nashua and Long Hill. Thus southeast there is a gradation from slate through schist, schist with quartz seams to gneiss, similar to that from the slate area northwest. Attempts to Harmonize Descriptions of Crosby and Hitchcock. — The above description of gradations in the character of the slate, schist and gneiss, suggests an explanation of an apparent lack of harmony between Crosby and Hitchcock. Crosby dis- tinctly records gradation between the three rocks, and because of this gradation seems to call both the slate and the schist argillite, even though Ihe argillite southeast of Nashua is exceedingly clear mica schist. Judging by the map, Hitchcock apparently recognizes the same gradation between the rocks, though I find no description in the text to confirm this infer- ence, and calls both schist. I fear, however, that because of the schistose character of many of the slate outcrops, the area of slate has been entirely neglected. Concerning Hitchcock's location of the gneiss area along the Nashua river, between Mine Falls and just south of the state line, there is a single area of probable gneiss on the river about four miles west of Nashua. Tnis area is cut off on the south- west by slate just south of Runnells' bridge, and on the north- east by mica schist at Mine Falls. Hitchcock has overlooked 70 IOWA ACADEMY OP SCIENCES. the gneiss east of Mine Falls, where two areas exist: one a mile west of Nashua (Main street) and south of the canal, where out- crops occur at a large quarry, and in the hill just west of the cemetery. The other area omitted is in the northeastern part of the city itself, at Shattuck's ledge, near the Merrimac river, a mile and a half from the outcrops just west of the city. It is possible that these two areas should be classed as one, since no outcrops exist between the two areas to tell what the rock between them may be. The line boanding Hitchcock's "Rockingham Mica Schist" seems to indicate the line between schist and gneiss, as if he did not recognize the slate as a separate rock from the schist. My northwestern line bounding the slate lies about parallel to his line bounding the Rockingham Mica Schist and a mile to the southeast of it. Strike. — On the map accompanying this paper numerous dips and strikes may be found recorded. It now becomes necessary to observe their relation to determine what folds may exist in the area, for there are no strata within the slate area itself whose repetition can indicate the structure. "Within the slate area and in the gneiss along the northwest- ern boundary the strikes measured are much the same. North of Nashua there is slight evidence that the anticline there tends to form a nose; but all other variations from N. 38° E. are such Figure 3. Section northwest-southeast across the area. as a badly crushed area might represent; variations too small to be systematized even by minute observatiocs at all poinrs. This general similarity of strike indicates horizontal folds extending in the direction of the strike. A study of the dip along lines at right angles to the strike reveals the anticline of a fold running in the direction cf the strike along the western half of the slate, while a syncline runs along the eastern half. These are here represented in a dia- gram. (Fig. 3.) IOWA ACADEMY OP SCIENCES. 71 Faults. — At the reservoir in Nashua are evidences of a fault; there is in the slate a seaca of graphitic slate with veins of quartz near by. In this graphitic slate much crushing and slipping has occurred. The strata are on edge with strike N. 73" E. The argument for a fault in this locality is sustained, in fact made necessary, by the structure of the region. The general succession of strata from southeast to northwest, is gneiss, schist, slate, schist, gneiss, with no evidence of unconformity; but at Shattuck's ledge the gneiss appears in close proximity to the slate, with little chance for schist between. The dip at Shattuck's ledge compared with the dip observed in the schist to the south indicates that the gneiss exposed at Nashua is in an anticline. North of the gneiss at the quarry just west of Nashua a fault is possible, but not necessary to explain the structure, if schist not exposed underlies the river valley. While schist occurs at Mine Falls, schistose gneiss occurs two miles farther west with no schist that is exposed to the north, and beyond Runnells* bridge the eastern boundary of the slate area bends southeast- ward across the line of strike. Thus while the evidence of faulting is very marked near Nashua it becomes less marked south westward. Other evidences of faulting exist near the mouth of Gulf brook, and just west of Hollis Center. Along this line the pres- ence of slickensides in graphitic slate, with quartz seams near by, indicate that a line connecting these two points is a line of faulting. Cause of Metamorphism. — Finally, it remains to ascertain the cause of the metamorphism. This involves a petrographical problem, especially on the gneiss. There is no igneous rock to be found in the area, unless the gneiss itself be of igneous, origin. If the gneiss itself is not of igneous origin there may be igneous rock not far below, or not far beyond the margins of the area, though no locality of such minerals as are common where igneous material comes in contact with sedimentary material is here to be found, nor is there any evidence of intense heat. Regional metamorphism affords a satisfactory explaration. The intense crumpling of the strata, the steep dip, the bands of quartz alternating with the slate along the margins of the gneiss, with lack of evidence of intense heat in the immediate vicinity, all indicate that the metamorphism is regional. 72 IOWA ACADEMY OF SCIENCES. NOTES ON THE GEOLOGY OF THE BOSTON BASIN. J. L. TILTON. The region about Boston forms a basin. Standing on the reservoir at College Hill one looks north, west and south upon lines of hills surrounding Boston and the thickly populated adjoining country. In the relation of the rocks underlying the drifts this region also forms a basin. The distant hills are of hornblende granite extending from near Marblehead southwest to near south Natick, thence east toward Qaincy. Close to this granite area are other igneous rocks, and within the basin, con- glomerate and slate so related and concealed by drift as to present many difficult problems. It is not surprising that the discussion* of the area contains not only a mass of conflicting conclusions, but even a mass of conflicting statements concerning field evidence. The rocks seemed to grade into one another; the felsite along the margin of the basin appeared where observed to penetrate the granite instead of the granite the felsite; the flow structure seemed stratification; the sedimentary material is so related to the igneous rock and presents plains of stratification so obscure and nearly vertical that to some the conglomerate appeared uppermost, to others the slate uppermost, while to still another there seemed to be two beds of conglomerate. 'For years it was agreed that the felsite, porphory and diorite were all originally sediments changed to their present conditions by varying degrees of metamorphism. In age the sedimentary rocks were variously classified, Cam- brian, Devonion or Carboniferous. Since 1877, Dr. M. E. Wads worth and Mr. J. S. Diller have given careful attention to these problems. In conclusion Mr. Diller, t after a presentation of evidence that seems incontro- *The discussion is given in full in "The Azoic System," Whitney and Wadsworth, Bull. Mus. Comp. Zool. at Oamhridge, Mass., Vol. VII. t '-Felsites and their Associated Rocks north of Boston," J. S. Diller, Bull. Mus. Oomp. Zool. at Cambridge, Mass., Vol, VII. IOWA ACADEMY OF SCIENCES. 73 PI O n H n z > H D O 74 IOWA ACADEMY OF SCIENCES. vertible, based as it is on both detailed field evidence and microscopic examination of the rocks, states that in the area he studied the stratified rocks within the basin are the oldest rocks, the granites surrounding the basin are next in age, then come the diorite, diabase and melaphyre in order. He also concludes that the granites, felsites, diorite, diabase and melaphyre are all eruptive rocks, not derived by metamorphism from any part of the stratified rocks. These conclusions relate to the part of the basin north of Boston where evidence is most abundant and complete. In the fall of 1894, it was the writer's privilege to study the south- western part of this basin and to prepare the accompanying map, the plate of which is now kindly loaned by the Boston Society of Natural History. This map and the paper that originally accompanied it* give the location of outcrops to be found in the area under consideration and a discussion of the relation of those outcrops based ia part on the field evidence and in part on the microscopical character of the rock. The basin itself was found to extend in narrow areas farther south- west than formerly supposed. * "Oq the Southwestern Part of the Boston Basin," Proc. Boston Soc. Nat. Hist, Vol. XXVI, June 28, 1895. IOWA ACADEMY OF SCIENCES. 75 NOTE ON THE NATURE OF CONE-IN-CONE. BY CHARLES R. KEYES. Cone in- cone is a term which has been applied more or less widely to a peculiar structure often found in beds of shale. Ordinarily it appears in thin sheets or layers, from three to six inches in thickness. The bands have a more or less well- marked columnar structure, each column being about half an inch in diameier and composed of a series of small conical seg- ments set one within another. In general appearance frag- ments resemble the familiar coral Lithosfcrotion. Much has been written on the origin of cone-in-cone, and numerous and widely different explanations have been offered. So far as I know, none of these numberless attempts to account for this peculiar structure appear to be satisfactory expositions of the true cause of the formation. Recently there have been obtained in Marion, Boone and Webster counties, in this state, some unusually instructive examples which offer, I believe, a correct solution to the prob- lem of origin. These specitnens range from a black, opaque, clayey variety — the common form — through all gradations to a white, translucent kind. The latter is found to be made up of numerous long, often needle-like crystals and flat plates which radiate from a center — the apex of the cone — new nee- dles coming in as rapidly as the spaces between those near the center become large enough to admit them. Chemical analysis shows that this variety is nearly pure calcic carbonate, in a well crystalized form. Analysis of the more earthy kinds also show a high percentage of lime. The results of examinations by Prof, G. E. Patrick are as follows: 1. Clear variety from Madrid 96.36 per cent Ca CO3 II. Clayey variety from Fort Dodge 83.12 per cent Ca CO3 As the clear cone- in- cone acquires more and more clayey matter the crystals of calcite gradually lose their mineralogical 76 IOWA ACADEMY OP SCIENCES. characteristics until in the common form the presence of cal- cite would not be suspected, and the surface of the cones, instead of showing clearly the individual calcite needles sharply terminating, has only a peculiar crinkled or roughened appear- ance. Owing to the very strong crystalizing force known to be possessed by calcite, so powerful an influence is exerted by this substance in solution, which is manifestly at the point of satu- ration, though distributed rather sparingly through the clay layers, that even the clay is pressed into the form assumed under normal conditions by the calcite. The process and results are not unlike those which have taken place in certain sand- stone beds in central France, in which calcic carbonate has crystalized in the sand, and large perfect models of sand cemented by lime are found, having the well formed and char- acteristic crystalographic faces of calcite. TWO REMARKABLE CEPHALOPODS FROM THE UPPER PALEOZOIC. BY CHARLES R. KEYES. There have been recently discovered in the coal measures of Mississippi basin some excellently preserved remains of Cepha- lopods, which are remarkable on account of the huge size attained. Both are representatives of the retrosiphonate Nau- toidea; but one is a member of the most closely coiled end of the series, while the other is a perfectly straight form. The former belongs to the genus Nautilus and the latter to Orthoceras . The first group comprises a series of shells, which were obtained Irom the upper coal measures at Kansas City, Mo. Several unusually fine specimens are the property of M. S. J. Hare of that place, and others are in the possession of other collectors. The form was originally de&cribed by White* as Nautilus ponderosus, the diagnosis of which is essentially as follows: U. S. Geol. Sur., Nebraska, p. 236, 1872. IOWA ACADEMY OF SCIENCES. 77 Shell attaining a large size, subdiscoidal; umbilicus large, or nearly equaling the dorse-ventral diameter of the outer volution near the aper- ture; volutions three, enlarging their diameter more than three-fold each turn; all broader transversely than dorse-ventrally; inner ones slightly embracing, while the last one is apparently merely in contact with the others near the aperture; each broadly flattened or a little concave on the periphery, and (particularly the last one) somewhat flattened between the periphery and the middle of each side, from which point the sides are broadly rounded into the umbilicus, the greatest transverse diameter being near the middle; ventro-lateral or outer angles of the last whorl (in some- what worn casts), each provided with obscure traces of about twenty wide, undefined nodes, scarcely perceptible to the eye; septa numerous, rather closely arranged, making a slight backward curve on each side, particu- larly between the middle and outer angles and crossing the broadly flat- tened dorsum with a strong backward curve; surface with distinct lines of growth, which curve strongly backward like the septa, in crossing the outer side. White's specimen was not as perfect; the recently acquired material, and consequently the latter, is of unusual interest as elucidating structural points which were previously obscure. The large dimensions which the shell attained is quite remark- able, especially when taken in comparison with the other forms of the group known from the same geologic ^1 formation. Rarely do any of the species of the genus from the Carboniferous of the region reach a diametric measurement of more than four or five inches. The specimens of Nautilus ponderosus recently found are twelve to fifteen inches in diameter and weigh upwards of fifty pounds. The second group to which atteation is called includes a huge Orthoceras — 0. fanslerensis —troui the lower coal meas- ures' at Fansler, Guthrie county, Iowa. It may be briefly described as follows: Shell very large, thin, tapering very gradually; septa very thin, mod- erately concave, about two to the space of an inch near the large end; sur- face smooth. Diameter at larger extremity three inches, length probably not less than six feet. It is a well known fact that the straight- shelled cephalopod was an abundant form of life during Paleozoic times. This is attested by the large number of species that have been described, those of the Orthoceras group alono numbering over 1,200. The culmination and greatest expansion of the group was in the Silu- rian, and from that period it appears to have gradually dwindled in number of species, siz3 and abundance until at the close of the Paleozoic the form was all but extinct. In the American Silu- 78 IOWA ACADEMY OF SCIENCES. rian some of the shells attained huge proportions, but with the general decline of the group the later ones have heretofore seemed to rapidly become dwarfed until only small, unimportant individuals were recorded after the Devonian. In the Carbon- iferous a few dimunitive species have been described, most of them but a few inches in length. In the coal measures of the Mississippi basin the remains found were of rather rare occur- FiGUBE i. Section of Orthoceras fanslerensis. rence, imperfectly preserved and of very small size. Seldom did the shells exceed six inches in length and half an inch in diameter. Of late years, however, some unusually fine material has been obtained in the black shales of the lower coal measures in the vicinity of Des Moines, Iowa. Several of these shells were so large as to excite considerable wonderment. Some were over two feet long and one inch in diameter at the larger end. These were thought to be giants of their kind and day. But these are small, and all the other Carboniferous species are mere pigmies by the side of the recently found shell from the coal mines of Fansler. The species is 0. fanslerensis, and the unique specimen here described was obtained by Mr. M. G. Thomas, state mine inspector. IOWA ACADEMY OF SCIENCES. 79 VARIATION IN THE POSITION OF THE NODES ON THE AXIAL SEGMENTS OF PYGIDIUM OF A SPECIES OF ENCRINURUS. BY WILLIAM HARMON NORTON. In defining the different species of the genus encrinurus (Emmrich) use has frequently been made of the disposition of nodes on the rings of the mid-lobe of the tail- shield. It is largely by this diagnostic that Foerste, for example, distin- guishes E. thresheri from E. ornatus. Hall and Whitfield* and the latter authors again, use the same criterion in separat- ing E. ornatus from the European species figured in Murchi- son's Siluria. f This has been the perhaps unavoidable result of the scarcity of materials at hand. Several species of this genus have been described, each from a single pygidiutn. The specific impor- tance of this feature having thus been exaggerated, any varia- tion in it is of paleontological as well as evolutional interest, and will be of value in the long-needed revision of the genus. The specimens which afford the facts I am about to present were taken some years since by Prof. A. Collins, Sc.P , of Cor- nell College, and the author, from a single stratum near the top of Platner & Kirby's quarry, Mount Vernon, Iowa. They were associated with a rich fauna, but unfortunately the fossiliferous area was so limited that, though the quarry has been largely extended, scarcely a fossil has since rewarded the search of the collector. The investigation is therefore simplified by the absence of such factors as would obtain if the specimens had been taken from widely separated localities, or from a consid- erable vertical range. Coming from a station near the summit of theAnamosa beds, which lie above the Le Claire, the position of the species is perhaps higher than that of any other American Eacrinurus. * The Clinton Group of Ohio, Part II, pp. 101, 102, A. E. Foerste. Bulletin of The liaboratories of Denison University, II. t Eeport Geological Survey of Ohio. Vol. II, pp. 155, 156. 80 IOWA ACADEMY OF SCIENCES. The species in question which is of the general type of Encrinurus imnctatus Wahlenburg, is well represented in the collections by two perfect, or nearly perfect, specimens and by scores of cephelons, moveable cheeks and pygidia, occurring both as external moulds and internal casts. The nearness of the fossiliferous stratum to the top of the quarry brought it well within the zone of weathering. The laminas of the rock were parted and the fossils thus disengaged with a single stroke of the hammer, and without any picking and cleaning that might mingle artificial with the delicate natural markings. The latter are exceptionally well preserved. To speak of the pygidia only, the caudal spine is shown in several specimens, the ninth pair of pleural are usually distinct, and even a tenth pair may sometimes be seen as min- ute ridges nearly aligned with the axial lobe and ending upon it in a tubercle. Oi: the segmental lines on the mid-lobe as many as thirty-one have been counted with the aid of a magni- fyiog glass, and in seven specimens over .twenty-five are thus vi&ible, and in several specimens eight and even nine axial nodes have been observed. The investigation has thus been specially favored in the number and perfection of the specimens at hand. The promi- nence also of the large rounded anterior tubercle affords a sure ground which would be lacking if the investigation were carried over to the less distinct tubercles on the broad pleural annulations. In the same way the size of the specimens is of advantage. The largest twenty- three mm. in length and width, slightly exceeds in these dimensions the largest Encrin- urus the author has seen figured or described. From this size the specimens rarge to a minimum of eight mm. in length and breadth. In several of the smaller pygidia, the axial lobe is slightly more convex and the central longitudinal space between the discontinuous segments is more or less obscure. The first nine segments in especial, are plainly continuous. While it is not thought that these are specifically distinct, they are separated in the following table by being marked with a star. Excluding these and considering the remainder whose specific identity can not be questioned, the following variation is observed: IOWA ACADEMY OF SCIENCES. 81 No. of Nodes. axial segments occupied. 1. 1st. 2d. (?) 3d. 2. 3d. 4th. 5th. 6th. •6. 7th. 8th. 9th. ]Oth. 4. 10th. 11th. 12th. 13th. 14th. 5. 14th. 15th. 16th 17th. 18lh. (?) 19th. The following table sets forth the facts observed graphically and in detail. It will be noted that not a single segmental line of the first twenty- three is unoccupied by a tubercle. No law obtains as to the successive number of the intervening segments. For comparison the sequences of nodes on two described species are inserted. Of the distinct trends observable in the grouping of the nodes that toward the formula of E. ornatus is most largely represented in the specimens at hand. Geological Laboratory, Cornell College, December 31, 1895. NUMBER OP AXIAL ANNUL ATIONS. NO. OF SPECIMEN. NUMBER OF AXIAL ANNULATIONS. <-: S s o 0 0 0 0 0 (1 0 0 c 0 0 0 0 0 0 0 0 0 0 1 '6 0 0 0 0 0 '6 '6 0 0 0 '6 0 0 0 0 0 0 0 0 0 "6 0 0 0 0 0 0 0 0 ■q 0 0 0 0 '6 0 0 '6 0 '6 '6 0 0 0 0 0 0 0 0 0 0 '6 •■ '6 0 ;« 'o '6 6 0 0 '6 '6 •• 0 6 it 1 0 0 0 0 0 0 0 '6 0 '6 0 0 '6 0 0 0 0 '6 0 0 0 0 '6 '6 0 '6 0 1 '6 0 0 '6 '6 0 to 0 0 0 0 :: 0 '6 0 0 0 u 0 0 0 '6 '6 0 "6 0 0 • ■ 0 "6 i 0 0 '6 "6 1 '6 0 0 0 5t i 1 2 0 0 0 0 0 0 0 0 0 0 i 0 ;; 3 6 0 10 11 Vi. 13 14 15.. 16 *17 0 0 18 19. 20 0 0 0 0 0 '6 0 0 0 0 0 0 0 0 0 31 22 23 24 25.. t26 0 27 28 29 30 ■• 0 ftl ... 0 '6 0 "6 32. 33 34 0 0 0 0 3.5 0 36 37 38 39 . 0 0 0 40. 0 0 0 42 43 'No. 17. E. ornatus, H. & W. . 31, E. thre>ihei i, Foerste. E. punctatus, Murch SJuria. PI. Ill, fig. 6 82 IOWA ACADEMY OF SCIENCES. A THEORY OP THE LOESS. B. SHIMEK. Some years ago in an article entitled "The Loess and Its Fossils,"^ the writer advanced certain opinions the modilica- tion of which seems to be called for by subsequent investigation and thought. In that paper it was shown, principally from a study of the fossils, that the theory of the lacustrine origin of the loess, held with very few exceptions by American writers,'- is unten- able, and that the origin of the loess in violent fluviatile floods, also sometimes suggested, is equally improbable, and the theory was there offered that the deposit was formed in ponds and lakes similar to those which were formerly abundant in northern Iowa, and by quiet overflows of the sluggish prairie streams. Although it is extremely probable that certain limited por- tions of the unmodified loess were deposited in this manner, the theory does not account for the most extensive deposits which usually cap the highest hills, especially along our streams which so often seem to cut their channels through the highest ridges. This difficulty led the writer to further investigation, which led to the conclusion that wind was the prime agency concerned in the formation of these deposits, and that Rich- thofen's theory of the formation of the Chinese loess, tempered and modified in important particulars, will account for all the phenomena of the loess of the Mississippi valley. That the loess is not of aquatic origin is indicated by the following facts: WuU. Nat. Hist. S. U. I., Vol. II, pp. 93-98. '^Vrof. C'Alvin, in Iowa Geol. Survey, Vol. IV, p. 81, recently suggested the aeolian origin of a part of the loess in Allamakee county. IOWA ACADEMY OF SCIENCES. 83 First. — The land area during the period of the formation of the loess was large as is shown by the remains of great num- bers of terrestrial molluscs, ' Not only the number of species but the number of individuals of the terrestrial forms is much greater, a fact especially sig- nificant since the pond molluscs are all very prolific and had the conditions been favorable to their development much greater numbers of the fossils should occur. That the shells of the loess were deposited in situ and were not carried any great distance by water has already been pointed out by the writer.* Second. — The occurrence of dry region molluscs, such as Suc- cinea lineata. Pupa atticola, Patula cooperi, etc., has also been pointed out."* The great majority of the remaining species occur now in a living state throughout Iowa and eastern Nebraska, more particularly in wooded regions. Most of them do not seem to require an excess of moisture, but thrive under present conditions. Third. — The deposits often occur so high above the surround- ing region that it is difiicult to conceive of the manner in which water laden with the fine silt could reach the places of deposi- tion. Fourth. — The siliceous and other particles which the loess contains are generally angular and often show a freshness of fractures which would scarcely appear in particles which had been rolled and washed about by the waters.'' Fifth. — The distribution of the loess is better accounted for by the consideration of the action of winds, and by the distri- bution of the forest areas, as will be shown in the following pages. The fact that stratification and lamination sometimes appear in the loess, showing the action of water, together with the presence of aquatic molluscs, can also be accounted for under the wind theory; for, as now, so at the time that the deposits were being formed, ponds and lakes of various sizes were scat- tered over the state, and much of the dust carried out in clouds over these bodies of water would have been deposited in them. 3See Bull. Nat. Hist. State Univ. Iowa, Vol. I. p. 209, ct seq. Succinca veriUi and Pupa decora should be stricken from the list, and Pupa Iwlzingcri Sterki should Ije added. This species is rather rare in the loess of Nebraska, but in the living state it is quite common in both Iowa and eastern Nebraska. iBuU. Nat. Hist. S. U. I. Vol. I[, pp. 95 and 96. ^Ibid. p. 93. ^'See also Prof. R. D. Salisbury's report in Ark. Geol. Surveij, Vol. II, pp. 235, 226. 84 IOWA ACADEMY OF SCIENCES. That such bodies of water existed, though, as before stated, not of the extent required by the lacustrine theory, is also shown by the distribution of the pond mollusca, which are found in bands or layers similar to those which may be observed on the edges of our small ponds to-day. These layers are usually of but slight vertical extent, showing that the ponds did not per- sist during the entire period of deposition of the loess, but, like the ponds of to-day, were subject to changes. But if the water area was not great, comparatively little of the material carried by the winds could be deposited in this manner, and as a matter of fact we find comparatively little loess which shows such origin. Secondary loess, which had been subsequently eroded and re-deposited on lower lands by running waters, and which usually shows stratification, should not, of course, be consid- ered in this conection. In the consideration of any theory of the mode of deposition of the loess, two propositions, which seem to be capable of sat- isfactory demonstration, should be borne in mind, namely, that the loess was deposited under climatic conditions essentially the same as those which prevail in the same region to- day; and that the deposition was slow and continued through a period of considerable extent. That the first of these propositions is true is shown by the molluscs which furnish the most satisfactory evidence of the character of the conditions supporting life during that period. The same species, with but very few exceptions, which occur in the loess, exist in abundance now throughout the region under consideration, the distribution of the fossils being exactly such as may be observed under present conditions. If, for instance, we compare the modern molluscan fauna of eastern Iowa with that of eastern Nebraska, we find certain differences which are almost exactly duplicated in the loess faunas of the two regions. ' For instance, Succinea lineata "W. G. B., the common suc- cinea of eastern Nebraska, is also the most common succinea of the loess of that region, whereas Succinea avara Say, the most common succinea of eastern Iowa, is also the most common species of the genus in the loess of the same region. The majority of our species show a like distribution, "^ plainly 7 No reference is here made to the Lamellibranch and Prosobranch fluviatile faunas, which seem to ha%'e spread into the region In question from their center of distribu- tion in the southeast comparatively recently. ^tThe loess fossils of Europe are likewise like the modern forms inhabiting the same region. IOWA ACADEMY OP SCIENCES. 85 indicating conditions not essentially different from those which now prevail.'-' Additional weight attaches to the evidence of these molluscs when we consider that they are ia themselves witnesses to an abundant flora of the period, for with scarcely an exception they are purely herbivorous, aad frequent places in which shade, protectioa and fooS are furnished by abundant plants. The presence of a vigorous vegetation is further attested by the leaching of peroxide of iron from the loess soil and its deposition in tubules and concretions. ^^ That the amount of moisture was not excessive has already been pointed oat. The great preponderance of terrestrial molluscs, at least some of them, now capable of living and multiplying in regions even drier than that under considera- tion, and the majority of them living abundantly in our state to-day, is certainly significant. But even if we grant that the average temperature was somewhat lower than at present, and the amount of moisture somewhat greater — conditions by no means essential to the phenomena of the loess — it cannot be questioned that the cli- mate of the loess was sufficiently mild to support an abundant fauna and flora from the very beginning of the formation of these deposits. Glacial conditions certainly no longer existed, for sufficient time must have elapsed after the recession of the glaciers to clothe these prairies with verdure, for the mollusc remains are found in the lowermost portions of the deposits and the favorable conditions necessary for their development must have existed from the very beginning. The prevailing conditions being then essentially the same as now, and the topography of the continent being essential as we find it to-day, it seems fair to assume that the prevailing strong winds were, as now, northwesterly. This point will again be emphasized. The truth of the second proposition that the loess was deposited slowly is supported by the following facts: 9The writer formerly leaned toward the conclusion, drawn by McGee and Call in a paper on the loess of Des Moines, that the occurrence of depauperate forms was proof of a much colder climate than now prevails, but he has since found recent forms of several of the species common in the loess wliich exhibit great variation under different conditions even in the same locality. For example, shells of living Mesudon multilin- eata Say, from different points in the immediate vicinity of Iowa City, vary from 15 to 26 mm. in greater diameter, while fossils of the same species from the same region now in the writer's possession vary from 12 to 23 mm. This variation seems to be purely local and cannot be assigned to general climatic conditions. This was sug- gested in the writer's paper to which reference has already been made, p. 93, foot- note 3. loSse Lc Conte's Geology pp. 136, 137 86 IOWA ACADEMY OF SCIENCES. First. — The vertical distribution of the molluscs. The writer has already shown" that these molluscs were most probably deposited in situ, and sufficient time must have elapsed at least for the production and developement of the successive genera- tions. Second. — The fineness and hooiogenity of the loess material. This is of importance, for had the deposits been made quickly by powerful concentrated agencies, whether wind or water, much more coarse material would have been mingled with the fine debris. Tidrd. — No plant remains of undoubted loess origin occur. As the plants undoubtedly existed during the entire period the deposition must have gone on so slowly that ample time was given the plant remains to crumble in decay and mingle with the soil. With these propositions as an aid let us consider the follow- ing conception of the formation of the loess deposits: The region formerly covered by the glaciers remained a vast drift-covered plain after the recession of the glaciers. No loess was to be found, but the surface material consisted of unassorted drift, here and there heaped up in ridges and moraines. Streams soon cut their way through this materiaP" and ponds more or less numerous remained ia the depressions of the plain. The climatic conditions having so improved, plants, at first the smaller forms, spread over the plain, and soon trees, in whose shades numerous molluscs lived and prospered, appeared in narrow lines along the streams, the surface conditions being not unlike those of the northwestern portions of the state to-day. Forests gradually spread over portions of the area, principally along the river- valleys and on hillsides in the man- ner pointed out by Prof. Macbride. '^ When vegetation, especially the forests, had gained a foot- hold, then commenced the deposition of the loess. iiCh» ^\^t. Hm. S. U. I., Vol. II, p. 95. i2If it be true that our streams senerally follow the lil^best ridges of the drift, even without reference to the loess, i. e. if the streams run in yJac.ial ridges (and the writer knows of some cases wtiere this is true), then the fact can be accounted for by the theory offered in the paper by McGee and Call already cited, pp. 22-23. but the theory fails when applied to the loess because of the climatic conditions reciuired. 13 See paper: Foi-csl Dist/'ihution in Iowa and its Sigiiijicancc, in tJiis volume. It is but fair to say that the theories thus presented by Professor Macbride and the writer, while leading to the same results, were developed from different standpoints along entirely independent lines of investigation. IOWA ACADEMY OF SCIENCES. 87 The strong northwesterly winds blowing over the prairies, which during a part of the year at least were quite dry, gath- ered up clouds of sand and dust. The coarser material was blown and rolled about on the surface, the constant grinding furnishing renewed supplies of finer material, while this finer material was carried higher, being finally swept over the for- ests, and there deposited.^* That this is not a fanciful view of the work actually per- formed by winds has been nicely demonstrated in eastern Iowa during the past two years. High winds prevailed during con- siderable portions of both years, the dry spring of 1895 being particularly remarkable in this respect, and observations upon the material so transported were made in Johnson county. In the northern prairie portion of the county, beyond Solon, fine sand was heaped up m open places, in some cases to a depth of over a foot, within twenty -four hours, while fine dust only was carried into adjacent groves, and was there deposited upon every available surface to a depth of not less than one mm- The writer's observations of the effect of the winds which so prevail in Nebraska also confirm this. That this fine material now constituting the loess, was so deposited in forests is further shown by its distribution. That the loess and the original forest area in eastern Iowa alaiost exactly coincide is a well established fact, which has been demonstrated beyond question by MsG-ea.^' The forests are found along the streams, and also principally on the southern and eastern slopes of the hills, and the loess is found in exactly the same situations. Indeed it has often been suggested that there is something peculiar to the loess which renders it favorable to the develop- ment of the forests — whereas the fact seems to be that the forest is especially favorable to the deposition of the loess if lying adjacent to or near drift-covered plains. That the forest could have preceded the loess is shown by the fact that scrub growths of bur oaks have been able to gain a foothold along the shores of some of our northern (Iowa) lakes and streams in a purely glacial soil, thus forming the nucleus of a forest in comparatively recent time, while in the same region in groves evidently somewhat older a thin layer 14 Interesting observations were made in 1894 by F. H. King (see Eleventh An Rcrt of the )ri)escens L. • Sioux City B. W.); A very common weed in neglected yards Missouri Valley, Council Bluffs, Onawa (L. H. P. observations). SCROPHULARIACE.E. Scropliularia nodosa L. var. MarUandica Gray. Sioux City (B. W.); Little Rock (C. R. Ball). Pentstemon grandijiorus Nutt. Sioux City, common on the sides of the loess mouDds (L. H. P., B. W.). Minmlus ring ens L. Sioux City in low grounds (B. W.). Ilysanthes riparia Raf. Sioux City, low grounds and muddy places (B. W.); Hawarden (L. H. P.); Hull (W. Newell). Veronica Virginica L. Sioux City (B. W.); Hull (W. Newell); Little Rock (C. R. Ball). Gerardia aspera Dougl. Sioux City, common on sides and tops of loess mounds (L. H. P.). G. tenuifolia Vahl. Missouri Valley, loess mounds (L. H. P.). 128 IOWA ACADEMY OF SCIENCES. Castilleia sessil'tjlora Parsh. Sioux City, abundant on loess mounds (B. W.). LENTIBULARIACE.E. Utricularia vulgaris L. Hull (W. Newell). PEDALIACE.E. Martynki i^roboscidea Glox. Missouri Valley, in fields, base of hills (L. H. P.). VERBENACE.-E. Verbena urtica'folia L. Sioux City (B. W.); Hall (W. Newell); Turin, Missouri Val- ley, low grounds (L. H. P.). V. Jiastata L. Sioux City, fields and low ground (B. W.); Hull (W. Newell). V. stricta Vent. Sioux City, base of loess mounds, prairies and fields, abundant (B. W.); Battle Creek (E. G. Preston); Little Rock (C. K. Ball); Turin, Missouri Valley (L. H. P.). Plirynia leptostachya L. 'siouxCity (B. W.). LABIAT.E. Teucrium Canadense L. Sioux City, low grounds, abundant (B. W.); Council Bluffs, abundant (L. H. P.). Mentha Canadensis L. Sioux City (B. W.); Hull (W. Newell); Little Rock, low grounds (C. R. Ball). Lycojnts sinutus Ell. Sioux City (B. W.); Hull, low grounds (W. Newell). L. Virginicus L. Sioux City (B. W.). Hedeoma Jiispida, Pursh. Sioux City (B. W.). Pijcnantliemum lanceolatiun Pursh. Spirit Lake (B. W.). Salvia lanceolata Willd. Council Bluffs (L. H. P. observations). Monarda Jistulosa L. Logan, prairies and borders of woods (L. H. P.). LophantJius scrophularia'folius Benth. Sioux City (B. W.). IOWA ACADEMY OF SCIENCES, 129 Nepeta Cataria L. Sioux City (B. W.). A common weed in western Iowa (L. H. P.). Scutellaria lateriflora L. Turin, rich, low woods near stream (L. H. P.); Sioux City (B. W.). S. parvula Michx. Little Rock (C. R. Ball); Sioux City (B. W.). Plujsostegia Virginiana Benth. Sioux City, low grounds (B. W.)- Stacliys imlustris L. Sioux City, low grounds (B. W.); Rock Valley (J. Jensen, W. Newell). PLANTAGINACE.E. Plantago major L. Sioux City (B. W.). P. Patagonica Jacq., var. gnapJialioides Gray. Rock Valley (J. Jensen, W. Newell). NYCTAGJNACEyE. Oxyhaplms liirsutus Sweet. Hull (W. Newell); Sioux City, common along roadsides and fields (B. W.); Little Rock (C. R. Ball). 0. angustifolms Sweet. Sioux City, loess hills near top (L. H. P.). amarantace^. A. retroflexus L. A common weed everywhere in western Iowa (L. H. P.); Sioi^x City (B. W.). A. albiLS L. Sioux City (B. W.); Onawa, Turin, a common weed (L. H. P.). A. blitoides Watson. Sioux City, loess mounds in open places (L. H. P.). Acnida tubercidata Mcq. Onawa, common weed in cultivated ground (L. H. P.). CHENOPODIACE^. Onawa, Turin, Des Moines (L. H. P.); Smithland (J. M. Wrapp); Sioux City (B. W.). G. urbicum L. Onawa, Missouri Valley, Turin near stables and houses (L. H. P.). 130 IOWA ACADEMY OF SCIENCES. G. Jiyhrklum L. Missouri Valley, Turin, Onawa (L. H P.); Sioux City (B. W.), a common weed in waste places. Salsola Kali L., var. tragus Mcq. Onawa, Sioux City, Missouri Valley, Ha war den, Council Bluffs (L. H.P.), spreading rapidly. POLYGONACSAE. Rumex vertkillatus L. Missouri Valley, in swamps, common (L. H. P.). R. crispus L. Council Bluffs, weed in streets (L. H. P. observations). B. maritimum L. Sioux City (B. W.); Little Rock (C. R. Ball), in low grounds. R. Acetosella L. Missouri Valley, Turin, weedy in yards and fields (L. H. P.). Polygonum avicula,re L. Sioux City (B. W.); Ha warden, weed in yard, (L. H. P.); Missouri Valley. P. erectum L. Missouri Valley, common weed in streets (L. H. P). P. ramosissimum Michx. Missouri Valley, Sioux City, L. H. P., B. W.) Hawarden (L. H. P.). P. la2)athifoUum Li. , var. incarnatumW a,t5on. Sioux City, (B. W.); Turin, low grounds (L. H. P.). P. Pennsijlvanicum L. Logan, Turin, Onawa, Missouri Valley, low grounds, (L. H. P.); Hull (N. Newell). P. MuJilenbergii Watson. Sioux City (B. W.), common along the Missouri river (L. H. P.). P. Persicaria L. Hull (W. Newell); Sioux City (B. W.). P. orientale L. Missouri Valley, an escape from cultivation (L. H. P.). P. acre HBK. Hull (W. Newell). P. Virginianum L. Sioux City (B. W). P. Convolvulus L. Sioux City (B. W.), Hull (W. Newell). IOWA ACADEMY OF SCIENCES. 131 P. dumetorum L., var. scandens Gray. Sioux City (B. W.). ARISTOLOCHIAGE.E. Asarum Canadense L. Cherokee (B. W.). EL.^^AGNACE^. Shepherdia argentea Nutt. Sioux City, sandy banks of Missouri river (B. Yf. , L. H. P., Hitchcock, Bot. Gazette, XIV, 128). EUPHORBIACE.E. EuphorMa maculata L. Missouri Valley, Des Moines, Turin and Onawa; w^ste places and along railroad (L. H. P.). E. hypericifolia. Onawa (L. H. P.), Sioux City (B. W.). E. marginata Pursh. South Dakota, opposite Hawarden. hills, Missouii Valley, Turin and in waste places (L. H. P.), Hull (W. Newell), Council Bluffs (L. H. P.), Sioux City (B. W., L. H. P.). E. coroUata L. Missouri Valley (L. H. P.), Sioux City (B. W.). E. serpens H. B. K. Missouri Valley, low grounds (L. H. P.). E. serpijllifolia Pers. Turin (L. H. P.). Sioux City (B. W.). Var. consanguinea. Oaawa, Turin (L. H. P.). E. glyptosperma Engelm. Missouri Valley (L. H. P.). Var. imbescens. Turin (L. H. P.). E. hexagona Nuit. Missouri Valley (L. H. P.), Sioux City (B. W.). E. Geyeri'En.gelm.. Missouri Valley (L. H. P.) E. heterophylla L. Sioux City, in woods, Council Bluffs (L. H. P.); Sioux City (B. W ). E. obtusata Push. Sioux City (B. W.). Acalyplia Virginica L. Sioux City (B. W.) 132 IOWA ACADEMY OF SCIENCES. URTICACE.E. Ulmus fulva Micbx. Sioux City, in valleys between loess mounds (B. W., L. H P.); South Dakota opposite Hawarden. U. Americana L. Sioux City, along the Big Sioux river and Missouri river (B. W., L. H. P.). Celtis occidentalis L. Sioux City, along Missouri and Big Sioux rivers (L. H. P.). Cannabis sativa L. Missouri Valley (L. H. P. observations); Sioux City (B. W.). Humulus Lupulus L. Sioux City (B. W.)- Urtica gracilis Ait. Sioux City (B. W.); Little Rock (Herb. C. R. Ball.). Laportea Canadensis Gaudichaud. Sioux City (B. W.). Pilea pumila Gray. Logan (L. H. P.) Parietaria Pennsylvanica Muhl. Turin (L. H. P.). JUGLANDACE.E. Juglans nigra L. Sioux City (B. W.). Carya oUvceformis Nutt. Sioux City (Hitchcock) ; this is further north than it occurs elsewhere in this state. C. amara Nutt. Smithland (B. W.). CUPULIFER.^. Corylus Americana Walt. Sioux City (B.W.). Ostrya Virginica Willd. Council Bluffs, in woods, back of steep mounds (L. H. P.); Logan (L. H. P.); Sioux City (B. W.). Quercus macrocarpa Michx. Council Bluffs (L. H. P.). Var. oUvceformis Gray. Sioux City, sides of bluffs (L. H. P., B. W.) Q. rubra L. Sioux City (B. W.). IOWA ACADEMY OF SCIENCES. 133 SALICACE^. Salix humilis Marsh. Sioux City, common on prairies and at base of loess mounds (L. H. P.). S. longifolia Muhl. Sioux City (B. W.). Populus monilifera Ait. Missouri Valley, in bottoms near streams, in swales between loess mounds; occasionally near top of mound. Com- mon (L. H. P.), South Dakota, opposite Hawarden (L. H. P.); Sioux City (B. W.). CERATOPHYLLACE^. CeratopTnjllum demersum L. Sioux City (B.W.). CONIFERS. Juniperus Virginiana L. Sioux City (B. W.). ORCHIDACE.'E. OrcMs spectcibilis L. Sioux City (B. W.). Hcibenaria leucopJicea Gray. Cherokee (B. W.). Sjjiranthes ceriMci Richard. Smithland (B. W.). Cypripeclium ])ubescens Willd. Caerokee, Smithland (B. W.). IRDIACE^. Iris versicolor L. Sioux City (B. W.). LILIACE.E. Smilax herbacea D. Sioux City (B. W.). Allium stellatum Fras. Alton, common on prairies (L, H. P.). A. Ganaclense Kalm. Sioux City (B. W.). Yucca angustifolia Parsh. Council Bluffs, Missouri Valley, Sioux City, Turin (L. H. P.); near top of loess, mounds common. South, north and west sides. Many seeds produced. Not all the plants which fl.)wer produce seeds — many empty stalks were found. It is a significant fact that this species does 134 IOWA ACADEMY OF SCIENCES. not occur on the east slopes of the mounds, perhaps because they are more or less wooded about Council Bluffs and Missouri Valley. Sioux City (B. W.), Hitch- cock Bot. Gazette, XIV, p. 128. Polygonatum giganteum Dietr. Sioux City (B. W., L. H. P. observations). Deep rich woods. Smilacina sfeUata .Desf. Sioux City (B. W.). Uvularia grancUflora Smith. Sioux City (B. W.). Erythronium albidum Nutt. Sioux City (B. W.). Lilium Philadelphicum L. Little Rock (Herb., C. R. Ball). L. Canadense L. Sioux City (B. W.). Trillium nivale Riddell. Cherokee (B. W.). Zygadenus elegans Pursh. Little Rock (Herb., C. R. Ball). COMMELINACE^. Tradescantia Virginica L. Sioux City (B. W.). JUNCACE.E. Juncus tenuis Willd. Sioux City (B. W., L. H. P. observations). J. nodosus. Sioux City (B. W.). TYPHACE^. TypUa latifolia L. Sioux City (B. W.). SjKirganium eurycarpum Engelm. ARACE.E. Dickinson Cj. (Hitchcock); Hull (W. Newell). Arisaema tripyldlum Torr. Sioux City (B. W.). ALISMACE^. Alisma plantago L. Sioux City (B. W.). Echinodorus rostratus Nutt. Sioux City, Big Sioux river (L. H. P.). IOWA ACADEMY OF SCIENCES. 135 NAIADACE^. Potamogeton natans L. Lake Okoboji (Hitchcock). P. lonchites Tuck. Spirit Lake (HUchcock). P. praelongus Wulf. Clear Lake (Hitchcock). P. 2ierfoliafi(s L. var. Bidiardsonii, Bennett. Lake Okoboji and Spirit Lake (Hitchcock). P. zosterifoUus Schum. Lake Okoboji (Hitclicock). P. mucronatus Schrad. Spirit Lake (Hitchcock). P. 2^ectinatus L. Woodbine (Burgess); Lake Okoboji (Hitchcock) CYPERACEAE. Oyperus diandrus Torr. Near Lake Okoboji (B. W.). C ScJiweinitzii Torr. Lake Okoboji (B. W.). Eleocliarls acicularis R. Br. Sioux City (B. W.;L. H. P.). Scirims lacustris 'Li. Council Bluffs (L. H. P. observations); Sioux City (B. W.). S. atrovirens Muhl. Sioux City (B. W.). Species of Carex numerous, but omitted bec3i.us9 they have not been studied critically. There are also a large nuoaber of grasses, localities and species will appear in another connection. SOME NOTES ON CHROMOGENIC BACTERIA. L. H. PAMMEL AND ROBERT COMBS. Quite a large list of chromogenic bacteria are kaowu to bacteriologists. Many of these are familiar objects ia bacteri- ological laboratcvries. Of the early works describing these in this country we may mention Sternberg and Trelease. For later works on North American chromogenic bacteria we must refer to Sternberg, Jordan and the numerous text books dealing with pathogenic species. 13G IOWA ACADEMY OF SCIENCES. Very few attempts have been made to study our local bac- teriological floras. It is indeed a very diffi3ult matter. The following works describe Chromogenes: Saccardo: Sylloge Fungorum VIII. Sternberg: Manuil of Bicteriology. 1892. Trelease: Ooservations on several Zoogloea (Studies Biol. Lab. of the Johns Hopkins University). 1885. P. & G. C. Frankland: Micro-organisms in Water. 1894. Adametz: Die Bakterien der Trink-und Naizwasser. Mitth. der Oaster Versuohstation fur Brauerei-und Maizerei in Wien, 1888. Heft 1. Jordan: A report on certain spacies ol bacteria observed in sewage. Rep. Mass. State B jard^of Health, 1883-1890, plate II. Eisenberg: Bakteriologiscae Diagnostik. 1888. Welz : Bakteriologisch^ Untersuchnyer der Freiburger Luf fc, Zairitschrift fur Hygiene XI, p. 121. No attempt will be made to give description of common species found here at Ames, simply a record of their occurrence including some laboratory observations. Micrococcus cyanogenus. N. SP. Source. — During the latter part of May, 1891, a foreign blue color was observed on an old milk culture of an organism obtained from cheese; later the same was found in an old milk culture of Bacillus aromaticus. A transfer from the first milk tube was made to another tabe of sterilized milk, the typical color appearing in three or four days. The organism was sep- arated by pouring plates of agar. Morphology. — A small micrococcus occurring singly or in groups; motility not determined. An aerobic liquefying micrococcus. Agar. — Nearly colorless, with a slight tinge of blue, iDroduc- ing an irregular film on surface, growing at temperature of room. Gelatin. — A creamy white layer not spreading on surface, soon liquefying, forming a funnel-shaped area, later the medium was liqueflad with a creamy white sediment in the bottom of the tube. Milk. — Sterilized milk inoculated produces in three da^j-s a slight blue layer on surface, which increases in intensity, becoming quite blue for one-third of an inch on the seventh day. On the eighth day it appeared rather muddy; on the ninth day only a faint blue color remained; it coagulated milk with a IOWA ACADEMY OF SCIENCES. . 137 blue liquid on top. The curd was dissolved slowly. In twenty- five days the process was completed, excepting a small portion in the bottom of the fl isk. Dunliani s 'peptone solution. — No color produced; > the medium became cloudy, which was ia no way characteristic. It failed to grow in Duaham's rosalic acid solution. Several blue organisms have been described. Bacillus cyanogenus is a well known inhabitant of milk. This is a non-liqaefyicg, actively motile bacillus. Has not been found here at Ames. Gessard has shown that in presence of an acid it produces an intense blue color, and in milk not sterilized containing lactic acid germs, a sky blue color is produced. Jordan has also described a Bacillus cyanogenus, which is less motile formiag a deep brown color on potato, but he says undoubtedly Bacillus cyangenus. Beyerinck^ has also described a blue organism obtained from cheese, the Bacillus cyaneo-fuscus. The original paper has not been seen but according to the description given by Sternberg this is a small bacillus 0.2-0.6 u. long and one half as thick. It is an aerobic liquefying motile bacillus, and when cultivated in a solution contaiuing one-half per cent of peptone the culture media acquires at first a green color, which later changes to blue, brown and black. Subsequently the color is entirely lost. More recently Wm. Zangemeister^ has described a biciJus cyaneo-flaorescens. This species is in many respects similar to Bacillus cyanogenus. It is however somewhat shorter and very actively motile. Gelatin is not liquefied and the bright greenish fluorescent pigment dfliu&es through it. Oar species also came from cheese and the blue color disap- pears, but the organism in question never produces a black color. The species so far as we have been able to determine is new, and we have therefore given it the name of Micrococcus cyanogenus. Staphylococcus pyogenes, Ogston var. aureus Rosenbach.— This, the most common of the pyogenic micrococci has been found quite frequently here at Ames. It has at different times been isolated from ordinary carbuncle, fistula, dirt under the finger nails, etc. It has been found more commonly in suppurative abscesses than any other organism. It is pathogenic to mice ^Sternberg: Manual of Bacteriology p. 72". SKurze Mitteilungen uber Bakterien der-blauen Milch. Centralblatt f. Bakt. u ParsitcDkunde. Erste Abt., XVIII, p. 321. 138 IOWA ACADEMY OF SCIENCES. and rats. Old cultures, however, soon loose their virulence. A culture nine months old failed to cause any lesions in mice, not even the local formation of pus. St. pyocjen^s, Ogston var. citreus Passet. — This species has not been found spontaneously in any of the cases of pus studied, though it has been cultivated in the laboratory. It has been included with the pyogenic cocci because of its occurrence in pus. Passet found the organism in the pus of an acute abscess and Sternberg* says: "As to its pathogenic properties, we have no definite information. It is included amoEg ihe pyogenic bacteria because of occasional presence in the pus of acute abscesses, although it has heretofore only been found in association with other micro-organisms." Mice have been inoculated here at Ames but in no case did fatal sep- ticEemia follow. We have, however, had no trouble in obtain- ing pus at tbe point of inoculatioQ under the root of the tail. From this pus, pure cultures of the organisms were obtained. St. pyogenes Ogston var., flavescens Trev. — Obtained from the fistula of a horse by Dr. S. Whitbeck in bacteriological labora- tory, Iowa Agricultural college. This organism does not differ from the foregoing in size; in color, however, it is much paler, being an ochre yellow. It produces fatal septictsmia in mice when fresh cultures were used, but in this case pure cultures were not obtained. Strej)tococcus cinnabareus, Plligge. — Obtained at first from butter, but probably came either from the air or water. Color in different media is quite constant, except in blood serum, where its color is much paler. It grows quite characteristic on the surface of bouillon, forming spherical masses paler than in agar or potato. A nearly related species was isolated by Dr. W. B. Niles from the heart of a diseased steer affected with corn-stalk disease. It differs from the cinnabarcus in the change of color. It is dark lemon-yellow at first, and then changes to a brick-red. This species will be described in another connection. Sarcma lutea Schroter. — This well known organism occurs chiefly in the air. Gelatin and agar i^lates exposed to the air invariably show this organism. It comes up somewhat more tardily than the non-chromogenic species. They appear as small, yellow, spherical colonies. The canary-yellow growth liquefies gelatin quite slowly. The same organism has been ^Manual of Bacteriology p 273. IOWA ACADEMY OF SCIENCES. 139 obtained frequently from butter and milk, but the organism undoubtedly came from the air. S. aurantiaca Fliigge. — This organism is also quite commonly met, and appears on gelatin and agar plates exposed to the air. Bacillus Jiuorescem Uqaefaciens Fitigge. — This common inhab- itant of water also occars on potato, milk and butter. Scarcely a sample of water can ba plated withouu obtaining this organism. B. pyocyaneus Gessard. — This has been obtained several times from wounds and Dr. S. Whibbeck obtained a pure culture in open synovial bursa. Inoculation into the peritoneal cavity was followed by death in forty-eight hours. In old cultures there is a gradual tendency for the organism to lose its power of forming coloring matter. Gessard'^ has isolated two pigments a fluorescent green and a blue, the latter called pycoyanin. Bacillus prodkjionsus Ebrenberg.— This species is well known to most bacteriologists. It has loEg attracted attention because of the red stains produced on potatoes, boiled bread, and the red color it imparts to milk. According to several investi- gators this organism is not a native to this country. The specie? is however, re3ori8d at Ames by Bissey. He commonly obtained a red organism on sliced potatoes exposed to the air. There are of course several red organisms and as the organ- ism was reported before the era of modern bacteriological methods I must therefore express some doubt as to the correct determination of the Bacillus prodigiosus foulid by Bessey. The senior writer has at various times had cultures of this organism in the laboratory. Thus we had good growing cul- tures in 1889, 1892, but all attempts to make old cultures failed. In 1894 a blood-red colony came up in culture plate. Cultures of this organism had never been in this laboratory so far as we know. In the spring we had received from Dr. Irving VV. Smith, cultures of several species obtained from the laboratory of Johns Hopkins University. The cultures appeared pure but they may have been contaminated. The senior writer observed this organism on one other occasion in the botanical laboratory of the Shaw School of Botany, St. Louis. Cultures of B. prodigiosus were obtaiaed from rotting sweet potatoes, but European cultures were common at the time in the labora- SGessard. De la pyocyanine et de son Microbe. These de Paris, 1882. Nouvelles recherches sur la Microbe pyocyanique. Ann. d VInstitut Pasteur. Vol. IV, 1890, p. 89 6Bull. Dept. of Botany, Nov. 1884. 140 IOWA ACADEMY OF SCIENCES. tory. Professor Trelease thought it probable that the species came from the E aropean cultures. We are therefore iuclined to believe wi':h Jordan, Russeli, and others that the species is not native in this country. FUNGUS DISEASES OF PLANTS AT AMES, IOWA, 1895. BY L. H. PAMMEL AND GEO. W. CARVER. In previous papers record has been made of the abundance of pirasitic fungi for the years of 1891, 1892, 1893 and 1894.^ We hope to continue these observations for the purpose of making comparison. Observations from year to year with climatic conditions should make it possible to say how much climate modifies the appearance of disease. Ooservations in a climate like ours are valuable because of the changeable conditions as to humidity and rainfall. From the nature of the diseases of plants it is difficult to make exact statements. We must speak in relative terms. la 1893 Puccinia gramiriis, P. ruMgo-vera and P. coronata were very destructive. In 1894 these rusts were not absent, but they were not destructive; in fact, scarce as compared with 1893. In the study of diseases of plants the condition of the atmos- phere with reference to moisture is an important factor. The universally low humidity of the atmosphere in 1894, no doubt, largely determined the amount of rust that year. So low was the humidity that during the growing season dew was an unusual condition. We append table, giving rainfall, relative humidity, 7 a. m. temparature (maximum and minimum), for the months of May, June, July, August and Saptembar, taken from the records made at Ames by Dr. J. B. Weems, Mr. W H. Heilemaa. 1 L H. Pammel, Jour. Mycology, VII, p. 93. Agricultural Science, VII, p. 20. Pr^c. Iowa Academy of Science, II, p. 201-203 IOWA ACADEMY OP SCIENCES. 141 « 1 : S§ § Is- se § 1 i §8S s 1 '■ s§ ^ i° g§ « 1 i t--* s 1 : §s ^ 1 : S3 ^ 1 ; ?:S ^ 1 ; 22S 53 1 : 5m S 1 '■■ gS S 1 : SS S 1 : S5 ^ ! i g^ - ! ; ss s 1^ §g 3 1 : s« " 1 ; ss S 1 : ss - 1 : ss o 1 S s,-? =^ 1 : OS to 00 : §g t- : §g o |S gs « |o ;£S -* 1 '• §5 CO |» SS .§& m s 2gg s Sg:s s gSSS gs ^SSS s «sg§ s :SS:§ ^ ^£g§ St ;sss SI :g?g s :§gtg N :gS£ s ^ggg CT> :gSS s iSSS t- «??-!§§ s :g?SS i5 ^g§8S ^ ^§gs s O00«5 ?? sss I-l S«:^ s «gg CT se^ 00 &:S5; - §ss to sgg « ggs ^ sss m gg§ ., g-Jeg - sg§ 1 a£.s •^aa lu 3^ a a s ® c © s :gS5: s issg? s jses g§ EHg^K ^ ^§S£ ^ :g£S !S 9SSS S :ssg ■?? ^g^s §1 ^^sss N isSSgg § igiSS o> :g;^5 s ;§e:s t- :gSS s :§3S iS Pg^S 3 iSSS S :gSS ;h jsss s igSif? s :ggg ^SS5 00 JSSSS - :5gS «o i^SS «= :§§§ ^ H§!2S CO o^SS Oi OS£g - :sss •ac.s : jsa igU .2- a a s g ggJS ^ sss iS sss 13 &S25; ^ igSS g S5?25 ^ g^-3S S5 SS3 ^ ^§g8S 53 :>SS S |.sss OS l^gS 2 :ggg S :SS£ S :§S5S S °=E£g§ ^ gs§ S ^SSS S sss ;:5 ggg o S3??i OS sss ^ sss - 555 ,o gg;§ in ^^g£.| ^ £gS CO §g5 (M g£g - §^S 1 z ;a|| J^sa 142 IOWA ACADEMY OP SCIENCES. We have followed Saccardo (Sylloge Fangorum) in the arrangement of orders, genera and species, and in most cases have used the syncnomy given by him. USTILAGINEAE. Ustilago hypodytes (Schlecfch.) Fr. Very abundant. On Stipa spartea. r. tritici (Pers.) Jensen. Not uncommon and was frequent in 1894 on Triticum vul- gare. r. horclei (Pers.) Kellerman and Swingle. Common on Hordeum vulgare. r. niida (Jensen) Kellerman imd Swbgle. Scarce on Hoi deum vulgare. r. avenue (Pers.) Jensen. Not uncommon on Avena sativa. U. segetum (Bull) Dittm. Common on Arrhenatherum avenaceum. U. neglecta Niessl. Abundant on Setaria glauca. U. Rahenhorsticma Kuhn. On Panicum sanguinale abundant. U. matjdls (D. C.) Corda. Abundant on Zea mays. U. pustulata Tracy & Earle. Locally abundant in one place, first time observed on Panicum proliferum. TtUetia-strkeformis (Westend.) Magnus. Not abundant on Pnleum pratense. T. foelens (B. & C.) Trelease. Not observed in 1895. Sdiizonella mekmograuuna (D. C.) Schroet. Abundant in May, Moingona. jSorosjJorium syntherisuHe (Schw.) Farlow. Abundant on Panicum capiliare. Urocystis Agropyri (Preuss) Schroet. Abundant in June and early July on Elymus Canadensis. UREEINE.^. Uromyces Polygoni (Pers.) Fuckel. Abundant August aud September on Polygonum aviculare and P. erectum. IOWA ACADEMY OF SCIENCES. 143 U. Trifolii (Hedw.) Lev. Abundant in September on Trifolium pratense. This fun- gus has been increasing in severity, large patches of second crop of clover being affected. U. aiypendiculatus (Pers.) Link. Abundant on Strophostyles angulosa, but not observed here on Phaseolus vulgaris. At Indianola it was, however, destructive to the cultivated bean. TJ. EupJwrbke Cooke & Peck. Abundant in August and July on Euphorbia maculata and E. Preslii. Melampsorafarinosa (Pers.) Schroet. Abundant on Salix, August and September, iff. PopuHna (Jacq.) Lev. Abundant on Populus monilifera, August and September. Puccinia Helianthi Schw. Abundant on Heliauthus tuberosus and H. grosse-serratus July, August and September. In August especially destructive to cultivated Helianthus annuus. P. Convolvuli (Pers.) Cast. Abundant on Convolvulus sepium July, August and Sep- tember. Oymnosporanghim macropus Link. Teleuto stage on Juniperus Virginiana not as abundant as in 1894; nor was the Eecidium (Roesteiia pyra,ta) so abundant on Pyrus lowensis. Locally, however, in Madison county it seriously affected the leaves, stems and fruit of the wild crab. May was unfavorable for the germination and development of the teleutospores. Phragmidion subcorticium (Schrank.) Winter. Abundant on the leaves of the cultivated rose, as Madam Charles, Frederick Worth, August and September. Aecidium Grossiilarke Schum. Not so common as in 1894 on Ribes Grossulariae, R. gra- ciie. Uredo Caeoma-nitens Schw. (C. inter stitiale, Schlecht and is supposed to be connected with Paccinia Peckiana.) Abundant on Rubus villosus; large patches of native blackberry destroyed; seriously affecting cultivated blackberiy locally. It was also observed in Story, Polk, Louisa and Henry counties. 144 IOWA ACADEMY OF SCIENCES. P. G rami n is Pers. Not common on Triticum vulgare, Avena sativa and Hordeum jubatum. June and July. Aecidium abun- dant on Berberis vulgaris May-June. Very destruc- tive en fall sown oats and wheat. August and Septem- ber; also Hordeum jubatum. P. coronata Corda. Not common on Avena sativa, June and July. Abundant August and September. Klebahn has recently sepa- rated another species out of what has passed as this, until further work in this country, the species is used here as it is by American authors generally. P. ruhifjo-vera (D. C.) Wint. Not common, on wheat June and July. Abundant on fall sown wheat, Hordeum jubatum, August and September. Squirrel-tail grass is held in check by this fungus. P. Sorgld Schw. Abundant August and September on Zea Mays. P. emaculata Schw. Abundant on Panicum capillare August and September. P, Androjxx/onis Schw. Not abundant on Andropogon furcatus. A. scoparius,. August and September. P. Xanthii Schw. Abundant on Xanthium Canadense, July, August and Sep- tember. In low grounds destroyed a large number of plants. PERONOSPORACE.^. Cystopus ccmdidus (Pers.). Lev. Abundant early in the season on Lepidium intermedium^ L. Virginicum, Capsella bursa-pastoris. Later, oos- pores abundant in infloresence of Rhaphanus sativa. C. Tragopogonis (Pers.) Schroet. Locally abundant in June and early July. a Portulacce (D. C.) Lev. Abundant on Portulaca oleracea from the middle of June to the first of September. Oospores abundant. a Bliti (Biv.) De By. Abundant July, August and September on Amarantus albus, A. retrcflexus. More severe on the latter species. Sderospora graminicola (Sacc.) Schroet. Abundant durirg the latter part of May till middle of June> IOWA ACADEMY OF SCIENCES. 145 destroying large numbers of young plants of Setaria viridis. In whole iDatches it prevented the maturing of seeds. Plasmopara Viticola (B. and C.) B. and DeT. Abundant. Destructive to cultivated grape (Vitis Labrus- ca), affecting leaf, stem and fruit. Also affecting the growing of young shoots of Vitis riparia, in some cases killing the young shoots. P. HalsteclLi (Parlow) B. and DeT. Not common, on Helianthus annuus, H. tuberosus, Silphium laciniatam, Xanthium Canadense, Centaurea. Breraia Lactucce Regel. Not observed although abundant in 1893. Peronosposa Vic ice (Berk.) DeBy. Abundant in latter part of May and early June on Vicia Americana. P. Arthuri Farlow. Abundant on Oenothera biennis. P. parasitica (Pers.) DeBy. Abundant on leaves and stems of Lepidium intermedia, L. Virginicum, killing the affected plants. On leaves of Capsella bursa pastoris not destructive. Brassica nigra, B. campestris, Raphanus sativa, Draba Carolin- iana. Sisymbrium officinale seriously affected. P. Potentilke DeBy. Not found in 1895. Local in 1894. P. effusa (Grev) Rabenh. Abundant on Chenopodium album in May and June. P. EuphorMce Puck. Locally abundant on Euphorbia Preslii and E. maculutp. P. alta Puckel. Abundant on Plautago major. PERISPQRIACEAE. Podosphcera Oxyacanthce (D. C.) De By. Abundant on cultivated (Prunus Cerasus) and P. pumila. Not common on P. Americana; also observed on young shoots of Crataegos punctata, and C. mollis; July, August and September. Spcerotheca 2Iali (Duby) Burrill. Common on suckers of Pyrus Malus and young shoots of P. toringo in nursery, June, July and early August. 10 146 IOWA ACADEMY OF SCIENCES. S. MTors-iivae (Schw.) Berk & Curt. Abundant on Ribes Grossulariae, R. floridum, June, July; leaves, stem and fruit. Phyllactinia suffulta (Reb.), Sacc. Abundant on Fraxinus Americana, August and September. Uncinula necator (Schw.) Burrill. Common on Vitis Labrusca, Concord, Worden and especi- ally Roger hybrids (Agawam). Microspiicera Aim (D. C ) Wint. Abundant on Syringa vulgaris, S. Persica, Lonicera, August and September. Abundant latter part of August and September. Erysiplie Cichoracearum D. C. Very abundant on Helianthus annuus, H. tuberosus. Not so common on H. grosseserratus. Abundant on Ambro- sia artemisiaefolia, A. trifida, Artemisia, Ludoviciana; generally attacked by Cicinnobulus Cesatii. Abundant on Verbena stricta; less common on V. hastata. E.. communis (Wallr.) Schl. Abundant on Rannuculus abortivus and Amphicarpasa monoica. SPH^RIACE^. Physalospora Bidwellii (Ell.) Sacc. None observed in 1895. DOTHIDEACE.E. Phyllachora Graminis (Pers.) Fuck. Common on Muhlenbergia Mexicana, Elymus Canadensis, Panicum scoparium Asprella hystrix. P. TrifolU (Pers.) Fuck. Abundant, conditial stage on Trifolium pratense, September. Plowriglitia morhosa (Schw.) Sacc. Abundant on Prunus domestica, P. Padus, and wild P. Americana, P. Virginiana and Japan plum. GYMNOASACE.E. Exoascus communis Sadebeck. Rare on Prunus Americana in 1895; abundant on Prunus Cerasus and P. domestica. Narsery stock defoliated in August. Not as severe on P. Americana. Also occurred on P. Mahaleb and P. avium. HYPHOMYCETE.E-MUCEDINE.-E. Monilia fructigena Pers. Abundant late in season on fruit of Prunus Americana. IOWA ACADEMY OP SCIENCES. I47 DEMATIACE^. Cladosparium caij^jophilum Thum. Rare on Prunus Americana, but abundant on Cratsegus mollis late in August and September. Helmhitliosiwrium Graminum Rabh. Nut common oa Hordeum vulgare in July. Cercospora Resedce Fuck. Abundant on Reseda odorata in August and September. C. Bet kola Sacc. Abundant on Beta vulgaris. (Sugar and mangel beets). September. In some cases leares completely covered with cinereous spots. G. angulata Winter. Abundant on Ribes rubrum, shrubs nearly defoliated lat- ter part of July and early August. Fungus appeared early in May. SPH^ROPSIDE.E SPH.'EROIDACE^. Septoria Rubi West. Abundant on Rubus odoratus, R. canadensis August and September. Septoria Eibis Desm. Abundant on Ribes nigrum, June and September. Melanconiaceae. Gijlindrosporium Padi Karst. Abundant on Cherry. Marsonia Juglandis Sacc. Trees of Juglans cinerea nearly defoliated by middle of August. Not so severe on Juglans nigra. M. Martini Sacc. Abundant on Quercus robur; majority of leaves affected; also occurred on Q. macrocarpa. BACTEKIAC.^. Bacillus amylovorus (Barrill) Trev. Blight more severe than in 1894. Pyrus Mains, P. pruni- folia, P. Sinensi'*, P. communis and P. lowensis espe- cially severe on the following varieties of P. Mains: Yellow Transparent apple, Red Queen-Lead, Arabskoe Antonovka, Thaler, Oldenburg. It seems, also, to have been severe in other parts of the state. Fruiting orchards less affected than nursery stock. It would seem that the condition of the soil may influence the 148 IOWA ACADEMY OF SCIENCES. severity of the disease. We should also observe that flowers are occasionally affected, but not so severe as in 1894. The disease gradually subsided by the rciddle of July and early August. B. Sorgld W. A. Kellerman. Not severe. It occurred on Andropogon Sorghum var Halepense and A. Sorghum (Sorghum). B. doacece (Jordan). On Zea mays; not abundant. B. cami^estris Pammel. Not observed in 1895. SOME ANATOMICAL STUDIES OF THE LEAVES OP SPOROBULUS AND PANICUM. EMMA SIRRINE AND EMMA PAMMEL. Numerous writers have called attention to the value of anatomical studies for diagnostic purposes in the recognition of Phaencgams. We may note in this connection the paper by Pfisterj, who has made a comparative study of the leaves of some palms. The author considers anatomical characters of value because so many palms are collected without flower or fruit. Bertrand^ in a general paper considers the characters and important points to be observed in making anatomical studies of this kind. He notes that we must not lose sight of: 1. Inequalities in the grouping of subdivisions with the association of higher groups. 2. The paucity of material of certain forms, many intermediate species having disappeared ia the lapse of time. These objections hold with equal truth to the characters now used in the classincation of Phaenogams. He states that there are good differential characters in fibro vascular bundle found in Gymnosperms, vascular cryptogams and Phaencgams, but the arrargement of the fibro- vascular bundle is of less value. For the families such characters as the veins of leaf; develop- ment of stomata; secretion reservoirs; arrangement of inner phloem; for species the cuticle and trichomes are of value in diagnosis. iBeitraege zur verleichenden Anatomic der Sabaleen Blartter. Inaugural Diss. 3 plates, Hofer and Burger (1892) Abst. Bot. Centralblatt, LI, p. 300. 2Des caracteres que I'anatomiue pent founir a classification des vegetaux, pp. 54> Antun (Dejussieu) 1891, Abst. Bot. Centrablatt Vol. L. p. 375. IOWA ACADEMY OP SCIENCES. I49 Priemer^ states that peculiar hairs, epidermal cells, crystals cystoliths are of value for diagnostic purposes in the order Ulmaceae. Bordet* has made some anatomical studies of the genus Carex. He concludes that in this genus anatomical characters do not offer any material aid in the separation of species. Although some good characters are found in fibro-vascular bundles. Mez, who has made an exhaustive study of cystoliths and anatomical characters found in the sub-family Cordieae of the order Borraginaceae, finds that hairs are very characteristic and are certainly valuable from a systematic standpoint. Nor should we omit in this connection the valuable paper by Sol- ereder^ on the value of the wood structure in dicotyledonous plants, Holle*^ who has made an exhaustive study of the order Saxifragaceae calls especial attention to the structure of pith cells of Cunoniece, the characteristic wood cells in certain gen- era, and crystals in the tribe Eijdrangeae. K. Leist' who has likewise made a study of Saxifragaceae concludes that the species of this order offer characters which makes it easy to separate them into groups, but this grouping does not always conform to the present systematic position of its members. Nevertheless general harmony prevails between morphological and anatomical characters as to species. Several other authors Christ^ Thouvenin*, Waldner' and Engler" have likewise studied this order with reference to diff" :>rent organs and parts. 3Uber seine unter Lietung von Prof.Prantl ausgefuehrteu untersuch ungen uber die Anatomiue Ulmaceen. Bot. Centralblatt, Vol. L, p. 105. iRecherches anatomiques sur le genere Carex (Eevue generale de Botanlque, Vol. Ill, 1891, p. 57-64. Abst. Bot. Centralblatt, Vol. LI, p. 116. ^Dber den systematischen Werth den Holzstructur bsi den Dicotyledonen. R. Oldenbourg, Muenchen. 1885. 6Be'itraege zur AnatomiederSaxifragaceen und deren Systematische Verwerthung. Bot. Centralblatt Vol. LIII. p. 33, 65, 97, 129, 161, 209. 7Beitraege der vergleicbenden Anatomie der Saxifragaceen. Bot. Centralblatt Vol. XLIII. p. 100, 136, 161, 233, 281, 313, 315, 377. ^Beltraege zur vergleicbenden Anatomie des Stengels der Caryopbylleenund Saxi- frageen. Diss. Marburg, 1887. sSur I'appareil de soutien dans les tiges des Saxifrages. "Die Kaldruesen der Saxifrageen. Graz 1887. lOMonographie der Gattung Saxifraga. Breslau 1872. Synopsis of North American Pines, based on leaf-anatomy. Bot. Gazette, XI, p. 256, 302; plate VIII. Die Anatomie der Euphorbiaceen in ihrer Beziebung zum system derselbon. Sepa- rate Engler's Botamische Jababucber, Vol. V, p. 384-421; plates VI and VII. 150 IOWA ACADEMY OF SCIENCES. Mention should be made of the splendid work of Coulter and Rose on the anatomical characters found in the leaves of coni- fers and their value in the recognition of species. A subject referred to long ago by Dr. George Engelmann. The work of Pax on the anatomy of Euphorbiaceae, Trecul and others on the stems of many plants. It will not be necessary to give other references; the litera- ture is quite extensive. More work should be done along this line. We should study the biological relations and the conse- quent peculiar anatomical structures of plants. It is a field full of interest. Theo. Holm has called attention to the value of this kind of work in studying our flora. Ganong, in a recent paper with reference to biology and morphology (Present Problems in Anatomy, Morphology and Biology of Cactacese, Bot. Gazette, Vol. XX, p. 130), says: "As to the tissues, it is enough here to say that the character- istic xerophilous appearances are strong cuticle, thick epidermis, perfect cork, sunken stomata, collenchymatous hypoderma, deep palisade layers; great development of pith and cortex, which consists of large, round, splendidly pitted water-storing cells, often containing mucilage * * * ." The whole sys- tem conforms closely to the external form and follows its morphological changes. We notice this especially because the same thing holds true in other plants outside Cactacece, especi- ally grasses. Great difference occurs between such plants as are habituated to humid climates and those occurring in a dry climate. This offers, indeed, a great field for investigation. ANATOMICAL STUDY OF GRASSES, Theo. Holm has done well in calling attention to some ana- tomical characters of North American Gramineae. In speaking of the studies which had been made he says: "The impor- tance of studies of that kind was very clear; they not only fur- nished additional and often even more reliable systematic char- acters, but the extended study of anatomy into wider fields than ever before, until anatomy has become one of the most impor- tant modern lines of botanical science." He emphasizes the importance of internal structure, as it will give a striking illus- tration of the physiological life of the plant. It will not be necessary here to refer to earlier writers on the subject; suffice _^oef=iTY or IOWA ACADEMY OP SCIENCES. "•^* "^ 151 it to say here that Duval, JouvGu, Hackelj,, GtintZig, Samsoe, Liind^^ and Bealj, have made valuable contributions. Theo. Holnijg has studied Uniola latifolia, U. gracilis, U. nit- ida, U. paniculata and U. Palmeri, Distichlis, Pleurogogon and Leersia. From a study of some of the species of Uniola growing under widely different conditions, he concludes, that of the five spe- cies, the genus show anatomical structures by which they may be easily distinguished. He says of the genus DisticMis, that, "Considered altogether, the anatomical structure of the leaf in the genus Distichlis is very uniform, and it does not seem possible to give any special characters by which either of the varieties or the sup- posed species thalasica and 'prostata may be distinguished from the species maritima\ because we have seen that male and female specimens of this last show variations among them- selves nearly equivalent with the differences in the two varie- ties and subspecies." Of Pleuropogon, he says: "Considering now these three species of Pleuropogon together, it is evident that they are, in spite of their great similarity, easily distin- guished from each other" by certain anatomical characters taken from leaf blade. THE GENUS SPOROBOLUS. The species of the genus Sporobolus are nearly all western or southern. Those occurring in Iowa are characteristic western plants and well adapted to dry climate conditions. The follow- ing species of Sporoholus were studied: Sporoliolus Jieterolepis Gray; S. cryptandrus Gray; S. Hookeri, S. vaginoBjiorus. SPOROBOLUS HETEROLEPIS. The epidermal cells (e) are rectangular in shape, with a strongly developed cuticle (c); they vary but little in size. The bulliform cells (b) occur between each mestome bundle (m), except between the last few at the tip of the leaf, where it is occupied by the streome (st.). The bulliform cells occur in four or five rows, a large central cell and three or four smaller cells "HIstotaxie des feuilles de Graminees. i8MonographiaFestucarum Europaearum, 1883. 13 Untersuchungen ueber die anatomische Structur der Gramineenblaetter, etc. Inaug. Dissert. Leipzig, 1886. 11 Vejlednlng til at If jende Graesser i biomterlos Tilstand, Kjobenhavn, 1883. 15 Grasses of North America for farmers and students. 16 A study of some anatomical characters of N. America Gramineae. Bot. Gazette, Vol. xvi. p. 166, 217, 375. 152 IOWA ACADEMY OF SCIENCES. on each side. The strongly involute character of the leaf is due to the bulliform cells. The carene (c') is occupied with one mestome bundle; this bundle is somewhat different than the others, as it is sur- rounded on the upper side by chlorophyll bearing parenchyma while the lower side contains stereome. The mestome bundles on right and left of carene are entirely closed (i. e. , entirely surrounded by chlorophyll bearing paren- chyma). This species is provided with three different types of mestome bundles; the first occurs in carene; this has stereome on lower side in contact with leptome; the second, those which have stereome both on lowir and upper side, in contact with leptome and hadrome; and third, those that are entirely closed. Those that are entirely closed occur alternate with those having stereome on upper and lower surface. As to the mestome bundles, there are, in this species, five on left side of the carene and seven on the right side. On the left, the leaf terminates with one closed mestome bundle. The right side of the leaf terminates with three mestome bundles. The mestome bundles, except those at the tip of the leaf, are separated from each other by the bulliform cells and three or four layers of colorless parenchyma. The uncolored parenchyma is more conspicuous near the median nerve, where it is quite strongly developed. In this species the mesophyll does not occur between the bundles but is found only in immediate contact with chlorophyll bearing parenchyma (c b p). The uncolored parenchyma cells are in immediate contact with stereome. The mestome bundles are entirely closed and do not have leptome (1) and hadrome (h) so well developed as in the other bundles. The leptome in the open bundles (i. e., having stereome in contact with both leptome and hadrome) seem to be in two parts, there being a depression on upper side of leptome. The stereome occurs on the upper side of all bundles, and also on the lower side of all bundles except those which are entirely closed. Below the uncolored parenchyma connecting the mestome bundles we find the stereome. The stereome occupies a prom- inent place on the sides of the leaf, forming on the left two triangular groups of cells separated by two layers of uncolored parenchyma. On the right side three such groups occur between the last four mestome bundles. IOWA ACADEMY OF SCIENCES. 153 The chlorophyll bearing parenchyma can be divided into two parts. First, large parenchyma cells surrounding the bundles; these consist of rather large cells somewhat roundish in shape; second, elongated cells in one or more rows around the first. SPOROBULUS CRYPTANDRUS. The epidermal cells in this species do not differ from those described for S. heterolepis. The bulliform cells (b) are some- what larger than those in the first species, usually two or three quite large cells and two smaller on each side. One or two groups of bulliform cells occur between a large ' mestome bundle, and, as in S. heterolepis, these do not occur between the last two bundles. The carene (c^) has one mestome bundle (m) which is open on both sides. It is somewhat larger than other mestome bundles. The leptome (1) and hadrome (h) are separated from each other by thick- walled parenchyma (p^); two rows of thick parenchyma occur around the leptome. The mestome bundles are of three types: First, those open above and below; second, those open above only, and third, such as are entirely closed. Those of the third type are more numerous than others. One mestome bundle is entirely closed and at the side of the leaf, those of the third type alternate with those of the second and first types. The second type is more numerous than the first. Ten bundles occur on each side of the carene. The mestome bundles of the third type are usually found between two groups of bulliform cells. The chlorophyll bearing parenchyma (c. b. p.) is about as in S. heterolepis. The leptome in this species differs from leptome in S. heterolepis in not being depressed on the upper side. The stereome (st) is found on the lower side of all bundles, and also upon the upper side of all bundles except those of the third type. The cells of the sterome are not so thick walled as in S. heterolepis. The mesophyll consists of elongated cells in one or two rows around each mestome bundle. There seems to be mesoxDhyll connecting the bundles beneath the unclosed parenchyma. The unclosed parenchyma is found in one or two rows around the bulliform cells in contact with the mesophyll. SPOROBOLUS HOOKERI. The epidermal cells (e) of this species are small, thick walled and uniform in size, they are more roundish than in 154 IOWA ACADEMY OF SCIENCES. other specie?. The cuticle (c) and cell wall, are well developed in this species. The leaf is strongly involute on the upper sur- face and here we also find papillae. The bulliform cells (b) are also much larger than in the other species, there being four to six in a row, sometimes one large central cell and sometimes two large central cells with two smaller bulliform cells on either side of the large ones. The carene (c), in this species consists of five mestome bundles (m), three very small, a large central, and one medium in size. The leptome (1) and hadrome (h) are fully developed in the two" large bundles. The hadrome is separated from the leptome by two layers of thick walled parenchyma. One small mestome bundle occurs on each side of the medium bundle. The mestome bundles are all connected with each other by the mesophyll (m). The mestome bundles number thirty- eight, eighteen on left and twenty on right side of carene (c). In this species three types of bundles occur: First, those open on both sides; second, those open above only; and third, those entirely closed. Those of the third type are of two sizes one very small, the other somewhat larger. The mestome bundles of the third type predominate. The sides of the leaf terminate with a closed bundle. In the mestome bundle of the second type the leptome and hadrome seem to be in immediate contact with each other, but in those of the first type they are separated by thick-walled parenchyma. The chlorophyll bearing paren- chyma does not differ materially from that found in other species. The stereome (st) is on the lower side of all the bundles and on the upper side of those of the first and second type. The leaf also terminates with irregular groups of stereome. The ste- reome is quite well developed in the carene where it occurs- in large groups. The mesophyll (mes) in this species connects the different mestome bundles and consists of both round and elongated cells. The uncolored parenchyma is more strongly developed in this than in any of the other species of Sporobolus studied. It is prominent in the midrib, where it occupies the space above the five mestome bundles. It also occurs immediately below the bulliform cells and on the upper side of the mestome bundles. I IOWA ACADEMY OF SCIENCES. 155' (m) of the second type cormecting these bundles with the stereome. SPOROBOLUS VAGINAEFLORUS. In this species the epidermis (e) resembles that of other species except the cuticle (c) which is much more fully devel- oped. The bulliform cells (b) in this species differ much from those of other species, they are very irregular in outline, the cells ranging in number from eight to ten, and occur almost the entire length of the leaf except near the sides where we find the uncolored parenchyma (p). The carene (c') consists of one mestome bundle which has stereome in contact with leptome (1). This is the only bundle which is open. On either side of this median bundle there are three or four small closed bundles. The leptome and had- rome (h) are separated by thick walled parenchyma. The mestome bundles number twelve, five to the left and six to the right of the carene. The bundles are of two types: first the median one which is open below and the second, closed; the bundles of this latter type are of two sizes, one very much smaller and the other nearly as large as that of the median nerve. The well developed leptome and hadrome in the median nerve and the larger bundles of the second type are character- istic. The smaller mestome bundles predominate, numbering nine in a leaf. The sterome occurs on upper and lower sur- face of the mestome bundles of the carene, and large sized mestome bundles of second type, but none are found in contact with smaller sized bundles. The cells of the chlorophyll bearing parenchyma (c. b. p.) in this species are much smaller than the cells of the other species. Tbe uncolored parechyma (p) is found only at the edges of the leaf above the last two mestome bundles. PANICUM. The large genus Panicum is widely distributed in tropical and warmer countries with a goodly number in temperate cli- mates. The representatives studied by us are common species in the Mississippi valley and southward. The three species, P. capillare L., P. proliferum L., and P. crus-galli L , grow in moist places or where there is considerable rainfall. The weedy P, capillare is perhaps an exception, as it is adapted to a wider range of climatic conditions, the structure of the leaf 156 IOWA ACADEMY OF SCIENCES. plainly shows that it can adapt itself to di-fferent conditions of soil and moisture. PANICUM CAPILLARE. This species has a hairy appearance and is harsh to the touch. The epidermal cells (e) are large, the cuticle (c) and epidermal cell walls are thicker than in P. crus-galli and P. proliferum, but not so well developed as in the genus Sporobolus. The walls of the epidermal cells of the upper and lower sur- face of the leaf have small conical projections (cp). The end of the leaf terminates in a small thickened point; on the edges of leaf occurs a buudle of stereome (st). The buUiform cells do not vary much from the epidermal cells, they are somewhat larger, however, and vary in number from three to five, the middle cell being the largest. The carene (c') has one mestome bundle (m) differing from those of secondary veins only in that it is larger, and beicg open on both upper and lower side. The mestome bundles are of three types: first, those which are open both above and below, second, those which are open below, and third, those which are closed. The leptome (1) is separated from hadrome (h) by thick walled parenchyma (p). In this species the arrangement of mestom.e bundles is irregular, the number varies from forty to fortj'-- three bundles in one leaf. There are from twenty to twenty- two bundles on each side of the carene, and of these, three on each side are of the first type, three of the second type and the remaining of the third type. In the closed mestome bundles the leptome and hadrome are not so well developed as in those which are open. The stereome occurs on the upper and lower surface of all open mestome bundles, while in those which are closed it is found sometimes on the upper surface and sometimes on the lower surface, and sometimes it is entirely wanting. It consists of from two to four rows, bordering immediately on the chlorophyll bearing parenchyma (c b p). At the sides of the leaf well developed stereome occurs for the purpose of protection. The mesophyll (mes) consists of elongated cells joining the chlorophyll bearing parenchyma. Between the mestome bundles surrounded by the mesophyll, we have colorless parenchyma. PANICUM PROLIFERUM. In this species the epidermal cells are much smaller than in P. capillare, and the conical projections (c p) are found more IOWA ACADEMY OF SCIENCES. 157 strongly developed OEly on the upper surface of the leaf; they are much more namerous than in P. capillare, but not nearly so sharply defined. The cuticle (c) is not so strongly developed as in P. capillare. The builiform cells vary from two to five, usually consisting of one large or two large central cells. The leaf is not so strongly involute in this species, but the builiform cells (b) extend farther down into the mesophyll (mes) than in P. capillare. The carene (c') has one mestome bundle (m), which is open at ihe lower side. There are from forty to forty-five mestome bundles in the leaf, the median being the largest. On either side of the carene are five small mestome bundles entirely closed , then occurs a secondary bundle on each side resembling the carene, only much smaller. The leptome is separated from the hadrome in the carene by thick- walled parenchyma cells (p). The mestome bundles are of two types; first, such as are open below, and second, those that are entirely closed. The closed are much more numerous than the open; only six or seven open in the whole leaf. The leptome (1) and hadrome (h) are not well developed in the small bundles. The mesophyll consists of elongated and somewhat loosely arranged cells of variable size. One larger surrounds the chorophyll bearing (cbp) parenchyma ceils and comes in con- tact with the stereome (st); the space between the mestome bundles and beneath the builiform cells is also filled with them. The stereome is found on the lower side of all bundles, in contact with the parenchyma and epidermis, and also on the upper surface of all the larger mestome bundles. PANICUM CRUS GALLI. The most obvious difference between P. crus-galli and P. capillare is that in this species the leaf is not involute; the epidermal cells (e) are large; the cell wall and cuticle (c) is not so strongly developed but conical prcjecticns are found on both surfaces of the leaf. The carene has one mestome bundle (m). It differs from the other species studied in that the stereome is not in direct contract with the leptome (1) and hadrome (h) bub is separated from them by two rows of thick walled parenchyma (p), while the leptome and hadrome are in direct contact with each other. 158 IOWA ACADEMY OF SCIENCES. The mestome bundles are of two types; first, those that resemble the open bundles of other species, only that in this case they are surrounded by thick walled parenchyma outside of which, on two sides occur the chlorophyll bearing paren- chyma cells (c b p); second, those that are entirely closed. The mestome bundles are differently arranged in this species, a small mestome bundle occurs beneath the bulliform cells, this bundle is smaller than the one occurring between the bulli- form cells, but is of the same type. Surrounding the bundles of the first type are small chlorophyll bearing cells and more numerous than in the other species studied. The chlorophyll bearing parenchyma cells surrounding those of the second type are larger than those of the first type, but not as large as those of the other type. la this species the leptome and hadrome are in immediate contact while thick walled parenchyma cells surround both. The stereome is found on the upper and lower surface of all mestome bundles of the first type and separated from leptome and hadrome by thick walled parenchyma. Stereome does not occur around the mestome bundles beneath the bulliform cells. The mestome bundles between the bulliform cells are always closed below and sometimes entirely so. The mesophyll consists of both elongated and rd^und cells bordering on the chlorophyll bearing parenchyma. ! COMPARISON. A comparison of the two genera shows that in the genus Sporobolus the cuticle and cell walls are much more strongly developed than in the genus Panicum. The mestome bundles in Panicum are more numerous than in Sporobolus. The epidermal cells in Sporobolus are uniform m size, in Panicum variations occur in different species, while in P. crus-galli, the epidermal cells on both sides of the median nerve are smaller than elsewhere on the leaf. The bulliform cells are larger and more numerous in Sporo- bolus than in Panicum. CONCLUSIONS. We feel safe in concludiag from our study of these genera that the anatomical characters are marked and constant enough to readily enable one to distinguish the species, and along with the work of others it shows that anatomical characters may be U5ed as a basis for the separation of genera and some species. IOWA ACADEMY OF SCIENCES. 159 EXPLANATION OF PLATE VI. In all figures the same letter is used for the same character — c, cuticle; e, epidermis; st, stereome; m, mestome; c b p, chloi^ophyll bearing paren- ■chyma; b, bulliform cells; mes, mesophyll; h, hadrome; 1, leptome; c p, oonical projections. All figures drawn with camera to the same scale. General drawings i inch objective; detailed drawings ^ inch objective. Figures I, II, III, Sporobolus heterokpis. ' ' vaginxHorus. " Hookeri. " cryptandrus. Panicum proliferum. " capillare. " Crus-galli. " IV, V, VI, " VII, VIII, IX, X, XI, XII, " XIII, XIV, A COMPARATIVE STUDY OF THE SPORES OP NORTH AMERICAN FERNS. BY C. B. WEAVER. Ferns have been objects of interest to botanists and culti- vators; they have therefore been studied more than many of the flowering plants. Their simple structure and the apparently well defined limitation of species has rendered them easier for purposes of study than many of the groups of Phaenogams. The purpose of this paper is to make a small contribution toward our kaowledge concerning the spore characters of the different genera and species of North American ferns. The measurements of a few spores are here given: 160 IOWA ACADEMY OF SCIENCES. ft q^ri o 5" fc£— H si £?l| |S2 ® ." £ to o o o s 3 o ftftft^ :S ft -III i^i-^ii sill's >.isil^5 ^ o-;^ « ^ >: 2 a g-^ 2 s o o 3 3+? o 5 o o o c 3 ft ft.- ftOftftftaftftft s:i^.^ ^-h-^ ^J3.ti W ? M ~ 5 "^■■"ftaS K 3 c ' :^ 2a§.-i »J M tn to a; o) o ai o oj S- t- fc, S, fc, o o o c o aaaftft %2% 41 O.-. If. Ji li (C 01 o 1^ t^ ^ o o c ftftft •9J0dS pezis ran -ip8ai JO m p B 9 J q <^>-<}i oos cj>n c to jc jc en M CO --D ci ij c TTtTTTTT i'" :SJ^? > O g: -*" 35 m - j-^o-^^rO'tj^iccccoc _ . _ ; N rc N m « CO N CO ococom-^ojoojcomw coco->iicom->*nomco?i-* (NX-* I Ml I lO TT CC to ■<*< •9JO(3S (JS9 -llTjms JO mp'Bajq puB mSaai tot- MCOi-H (» I I I liJ I I I ggsi§s^ £ r?^ :o (M CO 5i C2 T-f C J ro .-T c^ w (M CO -* ro :o -X) -* CO M a: cj o; 71 ;-^ to to CO N « o cs CO to CO Irt CO to -91 ra OJ S?5§U?^5§?? •aiods !IS9Sjt;i jo q 1 p B 9 jq JpuB q^gaai M I M I I I I to lO MCOiC COi-Jt- 5J ci ire M o: to •£-' 53 ire t--*jcm-<*ci5ireco-* OJJO -CK t-t- tOt-t-b- -tH (MCO u-'N-^to oocicsi-OSr^oioJcRcstosioJto'sJtoO i-oicsiM -jiwciN^cocoo«iNNcoinco-a>totoco itiii I doU Uj,,u.M 1,^1,1 1 si ^ 2 -5 CO oi to n t- OS to to to cs or iri t- c: y; to CO sotococo M-j-co-i>i0^ir3^coco-*it-oinoto-* ■^lII'BaoT; '_oeSfc.i.aaj;:;D':3j ."-■ S^SS:^3 sill S^»3 : :oo » o ;r cj «^ 3 ^Jla£-|l| g a .^ S aS K •/: M C 03 c3^J 2i JiisS^a a c3 2 : a ffl ilillfiililii= •3 3 2§-ft.S.25.2a^§l||' aaS«^aaftft»t^cg02 (i,iiz^<;pHOC!OEi,&:^r k J \.^-'\ ._£Vj 8 __^' \^. :^^ 1 -^ /""^ "^'^ i5\^ ^^--.^..^ isV^ ^;}^'> -^^ ^ >4 4r|m ^'\ ^^)j r^:.>^ p^^. w'-/ '-tj^SS^ ''lis] 1\ m f'T 0. B. Weaver, Del. IOWA ACADEMY OF SCIENCES. 161 EXPLANATION OF PLATE. No. No. 1. Acrostichum aureum. 31. 2. Polypodium vulgare. 32. 3. Polypodium fakatum. 33. 4. Polypodium Californicum. 34. 5. Polypodium pectinatum. 35. 6. Polypodium aureum. 36. 7. Gymnogramme triangularis. 37. 8. Notboleena ferruginea. 38. 9. Notboliena nivea. 39. 10. Vittaria lineata 40. 11. Adiantum capillus- Veneris. 41. 12. Pteris longifolia. 42. 13. Pteris cretica. 43. 14. Pteris longifolia. 44. 15. Cbeilantbes micropbylla. 45. 16. Cbeilantbes Alabameasis. 46. 17. Cbeilantbes viscida. 47. 18. Cbeilantbes lanuguinosa. 48. 19. Cryptogramme acrosticboides. 49. 20. Pellaea gracilis. 50. 21. Pellaea atropurpurea. 51. 22. Pellaea andromedsefolia. 52. 23. Pellaea ternifolia. 53. 24. Ceratopteris tbalictroides. 54. 25. Lomaria spicant. 55. 26. Blecbnum serrulatum. 56. 27. Woodwardia radicans. 57. 28. Asplenium pinnati£dum. 58. 29. Aspleaium tricbomanes. 59. 30. Asplenium firmum. Asplenium Tbelypteroides. Asplenium Filix- foemina. Scolopendrium vulgare, Camptosorus rbizopbjllus. Pbegopteris calcarea. Pbegopteris Dryopteris. Pbegopteris Polypodioides. Pbegopteris alpestris. Aspidium spinulosum. Aspidium Oreopteris. Aspidium Noveboracense. Aspidium Tbelypteris. Aspidium acrosticboides. Aspidium unitum. Aspidium Loncbitis. Nepbrolepis exaltata. Cystopteris bulbifera. Onocloa sensibilis. Woodsia obtusa. Woodsia Ilvensis. Woodsia glabella. Dicksonia punctilobula. Tricbomanes Petersii. Lygodium palmatum. Aneimia adiantifolia. Aneimia Mexican a. Osmunda cinnamomea. Osmunda regalis. Scbizeea pusilla. These tables show that there are differences with respect to size and character of species; in some genera species show marked differences in size of spores. Schizaea pusilla, the smallest of our ferns, has the largest spores of any species examined, OnocJea Struthiopteris has relatively small spores. Fig. 56. Spores of ferns, Ameimla Mexicana. 11 Fig. 58. Osmunda regalis. Fig. 59. Schizoli pusilla. 162 IOWA ACADEMY OF SCIENCES. INOCULATION EXPERIMENTS WITH GYMNOSPORAN GIUM MACROPUS LK. BY F. C. STEWART AND G. W. CARVER. The family of true rusts, Uredinese, is very interesting to the mycologist and important to the agriculturist. It contains about twenty- seven genera and a multitude of species, all of which are strict parasites, living within the tissues of their hosts. Several of the species produce destructive diseases in cultivated plants; as examples note the rust of wheat, oats and other grasses {Puccinia graminis, Pers.), blackberry rust {Cceoma luminatum, Schw.), and carnation rust {Uromyces caryojJhyUinus [Schrank], Schrceter). Thus far all attempts to cultivate the rusts upon artificial media have failed. Conse- quently the life histories of some species are imperfectly known. The determination of the life histories of some species is made still more difficult because of the fact that they do not complete their development upon a single species of host- plant, but inhabit different species at different stages in their development. The life history of the common wheat rust, Puccinia graminis, so frequently used to illustrate this peculi- arity of rusts, is so familiar to readers of botanical literature that it is unnecessary to repeat it here. It is sufficient to state that wheat rust has three stages, two of which are fouad upon the wheat or some other grass plant and upon the common barberry (Berberis). The species of Gymnosporartgiutn belong to this class of pleomorphic rusts. There are two forms, representing two stages in the development of the fuDgus. Until about ten years ago these two forms were supposed to be distinct species and were given separate names. The Gymnosporangium form (considered to be the higher form) inhabits, exclusively, species of the Cupressineee, a group of the family of cone bear- ing trees, Coniferse. The other form has received the name IOWA ACADEMY OP SCIENCES. 163 Roestelia. It is found on the apple and allied plants belonging to the tribe Pomega, of the family Rosaceso. In the United States there are nine species of Gymnosporan- gium. Chiefly through the investigations of Doctors Farlow and Thaxter, all of them have been connected with their cor- responding species of Roestelia. Gymnospomngium macropus, Lk., the particular species under consideration, is confined exclusively to the Red cedar, Juniperus Virginiana, L. Its Roestelia form is known as RcesteUa pirata, Tnax. , and is found on cultivated apple {Pints mains, L.), wild crab (Pirus coronaria, L.) and Juneberry {Amelanchier). The Gymnosporangium may be found in the autumn upon the twigs of Red cedar, where it appears in the form of small brown balls about the size of peas. In May of the foliowiiDg spring these balls enlarge and during rainy weather put out siveral orange-colored gelatinous horns. At this time the balls are very conspicuous objects and are uni- versally known as ' 'Cedar apples. " The gelatinous horns contain numerous two-celled spores on long pedicels. The spores germinate in situ each one producing several minute secondary spores which are readily carried by the wind. When these secondary spores chance to fall upon leaves of apples or other suitable plant, they germinate and enter the tissues. In about three weeks, small yellow spots appear on the upper surface of the apple leaf. This is the Roestelia, and when it is mature the spots will be one-fourth to one-half inch in diameter, yellow above and with tooth like projections beneath. Within the pro- jections are formed round one-celled spores (secidicspores) which may be carried to a cedar where they will germinate and repeat the life cycle. The connection of Gymnosporangium macropus with Eoestelia pirata has been establisaed beyond question by Dr. Thaxter^ The inoculation experiments here reported were not undertaken for the purpose of obtainicg further informa- tion concerning the relationship existing between the two forms of the fungus, but rather to ascertain why the cultivated apple in central Iowa should be iree from Roestelia. Although the field has been thoroughly canvassed nearly every season during the past twenty-five years, no species of Roestelia has ever been taken on any variety of cultivated apple in the lOn certain cultures of Gymnosporangium with notes on their RocstcUac. Am. Acad. Arts and Sciences, 1886, p. 359. 164 IOWA ACADEMY OF SCIENCES. vicinity of Ames, lowa.^" More 1han this, repeated effoits to artificially inoculate various varieties of cultivated apples with Gymnosporangium macropus have failed. In the spring of 1886 Dr. Halsted- inoculated G. macropus on two varieties of cultivated apple (Rawles' Janet and Tallman Sweet), wild crab Pirus coronaria^, pear, mountain ash, Pirus semipinnata, several species of hawthorn and two forms of Juneberry on the grounds of the Iowa Agricultural College, Ames, Iowa. In no case did Roestelia appear on the cultivated apples. He says*: " Tne individual experiments numbered among the hundreds, and in every case there was a perfect failure of the Gymnos- porangium to grow except with the crab apple, where the inoculation was most emphatic." further inoculations were made the following season, 1887. He says'^: "During the present season cultural experiments with the native cedar have been carried out by special students. It is an easy matter to inoculate the wild crab with this, but only failures have attended tests upon other plants." In 1893 Prof. L. H. Pam- meF made some inoculation experiments at Ames. A tree of the variety Tetofsky had been top worked with Fluke crab, which is an 'improved variety of Pirus coronaria; G. macropus was inoculated upon both parts of the tree on the same day, with the same cedar apple. In due course of time, Roestelia appeared in abundance upon the Fluke crab portion of the tree but not a single leaf of the Tetofsky portion was affected. Inoculations were also made upon pear, Japan quince {Ci/donia Japonica), cultivated apple and shadbush {Amelanchier alni- folia), but these all proved failures. The above is, in brief, the history of the experiments at Ames previous to 1894. It appears to be well established, that at Ames, Iowa, the cultivated apple is wholly exempt from the Rcestelia disease which is very abundant and destructive in New England and in some of the southern states. The Red cedar does not grow spontaneously in central Iowa, but it is la Professor Pammel writes that be has never known or heard of Roestelia on any- cultivated variety of apple in Iowa. 2Bulletin of the Iowa Agricultural College, from the Botanical department, November, 1886, pp. 59-64. 3Bailey considers the wild Pirus of Iowa to be specifically distinct from P. coronaria He has named it Pirus lowensis. See L. H. Bailey's Notesfrom a Garden Herbarium VI; The Soulard crab and its rise. The American Garden, Vol. XII, p. 469. * I. c, p. 63. SBull. from the Bot. Dept. of the Iowa Agricultural College, February, 1888, p. 91. ^Diseases of foliage and fruit. Eeport of Iowa State Hort. Soc, Vol. XXVIII, 1893, p. 470. IOWA ACADEMY OP SCIENCES. 165 frequently planted. There are several specimens in [different parts of the Agricultural college grounds, some of them stand- ing in close proximity to apple trees. Oymnosporangium mac- ropus is fairly abundant, the amount varying according to the nature of the season as regards moisture. It is usually suffi- ciently abundant to thoroughly inoculate the wild crab trees. There is only oiie species of Gymnosporangium and only one species of Roestelia at Ames. A second species of Gymnos- porangium, G. globosum, Pari., has been found but once by Professor PammeF. This species occurs in Wisconsin as indi- cated by Professor Trelease^ and may be more common in eastern Iowa. It has not, however, been found since and Pro- fessor Pammel writes us that it may have been a chance introduction from material sent to Dr. Halsted. So far as we know, only one species of Boestelia has been found at Ames. This tends to simplify matters considerably. Were it not for the fact that Pirus coronaria is so generally affected with Bcestelia and so easily inoculated artificially, we would at once conclude that the immunity of the cultivated apple is due to the climatic conditions in Iowa being unfavorable to the growth of Roestelia. It is well known that the range of some fungi is limited by slight differences in climate; for example, the potato-blight fungus, PhytopMliora infestans, De By., which causes great losses in some parts of the United States, has, I believe, never been collected in the state of Iowa. The climate there is too dry for it. Another way to account for the facts is to suppose that cer- taia varieties of apples are not susceptible to the disease and that only non susceptible varieties are grown at Ames. This theory comes nearest to accounting for all the facts. There are two chief objections to it. First, the college orchard con- tains a large number of varieties and it is a remarkable circum- stance that they should all be Boestelia — resistant. However, it should be noted that most of them are Russian varieties; second, as a case of varietal differences in susceptibility to fungus attacks, it is unparalleled. In the spring of 1894 we started some inoculation experi- ments at Ames. Pirus coronaria eleven varieties of cultivated apples and the previously mentioned Tetofsky tree top- worked with Fluke crab, were inoculated with the native G. macropus ^Journal of Mycology, Vol. VII., p. 103. 8 A Preliminary List of the Parasitic Fungi of Wisconsin, p. 29. 166 IOWA ACADEMY OF SCIENCES. and with G. macropus from Cambridge, Mass., by Mr. B. M. Duggar. All were complete failures. The spring and summer were unusually dry. This probably accounts for the failures with Fiuke crab and wild crab. Natural cultures of RcesteUa on wild crab were rare. In ihe spring of 1895 one of us being on Long Island, N. Y., and the other at Ames, Iowa, we again undertook some experi- ments with G. macropus. We will speak first of the experi- ments on Long Island. They were conducted in the nursery of Isaac Hicks «& Son at Westbury, N. Y. On May 18 th, four varieties were inoculated with New York G. macropus — Yellow Transparent, Red Astrachan, Ben Davis and Red Pippin, The first three were two-year-old nursery trees; the last was a large tree. Many leaves on one tree of each variety were smeared, both sides, with the gelatinous spore- masses of G. macropus. The results were as follows: Yellow Transparent showed no signs, whatever, of Boestelia. Both Red Astrachan and Ben Davis showed yellow spots which appeared like the beginning of Boestelia, but none of them developed. Red Pippin pro- duced the Bcestelia, but the spores did not mature properly and the fungus presented a stunted appearance. On May 24th, six varieties were inoculated with Iowa G. macropus — Yellow Transparent, Red Astrachan, Ben Davis, Red Pippin, Maiden's Blush and Wealthy. All were two-year-old nursery trees except the Red Pippin. One tree of each variety was inocu- lated as before. The results were as follows: Yellow Trans- parent and Red Pippin showed no signs of Boestelia. Red Astrachan and Ben Davis started Boestelia spots which never matured. Maiden's Blush and Wealthy developed numerous Boestelia spots and matured the aecidiospores thoroughly. As no bags were used to cover the inoculated leaves, it can not be said positively that the Boestelia on Maiden's Blush and Wealthy resulted from the Iowa G. macropus, but the condi- tions were such as to warrant the above conclusions. In the case of Red Pippin there can be no doubt as to which inocula- tion produced the Boestelia. A large tree which stood at con- siderable distance from the other inoculated trees, was inocu- lated on one side with New York G. macropus and on the other side with Iowa G. macropus. The leaves of the branch inocu- lated with New York G. macropus, and a few other leaves in the immediate neighborhood, produced Boestelia while the remainder of the tree showed not a Boestelia spot. It is also IOWA ACADEMY OF SCIENCES. 167 practically certain that all of the Rcestelia found in connection with these experiments was the Rcestelia of G. macropus. Careful search was made in Mr. Hicks' nursery and in orchards at Floral paik and Queens, Long Island, but no Roestelia on cultivated apple was found anywhere on Long Island during the season of 1895, except at Flushing, where a few specimens were taken by Mr. F. A. Sirrine. The following table presents, in a condensed form, the results of the experiments on Long Island: Variety. Material Used* Condition June 15. Condition Jdne 29. Condition Aug. 21. Yellow \ Transpar- - ent. \ Iowa tr. ma- cropus. N. Y. ditto. No Roestelia. ditto. No Roestelia. ditto. No Roestelia. ditto. Red \ Astrachau, i Iowa G. ma- cmpus. N. Y. ditto. Yellow spots on a few leaves. ditto No further devel- opment, ditto. No further devel- opment, ditto. Beu Davis, J. Iowa G. ma- cropus. N. Y. ditto. Not observed, ditto. Yellow spots on a few leaves. ditto. No further devel- opment, ditto Red Pippin J Iowa G. mci- cropns. N. Y. ditto. No Roestelia. ditto. No Roestelia. Roestelia appear- ing. No Roestelia. Partially devel- oped. Maiden's i Blush. ■( Iowa G. ma- crop-US. Roestelia appear- ing. Continuing to develop. Aecidia well devel- oped. Wealtliy, J Iowa G. ma- cropus. Roestelia appear- ing. Continuing to develop. Aecidia well devel- oped. * All inoculations with N. Y. O. mac7-oims were made May 18. All inoculations with Iowa G. macroims were made May 24. The experiments at Ames, Iowa, were conducted at the Agricultural college. May 26, 1895, G. maciX)pus, from New York, was inoculated on Yellow Transparent, Grimes' Golden, Duchess of Oldenburg, Whitney's No. 20 and Pirus coronaria. A large number of leaves on one tree of each were inoculated. In each case, some of the leaves were rubbed on both surfaces with the moistened cedar- apple horns, while others were inocu- lated by making punctures with a sterilized scalpel. On the same day, other trees of the same varieties were inoculated in the same manner with G. macropus collected in Iowa. All of the inoculations, except those on Pirus coronaria, failed. But the Pirus coronaria trees were so completely covered with Roes- telia that scarcely a single perfect leaf could be found. "What part of this was due to artificial inoculation and what part to natural inoculation it is impossible to say. It simply shows that the season was a favorable one for Roestelia. Our experiments at Ames are entirely in accord with those made by Doctor Halsted and Professor Pammel. Taken in 168 IOWA ACADEMY OF SCIENCES. connection with our experiments on Long Island, they show that some varieties (notably Yellow Transparent) are wholly exempt from BoesteUa jnrata and that there is good reason for believing that the absence of EoesteUa from cultivated apples in Iowa is not due wholly to unfavorable climatic conditions, but chiefly to the fact that the varieties grown there are not susceptible to the disease. TJie severe climate of this section has obliged orchardists to abandon all except the most hardy varieties. These are mostly either Russian varieties or vari- eties which have originated in the northwest. However, the fact cannot be overlooked, that Wealthy, a variety shown by our own experiments to be very susceptible on Long Island, is frequently planted in Iowa, Wisconsin and Minnesota and is there exempt from EoesteUa. We have by no means a com- plete solution of this problem. In the Long Island experiments it is interesting to note that while some varieties showed themselves wholly exempt and others were very susceptible, there were also varieties which presented intermediate degrees of susceptibility. Yellow Transparent showed no signs of EoesteUa; Maiden's Blush and Wealthy contracted the disease readily and matured secidio- spores; on Ben Davis and Red Astrachan the EoesteUa started to grow but never reached maturity; on Red Pippin, only part of the secidiospoies matured. There are few fungous diseases of cultivated plants which are equally distructive to all of the varieties of the species which they attack. Usually some varieties are much more severely attacked than are others. Some varieties may be but slightly affected, while others are ruined. Observant fruit growers know that Flemish Beauty " scabs "-worse than most other varieties of pears, while the fungus which produces the leaf-blight and cracking of the pear, Entomosporiuin macula- turn, Lev., has a preference for the variety White Doyenne. Wheat growers know that some varieties of wheat are more liable to rust than are others. These are but a few examples. Many more might be mentioned. In the case of EoesteUa pirata, this preference for certain varieties is carried to the extremes. We know of no other fungus which attacks some varieties of a species so severely and yet cannot even be inoculated upon a large number of other varieties of the same species. Carnation rust, Uromyces caryophylUnus (Schrank) Schrcoter, perhaps most nearly approaches it. This rust is exceedingly destructive IOWA ACADEMY OF SCIENCES. 169 to some varieties of carnations, while several other varieties are nearly exempt from its attacks. One variety (Wm. Scott) is nota- bly immune. We know of no well authenticated case in which the true rust (Uromyces) has been found upon this variety, although we have repeatedly observed it growing in green- houses where other varieties were badly rusted. In the present state of knowledge concerning the conditions of parasitism, it is impossible to completely explain the immunity of varieties. The structure and chemical composi- tion of a variety are intimately associated with its suscepti- bility or non- susceptibility to the attacks of a particular fungus; but what is the relative importance of these, or what part is played by the mysterious factor called "inherent vigor" we do not know. In conclusion we will record our observations on the eifect of moisture on the prevalence of Gymnosjjorangium and Koestelia. In the spring of 1894 G. macropus was fairly abundant at Ames, but the spring and summer were very dry, and, as a consequence of the drouth, Eoestelia pirata on Pirus coronaria was rare. As previously stated, even attempts at inoculation of P. coronaria failed that season. In the spring of 1895 showers were frequent during the month of May. This season Eoestelia was so abundant on P. coronaria that it was difficult to find leaves which were not affected. Everywhere the wild crab trees were conspicuous because of the Eoestelia on their leaves. On Long Island the summer of 1894 was very dry. The Red cedar grows spontaneously here and is very common. May 15, 1895, we searched very carefully through a large grove of Red cedars standing near an orchard and found only three cedar apples. At Westbury, N. Y., a Red cedar standing in the midst of a nursery bore only tivo cedar apples. At Queens, N. Y., three Red cedar trees grew on one side of a road, on the other side of which was an orchard; not a single cedar apple could be found on the cedars. 170 IOWA ACADEMY OF SCIENCES PRELIMINARY NOTES ON THE IOWA ENTOMOSTRACA. BY L. S. ROSS. The careful work done by a few investigators has shown the relation existing between our common fresh water fish and the minute Crustacea of the streams and lakes. The results of these investigations prove the importance of the Entanostraca as a source of food supply for the young fry of many species, and even for the adults of some. The most extensive work upon this subject is that done by Dr. S. A. Forbes of the Uni- versity of Illinois. An account of the methods pursued and of the results obtained is given in the bulletins of the Illinois State Laboratory of Natural history; Bulletins Nos. 2, 3 and 6, and articles VII and VIII, Vol. II. Since the young fish depend for subsistence, to such an extent, upon the relative abundance or scarcity of the Entom- ostraca, it becomes a question not only of scientific interest, but of economic importance to learn concerning the distribution and abundance of the various species of this group of our fresh water fauna. The knowledge of the vertical distribution of different species in the lakes is of importance because some species of fish feed at one level and some at another. Some have their favorite haunts among the weeds of the shallows, others in the clearer, deeper waters. Consideration of these facts induced me to begin work upon the occurrence and distribution of Entomostraca in the state of Iowa. The paper presented is a report of work begun, rather than work completed. In order to combine pleasure with business, I decided to make a bicycle journey to the lake region of Iowa. In the first part of August of the past year, Mr. McCormack of Drake Uni- versity, and myself started across country en route for Lake Okoboji. We carried vials of alcohol and a coarse and a fine net; the latter being of bolting cloth. The streams did not IOWA ACADEMY OF SCIENCES. 171 offer good collecting ground at that season of the year, as they were nearly all dry. As we did not wish to overburden our- selves, we did not collect dried mud from the ponds and water courses. Collections were made in a few places from, the streams, but principally from West and Eist Okoboji and Spirit Lake, rang- ing from the surface to a depth of twenty feet. With the limited apparatus and short time at our disposal, not all the species of the lake were taken, very probably only a minority. To make a thorough investigation the apparatus should be such that hauls could be made among the weeds and along the bot- tom of the lake, as well as in the clear surface water. Not only should the nets be such as are needed to collect from places of all kinds, but such should be used as are necessary to deter- mine the quantity of life in the water. For collecting in open water or where there is some rubbish, the ordinary fine-meshed net protected by two coarser nets, one outside and the other inside may be used. The inner coarse net should not be as deep as the fine one; it serves to catch and hold back the rub- bish. The net or cone-dredge devised by Dr. E. A. BLrge of Wisconsin,. is the best for collecting among weeds. For quanti- tative work the plankton apparatus should be used. This is so arranged that the net can be drawn through the water at a definite rate of speed, the speed being regulated so there will be no overflow of water from the mouth of the net. The con- tents of the net are determined quantitatively as compared with the known amount of water that passed through. As yet I have determined no species outside the order Clad- ocera. Of this order probably twenty-five species and varieties have been noted but no new ones have been described, nor have any new to America been found. Undoubtedly, with better apparatus and with more literature upon the subject, many more species may be collected and determined. The following families are represented in the collections: Sididae.—By the genera, Sida and DapbneJla. Dapbniidae. — By the genera, Simocepbalus, Ceriodapbnia, Scapboleberis and Dapbnia. Macrotbricidae. — By the genera, Macrotbrix and Iliocryptus. Lynceidae. — By the genera, Earycercus, Alona, Danbevedia, Pleuroxus, Chydorus, Camptocercus and Leydigia. Leptodoridae. — By the genus Leptodora 172 IOWA ACADEMY OF SCIENCES. The species found are as follows: Family Sididae... 3 ^^'^^ crystallinaO. F. M. ( Daphnella brachyura Liev. Simocephalus vetulas O. F. M. Simocepbalus serrulatus Koch. Ceriodapbnia reticulata Jur. Ceriodaphnia consors Birge. Ceriodapbnia lacustris Birge. Family Dapbniidae - --- J Scapholeberis mucronata O. F. M. Scapholeberis ohtusa Schdl. Dapbnia byalina Leydig. Dapbaia kalbergensis Schoedler. Dapbnia kal. var., retrocurva Forbes [ Dapbnia sp? Family Macrotbricidae Macrotbrix laticornis Jur. Iliocryptus sordidus Lieven. M. Family Lynceidae { Eurycercus lamellatus O. F. I Alona sp? Dunbevedia setiger Birge. Pleuroxus denticulatus Birge. { Pleuroxus procurvatus Birge. Cbydorus spbaericus O. F. M. Cbydorus globosus Baird. Leydigia quadrangularis Leyd. Camptocercus rectirostris Schdl. Family Leptodoridae Leptodora byalina Lillj . The distribution of the species is given in the table: Daphnella bracbyura. Dapbnia kalbergensis. Dapbnia kal. , variety retrocurva. Dapbnia byalina. Ceriodapbnia lacustris. Cbydorus spbaericus. Cbydorus globosus. Leptodora byalina. Sida crystallina. Ceriodapbnia consors. Simocephalus serrulatus., Cbydorus sp.'' Pleuroxus denticulatus. Pleuroxus procurvatus. ( Ceriodaphnia reticulata. Simocepbalus serrulatus. Streams near Newell, Iowa ] Simocephalus vetulus. Scapholeberis mucronata. Pleuroxus denticulatus. Cbydorus spbaericus. West Okoboji, open lake, from six to eight feet below surface . West Okoboji, among weeds near shore IOWA ACADEMY OF SCIENCES. 173 West Okoboji, fifteen to twenty feet below surface f Dapbnella bracbyura. Daphnia kal. , vai-iety retrocurva. Simocepbalus serrulatus. Ceriodapbnia consors. Eurycercus lamellatus. Danhevedia setiger. Cbydorus spbaericus. Cbydorus globosus. Camptocercus rectirostris. ( Sida crystallina. Ceriodapbnia reticulata. Ceriodapbnia consors. Dapbaia kal., variety retrocurva. Daphnia byalina Macrothrix laticornis. Eurycercus lamellatus. Cbydorus spbaericus. Leydigia quadrangularis. r Dapbnella bracbyura. below surface ] Dapbnia kal., variety retrocurva, I Cbydorus spbaericus. East Okoboji, surface . Spirit Lake, ten to fifteen feet Raccoon River, Adel, Iowa. Raccoon River at Sac City. I Ceriodapbnia reticulata. J Scapboleberis mucronata. I Iliocryptus sordidus. [_ Pleuroxus denticulata. ( Scapboleberis mucronata. Simocepbalus serrulatus. < Cbydorus spbaericus. Pleuroxus denticulatus. [_ Alona sp? THE ANATOMY OF SPH^RIUM SULCATUM LAM. BY OILMAN A DREW. For a number of years the embryology of the Cyrenidas has been attracting considerable attention, but little has been added to our knowledge of the general anatomy since Dr. Franz Leydig's publication in 1855 (No. 5), who recorded such anatomy as could be made out from young and rather trans parent specimens.* It is my present intention to continue the work here begun on Sphsorium to a comparative anatomy of the Cyrenidse, but in *I find a reference to a paper by Temple Prime, entitled: Notes on the Anatomy of the Oorbiculidas and Translation from the Danish of an article on the Anatomy of Cyclas by Jacobson. Bui. Museum Comp. Zool., Cambridge, Vol. V. This volume unfortunately is not to be found In the reference libraries of Baltimore. 174 IOWA ACADEMY OF SCIENCES. the meantime it seems to me that the anatomy of a single genus and a single species of that genus may not be wholly without interest, especially to those who are working in the interior, where the Unionidse and Cyrenidge are the only available Lam- ellibranchs. Regarding the systematic position of Sphserium, suffice it to say that the old genus Cyclas includes the present genera Sphserium and Pisidium, and that these, with four or more other generally accepted genera, go to form the family which has been variously known as Cycladae, Corbiculidse and Cyrenidse. SHELL. (Pig. 2.) The shell of this species is comparatively thick, of a dark horn color, frequently lighter near the margins of the valves, and is composed of a rather thick bluish- white nacre, covered exteriorly by epidermis. Tne lines of growth are well marked. The teeth are thin lamellae, 2-2 on the right valve and 1-1 on the left valve. The adductor scars, as andj;s, are quite distinct and are joined dorsal] y by the retractor pedis scars. The pallial line is rather obscure. A large specimen measures 15x12x9 mm. MANTLE. The mantle consists of two thin lobes of connective tissue covered by epithelium, free at their anterior and ventral mar- gins, united to form the siphons posteriorly, and continuous over the back. The lobes lie closely applied to the shell nacre, which is secreted by them, and are attached to the nacre at the pallial line by the pallial muscles, and to the epidermis through the epidermal gland, which lies in a groove in the mantle mar- gin. A ridge. Pig. 3, r, extending from the ventral end of the anterior adductor muscle to the branchial siphon, runs along the inside of each mantle lobe near its ventral margin and serves, by meeting its fellow on the opposite lobe, or sides of the foot in case that organ is protruded, to close the open side of the branch- ial chamber and force currents of water to enter through the branchial siphon, which is protruded above the mud or sand in which the animal lives. The siphons, Pigs. 1 and S, b s and c s, are quite muscular and are capable of considerable protru- sion. Neither one is fringed with tentacles. MUSCULAR SYSTEM. The muscular system may for convenience be classed as adductors, retractors, foot muscles and mantle muscles, includ- ing those of the siphons. IOWA ACADEMY OP SCIENCES. 175 The adductors, Figs. 1 and 3, are two in number, anterior, aa, and posterior, pa. They differ slightly in size and shape, and have for their only function the closing of the thell. There are two pairs of retractors, anterior and posterior retractor pedis muscles. Figs. 1 and 3, arp and prp. They serve to withdraw, or retract, the foot from an extended position. The foot is largely made up of crossing muscle fibers, extending more or less in all directions, but capable of being classed as longitudinal, vertical and horizontal. They aid in protrusion, by forcing the blood where most efficient, in retraction and in special movements of the protruded foot. The pallia! muscles. Figs. 4 and 5, are distributed to the inner end of the epidermal gland in the edge of the mantle and to the ridge already described. They serve to withdraw the edge of the mantle from between the edges of the valves when the valves are tightly closed. BYSSAL GLAND. A rudiment of the byssal gland, Fig. 1, &, persists in the adult animal as a single closed sack, often showing a slight sagittal constriction. It is supplied with a small nerve on each side, which spring from trunks that have their origin in the pedal ganglia. Most of the specimens which I have examined have the rudiment of the byssal gland nearer the pedal ganglia than is shown in Fig. 1. GILLS. The gills, four in number, consist of a pair, an outer and an inner gill, on each side of the body. The outer, Fig. 3, o g, is much smaller than the inner, i g, and falls short anteriorly by about a fourth of its length. Each gill is composed of two lamellee. The outer lamella of the inner gill is attached to the inner lamella of the outer gill on the same side, the cuter lamellae of the outer gills are attached to the mantle lobes on their respective sides, and the inner lamellae of the inner gills are attached anteriorly to the body wall aud posteriorly to each other. Fig. 5. The gills function as respiratory organs, procurers of food and brood pouches. The latter function is monopolized by the inner gills, which carry the embryos until they are ready to function as adults. Fig. 6, which represents a piece of gill cut squarely across the lamellse and seen obliquely from the cut surface so that the 176 IOWA ACADEMY OF SCIENCES. side of a lamella may be seen, may aid in understanding the structure of a gill. The descending and ascending portions of each filament, / 1 I, are fused throughout their length, thus uniting the lamella at very short intervals and restricting indi- vidual water- tubes, 2v t, between adjacent filaments. The filaments are strengthened by chitinous rods, c r, and attached to one another laterally by inter-filamenter junctions, i f j, which are places where, during development, adjacent filaments have fused together. There are thus left openings, i 0, known as inhalent ostea, which lead into the water-tubes. Beneath the epithelial covering of the filaments is a loose con- nective tissue, through which more or less definite blood spaces, & I s, may be traced. The outer surfaces of the filaments are covered with rather short cilia, besides which there is a row of longer cilia on each side of each filament near the outer sur- faces, and another row of long cilia placed far in on the sides of the filaments, nearly opposite the chitinous rods. It seems that the inner rows of cilia serve largely to drive the water through the inhalent ostea and water-tubes and thus keep up a continuous supply of fresh water, while the other cilia are engaged in forming surface currents and in separating and transporting food particles. LABIAL PALPI. The labial palpi, Fig. 3, I %), are very long and slightly curved. There is a pair, consisting of an outer and an inner palp, on each side of the body. The anterior edges of the outer palps are connected in front of the mouth by a slight ridge, as are likewise the anterior edges of the inner palps behind the mouth. The adjacent sides of each pair are grooved and densely ciliated. Particles of food passed between them from the gills are transported to the mouth. ALIMENTARY CANAL. The mouth, situated behind the anterior adductor muscle leads into a rather long and slender oesophagas. Fig. 1, o e, which communicates with a somewhat spacious horn-shaped stomach, sacculated at its upper end, which curves downward and forward and gradually tapers into the intestine which at this point forms a coil. The relative positions of the loops of this coil to one another, may be made out by comparing Fig. 1, with Fig. 4, which latter represents an obliquely transverse section through the coil. The stomach 1, situated on the left IOWA ACADEMY OF SCIENCES. 177 side of the body, communicates anteriorly with 2, which, near the plane of the section turns to form 3, and so on. It is of interest to note that in the young animals no such coil exists. As the alimentary canal lengthens the loops are formed and gradually lengthen. Fig. 1 is reconstructed from a smaller and apparently younger individual than the one represented in section by Fig. 4, and it will be observed that the loop ^ 5, Fig. 4, must be longer than the corresponding loop of Fig. 1, else the arms could not be separate at a point where the loop 2 3, is turning. From the point 6, the intestine follows back along the convex border of the stomach, then rather abruptly turns nearly at right angles to its former course, passes through the ventricle of the heart, then passes over the posterior adductor muscle dors ally and posteriorly to open in the cloacal chamber. The typhlosole is not strongly developed but is present as a small ridge as shown in Fig. 5. The alimentary canal throughout its length is lined by elongated ciliated epithelial cells. Fig. 9 represents these cells as they appear in a section through the lower end of the stomach. LIVER. The liver, Fig. 1, /, is a paired organ, consisting of two large racemose glands, one on each side of the body. Each gland communicates with the stomach through anterior lateral pouches. The liver cells are often densely crowded with gran- ules that stain deeply, but not infrequently part of the cells of some follicles will be full while adjacent cells will be empty. This condition is indicated by Fig. 10. It is not unlikely that, as the animal probably feeds most of the time, digestion is a continuous process and that the liver cells are continually filling up and discharging. NERVOUS SYSTEM. The regular three pairs of Lamellibranch ganglia are pres- ent. The cerebral ganglia. Fig. 1, c. g. lie on opposite sides of the oesophagus, on a level with the dorsal end of the anterior adductor muscle. They are somewhat oblong in shape and are connected with each other by an oesophageal commissure which runs between the oesophagus and the anterior adductor muscle. The parieto- splanchnic ganglia Fig. 1, p s g, also oblong in shape, lie anterior to the ventral portion of the posterior adductor muscle and are fused together by their adjacent sides. The pedal ganglia, Fig. 1, jj g, are more nearly circular than 12 178 IOWA ACADEMY OF SCIENCES. either of the other ganglia, when viewed from the side. They lie beneath and a little posterior to the intestinal coil at the line where the muscles of the foot come in contact with the con- nective tissues of the body proper, Fig. 4. The pedal ganglia are likewise fused together by their adjacent sides. The cerebral ganglia are connected, Fig. 1, with the parieto- splanchnic ganglia by the cerebro-visceral commissures and with the pedal ganglia by the cerebro-pedal commissures. Beside these commissural connections each cerebral ganglion gives rise to a small nerve which supplies the anterior adduc- tor muscle and a larger nerve which passes down behind the anterior adductor muscle into the mantle and supplies the pallial muscles of its anterior portion. Each parieto- splanchnic ganglion besides its commissural connection, gives rise to a small nerve which supplies the pos- terior adductor muscle, a larger branchial nerve which runs forward a short distance, passes over into the junction of the outer lamella of the inner gill with the inner lamella of the outer gill, where it turns abruptly backward and apparently ends at the posterior ends of the gills not greatly reduced in size, and a large nerve that runs around the ventral surface of the posterior adductor muscle and branches. The smaller branch is probably distributed to the muscles of the siphons, but I have been unable to follow it far. The larger branch runs along the mantle near the inner ends of the pallial muscles, giving off a branch near the upper border of the branchial siphon and numerous small branches to the pallial muscles. Each pedal ganglion, besides its commissural connection, gives rise to at least five more or less distinct nerves which branch among the muscles of the foot. OTOCYSTS. A pair of otocysts, Fig. 1, o t, lie directly in front of the pedal ganglia, almost, if not quite in contact with the cerebro- pedal commissures. They are nearly spherical in shape, and consist of a wall of cells with a nearly spherical otolith inside (Nos. 4 and 5). Thus far I have been unable to find cilia in the otocysts, but this may be the fault of preservation. The otocysts of most Lamellibranches are described as being ener- vated by fibres from the cerebro-pedal commissures. With Sphserium a small branch is given off from the nerve which passes immediately below each otocyst that passes up, and may IOWA ACADEMY OF SCIENCES. 179 often be traced into contact with the otocyst, but I have been unable to demonstrate actual connection with this or with fibres from the cerebro-pedal commissure. Regarding the function of otocysts see Dr. Brooks' article (No. 1). CIRCULATORY SYSTEM. The heart, Figs. 1 and 5, consisting of a single median ventricle, v t, and a pair of lateral auricles, a u, lies in the per- icardial cavity, near the dorsal surface of the animal, and somewhat in front of the posterior adductor muscle. All the blood channels issuing from the ventricle are without very definite walls or calibre. Immediately in front of the peri- cardium the blood channel. Fig. 1, which leaves the heart in this direction, divides. The larger branch is continued for- ward along the dorsal line of the body, turns to the left and passes beneath the oesophagus, which it follows to the mouth. When opposite the dorsal end of the anterior adductor muscle, a branch is given off which passes in front of the adductor and, dividing, sends a branch to each mantle lobe. The main chan- nel is continued down in front the cerebro-pedal commissures into I he foot, where it divides into a number of small branches that apparently ultimately end in the connective tissue spaces with which the whole body is permeated. The smaller branch, which arises immediately in front of the pericardial cavity, passes downward, sends a branch to either side of the stomach, supplying that organ throughout its length with small branches, and finally ends among the loops of the intestinal coil. Posteriorly the ventricle gives rise to a channel of consider- able dimensions which surrounds the intestine, but is more spacious beneath than above it. Tne intestine seems to be held in the dorsal part of this channel by strands of connective tissue. Behind the posterior adductor muscle this channel widens on opposite sides of the intestine and is continued into the maatle lobes. It is not improbable that other important channels exist. Fig. 5 is a section across the body in the region of the heart showing the connection that exists between the auricles and the blood spaces of the gills. ORGANS OF BOJANUS. The organs of Bojanus consist of a pair of coiled and saccu- lated tubes, one on each side of the body, lying between the pericardium and the posterior adductor muscle. At one end 180 IOWA ACADEMY OF SCIENCES. each organ opens into the pericardial cavity, and at the other end into the cloacal chamber. Fig. 1, o B, shows the right organ as seen from the left or inner side, and Fig. 7 is a dia- gram of the left organ as seen from the left or outer side. By- comparing the two figures the relations of the loops will be seen. The cells lining the organ are apparently not glandular in the immediate vicinity of the pericardial opening, and are rather small near the cloacal opening, but throughout the rest of the tube the cells are large and vacuolated, as shown by Fig. 11^ which represents specially large cells from the dorsal part of the organ. I have been unable to find cilia on any of the cells. REPRODUCTIVE ORGANS. The animal is hermaphroditic. The reproductive organs^ which are paired, each consist of a racemose gland. Fig. ] , r o, situated beneath the pericardium and behind the stomach, varying in extent according to the age of the individual, and opening into the cloacal chamber close to the cloacal opening of the organ of Bojanus. Part of the follicles bear ova, oth- ers sperm. The ova-bearing follicles are generally among those most posterior. They are fewer in number than the sperm follicles, and, in this species, bear comparatively few ova. Fig. 8 represents a section of an ova-bearing follicle, in which are a number of nearly or quite mature and several very young ova. The sperm-bearing follicles are generally full of sperm, which lie free in their cavities. Reproduction, apparently, goes on during the greater part of the year. LITERATURE. 1. Brooks, W. K. Sensory Clubs or Cordyi of Leodice. Jour, of Morph. Vol. X, No. 1. 2. Kellog-g, James L. Contributions to our Knowledge of Lamelli- branchiate Mollusks. Bui. U. S. Fish Commission, 1890. 3. Lang, Arnold. Lehrbuch der Vergleichenden Anatomie. 4. Lankester, E. Ray. Mollusca. Enc. Britt. 5. Leydig, Franz. Ueber Cyclas Cornea. Miiller's Archiv., 1855. 6. Mitsukuri, K. On the Structure and Significance of some Aberrent Forms of Lamellibranchiate gills. Quart. Jour. Mic. Sci., Vol. XXI, 1881. 7. Peck, R. H. Gills of Lamellibranchiate Mollusca. Quart. Jour. Mic. Sci., Vol. XVII, 1877. 8. Pelsener, Paul. Contribution a I'etude des Lamellibranches. Arch. de Biol., Tome XI, Part 2, 1891. 9. Rankin, Walter M., Uber das Bojanus' sche Organ des TeichmuscheL Jena, Zeit. Bd. XXIV, 1890. 10. Zeigler, E. Die Entwickelung von Cyclas cornea Zeit. f . wiss. Zool. ,. Bd. XLI. IOWA ACADEMY OF SCIENCES. 181 My thanks are due to Mr. C. P. Sigerfoos for the loan of series of sections of two undetermined species of Sphaerium, with which some comparisons were made. EXPLANATION OF PLATES. 3. a. Anterior adductor muscle. a o. Anterior aorta. arp. Anterior retractor pedis muscle. a s Anterior adductor muscle scar. a. u. Auricle. b. Byssal gland rudiment. bis. Blood space. bs. Branchial siphon. c. Cloacal chamber. eg. Cerebral ganglion. c r. Chitinous rods. c s. Cloacal siphon. f. Foot. ni. Gill filament. H'j- Inter-fllamentar junctions. ig- Inner gill. i o. Inhalent ostea. 1. Liver. Ip. Labial palpus. m. Mantle. o B. Organ of Bojanus. OS. CEsophagus. og. Outer gill. o t. Otocyst. O V. Ovarian follicle. p- Pericardial cavity. pa. Posterior adductor muscle. Pg- Pedal ganglion. prp. Posterior retractor pedis muscle. ps. Posterior adductor muscle scar. psg. Parieto-splanchnic ganglion. r. Mantle ridge. r o. Reproductive organs. t. Male follicle. rt. Ventricle. w t. Water-tube. PLATE I. Fig. 1. A reconstruction of an adult specimen from serial sections, seen from the left side. Median, and the paired organs of one side shown. The liver and reproductive organs of older specimens are more extensive. 182 IOWA ACADEMY OF SCIENCES. PLATE II. Fig. 2. Enlarged view of the outside of the right valve and ihe inside of the left valve of a shell. Fig. 3. View of the animal with the right valve of the shell removed, and most of the right mantle lobe cut away. Fig. 4, Oblique cross-section of an animal through the intestinal coil and the pedal ganglia. Seen from behind. Fig. 5. Section through the heart in the same series as preceding. I PLATE III. Fig. 6. Cross-section of a piece of gill seen obliquely from the side so as to show both the section and the outer surface of a lamella. ' Fig. 7. Diagram of the outer, left, side of the left organ of Bojanus. Fig. 8. Section across an ovarian follicle. Fig. 9. Epithelial lining of the distal portion of the stomach. Fig. 10. Liver follicle showing charged and discharged cells. Fig. 11. Epithelial cells of the organ of Bojanus. A STUDY OF THE GENUS CLASTOPTERA. ELMER D. BALL. In the development of the hind tibiae and the structure and venation of the wings, the insects under consideration repre- sent the highest and most specialized forms of the Cercopidse if not of the Homoptera; marking, as Uhler suggests, an important advance toward the Heteroptera in the increased freedom of the anterior coxae and the possession of a terminal membrane to the corium. In order to correctly establish generic characters it will be necessary, first, to separate off those of family value. ^ FAMILY CERCOPID.E. The representatives of the family in this country, at least, agree in possessing the following characters: Front inflated, convex or compresso produced; antennae inserted in front of and between the eyes; ocelli, two, situated on the disc of the ver- tex; thorax large, sexangular or trapeicoidal; hemelytra coriaceous; pos- terior coxte and femurs short, tibiie spatulate, armed with two spurs, the first once, the second twice as long as tibi;y are wide; tibite and two first joints of tarsi terminated with crescent-shaped rows of spines, third joint with a bifid claw. The following genera are represented in the United States: Monecphorap Lepyronia,^ AphroiJlwrap Philaenus and*^ Clastoptera. These may be easily separated by the character of the venation of either pair of wings by reference to plate XII. IOWA ACADEMY OF SCIENCES. 183 The Clastoptera may be separated from the others, directly, by the rounded apex of the clavus and the terminal membrane of the corium. ^ CLASTOPTERA. Germar's original description published in his ' ' Zeitschrif t fur Entomologie," Vol. I, p. 157, is as follows: Kopf gross, stumpf dreieckig, so breit wie der Vorderrucken, Stirn gewolbt, queerstreifig, Scheitel brelt viereckig, vorn und hinten scharf g-erandet, die Nebenaugen auf der mitte desScheitels genahert. Schnabel bis an die Hinterbrust reiehend. Fuhler in einer Grube an der Wurzel der Wangen, selir kurz, mit langer feiner Endborste. Vorderrucken breit am Scheitel vorgezogen und gerundet, bei den Augen gebuchtet, von den Schultern nach hinten in einer Rundung verschmalert, an der spitze sclimal aber tief ausgerandet. Schildchen ein langgezogenes spitzwinkeliges dreick bildend, Deckschilde lederartig, an der Spitze gewolbt, uber einander klapfend, die hintere Randader weit von dem Hinterrande ent- fernt. Flugel hautig, unter den Deckschilden vorborgen. Beine maszig lang, unbewehrtumdie hintersten verlangert, mit zweistachelnam Rucken die Schienen und einem Dornenkranze an der Spitze der Schienen, und ersten beiden Tarsengliedern. A careful study of all the American forms leads to the fol- lowing summary of characters: Broad, oval forms; very variable in size and color markings; front inflated, circular, not longitudinally carinated; antenna? arising from a deep cavity between the eyes, basal enlargement not extending outside of cavity; vertex narrow, transversely depressed, outline regular, not inclosing front; eyes broad, a row of curved hairs on the outer and posterior margin; pro- notum convex, trapezoidal, transversely wrinkled, deeply emarginated behind; scutellum narrow, triangular, longer than pronotum; hemelytra convex, deflected posteriorly, overlapping behind in a perpendicular plane; corium with three apical cells and two widely separated discoid cells, a broad membrane beyond; membrane and apical cellules hyaline; clavus with apex broadly rouaded; an oval, convex, callous dot near apex of hemelytra; under wing with a single discoid cell, terminal apical cell open; posterior tibia with a single terminal row of spines: ovipositor carried perpendicular to the plane of the body; males usually smaller and slightly darker than females; smallest varieties nearly black. Specific characters are based upon the size and shape of front, the facial angle, sculpturing of vertex and pronotum, size and shape of discoid and apical cells, pubescence of prono- tum and hemelytra, and the color markings of the face and legs. Sub-species are based upon size, food habits and associated groups of constant color markings; varieties, on locality, size and color markings of vertex, pronotum and clavus. 184 IOWA ACADEMY OF SCIENCES. SYNOPSIS OF SPECIES. A. Front strongly inflated, rising abruptly from face at sides, meeting vertex in same plane: pronotum with broad wrinkles; first discoid cell equal to second. B. Front, outline a regular curve, entirely black, or yellow with transverse interrupted brown bands above, light below; prono- tum scabrous, with about eight distinct wrinkles; veins on cla- VU3 pi'ominent. ..deUcata, Uhl. 0 BB. Front, outline an irregular curve, upper half black with a narrow yellow margin next to vertex, lower half yellow, lorse and clypens yellow: pronotum, bare, with about twelve indistinct broad wrinkles proteus, Fitch. 0 AA. Front, less inflated, rising gradually from face at sides, meeting ver- tex at an obtuse angle above: pronotum finely, sharply wrinkled, about twenty on the median line": first discoid cell smaller than second. B. Hemelytra strongly impunctured, sparsely pubescent; second api- cal cell short and broad: insects small, of a uniform color above — xaiitbocepbala, Germ. ^ BB. Hemelytra minutely impunctured, thickly finely pubescent, second apical cell long and narrow: insects large, usually banded above ohtusa, Say. C ARTIFICIAL KEY TO SPECIES. A. Face entirely black '.delicata-lineata, var. b. or binotata. AA. Face not entirely black. B. Upper half of front black: lora?, clypeus and lower half of front yel- low proteus. 0 BB. Upper half of front light with transverse, interrupted, brown bands C. Pronotum with five transverse straight black bands, not par- allel with anterior margin.. .delicata-lineata, var. a. o CC. Bands on pronotum parallel to anterior margin or wanting. D. Hemelytra strongly impunctured, sparsely pubescent: pronotum without bands: lower half of face with a light band: insects small xanthocepbala.-^ DD. Hemelytra minutely impunctured thickly, finely pube- scent; pronotum generally banded or colored where not, face all light: insects large .obtvsa.^ C. DELICATA UHL. '^ G. binotata Uhl. ms. Uhler's original description found in his list of Hemiptera west of the Mississippi river is as follows: r" O Form of C. protevs, Fitch, but with a more prominent front. Pale green- ish-yellow. Head broad, apparently iropunctate: cranium short, trans- A^ersely depressed, as is also the tylus: anterior edge of the vertex carinately elevated, bordered from eye to eye with a black line: eye margined behind with black; front smooth, polished, bright yellow, rounded, the transverse ruga? substituted by slender black bands: lower down grooved, and with a broad black spot, adjoining which each side on the cheeks is a smaller spot; IOWA ACADEMY OF eCIENCES, VOL. HI Gilmjin A. Drew, del. IOWA ACADEMY OF SCIENCES \ OL III Oilman A. Drew, del. IOWA ACADEMY OP SCIENCES. 185 under side bright yellow; rostrum black, reaching almost to the posterior cox£e: antennae black at base. Pronotum banded on the anterior margin by a slender black line, and with five straighter and more slender lines which stop just short of the lateral margins, these lines feebly impressed and obsoletely, minutely scabrous, surface not wrinkled, almost smooth, moderately convex, deeply emarginated behind, the lateral margin nar- rowly produced as far as the outer line of the eyes; the humeral margin recurved, and with a small black dot before it. Scutellum pubescent, yel- low, transversely wrinkled, with a slender black line at base, and an inter- rupted one behind the middle. Hemelytra with short, remote, golden pubescence, coarsely punctate at base, more obsoletely so posteriorly; the inner and posterior margins, the suture between the corium and clavus, an oblique short streak on the disc, and a spot on the middle of the costa fus- cous: posterior margin of the corium with a sinuous brown band, the mem- brane and posterior one-third of the corium, and spot at base of costa pale brown; the bulla very prominent, black; under side yellow; the mesoste- thium, discs of the plural pieces, and middle line of genital segment pitch black Legs, yellow, the tibite having a band below the knee, another on the middle, and a third at tip, and the spines of tibia; and tarsi, including the nails, dark piceous. Length to the tip of hemelytra, four and one-half mm., width of prono- tum, two mm. After a careful study of representatives from every state from which it has been reported so far, the following descrip- tion, embracing only characters of specific value was prepared. Size variable; color from yellow to black; front much inflated; two cir- cular yellow depressions on vertex near eyes; pronotum strongly, broadly wrinkled. Front rising abruptly from face at sides, meeting vertex in same plane above, outline a regular curve. Vertex very slightly transversely depressed; a distinct, circular, yellow depression midway between eye and ocellus on either side. Pronotum coarsely pubescent, strongly, transversely, wrinkled, about eight on the median line. Hemelytra coarsely pubescent; veins on clavus strongly raised; apical cells transversely compressed, third cell triangular, not reaching beyond angle of posterior marginal vein. Legs stout; spurs and spines strong; femur and tibia with dark lateral lines coalescing with two dark spots on outside of tibia. Sub. sp. I. lineata. Pronotum yellow, with five black bands. " ' Var. a, Clavus with veins and margin yellow inclosing dark areas. b. Clavus entirely fuscous. ^ Sub. sp. II. binotata. Pronotum entirely black. Habitat: Utah (Uhl), Cal. Col. and Ariz. This species is so widely variable that with only the extreme forms there would be no hesitancy in pronouncing them sepa- rate species, but with a large amount of material a series can be found which clearly establishes their relationship. Uhler's description is an absolutely perfect one for Sub. sj>y lineata var. 186 IOWA ACADEMY OF SCIENCES. a, but would, apply only slightly to var. h, and would abso- lutely exclude Sub. sp. binotata. ^ C. binotata was a rns. name given to that var. by Uhler, I believe, and under which name specimens have been distributed in col- lections. ^ C. PROTEUS, FITCH. C. saint cyri. Prov. The original description was published in the fourth annual report of the New York State Museum (1851). Repubhshed in the ninth report of the State Entomologist of New York, page 394, from which the following description and sub-divis- ions are copied: Head bright yellow, a black band on anterior margin of vertex and a broader one on the front; front polished, without transverse striae; a callous black dot near the apex of the elytra; legs yellowish-white, tarsi black. Length, 0.16; males slightly smaller. Closely allied to the C atra of Germ , but on examining a host of speci- mens not one occurs in which the legs are annulated with black or fuscous. He then divides the species up into sub-species and varieties as follows: Sub. sp. I. flaricoUis. Thorax entirely yellow, o Var. a. Elytra yellow. ^ b. Elytra with an oblique blackish vitta. ^ Sub. sp. II. cincticoUis. Thorax with a black band. Var. a. An interrupted black band on the anterior margin of the thorax. " ^ b An entire black band on anterior margin of the thorax. '-' c. Thoracic band crossing the disk instead of the anterior margin. ''-' d. Band on the disk of the thorax, and scutel black. ^ Sub. sp. III. maculicoUis. Thorax with one or two discoidal spots. 0 Var. a. A black spot on disk and au interrupted band anteriorly. V o b. A black spot on the disk and anterior band entire. 0 c Two black spots on the disk of the thorax. ^ Sub. sp. IV. nigricoUis. Thorax black, with a yellow band forward of the disk. v' C- Var. a. The black band on the anterior margin of the thorax inter- rupted. ^ <^ 6. The band continuous. >>■ 0 c. Scutel black, with a yellow dot at its base. y Q d. Scutel entirely black. Fitch's "host" of specimens were probably all from one locality and may all have belonged to one sub. sp , according to my classification below. At any rate I have at hand four specimens, that are all clearly and uaquestionably varieties of IOWA ACADEMY OP SCIENCES, VOL. III. 'til his f.U. T^l J CJ' w t -^fil Fig.6 Fig. 11 Fig. 7 Fig.S Fig.0 Gllman A. Drew, del. IOWA ACADEMY OF SCIENCES. 187 my sub. sp. vittata, eaoh one of which answers the require- ments of a different sub. sp. of Pitch; on the other hand I have specimens which are uaquestionably of different sub. sp., and occurring in widely separated localities which would be placed in the same sub. sp., and the same variety by Fitch's classifi- cation, clearly showing that the color of the pronotum is not of sufficient value oa which to base sub-species. He made no pro- vision for the, .black varieties and from his remark about the relationship otC atra, Germ. , it is highly probable that he had none. A careful study of about seventy -five specimens, embracing representatives from widely separated areas resulted in the adoption of the color marking of the clavus as a character con- stant for a given sub-species, and in the determination of specific characters as follows: Size, medium; front strongly inflated, upper half black, lower half yel- low; legs bright yellow, with lateral black lines. Front rising abruptly from face at sides continuing in same plane as vertex above; upper half black; lower half, loras and clypeus yellow, a black dot on center of clypeus. Vertex slightly, transversely depressed, anterior margin not distinctly carinated; suture between front and vertex indistinct. Pronotum bare, broadly, indistinctly, transversely wrinkled, wrinkles minutely striated, about twelve on the median line. Hemelytra with a fine short pubescence; first discoid cell wider than second second apical cell broad, nearly equal to third. Abdomen black or fuscous; legs bright yellow; a lateral line on front of fetnur, one on each side of tibia; all three joints of tarsi, and last segment of rostrum black. Length, four mm , width of pronotum about one and one-half mm. Habitat:' Iowa, Illinois (Forbes), Qaebec, Canada, Ontario, Canada,"^ New Hampshire, ^Massachusetts, ^Pennsylvania,*^New York,^ District of Columbia; New Jersey (Smith), 'West Virginia. ^ Sub. sp. I. /lava. Anterior two-thirds of clavus yellow. •^ "^ Var. a. Scutellum with a yellow spot / O b. Scutellum black. 0 Sub. sp. II. vittata Clavus yellow with an oblique black vitta through the middle. / (} Var. a. Pronotum with one yellow band anteriorly. • C- b\ Pronotum with two yellow bands. , V c. Pronotum entirely yellow. Habitat: New York, Pennsylvania, Massachusetts, Con- necticut, District of Columbia. O Sub. sp. III. nigra. Clavus entirely black. ^ 0 Var. a. A yellow band on vertex, and one on face next to vertex. (J b. Yellow bands wanting; entirely black above; legs darker. 188 IOWA ACADEMY OF SCIENCES. Habitat: West Virginia, Pennsylvania, District of Columbia, Massachusetts, New York. o Specimens of C. saint cyri Prov., that I have from Quebec, Canada, belong to sub. sp. '^flava. G C. XANTHOCEPHALA GERM. ^ Germar's original description (Germ. Zeit. fur die Ento., 1- 189) is as follows: Nigra, capite flavescente, frontis, fascia nigra, elytris maculis margin- atibus hyalinis, puncta coUoso ante apicum nigro, pedibus pallido-fuscaque annulatis. Habitat in Pennsylvania, Carolina, Zimmermann. One and one-half lin lang. Kopf gelb, um der scheitel dunkel, eine queerbinde auf der unter- seite schwarz. Deckschilde schwarz, ein Fleck am vorderrande vor der Spitze, ein anderer, der den ganzen Hinterrand einnimmt, glashell, latz- terer mit einem schwarzen schwieligen Punkte vor der Vorderecke. Beine gelblich, braun geringelt. This species is the most constant in size and coloration of any in the genus. From a study of over one hundred specimens representing every locality mentioned below, I have prepared the following description: Small, brown or black without markings of any kind above; face with brown bands above, dark below with a distinct light band crossing the cen- ter; hemelytra very sparsely pubescent. Front moderately inflated, light above with about nine transverse inter- rupted brown bands, band below these, and clypeus black, lorae, included portions of front, and margin of anterior coxal fossas yellow. Vertex not strongly depressed; suture between vertex and front distinct. Pro- notum with about nineteen fine indistinct wrinkles. Hemelytra strongly impunctured, very sparsely pubescent; second apical cell broad, irregularly wedge-shaped. Under side black; legs brown, spurs and spines tipped with black. Length, three and one-half mm., width of pronotum, one and four-tenths mm. G Var. a. Black above; a small white spot on center of costa. ^ h. Glaucus above. Habitat: Mississippi, Arkansas, Texas, Louisana, Mary- land, District of Columbia, Virginia, Florida, Iowa, Pennsyl- ■vania, Carolina (Walker) and New Jersey (Smith). 0 C. OBTUSA, SAY. ^ Cercopia oUusa Say. Jour. Acad. Nat. Sci., Phila., IV, 339. (1825.) P '' Clastoptera achatina GeTm. Zeit fur die Ent., t, 189. (1839.) ^ ^ C. testacea Fitch. Fourtli An. Rep. N. Y. State Mus. (1851.) d d C. pini Fitcli. Fourtli An. Kep. N. Y. State Mus. (1851.) Q O C. lin&atocoUis Stal. Eng. Resa Omk. jord.. IV, 286. A <5- C. ostiorMi Gillette. Hemip. Col., 71. (1895.) O 6 C. stolida Uhl. ? X) O C. undulata Uhl. ? IOWA ACADEMY OP SCIENCES. 189 Say's original description (Coll. Writings, Vol. II, page 256) is as follows: 0 Head and anterior part of thorax pale, with three transverse lines; wings varied with brown and pale: body short, oval; head pale yellowish, an elevated, reddish-brown, transverse line between the eyes and before the stemmata; front with about nine parallel, equidistant, reddish-brown lines, which are interrupted in the middle and abbreviated in the cavity of the antenna?; antenna? placed in a deep cavity, beyond which the seta only projects, head beneath black; thorax pale yellowish before, reddish- brown and rugose with continuous lines behind, anterior edge elevated, reddish-brown, a reddish-brown transverse band on the middle; scutel pale reddish-brown; hemelytra varied with fucous and pale, generally forming a band on the middle which is more distinct on the costal margin, spot at tip and larger one at base; nervules dark-brown; feet black, joint whitish; tibia? and tarsi whitish, posterior tibia bi-spinous behind, of which one is very robust; length rather more than one-fifth of an inch. The band of the hemelytra is sometimes indistinct, three brown dots near tip; female generally paler, with the abdomen whitish. This species presents a remarkable number of quite distinct sub species and varieties, and, owing to the fact that Say's description was of an extreme variety, a great deal of confus- ion has existed as to its limits, resulting in quite a number of these varieties being described as distinct species. I have appended these descriptions and have retained their names for the sub-species, except testacea and pinl, which I lind to be simply varieties of a sub-species of which the description of osborni is more nearly true; and it is therefore retained in pref- erecce. The following synopsis of the species is a result of a sum- mary of the different descriptions, and the study of 200 speci- mens representing every state given below with the exception of New Jersey. I am reasonably confident that with the pos- sible addition of a few more varieties, it will stand the test of any farther discovery of material: Large; front broad, fiattish, with about nine bands above; second apical cell rectangular, elongate; pronotum finely, sharply wrinkled. Front rising gradually from face at sides, making an obtuse angle with vertex above, upper portion light with about nine parallel, equidistant, transverse, interrupted, brown bands. Vertex very strongly, transversely depressed, carinated anterior margin prominent; suture between vertex and front distinct; ocelli situated near front margin. Pronotum with about nineteen minute distinct wrinkles. Hemelytra minutely punctured, with a fine thickly set pubescence; second apical cell rectangular, elongate. First, discoid cell curved, narrower than sec- ond. Legs stout; spur?, spines and third tarsal segment tipped with black. Length, four and one-half mm., width of pronotum, two mm. 190 IOWA ACADEMY OF SCIENCES. ^ Sub. sp. I. ohtusa. Lower half of face fuscous or black. ^ (s Var. a. Dark; a distinct oblique, light band on hemelytra; prono- tum, anterior half, light yellow, divided by a transverse brown band. Habitat: Iowa, New Hampshire, Massachusetts, New York, Maryland, District of Columbia, West Virginia, Ontario, Canada. 0 Var. b. Light; same markings as above, only much lighter and less distinct. Habitat: Iowa, New York, District of Columbia. V c^- Var. c. Dark; hemelytra coppery; thorax without band; pronotum yellowish [achatina). Habitat: Pennsylvania. Sub. sp. 11. lineatocoUis. Lower half of face dark with a light band •crossing the middle, ^ ^ Var. a. Pronotum entirely dark; scutellum yellow; legs light with lateral dark lines. California. V 0 b. Pronotum, posterior half dark, anterior half sulphur yellow; lines on femur and tibia broad, almost confluent. Colorado. 1/ o c. Pronotum light yellow, narrow brown band anteriorly; legs light, lateral line faint; dark band on clypeus reduced to a dot; hemelytra pale rufous, nervules brown, very distinct West Virginia, District of Columbia. ^ d. Pronotum entirely sulphur yellow; hemelytra dark coppery; legs brown. Maryland, District of Columbia. Figure 7. 0 Figure 8. <> Figure 9, ^ Figure 10. 6 Figure 11. 1, 2 and ^ Figure 1./ ^ Figure 2. (5 Figures. O Figure 4. o Figures. ':^ Figure 6. Ci Figure 7. 0 Figure 8. C Figure 9. a Figure 10. PLATE XIII. Leg of Aphropbora quadrinotata, Say, showing double row of spines. Leg of Lepjronia quadrangularis, Say. Leg of Clastoptera proteus, Fitch, showing single row of spines. Side view of C. delicata, Uhl., showing outline of face. Oblique dorsal view of same showing inflation of front. C. proteus, Fitch, same as above. C xantbocephala, Germ. C. ohtvsa, Say. Venation of hemelytra, C delicata. Same ff r C. proteus. Same for C. xanthocepbala, Germ. Clastoptera obtusa, Fitch. 3; first, second and third apical cells, a and b; first and sec- ond discoid cells. PLATE XIV. Abdomen of Lepyronia quarangularis Say, male, ventral view. Female, of same. Male, dorsal view. Abdomen of Apbrophora psrallela, Say, male, ventral view. Female, ventral view. Same, dorsal view. Abdomen of C. obtusa, male, posterior view. Female, same view. Abdomen of C xantbocepbala, Germ., male, posterior view. Female, same view. OBSERVATIONS ON THE CICADID.^ OP IOWA. HERBERT OSBORN. The members of this interesting group of insects, which con- tains the largest of our native Homoptera, have at least four representatives in the state of Iowa and it is the intention to call attention to these in this paper and also to put on record some observ'^ations regarding their habits and distribution which may serve as a basis for further investigations concerning them. fj Cicada dorsata Say. One specimen of this large species n the collection of the Iowa Agricultural College from a student who stated that it was taken in Poweshiek county, is the only example indicating its occurrence in the state. IOWA ACADEMY OF SCIENCES. 195 THE DOG-DAY CICADA. 0 ( Cicada tibiceri' Ijinn. ) This is our larger common species, and one -which, by its penetrating note, renders itself a conspicuous feature of the autumn weeks. First described by Linne it has since received various appeWdbtiori'^-hpercularis, Olivier; -^jrwrnosa, Say ;^i^ricen, DcGeer andLlanicuIaris, Harris. This synomony arises partly on account of uhe variability of the species. This variation is considerable when its range over a large part of the United States is considered, but within our own state this variation is somewhat limited. Specimens collected here generally conform closely to the descripiion given by Say for hispruinosa. Its distribution is quite general and I assume that it occurs throughout the eastern part of the state, at least, and in general over ttie timbered portions. I am assured by good observers, however, that there are places in the northwest part of the state where it is unknown. Specimens have been collected or received from many widely different localities. In spite of its abuadance and wide distribution our knowl- edge of its habits and life-history is very meager, though it is stated to require two years to complete its growth and to deposit its eggs in apple trees as one at least of the plants it may injure. THE PERIODICAL CICADA OR "SEVENTEEN- YEAR LOCUST." (^Cicada septen-decem Linn.) The "seventeen-year cicada" is doubtless the most interest- ing of all the Cicadas on account of its phenomenally long larval life. As is well known it lays its eggs in twigs of vari- ous trees and the larvse entering the ground feed upon the roots of plants, and require a period of seventeen years to complete their growth. Two broods are represented in the state. Brood V, Distribution. — In 188S, th3 locust year for the east- ern part of the state, I secured, through the state crop service, reports from many of the localities which gave decidedly use- ful information with reference to limitations of the brood and comparison with previous occurrences. Records were received from over thirty counties and about ninety correspondents. The limits of this brood have been outlined heretofore by Mr. Suel Foster, Dr. William LeBaron and Prof. C. E, Bessey. 196 IOWA ACADEMY OF SCIENCES. Dr. LeBaron (2d Rept. 111. Insects p. 130) writes as follows: "In the Prairie Farmer for July 29tli, a brief outline of the locust racge was published by Mr. Suel Foster, of Muscatine, Iowa, bub in this outline, as Mr. Foster himself stated, many gaps were left undetermined. I have found Mr. Foster's out- line to be, in the main, correct, and have filled, as far as pos- sible, the gaps which he left. I will take the same starting poinb with Mr. Foster, namely, the junction of the Iowa River with the Mississippi in Louisa county, Iowa. Thence, in a northwesterly direction, following the eastern branch known as the Cedar River as far north as about opposite the mouth of the Wisconsin river. Thence east in about the same line of latitude to Lake Michigan, following the Wisconsin river so far as it lies in this line, thus leaving out the northernmost counties of Iowa and the two lower tiers of counties of Wisconsin." The rest of the description refers only to territory outside of Iowa. In 1878 at the time of the occurrence of Brood XIII in south- ern low^a, Prof. C. E. Bessey, then of the Iowa Agricultural College, collected data for the determination of the boundaries of that brood and incidentally collected considerable informa- tion concerning the distribution of Brood V in the eastern part of the state. His report upon this investigation appeared in the American Entomologist, Vol. I. N. S. , p. 27. As there given the area included is considerably greater than that outlined by Dr. LeBaron. He does not seem to have noticed the record of LeBaron given above. His outline is as follows: Starting at nearly the same point in Wapello, Louisa county, the line he draws extends more to the westward, including the western or Iowa branch of the Iowa river as far west as into Tama county, and considerable territory to the southward, including all of Johnson, more than half of Iowa and a portion of Poweshiek counties. From Tama county northeastward to the extreme northeast corner of the state includicg nearly all of Black Hawk, Fayette and Allamakee counties, and part of Bremer, Chickasaw and Winneshiek, with a possible extension westward so as to include all the counties to the north and east of Tama, though reference to his notes indicates some of the counties included, as Allamakee, Winneshiek, Black Hawk, Fayette and Bremer to be doubtful. IOWA ACADBMV OF SCIENCEjJ, VOL. II [ E. D. Ball, del. IOWA ACADEMY OF BCIENCES, VOL. III. E.D. Ball. del. IOWA ACADEMY OF SCIENCES. 197 The counties reporting Cicadas for 1888 are as follows: Ben- ton, Black Hawk, Bashanan, Clayton, Clinton, Cedar, Delaware, Dubuque, Iowa, Jackson, Johnson, Jones, Louisa, Muscatine, Scott, Tama. This shows only the counties reporting but does not indicate the extent or distribution in the counties, and this, for th^. border counties particularly, is quite important in fix- ing a definite boundary. I took pains therefore to locate the particular township from which the reports came, which was possible by examining the records at the secreta-ry's office in Des Moines, and was thus able to locate the actual boundary usually within six miles at most, certainly within the limits of the ordinary flight of the insect. The line of townships beginning at the Mississippi river in Muscatine county and naming those on the border line from which positive reports were received is as follows: Muscatine county, Fruitland, Cedar; Louisa county, Columbus City; Iowa couaty, York, Summer; Benton county, Saint Clair; Tama county, Clark, Geneseo; Black Hawk county. Spiny Creek; Buchanan county, Sumner; Clayton county. Cox Creek, Clayton. For convenience sake we may carry our line through the towns and villages nearest this lino and it will be approxi- mately as follows: Fruitland, along south line of Muscatine to Columbus City, then along the west of the Iowa river till in Johnson county, then northwest to York Center, Iowa couaty and to near Ladora, then northeast to Blairstown, then north- west to Dysart, then northeast through Laporte City, Independ- ence, Strawberry Point, Elkaier aad Clayton. The area of natural timber corresponding for the most part with the valleys of the rivers and smaller streams, the distribu- tion of Cicada may be pretty accurately expressed by defining them, and on this basis they may be said to occur in the valley of the Iowa river from Columbus City to west of Mareago, in the valley of the Cedar river and its tributaries as far to the northwest as Laporte City. Iq the Wapsipinicon to Independ- ence, in the Maquoketa to Strawberry Point, in the Turkey to Elkader, and north on the Mississippi from south central Muscatine county nearly to McGregor. Numerous reports not specially indicated, attest their abun- dance in all the central counties of this area and need not be specified but some which bear particularly upon the border line may be quoted here. 198 IOWA ACADEMY OP SCIENCES. Mr. V. C. Gambell, a student in entomology whose home was at Winfield, in Henry county, saw no locusts there but a man in that vicinity reported hearing them and had seen one shell. This is rather uncertain testimony especially in view of absence of reports from this and the adjoining county to the north. If correct it shows a very feeble rex)resentation of the insect there. Mr. Gambell noticed in traveling on the Chicago, Rock Island & Pacific railroad from Brooklyn to Iowa City that the trees were injured, apparently by Cicada. If all due to Cicada this would carry the brood into Poweshiek county several miles further west than indicated by other reports. Mr. E. N. Eaton of Keota, in the extreme east of Keokuk found no locusts and no reports of them for that county. Mr. P. H. Rolfs reports for the central eastern border of Tama county that there were no locusts and none for about five miles to the east of the county line, while Mr. F. A. Sir- rine reports for a point about six miles further north that locusts were in Tama county, two miles west of the county line in Geneseo and Clark townships, but not in townships west so far as he could learn. The following additional statements from correspondents have a special significance in determining the border line: Louisa county, Wapello township, "None; a few in north part of the county. " Columbus City, "Locusts present." In Keokuk county. Clear Creek township, "None here this year, but here seventeen years ago. " Prairie township, "None yet; were here seventeen years ago." Garman township, "No locusts, last in 1877" [1878 Brood XIII probably]. Iowa county, York township, "Locusts in limited numbers in northeast third of this township." Poweshiek county, Malcom township, "None." Sheridan township, "None." Bear Creek township, "None. None seventeen years ago." Warren, "None yet, July 15th. Were here sixteen and seventeen years ago; second year in great nucabers and did great damage to fruit trees and shrubbery," Cnester township, " No seventeen year locusts to amount to anything; appeared in 1861 and lb78." [Brood XIII]. Black Hawk county. Spring Creek township, "Yes, and seven- teen years ago. " East Waterloo township, one correspondent says: "No, never here." Another says: "No. A few seven- teen years ago." Payette county, Westfield township, " None; IOWA, ACADEMY OF SCIENCES. VOL. III. = LATE XIII. E. D. Ball, del. IOWA ACADEMY OF SCIENCES. VOL. III. PliATE XIV. E. D. Ball, del. IOWA ACADEMY OP SCIENCES. 199 none seventeen years ago. " Eden township, " None. " Jeffer- son township, "None within thirty-four years to my knowl- edge." Clayton county, Giard township, "None this year; a few seventeen years ago." Brood XIII. — Professor Riley (1st Ann. Kept. State Eatomol- ogist of Mo.) mentioDS this brood as occurring along the southern border of Iowa, but does not specially define its limits. The 1878 occurrence was studied by Professor Bessey and the data collected enabled him to define the limits of the brood with considerable exactness (Amer. Entom., N. S. Vol. I, p. 27). According to this record they occurred in the following counties: Van Buren, Davis, Wayne, Decatur, Des Moines, Henry, Jefferson, Wapello, Monroe, Union, Louisa, Keokuk, Mahaska, Marion, Warren, Madison, Adair, Cass, Iowa, Powe- shiek, Jasper, Polk, Dallas, Marshall, Story, Boone, Greene, Hamilton, and they were assumed to occur in the counties embraced within the area encompassed by these, Clarke, Appa- noose, Ringgold, Washington, Johnson, as indicated on his map, outline of which is shown. (Plate XV.) On the recurrence of this brood last season (1895) I published requests in a number of state papers and also obtained from students and others, data covering as much territory as possi- ble. Tne responses to the published requests were not so general as could be wished. In some cases many reports com- ing from the same locality, while a number of counties, where they must have occurred, furnished no reports. Taking the counties reported in their order from the eastern border of the state they run as follows: Louisa, Keokuk, Poweshiek, Tama, Marshall, Story, Webster, Boone, Dallas, Madison, Union, Decatur, and for counties within the outer limits, Polk, Jasper, Marion, Monroe, Wapello, Jefferson, Van Buren, Lee. The counties within this area which must, in all probability, have been visited, are Warren, Mahaska, Lucas, Wayne, Appa- noose, Davis, Washington, Henry, Des Moines, while the doubtful ones are Johnson, Iowa, Hamilton, Greene, Guthrie, Adair, Ringgold. Reports from Iowa and Johnson are quite positive as to their non-appearance in those counties, though it is possible our informants could speak for only a part of the area. There is also a probability that they occurred in Hamilton county, close to the Des Moines valley at least, if not in the Skunk. 200 IOWA ACADEMY OF SCIENCES. In Greene, Guthrie and Adair they may have occurred in the valley of the Raccoon or tributaries. By river valleys, then, which give really the more impor- tant distribution, we can say that they appeared in the Iowa valley at Louisa county, were absent or possibly scarce in Johnson and Iowa counties, but present in Tama and Marshall and north as far as Marshalltown; in the valley of the Skunk river from its mouth to Ames in Story county; in the valley of the Des Moines and its tributaries as far north as to near Fort Dodge and Lehigh, and in the Raccoon in Dallas county; also in the valley of the Grand river and its tributaries in Decatur, Union and Clarke couaties. Comparison of the points giving actual occurrence in 1895, represented on our map by square black spots, with the out- line of Professor Bessey's map shows a reduction in most of the outline, with a slight extension in the Des Moines valley. These reports on the whole would suggest a reduction of the area, and many of the reports state a reduction in number of cicadas as compared with previous occurrences. It is of course impossible with the records for even three or four occurrences to draw any conclusions as to the future his- tory of the insect or assign causes to any apparent changes, still some suggestions as to probable influences may not be out of place as indicating lines of future observation and record. It is evident that many years must elapse before the problems connected with the species can be properly discussed. Admitting that the broods in these respective areas have declined, it is interesting to inquire into the possible conditions affecting the perpetuation of the species. It should be borne in mind that the great bulk of settlement in these parts of the state occurred between the appearance of the broods in 1854-1871 and 1831-1878 respectively, and that the settlement resulted in some important changes of the timber distribution. These changes took two forms, first a diminution of the natural timber belts along the streams from the neces- sities for fuel and in much less degree the clearing of limited tracts for cultivation. Second, an extension of the timbered area by the planting of groves, wind-breaks, orchards, etc., on the treeless portions. The former I believe not to have affected the area or quantity of timber very greatly, as it would be made good by the natural growth and extension and, especially as regards the Cicada, had, I believe very little influence. The IOWA ACADEMY OP SCIENCES. 201 latter, though perhaps having very little effect as increasing the actual quantity of timber, seems to me a much more impor- tant factor in connection with the Cicada problem. These insects show a very decided tendency to deposit their eggs in young trees, and in 1871 and 1878 found abundant opportunity in the numerous young orchards and groves developed since their prior occurrence to satisfy this propensity, so much so that they must have in many places deserted in no small degree the natural tinjber areas for these artificial ones. Now, it seems natural to suppose that depending normally for their food on roots common to areas of natural timber they should have been met with a deficiency of such food in many of the localities to which the adults had flown to deposit eggs, and consequently have failed to develop and mature. Such an influence will, of course, not be permanent and if this be the only factor of importance Cicada should recuperate in the future. It has been my privilege to observe personally the occur- rences of both these broods since 1871, and I hope to have the opportunity to observe many of their generations in the future. '^TIBICEN RIMOSA, SAY. This species, which may be considered as belonging more particularly to the northern and western fauna, is represented in this state by a depauperate form and in the northern and western portions by a form more closely approaching the west- ern type. It was described by Thomas Say in Proc. Acad. Nat. Sci. for 1830, p. 235, who ascribes it to the Missouri and Arkansas and says further ' ' Mr. Nuttall presented me with two specimens which he obtained on the Missouri, and I found one on the Arkansaw." While Mr. Nuttall's specimens may have been secured on Iowa soil the probability seems strongly in favor of a location further west in the then extensive territory of Missouri. But slight mention has been made of the species since that time and if it is found in the Mississippi valley as a species at all common, it has failed to receive due mention. It is col- lected in abundance in the Rocky Mountain region, and I have numerous specimens from Colorado and New Mexico. Aside from the depauperate form to be mentioned further, I have specimens from Tama county, collected by Mr. F. A. 202 IOWA ACADEMY OF SCIENCES. Sirrine, of the larger form approachiug typical examples also from Worth county, collected by Mr. S. W. Beyer. It occurs somewhat commonly in the northwest part of the state and probably is responsible for some of the reports of seventeen year Cicada emanating from that quarter. Mr. E. D. Ball, a graduate of the Agricultural college and whose home is at Little Rock, Lyon county, states that it is found quite abundantly throughout the prairie regions of the northwest part of the state and that it was more abundatt in the 70's, before the prairies were broken up, than at present. He gives some interesting obseivations regarding its habits, the most striking being that it occurs on prairie land remote from tim- ber, thus indicating a habit quite different from the other mem- bers of the genus. He states that in herding cattle on the ranges years ago, he has seen them as many as four or five to the square rod of grass in localities where the nearest trees were ten miles away and these only bush willows fringing a stream. During the summer of 1893 he carefully observed them in a lot in town. The lot was bordered on two sides by a double row of trees, box-elder and maples. At any time plenty of the cicades could be found or heard in the grass, but careful search- ing failed to fiad a single one or any indications of egg deposi- tion. They occur more abundantly in the rich upland grass at the foot of a hill or bordering a meadow, a situation equally favorable to the growth of certain prairie weeds, notably the "shoestring" or Lsad plant, Amorplia canescens, which has a very tough woody stem, a plant which was particularly abun- dant in the lot above mentioned. The cicadas were frequently seen on this plant, but no eggs were found. They appear the latter part of June and only live for two or three weeks at most. The form of this species which occurs at Ames is much smaller and with more extensive orange markings than in the western forms ; it is by no means co mmon and no observations have been made as to its breeding habit here. It is so different from the larger Rocky Mountain form that were it not for the inter- mediate forms occurring throughout the range of the species as a whole, there would be little question as to its being recog- nized as distinct. This form agrees with the one described by Emmons as noveboracensis. IOWA ACADEMY OP SCIENCES. 203 - MELAMPSALTA PARVULA SAY. This interesting little species has been taken once at Ames and this is, so far as I know, the only record of its occurrence in the state. It is a more southern form, being credited to the southern states as far north as southern Illinois and central Kansas. Very likely it may be found occasionally in the south- ern part of the state when collectors become more plentiful. Any addition to these records will be gratefully received and duly credited in future records. BIOLOGIC NOTES ON CERTAIN IOWA INSECTS. HERBERT OSBORN AND C. W. MALLY. The followiDg notes are extracted from Bulletin 32 of the Iowa Experiment Station, and embrace such portions of work upon certain injurious insects as have a biologic interest. We are indebted to the Experiment Station for the use of the figures. THE GROUND CHERRY SEED MOTH. {Gelechia sp.) Our attention was called to this insect by Dr. J. C. Milnes, of Cedar Rapids, who reported it as very destructive on wild ground cherries under cultivation; writing further, that this cherry being very prolific and of excellent quality would be a desirable garden plant were it not for the great injury from this pest. The specimens sent contained the insect in the pupa stage. Cultivated ground cherry at Ames suffered from similar attack, and the pest seems likely to occasion much loss. Examination of wild ground cherries in the vicinity of Ames revealed a considerable icjury from the pest, and steps were taken to secure the early stages and determine as fully as pos- sible the habits of the insect. Out of 1,000 berries examined 130, or 13 per cent were infested. All of these infested berries contained the pupae enclosed in a white silken cocoon which filled most of the cavity of the berry, the seeds being entirely devoured. Near the stem end of the berry and opposite the head of the pupa was an opening presumably prepared for the emergence of the moth. 204 IOWA ACADEMY OP SCIENCES. Observations on these berries would favor the conclusion that the larvae develop within a single berry, no injured berries being found which did not contain pupae, However, two ber- ries were found with an opening on the side and containing well developed larvae with very little of the inside of the berry devoured, suggesting that the larvas, under exceptional condi- tions migrate from a berry of insufficient food material to a fresh one. But very few larvas were found and these during the last week in September. They were at that time mature and apparently ready to pupate; so of the early molts and even of the full grown larvae we cannot-give a satisfactory description. Those observed were rather contracted, spindle-shaped, whitish, with a reddish- brown head, sparsely haired. Papation occurs during last two weeks of August and is in nearly all cases completed by the last of the month. The pupae are dark brown, six mm. long, and no distinctive characters that v/ould separate them from related species were detected. The cocoon is thin but of tough, close woven silk. In forming the cocoon the larva attaches itself to the blossom end of the berry by means of the caudal prologs and then builds the cocoon which practicajly tills the cavity of the shriveled berry. 1. {Oelechia sp.) a, injured berries, b, moth, c, mature larva, d, pupa, e, parasite Ccntcterua suturalis. Moths first appeared October 3d, so the period of pupation may be stated as from two to three weeks. The moth shown at b in Fig. 1 is of a gray color with darker spots on the wings. It closely resembles G. quercifoliella. IOWA ACADEMY OF SCIENCES. 205 Out of the 130 berries containing pupee mentioned above we secured four specimens of moths. This low per cent of adults is due to the fact that a large proportion of the pupse, over 100, were destroyed by a fungus, apparently quite similar to Sporo- trichum, and of the remainder a number were attacked by a Hymenopterous parasite {Centeterus suturalis Ash), seven of which issued prior to September 24th. The fungus was not observed to attack healthy berries, always making its appearance after the hole had been made near the stem, and, while it seemed to develop in the tissues of the berry, there seems scarcely any doubt but that it is a par- asite of the insect. Some of the Hymenopterous parasites issued from berries showing fungus growth, so that it would appear possible for these to resist the fuugus, even when pup£e were infected with it; that is, supposing the fungus to infest primarily the Gelechia. Doubtless a parasitized larva would be a more easy victim of fungus attack. The appearance of moths so late in the season, the impossi- bility of their producing another brood, and the improbability of their depositing eggs in any situation where they would winter and assure the larvse access to their food plant the fol- lowing spring, almost forces us to the conclusion that the moths hibernate and deposit eggs when ground cherries bloom the following season. This view is strengthened by the fact that a specimen was captured in an office room of one the col- lege buildings December 7, 1894. Nevertheless, so long an existence of the adult for so delicate a lepidopterous insect seems doubtful, and the possibility of some pupse hibernating or of a spring brood of larvse, even in some situation different from the berries of Physalis, must not be overlooked. This species, as already intimated, very closely resembles G. quercifoliella, and it was so determined with some doubt by Mr. Marlatt from specimens sent to Washington for identifica- tion. The fact that it affects a totally different plant indicates it to be quite distinct from that species. It is certainly differ- ent from jJhysaUella as described by Chambers, and has a totally different larval habit, that species being said to mine the leaves of Physalis in September, to pupate in leaves and rubbish on the ground, and to issue as adult in April. Still another species described as physalivorella was thought possibly to represent our form, though no record of its larval characters or habits were accessible. Mr. Marlatt has, however, kindly 208 IOWA ACADEMY OF SCIENCES. compared our specimens with three specimens oi physalivorella in the National museuon, and states, "these are very distinct from your specimen " " The latter agrees quite well with G. quercifoliella, but may be a distinct species." From this it seems most prob^ible that this insect is unde- scribed, but we prefer to leave the technical description to some specialist ia this group of delicate and inetresting moths. ON THE EARLY STAGES OF THE IMBRICATED SNOUT BEETLE. {Epicaerus imbricatus Say.) While this species has been recognized as a pest since its first economic treatment by Walsh in 1863, our knowledge of its life history has remained as meagre as at that time, nothing being known as to its early stages, except the record of egg laying by Professor Forbes. This led us, on receiving specimens of the beetle with the report of their injary to strawberry plants, to attempt their breeding upon this food plant. While we did not succeed in tracing the full history of the species, the securing of eggs and the partial development of the laivss, and the possibility that this clue may assist in the further elucidation of its history is our excuse for presenting this fragmentary acccuut. On May 14, 1895, the adulis were placed on a strawberry plant having three or four open leaves and a number of small berries. They immediately crawled up the stems and soon began feeding upon the leaves, cutting a crescent correspond- ing to a line described by the end of the snout. The crescent was apparently quite uniform but soon became irregular when the beetle had to move in order to reach the tissue; so in reality there is no regularity in devouring the leaf and finally nothing is left but the veins and a few angular fragments of leaves. By the following day the effect on the leaves was quite apparent, the beetles eating rapidly, and by the 20th the leaves were ail devoured except a few dry, curled pieces and the stems. They did not attack the berries, but in some cases ate the sepals at the base. The beetles began pairing the first day and continued for five or six days. No eggs were observed till the 21st when a number of small, white, glistening eggs were found under a fold of a leaf and as no folded or dry leaves had been left on the plant these eggs had certainly been deposited by the Epicaerus. On the 22d another leaf containing eggs was found IOWA ACADEMY OF SCIENCES, VOL. HI IOWA ACADEMY (^ SCIENCES. 207 and these, with those previously found, were placed by a fresh leaf that had been carefully freed f i-om all matter that might possibly contain eggs of other species, and the beetles removed to avoid possibility of their injuring the egg. The eggs appeared in all cases to be protected by a fold of leaf carefully ^lued down. Pig. 8. Epicaerus imbriC:.itus eggs. (Drawn by Miss King.) Forbes^ says of Epicaerus that they "were found by experi- ment to feed freely on pear leaves, and also to lay their eggs npon these leaves, concealing their deposit by gumming another leaf to the surface." The eggs are 1.3 mm. long, glistening white, nearly cylindri- cal, sometimes very slightly curved, the ends broaJ.ly rounded, the surface smooth, transparent and the shell very thin. The first larvas to hatch escaped before beiig seen, the empty shells being first noticed on the 30th. Hatching there- fore occurs within ten days from time of deposition. Other eggs isolated and kept under close observation showed that the larvee immediately work their way into the ground and these observed in root cages, during the following three weeks, could be seen to move about among the roots and as they very evidently increased in size and appeared to thrive it is safe to say that they fed upon the roots of the strawberry plant. The death of the plants in the root cages and the loss of the larvae unfortunately brought the observation to an end. The young larvas are two mm. long, without any trace of eyes or legs. They are yellowish-whice in color, the head from above oval with a few strong bristles and the mandibles very conspicuous. The maxillary and labial palpi are short, stumpy and in the living larvae stand out rather prominently from the under side of the head. The body segments are pro- vided with a few small hairs. 1 Sixteenth Report State Entom., 111. p. 76. IOWA acaiJemy of sciences. Adult beetles have been observed in autumn, as early as August, but the probability is that ouly one brood occurs each year, the adults surviving the winter. This fragmentary result enables us to say with certainty that the eggs are deposited in dry and folded leaves of the food plants of the adults and that the larvse immediately enter the ground to feed upon the roots. To this extent they show what measures of control must be adopted for this insect. Fig. 9. Epieaerus imbricatus. a, b, young larva, back and side view, c, head above. d, head below, e, terminal segment. (From drawings by Miss King ) THE COSMOS WEEVIL. {Baris confinis Lee.) This weevil, Fig. 4, was found September 1, 1895, to work very extensively in the root-stocks and the base of the larger branches of Cosmos hipinnata causing the ultimate destruction of the plant. The presence of the insect is first manifested by Fig. 10. Baris confinis. (Drawn by Miss King.) the breaking off of the larger branches. By examining the base of these branches, and especially the root- stock, it will be • IOWA ACADEMY OP SCIENCES. 209 found that numerous white larvee and pupte about one-eighth inch long are present and working in the woody tissue of the plant. They make small tunnels, packing the borings around them much as does the potato-stalk- weevil. They pupate in these tunnels and emerge as a small black beetle. The adult when first formed is white and takes on the black color gradually, beginning on the head and thorax and then extending backward to the scutellum and base of elytra and then gradually over the whole body. The adults are quite active but drop to the ground as soon as disturbed and remain very quiet for some time. Specimens of the adults kept on plants under observation in the laboratory worked in the young tender tissues, either eat- ing into the terminal portions or into the stems at the axils of the leaves, almost burying themselves and finally causing the small leaf or branch to break down, as do the larger branches. They were not confined entirely to the parts just mentioned but would eat into the little leaflets as they were expanding, thus preventing their complete opening. One individual was found boring into the end of a broken stem making its way into the pith and almost disappearing in a short time. It remained in that position for some time. Think- ing that it might be a female and that the eggs were being deposited, the cavity was examined at the end of four or five days, but no eggs were found. This adult was placed on a grow- ing plant and soon began feeding in the young tissues as stated above. On one small plant in the laboratory the young leaves were so badly eaten into that the plant died in a short time. One specimen was taken while collecting in the woods August 31st. So the species undoubtedly infests other plants besides the one recorded above. Nothing can be stated concerning oviposition and the early larval stages. As stated above, numerous fully grown larvse and pupce were found in the root-stock and base of the larger branches September 1st. A few fully colored adults were found a few days later. One root-stock was isolated during the sec- ond week in September and adults kept gradually issuing until about the middle of October. From this one root- stock as many as twelve to fifteen specimens issued besides the numerous larvee and pupae that were removed for the purpose of examination. Since no eggs were deposited by the specimens kept under observation and adults were still very active after the plants 14 210 IOWA ACADEMY OF SCIENCES. had all been killed by frost, it is quite safe to say that they hibernate and deposit eggs the next spricg, there probably being but one brood each year. A nearly related species, determined at the Division of Ento- mology, U. S. Department Agriculture, as Baris dolosa Casey, was brt d in small numbers Irom the same stems. Is was thought to be the same and differences in appearance due to imperfect maturing, but there is a decided difference in form of thorax and it seems probable that both species breed in the same plant and with practically the same life history. DESCRIPTIONS. Larva: Fig. 11, a. The fully grown larva is about 5-32 in. long and 1-16 in. diameter, and a yellowish-white color; head light brown, mandibles reddish-brown; legs represented by mammiform protuberances. The body tapers somewhat toward posterior end, the last seginent usually showing four bristles. Fig. 11. B. confinis. a, larva, h, pupa. Papa: Fig. 11, b. About the same length as larva, but com- paratively wider. Head (from beneath) fits closely to the body, eyes not especially prominent; antennae wide in proportion to the length, normally not projecting beyond the sides of the thorax, club conspicuous, usually somewhat denser in appearance. Snout reaches base of first pair of legs and shows small, roundish portions at tip corresponding to the mouth-parts. First and second pair of legs cluoQsy in appearance; joints of the tarsi indicated, the last one distinctly curved; third pair of legs hidden, only a slight portion being visible along the inner margin of the hind wing-pads. Four abdominal segments visi- ble for their entire width. The last segment usually has two apical bristles and a group of small spiny processes. IOWA ACADEMY OF SCIENCES. 211 Adult Fig. 10. (a, dorsal view; b, side view; c, tarsus.) Widest at base of elytra and tapers strongly toward either end ; shining black, glabrous; numerous medium sized punctures on the thorax and between the str;9e of the elytra. Snout about 1-24 inch long, curved, usually extending directly downward, but sometimes drawn backward or slightly pro- jected forward. Thorax narrows perceptibly toward the head. Tarsi strongly pubescent beneath, claws strongly curved, diverging. Elytra emarginate at tip, making the tip of abdomen more distinctly visible from above. REMEDIES. Collecting and burning the old root-stocks and stems in early autumn will be the most effective treatment that can be sug- gested from present knowledge of the species. AN INSECT OCCURRING IN WATER TANKS AND RESERVOIRS. {Chironomus Sj) ) Early in July I received some specimens of a slender red larva from Boone, with the following letter: Professor Osborn: Dear Sir — Enclosed I send a sample of the worm that appeared in our city water about a week ago in countless numbers. Would like to know what they are and where they would be likely to come from. The water we use comes from a 3,030-foot well, but aboat two weeks ago our pumps failed and we were supplied with water from a forty-five foot vein owned by the C. & N. W. Ry. Co., and pumped to our reservoir through a hose. Yours truly, E. E. Chandler, Chairman Water Committee. Boone, Iowa. The larvae were evidently Chironomus, and in replying to the letter it was so stated and that in themselves they could be considered harmless, though of course the presence of masses of such ugly looking creatures would be objectionable, and if dying in the water they might become a source of pollution Also that the larvae must have gained access to the water from the eggs of the adult mosqaito-like insect being deposited in the reservoir or the mains by which it was filled. They could not be derived from a deep well. It was suggested that pro- vision be made to exclude the insects from the water to prevent deposition of eggs. The larvae (Pig. 12) a and &ij|piich are an inch or a little more in length and of a light red color with green reflections on the sides near the head, construct a lube at the bottom of 212 IOWA ACADEMY OF SCIENCES. the water in which they live, and in this remain protected and from it extend themselves to obtain food. The food is for the most part apparently minute aquatic organisms, algas, etc. Their presence might be considered a means of clearing water of such matter did they not at times become so numerous as to prove an element of danger. Fig. 18. (C?iironomt(8 sp.) a, larva, dorsal view, b, side view, c, head and first seg- ments of body, d, terminal segments of body showing appendages, e, upper surface of head. /, lower surface of head. g. side, h, dorsal, i, ventral view of pupa. (Orig- inal, drawn by Miss King.) IOWA ACADEMY OF SCIENCES. 213 Later in conversation with Mr. G. W. Brown, a civil engi- neer of Boone, it was learned that the water was pumped into a large cement-lined reservoir which contained the larvae in immense numbers and was without question the point where the eggs were laid, it being exposed to easy access by insects. It appeared also that the larvas were drained into the mains at times when the reservoir was low, doubtless causing strong currents over the bottom. Specimens have also been received from Des Moines. When mature they change to a delicate pupa (Pig. 12, g, h, i,) and then rise to the surface of the water and soon the adult insect escapes from a slit along the back of the pupa case. The adult is a delicate mosquito-like insect (Fig. I'd.) belong- ing to the genus Ghironomus but it cannot be referred to any of the described species and the present state of the classification of this genus is such as not to warrant us in giving it a scien- tific name or description. Fig. 13. (CMronomussp ) a, adult male, d, antenna of female. (Original). The Id sect is of interest at this time because of the great number of water tanks and reservoirs established, not only in cities and towns, but on many farms, and the probability of its frequent occurrence where these are open to visits of the adults. Exclusion of the adults, where practicable, may be accom- plished by the use of ordinary mosquito netting or wire gauze. Where this is impracticable the providing of an inlet to dis- tributing pipes that will draw water from a few inches above the bottom of the reservoir (which might further be protected by a fine screen) will, it is believed, avoid the distribution of the worms in the mains. 214 IOWA ACADEMY OF SCIENCES. CONTRIBUTIONS TO A KNOWLEDGE OF THE THRIP- ID^ OP IOWA. ALICE M. BEACH. This paper represents the results of a study of some of the Thripidag of Iowa, and is based upon an examination of mate- rial found in the collection of the Iowa Agricultural College, some specimens kindly loaned by Miss Emma Sirrine, Messrs. F. A. Sirrine and C. W. Mally, and some in the writer's own collection. Descriptions of seven new species and three new varieties are herewith presented, including a new species of Phloeothrips described by Prof. Herbert Osborn. The descrip- tions are preceded by an artificial key, arranged to aid in the identification of all the described Iowa species known to the author. The table for the determination of genera is substan- tially that found in Comstock's Introduction to Entomology, pp. 125-127. The writer is indebted to Mr. Pergande for an outline of the characters of Euthrips, and is under special obli- gations to Professor Osborn for valuable aid in the prosecution of this work which has been done in the Entomological Depart- ment of the Iowa Agricultural College. TABLE FOR DETERMINATION OF GENERA. A. Last abdominal segment in both sexes elongated, narrow, tubular; both pairs of wings similar, veinless, margins equally ciliated; maxillary palpi two-jointed; borer in female absent. -. Sub-Order I. Tubulifera. B. Contains but a single family Fam. I. Tubuliferidse. C. Contains but a single genus. Gen. 1. Phloeothrips. AA. Last abdominal segment not elongated and tubular in both sexes; both pairs of wings unlike in structure, front wings always veined; margins unequally ciliated; maxillary palpi three- jointed; borer in female present Sub-Order II. Terebrantia. B. Females with borer curved upwards Fam. II Stenopteridae BB, Females with borer curved downwards.. .Fam. III. Coleoptratidee. IOWA ACADEMY OP SCIENCES. 215 FAM. II. STENOPTERID^. A. Body above netted with elevated lines... Gen. 2. Heliothrips . AA. Body above smooth. B. Abdomen clothed with silky hairs; apex conical, formed alike in both sexes Gen. 3. Sericothrips. BB. Body smooth; apex of abdomen unlike in the two sexes. C. Prothorax produced in front, and narrowed __ _ Gen. 4. Chirothrips. CC. Prothorax not produced in front and narrowed. D. Last segment of abdomen with a pair of spines in female; male, wingless ...Gen. 5. Limothrips. DD. Last segment of abdomen unarmed. E. Last two segments of antenna? shorter than the sixth segment ..Gen. 6. Thrips. EE. Last two segments of the antennEe longer than the sixth segment... Gen. 7. Belothrips. FAM. III. COLEOPTRATID.E. A. Antennfe with nine distinct segments Gen. 8. Melanthrips. AA. Antenna? apparently five jointed, the last four segments being minute and compact B. Body somewhat flattened; meso-metathorax broad; front wings without fringe on costal border, and with four distinct cross veins; males with lateral abdominal appendages Gen. 9 Coleothrips. BB. Body cylindrical, mesothorax and metathorax constricted, wings rudimentary Gen. 10 Aeolothrips. SYNOPSIS OF IOWA SPECIES. GENUS PHLCEOTHRIPS, HAL. A. Proximal joint of anterior tarsi armed with a tooth on inner side -.1 A A. Proximal joint of anterior tarsi unarmed 2 1. With postocular bristle; three bristles on each side of pro- thorax; antennal joints 3-6 yellow verbasci, Osb. Without postocular bristle; a single bristle at each posterior angle of prothorax; antennal joint 3 and base of joint 4, some- times base of joint 5, yellowish nigra, Osb. 2. Black; head slightly longer than wide; tube three times as long as wide--. ...carya;, Fitch. Purplish-black; head one and one-half times as long as wide; tube twice as long as wide ma//, Fitch. PMoeotlirips verbasci, Osb. Description follows this paper. Phloeothrips nigra, Osb. Can. Ent., Vol. XV, p. 154 [1883]. Phlceothrips carijce, Fitch. [Third Report.] Trans. N. Y. State Agr. Soc. for 1856, Vol. XVI, p. 446. 216 IOWA ACADEMY OP SCIENCES. PJiIoeotJiri2:)S mali, Fitcb. [First Report.] Trans. N. Y. State Agr. Soc. for 1854, Vol. XIV, p. 806. GENUS HELIOTHRIPS, HAL. This genus is represented in the collections by a single species, H. hcemorrhoidalis, Bouch6. It is probable that H. draccence Heeger also, which occurs frequently in hothouses in this country and in Europe, is found in this state. These two species may be separated as follows: Fuscous, apex of abiomen ferrug-inous; antennaB and feet pale; first and second joints of the former fuscous, sixth joint black.- --- -.- heemorrboidalis, Bouche. Yellowish-brown; wings white, sub-fasciate with brown.. drac^'er/a?, Heeg'er. Heliothrips hcBmorrhoidalis, Bouch^. Naturgeschichte der schadlichen und ntitzlichen Garten- Insekten, p. 42 [1833]. Hellothrips draccenm, Bouche. Sitzungsb. d. mathem — naturw.Klasse d. Wissensch., Vol. XIV, p. 365 [1854]. GENUS SERICOTHRIPS. One species, Sericothrips? 2)erplexa, containing representatives of the male sex only, has been doubtfully referred to this genus. This species possesses well marked characters, evidently of generic importance, which do not accord with those of any genus of this family with which I am familiar. They are as follows: Head somewhat flattened or depressed and produced in front with the ocelli placed very far forward; fourth antennal joint decidedly longer than the third, apex of abdomen in male formed like that of females of this family. Tn Burmeister's Handbook of Entomology, Vol. 2, p. 413, the genus Sericothrips is characterized as having the abdomen covered with silky hairs, head hidden up to the eyes in the thoracic segment and the tip of the abdomen formed alike in both sexes. In the enumer- ation of species, the same authority records but a single species, hence it may prove that a more extended knowledge of allied forms will make it necessary to enlarge the limits of the genus, therefore it seems best to place this species here provisionally rather than to erect a new genus. Sericothrips? pjcrplexa, n. sp. Male: Length, 1.33-1.55 mm. General color fuscous; legs and annulus on antennas yellowish; thorax tinged with yellow-ferruginous; abdomen IOWA ACADEMY OF SCIENCES. 217 ■except apex, varying from pale to deep fuscous; anterior wings subfuligi- nous, clearer at base. Form slender; bristles and spines sbort, inconspicu- ous; head, from dorsal view, subpentagonal ; antenna? seven-jointed, approximate; ocelli placed very far forward toward front border of head; posterior angles of prothorax bisetose; spines on cubitus 15-16, arranged in a basal series of three or four followed by an intermediate group of nine, and this by two, more widely separated, at distal end of vein. Head, seen from above, subpentagonal, its greatest length equal to its greatest width; sides constricted behind eyes; front margin produced, and subangulated in middle, its width almost completely occupied b.v the antenna?; eyes dark red-brown, of medium size, moderately granulated, pile scattered, long; posterior orbits depressed, with a row of short sparse hairs parallel to them; vertex scarcely elevated, gi-adually descending toward apex where it merges into the front; ocelli yellow, inner margins red; anterior ocellus on uppar margin of front; lateral ocelli contiguous to upper orbits; ocellar bristles moderately long; small bristles between ante- rior ocellus and the eyes; occiput striate, provided with two weak bristles; front produced to base of antenna? thence receding toward clypeus, fur- nished with a row of four weak bristles just beneath antenna? and two similar bristles near clypeal margin. Antenna? seven-jointed, approximate, base plainly visible from above; joint 1 shortest and thickest, one-half the length of the second; joints 2-4 increase in length in the order named; joint 4 is nearly as long as joint 6, which is larger than any other joint; joint 5 is slightly longer than the second and more slender than any of the preced- ing; joints 6 and 7 are closely united and together pyriform in shape; the latter is nearly one-half the length of the former; the first joint is sub- rotund; the second, somewhat barrel-shaped; the third subfusiform; the ■fourth and the sixth elongate- ovate; the fifth submoniliform; the seventh lanceolate, its base narrower than the apex of the sixth; bristles and sen- sorial spines of joint 4 placed nearer the middle than usual. Prothorax subquadrate, scarcely broader than head; sides very slightly constricted at anterior border; posterior angles narrowly truncate, pro- vided with two bristles; shorter bristles or hairs are scattered over a trian- gular area extending backward from the front margin, and a smaller area near the posterior angles; anterior angles provided with equally small, but heavier bristles; surface apparently smooth; mesoscutum broadly convex, nearly smooth, furnished with short inconspicuous bristles each side and two submedian bristles on disc. The scutellum, obtusely ridged, feebly •sculptured, provided with two short, heavy, approximate bristles on ridge near basal margin. Abdomen slender; apex abruptly conical, resembling that of females of this family; sides distinctly sculptured; segments with a few bristles or coarse hairs laterally and on apical border of their ventral surface; caudal segments with longer and stronger radiating bristles arranged in two rings as in females. Legs slender; anterior femora scarcely expanded; posterior tibia? spiny on inner margin and at apex; their tarsal joints with apical spines. Anterior wings lanceolate, humeral angle moderately arched; cubitus extending entire length of wing; radial vein obsolete at base and nearly obsolete at tip; costal spines, 22-24; cubital spines, 15-16, arranged in 218 IOWA ACADEMY OF SCIENCES. groups, three or four at base, followed by a group of nine, and this by two more widely separated, placed at distal end; radial spines, 13; anal spines, 5; longitudinal vein of posterior wing distinct. General color fuscous; third and fourth joints of antennas entirely and sometimes base of fifth, legs, except more or less of dorsal surface, yellow- ish: thorax, especially the sutures, tinged with yellow-ferruginous; abdomen varying from fuscous to yellowish or pale fuscous; apex always dark; dorsal aspect of femora genei-ally concolorous with head; anterior wings sub- fuliginous with a broad, indistinctly defined, pale sub-basal band; posterior wings subhyaline. Described from eleven specimens taken at Ames, Iowa, on Cyperus, corn and in sweeping grass in August and November. GENUS CHIROTHRIPS, HAL. This genus is represented by a single species, Gldrothrips antennata, Osb. , which is of a brownish-black color with third joint of antenDEe paler; second joint is quite characteristic, being trapezoidal with acute angle outward. Ghirothrips antennata Osb. Can. Eat. Vol., XV, p. 154. [1883.] GENUS THRIPS. A. Head of medium size; eyes moderately prominent; antennal joints 3-5 elongate. 1 AA. Head small; eyes very prominent; antennal joints 3-5 not elongate .8 L Antennas eight-jointed.. 2 Antennas seven-jointed 7 2. Sixth joint of antennas annulated .3 Sixth joint of antennee not annulated & 3. Ocelli widely separated; long bristles at all angles of pro- thorax; spines present at apex of all tibias, numerous and heavy on wings, on radial vein 12-14 4 Ocelli subapproximate; single bristle of medium length at each posterior angle of prothorax, none at anterior angles; spines present at apex of posterior tibias only, on radial vein 2 5 4. Size medium; head, from dorsal view, rectangular^ antennas approximate (Euthrips) tritid Fitch. Size large; head from above pentagonal; antennae subapprox- imate [Euthrips) mairlis n. sp. 5. Wings more or less distinctly clouded; brown markings on thorax and band at base of abdominal segments 2-7 distinct.. . - „ variabilis, n . sp ► Wings nearly uniformly fuliginous; brown markings distinct on thorax; abdomen immaculate ..var a. Wings and body, pale; markings, obsolete .var. b. Wings distinctly trifasciate; broad brown band on head IOWA ACADEMY OF SCIENCES. 219 and thorax respectively; abdominal segments 1-3 and 7-10 entirely brown var. c 6. Head, from dorsal view, semiovate; ocelli subapproximate, conspicuous; spines and bristles, short and few; bristles on penultimate segment of abdomen equally long striata, Osb. Head, from dorsal view, subrectangular; ocelli remote, inconspicuous; single strong bristle at each posterior angle of prothorax; intermediate bristles on penultimate segment of abdomen, one-half as long as lateral bristles, iasequalis, n. sp. 7. Size medium; antennae sub-approximate; ocelli inconspicu- ous; prothorax, transverse; bristles at posterior angles of medium length; spines at base of cubitus arranged in two groups -- -- --. tabaci, Lind. Size large; antennte approximate; ocelli, conspicuous; pro- thorax, subquadrate; bristles at posterior angles of prothorax, long; spines at base of cubitus in single group .. lactucse n. sp. 8. Antenuce eight-jointed; ocelli approximate; spines and bristles, except those on abdomen, long and slender; bristle at middle of each lateral margin of prothorax, one at each ante- rior and two at each posterior angle pallida, n. sp. Thrips {Eutlirips) ti'itici, Fitch. [Second report.] Trans. N. Y. State Agr. Soc. for 1855, p. 536; Osborn Can. Ent, Vol. XV, p. 156 (1883). Thrips (Euthrips) maidis n. sp. Female. Length, 1.83-2.mm. A large species slightly variable in color, brownish-black, but sometimes paler; annulus on antennae, extremities of femora and tibise, lower surface of the latter and sutures of abdomen yellow- ish-white; thorax, especially its sutures, tinged with yellowish-ferruginous; anterior wings dusky white; head pentagonal, front margin produced and rounded in the middle; ocelli distant, antennae subapproximate; spines and bristles. strong, blackish, arranged much as in E. tritici, Fitch; costal spines 25-29; cubital, 19-23; radial, 15-16; anal, 5; internal, 1. Head, from dorsal view, pentagonal, scarcely broader than long; its sides parallel; anterior border produced and rounded in the middle; occiput less than one-half the length of the head measured on a median line, plainly striated; genae uniformly full; eyes rather large, coarsely granulated, feebly pilose; orbits yellow, encircled with a few short hairs; ocelli, pale yellow, margined with red crescents, widely separated and arranged in a broad triangle with its lateral angles contiguous to superior orbits; vertex broad, gently coavex between lateral margins; produced cephalad and provided with a transverse row of four short hairs near its anterior margin; the front wide with medial, longitudinal elevation; antennal sockets occupying less than its entire width, making antennse subapproximate, more widely separated than in B. tritici, Fitch; anten- nal joints 3 and 4, occasionally base of 5, white, the rest, black; joint 1 globose, more than one-half as long as joint 2; the latter subglobose, somewhat contracted toward base, both joints more robust than those fol- lowing: joints 3-5 elongate, submoniliform, decreasing in size in the 220 IOWA ACADEMY OF SCIENCES. order named; the third nearly as long' as the sixth; apical joints subequal, minute; all joints thinly covered with microscopic hairs; bristles or stiff hairs on basal and intermediate joints which on distal joints are replaced by slender hairs; sensorial spines on the third, fourth and sixth joints, dis- tinct; clypeal, subantennal and postocular bristles present, the last less conspicuous than in tritici; mouth parts distinctly asymmetrical; each joint of maxillary palpi cylindrical, narrower than the preceding^; first and third subequal in length, and second shorter than either. Prothorax about one and one-half times as broad and equally as long as preceding segment; anterior angles rectangular, posterior rounded, sides slightly converging cephalad; disc striate and sparsely hairy; front and hind borders more deeply striate or rugose, brislly; the most conspicuous bristles are arranged as follows: One long bristle at each anterior and two at each posterior angle; two shorter bristles on anterior margin, two on posterior margin and one on disc near each posterior angle. Meso-metathorax, subquadrate; mesoscutum more finely striate than prothorax, with small bristles, one at each lateral angle, two near and two on posterior margin; scutellum as long as mesoscutum, narrow, not strongly carinate; base transversely striate, sides longitudinally rugose; basal bristles as in tritici. Abdomen broad, ovate, basal segments and sides sculptured, bristles similar to those of tritici. Legs, with numerous short bristles; all tibife and joints of posterior tarsi with terminal spines; anterior femora incrassate, their tibite stout. Wings rather broad; humeral arch not prominent; surface minutely pilose; veins distinct, uniformly and heavily spiuose; anterior and poste- rior basal cross veins present; cubitus inserted in marginal at tip of wing; radius obsolete at proximal end, but perceptible before it unites with the posterior basal cross vein; costal spines longer than those on the other veins, numbering from twenty-five to twenty-nine; cubital, from nineteen to twenty-three; radial, from fifteen to sixteen; anal, five, gradually increasing in size from one to five; internal, one; postei-ior wings hyaline; longitudinal vein indistinct, except at base. This form approaches closely the dark colored specimens of tritici, from which it may be separated by its larger size, the annulus on the antennte, and especially by the shape of the head, which is pentagonal instead of rectangular, and the less approximate antennae. Described from twenty-nine specimens taken at Ames, Iowa, in July, August, September and January. ThrijJS variabilis n. sp. Head transverse Antennae eight-jointed, distant; ocelli approximate. Each posterior angle of prothorax provided with a single- medium sized bristle; bristles on penultimate segment of abdomen not strongly radiat- ing, not extending backward beyond the base of the succeeding row; radial vein bispLnose, obsolete; legs slender. Female. Length from .81-1.23 mm. Head one-half as long as broad; viewed from above, subrectangular; anterior margin straight; occi- put short, transversely convex and striate; distinct oblique depression behind each eye; gena3 moderately full; vertex abruptly ascending, tumid IOWA ACADEMY OF SCIENCES. 221 across whole anterior border; ocellar area small, elevated; ocelli approxi- mate, inner margins heavy, conspicuous: ocellar bristles not more than one-half the length of the head; eyes large, prominent, feebly pilose. Antenuce eight-jointed, distant, moderately bristly; basal joint short, thick, hidden from dorsal view by vertex; the following joint longer, more robust, globose; joints 3-6 elongate; joint 3 the longest, subfusiform; joint 4 a little shorter than joint 3, elongate-modioliform; joint 5 obovate, inter- mediate in length between 2 and 4; the remaining joints sessile, together eloxjgate-conical; joint 6 equal to joint 4 but a little stouter; joints 7 and. 8 minute, together one-half as long as preceding, line of separation between them oblique; sensoi-ial spines on joint 6 originate beyond middle; four short bristles in transverse row on front above antennae, and one behind each eye; mouth parts nearly symmetrical. Prothorax broader than long; anterior angles prominent, rectangular; posterior angles broadly rounded and furnished with a single bristle; sur- face plainly and uniformly marked with transverse strife, with a few short slender bristles on front margin and more on disc Mesoscutum is quite con- vex from base to apex, marked with fine transverse striee, and provided with four short bristles on disc. Scutellum with triangular area at base striate as in mesoscutum, furnished with four basal bristles. Abdomen broad, ovate; sides, under high power, appear thickly set with minute appressed hairs; a pair of bristles occurs on disc of each seg- ment from the second to the seventh; they are approximate on the second and gradually become more widely separated on the succeeding segments; lateral bristles few and short; apical border at sides and on ventral surface of segments bordered with minute cilias interspersed with coarse hairs or bristles; caudal spines rather light; those on penultimate segment directed backward and extending only to base of following segment; terminal spines a little longer than the preceding, radiating at sides. Legs very slender, somewhat bristly; tarsi elongate; anterior femora not dilated; apex of intermediate and posterior tibias and of posterior tarsal joints terminating in short spines; inner margin of posterior tibiae feebly spinose. Wings; veins heavy; in anterior pair radius and cross veins obsolete; costal spines number 22-30; cubital, 20-26, arranged in two series; radial, 2; anal, 4; one near base of anal cell; longitudinal vein of posterior wing very heavy for two-thirds of the length. Male. Length, 78-86 mm. Resembles the female very closely. Differs in being of smaller size, in having from 23-25 costal spines, 20-21 cubital: the remaining spines on the wing as in female. The apex of the abdomen is more blunt; the anal segment is cleft on either side, the lateral lobes terminate in two spines; the middle lobe is prolonged consider- ably beyond the lateral lobes, making apex more pointed than apex of male of T. tritici. The spines on preanal segment are similar to those in female. This species presents considerable variation in color. The extreme forms are quite distinct and might almost be considered separate species were it not that in addition to the similarity in structure there is the occur- rence of a series of intergradient forms. 222 IOWA ACADEMY OF SCIENCES. Var. a. Female: General color yellowish -white, meso-metathorax pale yellow, basal joints of sntencffi concolorous with head, joint 3 and taseof joint 4 dusky; the remainder of the antenniB and spot at distal end of tarsi, brownisih-black; eyes dark red-brown; ocelli nearly colorless; inner margins red; anterior wings indistinctly clouded with fuliginous at base, distal portion clearer; brown markings as follows: A clearly defined saddle-shaped patch on posterior portion of prothorax, concave along its front border, nearly interrupted by a wedge-shaped incision extending forward from posterior border: anterior border of mesonotum; scutellum except median stripe; bands at base of abdominal segments two to seven, dilated at sides, and narrower and fainter along intervening space; patch on upper side of all the femora, darkest on posterior pair. One specimen, taken en clover August 14, 1893, and one on hackberry, October 6, 1893, Ames, Iowa. Anotiier specimen taken on hackbsrry, October 6, 1893, at Ames, Iowa, corresponds with the description of variety a except that the thorax is a deeper yellow. Another specimen taken oa elm, August 21, 18M, is more uniformly yellow, the anterior wings more unifoimly dusky, bands at base of abdominal segments narrower and other markings fainter. A fourth specimen that may be placed in this group resem- bles the first, but it is of a deeper yellow color; the markings on the prothorax are prolonged farther backward, and the wings are more uniformly fuliginous. Ames, Iowa, Oct. 8, 1893. Var. b. Male and female: Body pale yellowish, immaculate; apical joints of antennse black, remainder pale; wings and fringes tinged with yellowish. Hawthorn and hackberry, Ames, Iowa, October 6, 1893. Var. c. Male and female: Wings nearly uniformly fuliginous; last three joints antennae, distal half of joints 4 and 5 black, sometimes inter- mediate joints altogether dusky; brown markings very distinct, confined to two large spots on thorax and scutellum respectively, the latter oblong and approximating posteriorly; abdomen immaculate. Hawthorn and hackberi-y, October 6, 1893, Ames, Iowa. Var. d. Male and female: This variety is characterized by having the wings fuliginous, trifasciate with white bands, and in being more heavily marked with brown; the markings on the thorax and bands at base of first, second and third (sometimes of second and third only), and seventh and eighth segments of the abdomen are extended until they coalesce and form broad bands; the dorsal surface of the head is brown; sometimes all of the caudal segments are brown; the legs are white, with brown streaks on dorsal surface of femora, and frequently on tibias also; antennae as in pre- ceding variety. IOWA ACADEMY OF SCIENCES. 223 On smartweed, June 16, 1893, and on cucumber, July 28, 1893, Ames, Iowa. By the shape of the head aud by the antennal characters this species is allied to T. tritici, but it may readily be distinguished from it by the smaller and more approximate ocelli, the absence of large conspicuous bristles on the thorax, the differ- ence in the number of spines on the wing, and the more slender legs. Tfirips {Ei(tJiri2)s) striata, 0»b. Can. Ent., Vol. XV, p. 155. Thrlps inequaUs, n. sp. Female: Length, 88 mm.; yellow: style and distal portion of antennal joints, 3-6, black; joint 6 distinctly annulated toward apex; posterior ang-les of prothorax with a single bristle; lateral bristles on dorsum of penultimate segment of abdomen twice as long as intermediate pair. Head, broader than long, contracted at posterior border, occiput form- ing not more than one-half of its dorsal surface; gente uniformly full; eyes of medium size, moderately promicent, distinctly pilose; vertex uniformly tumid at anterior margin, becoming transversely convex and descending toward posterior margin; ocelli subapproximate; front, above insertion of antennae, longitudinally elevated along median line. Antennte subapproximate; the two basal joints stout, subequal; the second barrel- shape J, more than one-half as long as succeeding; joints 3-6 subequal in length and less elongate than in T. tritlA; joints 3 and 4, thick, irregularly turbinate, gibbous below insertion of sensorial spines; joint 5, smaller and more regular in shape; the remaining joints form an elongate oval; joint 6 has a distinct articulation on distal half, similar to the annulation on the sixth antennal joint of T. striata, Osb.; this may be an indistinct annulation, in which case the antenna would be properly considered nine-jointed, three of the joints forming the style; the ultimate joint is nearly cylindrical and longer than the penultimate, which is of the same length as that portion of the joint 6 between the annulation and the apex; the joints are furnished with a few medium-sized bristles or stiff hairs, which become liner toward the distal end of tLe antennie; sensorial spines as in T. tritici. The prothorax is one and one-half times as long as the head, equally as broad at anterior border and about one-thii-d broader at posterior border. The disc is convex, rather indistinctly striate and sparsely set with stiff, blackish hairs or bristles, which are almost entirely wanting on median portion, and most numerous near lateral and posterior borders. Posterior angles with a single long bristle. The disc of the mesoscutum is convex, finely striate, elevated at posterior border, provided with a single short bristle near each lateral angle, two on disc and two on posterior margin. The scutellum is trapezoidal, gently sloping from the very small elevated area near base toward posterior and lateral margins; on the basal mai^gin are two widely separated and two short approximate bristles. 224 IOWA ACADEMY OF SCIENCES. The abdomen is ovate, resembling that of T. tritici, Fitch, in an arrange- ment of bristles, except that the median pair on penultimate segment is but one-half as long as those on either side. Legs, especially femora and tibise, thinly covered with short, coarse hairs which are replaced by bristles at apex of anterior and intermediate tarsal joints; inner margin of posterior tibite feebly spinose; its apex and apex of its tarsal joints terminating in spines; anterior femora moderately dilated. Anterior wings nearly attain tip of abdomen: veins heavy; inner mar- ginal vein very distinct; costal fringe rather heavy; costal vein bears from 24-28 spines; radius, 18-19, those on basal half of vein separated into twa groups of four each, the intervals between the rest growing wider toward the distal end of the vein; cubitus, 10-Jl; anal, 5; anal cell, 1. Color yellow, deeply tinged with orange on thorax and abdomen, faintly dusky along median line of thorax and abdomen; head and two basal joints of antennte, whitish; proximal portion of joints 3-6, dusky; remainder of antennaa and spot near apex of tarsi, black; eyes, red-brown; ocelli, pale yellow; inner margins, orange- red; spines and bristles black- ish; anterior wings and fringes tinged with dusky yellow. Described from a single specimen taken with f. tritici on aster at Ames, Iowa, September 16, 1893. Thrips tahaci, Lind. Schadlichsten Insekten des Tabak in Bessar. Abien., pp. 62-63. (1888.) Thrips lactucoe, n. sp. Female: Length, 1.40 mm. General color pale yellow, with two broad diverging stripes on middle of thorax, a narrow band at base and one or more spots at sides of abdominal segments brown. Form elongate; anterior border of head convex. Antennas seven-jointed, proximal joints pale, remaining joints black. Wings variable in size. Ocelli conspicuous, placed close together near posterior margin of vertex. Spines and bristles stout, on thorax, arranged much as in T. tritici; the cubital spines are grouped into two series, a basal group of seven, followed by three, more widely separated, on distal portion of vein. Head scarcely broader than long; outline seen from above semiovate;. occiput, feebly striate, one-half the length of the head, with shallow, longitudinal furrow each side behind the eye; gena3, broad, full, prolonged posteriorly ; vertex elevated, convex between the eyes, ascending and expanding towards apex, front margin arcuate; ocelli conspicuous, remote from anterior border of vertex, inner margins heavy, contiguous in front; ocellar area elevated; ocellar bristles of medium size; eyes, moderate, pilose: a row of bristles on front, beneath insertion of antennt^, is partially visible from above; a few microscopic bristles around orbits; antennal sockets prominent, easily seen from above; antenna? approximate, seven- jointed: the intermediate joints elongate; joint lis one-half the lengih of joint 2, equal to or longer than joint 7, semiglobose; joints 2-5 are sub- equal in length; joint 2 is cupshaped, a little shorter but much stouter than any of the three immediately following; joints -3-5 are moniliform;. IOWA ACADEMY OF SCIENCES. 225 pedicel of 3 is short; joints 6 and 7 together form an elongate oval; the latter is acuminate at apex two-fifths the length of the former and terminates in two or three long slender hairs; surface of all the joints set with minute appressed hairs and furnished with a few bristles which are arranged in a preapical ring on joints 2-5, and on remaining segments are replaced by slender hairs; sensorial spines on joints 3, -4 and 6, distinct. The prothorax is subquadrate, a little longer and wider than preceding segment; posterior angles nearly rectangular; posterior border margined; surface nearly smooth and, with the exception of two discal areas, covered with coarse, stiff hairs which are largest near lateral and posterior borders; two short bristles at each anterior angle and four longer ones near front border; two large, strong, subequal bristles at each posterior angle, two of moderate length on hind border, and a similar one on disc near each posterior angle. The surface of the mesoscutum is apparently smooth, its posterior discal portion only moderately elevated, provided with two small bristles; two similar bristles occur on the posterior border, and one at each lateral angle. The metanotum is very short. The scutellum is obtusely carinated, its surface longitudinally striate, provided with two approximate submar ginal bristles on anterior portion of disc, and two, more widely separated, on basal margin. Abdomen is quite uniform in width, convex above, striate at base and at sides; base slender; apex short, conical; segments constricted, bearing a few stiff hairs on dorsal and ventral surfaces and a few bristles at sides; both hairs and bristles become stronger on anal segments, where the latter are arranged in two rings. Legs, especially posterior pair, slender; anterior femora but slightly expanded; hind tibiaj spiny on inner margin, terminating in three strong spines, joints of their tarsi also furnished with apical spines; entire surface bristly, especially at apex of intermediate and anterior tibice. Wings varying in size from rudimentary to fully developed; the ante- rior pair slightly dusky, posterior pair hyaline; in fully developed wing the cilia on costal border of each pair is short and sparse, on posterior border longer but not very heavy; venation of anterior wings rather weak; ante- rior and posterior basal cross veins present, but not distinct; costal vein furnished with 18-21 spines; cubitus, 10; radius, 10-11; anal, 5; anal cell, 1; spines on cubitus are arranged in a basal group of seven, followed by three more widely separated on distal end of vein; longitudinal vein of posterior wings incrassate at base, not quite attaining tip of wing. Color usually pale yellow, deeper on thorax and legs, the latter frequently dusky; head and proximal joints of antennte white, intermediate joints brownish-black at base, the rest of the antennas deep black; occiput often tinged with yellow, sometimes dusky; eyes dark red-drown; ocelli yellow, inner margins brick-red; prothorax at margins, disc of mesonotum, pleura3, except upper portion of mesopleuras in front, narrow medium stripe on scutellum, pale; two spots or patches on prothorax, sometimes diffuse and coalescing sometimes nearly or quite obsolete, two broad, approximate stripes on scutellum, diverging slightly and extending outward and back- ward in a broken and interrupted line to lateral margin, upper portion of mesopleurse in front, brown; abdomen somewhat dusky, more or less pale 15 226 IOWA ACADEMY OP SCIENCES. at sides and toward apex; narrow basal band on segments 2-7, expanding laterally and broken up into spots, one of which is more conspicuous than the others, brown. Femora and tibias dusky or brownish on upper surface, pale on lower surface and at base, the latter also pale at tip; anterior wings dusky yel- lowish; spines brown. By its seven-jointed antenucC. T. lactuae is allied to T. tahaci, Lind., but it is more heavily marked with brown; the color of the intermediate joints of the antennae is darker; the antennte and the ocelli more approx- imate; the ocelli more conspicuous and farther removed from the anterior margin of the vertex; the prothoracic bristles larger and less uniformly distributed, being entirely absent from two discal areas; those at posterior angles, longer; proximal spines on cubitus arranged in a single group. Described from numerous specimens taken on wild lettuce in October, November and March, at Ames, Iowa. T. lactucce bears some resemblance to T. tritici in size and general color, from which it may be easily separated by the fewer antennal joints, less rectangular head, less widely sep- arated ocelli, absence of long bristles at anterior angles of prothorax, less numerous cubital spines and their arrangement in groups, absence of spines at apex of intermediate and anterior tibias and inner margin of posterior tibise. From T. striata it may be known by the difference in number of antennal joints, absence of annulation on sixth joint, pres- ence of longer and more numerous spines and bristles. Thrips ixdlida n. sp. Female: Length 1.12 mm. Color varying from white to pale yellow. Antennae, beyond basal joints, more or less dusky. Head small, eyes large. Anterior wings partially trifasciate. Bristles on anterior portion of body long and slender. Prothorax characterized by the presence of a long bristle on the middle of each lateral margin in addition to those at anterior and posterior angles. Head small, about as long as broad. Occiput very short, not more than one-third the length of the head. Eyes dark red-brown, very large and prominent, sparsely and feebly pilose. Vertex narrow, elevated, trans- versely convex, ascending toward the anterior margin, the latter arcuate. Ocelli in middle of vertex, nearly colorless, their inner margins white, con- tiguous anteriorly. Ocellar bristles as long as the head. Front prominent, bearing a row of recurved bristles above insertion of antennas. Mouth parts short, nearly symmetrical. Antennas approximate; the two basal joints the stoutest; joint 1 semi- globose, one-half the length of joint 2; the latter is stouter than the former, barrel-shaped, equal in length to joint 5, and a little shorter than joints 3 or 4; these are robust, subequal in length and broadly obovate, the pedi- cel of joint .3 is short and slender; joint 5 is oval and less robust than the two immediately preceding; the remaining joints are sessile, together form IOWA ACADEMY OF SCIENCES. 227 an elongate oval; joint 6 is longer than any other joint; joints 7 and 8 are short and of equal length, base of former narrower than apex of 6; apex of 8 is lanceolate. Bristles and hairs are of equal size, and arranged much as in T. tritici. The long sensorial spine on outer side of joint 6 originates below the middle of the joint. The prothorax is convex; its sides converge cephalad; its surface is nearly smooth, with a double median transverse groove or double impressed line and a few short and several long slender bristles, the latter arranged as follows: one at each anterior angle, two on intervening space of anterior border, one at middle of each side, one near and two at each posterior angle. The mesoscutumis longitudinally convex, its surface nearly smooth, furnished with two lateral bristles directed inward, and two smaller ones on disc and on posterior border, respectively. The scutellum is subrec- tangular, obtusely carinated, descending toward the apex; on basal margin provided with two distinct bristles which extend nearly to apex. The abdomen is slender at base, ovate, with few conspicuous bristles; those at apex of ultimate segment much shorter and weaker than those on preceding segment. Legs are moderately stout, bristly; anterior femora incrassate, their tibiai stout; spines present at apex of posterior tibial and tarsal joints, on inner margin of tibite replaced by bristles. The anterior wings are whitish, slender, rather thin, subfasciate with three dusky spots; the first near base of anal area, the other two dividing the remainder of the wing into three subequal parts; sometimes a faint spot may be detected near apex of wing; these spots are variable in distinctness and may be obsolete; cilice of inner margin, light; of outer margin, sparse and scarcely longer than the spines with which they are interspersed. RadiaLvein is obsolete between base of wing and posterior basal cross vein, consequently it appears to originate in the cubitus. Both radius and cubi- tus terminate abruptly before attaining marginal vein. Cross veins con- necting costal and cubital veins are obsolete. The costal vein bears from 15-20 spines; the cubital, 10; radial, 5; anal, 4, and posterior marginal vein 1, placed opposite the posterior basal cross vein. The posterior wings are hyaline; proximal end of longitudinal vein incrassate. Male. Length .97 mm. Smaller than the female, but very similar in distinctive characters. Apex of abdomen is bluntly conical, less truncate than in male of T. tritici, partially trilobate, the lateral lobes are very narrow, shorter than the middle lobe, and terminate in a single long bristle. Penultimate segment terminates in a row of short sparse bristles, on dorsum, and single long spine on each side. Described from ten females and seven males. Taken on bean and elm at Ames, Iowa; on blackberry at Belle Plaine, Iowa, and on hop at Barraboo, Wis. Thrips x^cillkla is a well marked species and is readily sepa- rated from the other species included in this paper by the small head, the presence of a bristle on middle of lateral margin of prothorax, the feeble armature of inner margin of posterior tibias and the number of spines on the front wings. 228 IOWA ACADEMY OF SCIENCES. NOTE ON A NEW SPECIES OF PHLCEOTHRIPS, WITH DESCRIPTION. HERBERT OSBORN. In connection with the paper by Miss Beach on the Thri- pidso it seems desirable to describe a species which has for a long time been in our collections, but has not received a techni- cal description. Pblceothrips verbasci, n. sp. Black, polished; head quadrate with a prominent post-ocular bristle: prothorax widened behind; first joint of anterior tarsi armed on inner side with a curved tooth. Fern tie: Head quadrate, very slightly constricted behind, a prominent bristle behind the eye; antennas light yellowish with dusky base and tip, joints 1 and 2 black, 3-6 yellow, 7-8 dusky, ending with two bristles; pro- thorax widening behind, with prominent angles, three lateral bristles: meso and meta-thorax subquadrate. Legs black except anterior tihise and all tarsi which are yellow, the tarsi somewhat clouded with dusky. Anterior tarsi with a short curved tooth on inner side of first joint at mid- dle. Wings hyaline except base of anterior pair, which is fuliginous; anterior pair with no fringe at base: anal vein entire; median vein distinct at base, but becoming obsolete; three long spines in a row on the inner side of the median vein near base; posterior wings at base with two long, slender bristles near together on hind margin; abdomen at apex with six long and seven short bristles; tube reticulate. Male smaller than female and having two slender spines on a slight elevation at side of the anterior margin of the first segment of the abdomen. Length of male 1.50-1.60 mm., female 1.80-1.90 mm. This species stands near to nigra, Osb., but differs decidedly from that species in the more quadrate head, prominent poste- rior angles of the prothorax, as also in the presence of two prominent bristles just behind the eyes and the different num- ber and character of bristles at apex of tube. It occurs almost invariably in mullein, hibernating in the stools, and may be found in early spring at the base of the fresh leaves, especially among the dense interior leaves. The whitish, cylindrical eggs are deposited during April, and larvaD develop on the mullein leaves. The larvaa differ decid- edly from the larva3 of nigra, in being yellow or orange instead of deep red. Adults, bred forms of which matured June 20th to 26th, are found in mullein blossoms in midsummer (July), and probably produce a second brood. Adults have been taken in Septem- ber in the seed pods, and in November at the base of dead mullein stalks. This is the species referred to in my article on "The Food Habits of the Thripidce " (Insect Life, Vol. I, p. 141) as Phloio- thrips sp., the species being cited in evidence of an herbivorous di t for the Thripidce. iis[ide:^::?c. Address, annual, of president, 17. Anatomical studies of the leaves of Sporobolus and Panicum, 148. Anatomy of Sphajrium, 173. Andrews, L. W., on reduction of sulphuric acid, 37. Annual address of president, 17, Articles of incorporation, 8. Area of slate near Nashua, N. H., 66. Associate members, list of, 11, Bacteria, Chromogenic, 135. Bain, H. F., report of librarian, 14. Ball, E. D., a study of the genus Clastop- tera, 183. Baris confims. 207. Baris dolosa, 210. Beach, Alice M., contributions to a knowledge of the thripidaj of Iowa, 314, Biologic notes on certain Iowa Insects, 203. Boston basin, geology of, 72. Buchanan gravels: An interglacial de- posit In Buchanan county, Iowa, 58. Calvin, S., the Le Olalre limestone, 52. Buchanan gravels, 58. Carver, G. W. and Pammel, L. H., fungus diseases, 140. Carver. G. W., and Stewart, F. C, Inocula- tion experiments with Gymnosporan- gium macropus. Cephalopods, two remarkable,from upper Paleozoic, 76. Cercopida\ 182. Chironomiis, sp., 211. Chromogenic bacteria, some notes on, 135. Cicadidas of Iowa, observations on the, 195, Cicada dorsata. 193. septen-decim, 194. tihicen, 193. Olastoptera, a study of the genus, 182. Clastoptera, 183. Clastoptera delicata, 184. obtusa, 188. proteus, 186. xanthoceplMla, 188. Clays of the Indianola Brick, Tile and Pottery works, 40. Combs, Robt., and Pammel, L. H., Chromogenic bacteria, 135. Cone-in-Cone, nature of, 75. Constitution of the academy, 7. Corresponding members, list of, 11. County parks, 91. Cyclostome ear, homologies of, 29. Cosmos weevil, 307. Deep Wells in Des Moines county, some facts brought to light by, 62. Drew, G. A., Anatomy of Spha^rium sulca- tum, 173. Ear of cyclostome, homologies of, 29. Encrinurus, variation In the position of the nodes in axial segments of pygi- dium of a species of, 79. Entomostraca, preliminary notes on the Iowa, 170. Epicccrus imbricatus .305. Flora of Western Iowa, 106. Fellows, list of, 10. Ferns, comparative study of spores of North American, 159. Flora of Western Iowa, 106. Forest distribution in Iowa. 96. Forest preservation, resolutions on. 15. Frisk, E. E , and T. P. Hall, mad stone, 45. Fultz, F. M., Recent discoveries of glacial .scorings, 60. Some facts brought to light by deep wells. 62. Fungus diseases of plants at Ames, Iowa, 1«95, 140, Geology of the Boston basin, 72, Gelechia sp.. 303. Glacial scorings, recent discoveries of, in S. E. Iowa, 60. Grasses, anatomical study of, 150. Gravitation, physical theories of, 47. Ground cherry seed moth, 302. Gymnosporangium macropus Inoculation experiments with, 162. Hall, T. P , physical theories of gravita- tion, 47. Unit systems and dimensions, 45. Hall, T. P. and Frisk, E.E.,amad stone, 45. Heliothrips, 216. Homologies of the Cyclostome ear, 29. Hendrixson, report of library commit- tee, 16. Inoculation experiments with Gymnos- porangium macropus, 162. Insects, biologic notes on certain Iowa, 203, K«yes, C. R., note on the nature of cone- in-cone, 75. Two remarkable Cephalopods from the Upper Paleozoic, 76. Lake preservation, resolution on, 15. Lead and Zinc mines, 64. Le Claire, limestone, 53. Leonard, A. G., recent developments in the Dubuque lead and zinc mines, 64. Librarian, report of, 14. Loess, a theory of the, 82. ad stone, a, 45. acbride, T. H., county parks. 91. Forest distribution in Iowa, 96. The nomenclature question among the slime moulds, 101. SCa 230 INDEX. Melampsalta parvula, 203. Members, associate, 11. Corresponding, 11. Membership of the Academy, 10. Metazoa, sex in, 35. Myxomycetes, 101. fiautilus ponderosus, 76. Needed changes in scientific methods, 17, Nomenclature question among the slime moulds, 101. Norris, H. W , address by, 17. Homologies of Oyclostome ear, 39. Norton, W. H., variation in the position of the nodes on the axial segments of Pygidium of a species of Encrinu- rus, 79. Nutting, C. C, origin and significance of sex, 33. Officers of the Academy, 5. Origin and significance of sex, 33. Orthoceras fanslercnsis, 77. Osborn, H., Observations on the Oicadidaj of Iowa, 195. Note on a new species of Phloeothrips with description, 338. Report of secretary-treasurer, 13. Osborn, H. and Mally, 0. W., biologic notes on certain Iowa insects, 303. pammel, Emma, and Sirrine, Emma, some anatomical studies of the leaves of Sporobolus and Panicum, U8. Pammel, L. H., notes on flora of western Iowa, 106. Pammel, L. H., and' Carver, G. W., fun- gus diseases of plants at Ames, Iowa, 1895, 140. Pammel, L. H., and Combs, Robt., some notes on Ohromogenic bacteria, 135. Panicum and Sporobolus, anatomical studies of the leaves of, 148. Panicum, 155. Panicum, capillars, 156. crus-galli, 157. proliferum, 156. Parks, county, 91. Phloeothrips, note on a new species of, with description, 338. PhJccothrips verbasci n sp., 328. Physical theories of gravitation, 47. President's annual address, 17. Proceedings of tenth annual session, 13. Recent developments in the Dubuque lead and zinc mines, 64. Recent discoveries of glacial scorings in southeast Iowa, 68. Reduction of sulphuric acid by copper, as a function of the temperature, 37. Report of librarian, 14. Report of secretary-treasurer, 13. Resolutions on preservation of forests and lakes, 15. Ross, L. S.. Preliminary notes on the Iowa Entomostraca, 170. Secretary-treasurer, report of, 13. tSalix amygdaloides, perfect flowers of, 89. SericothHps? 216. Sericothrips? perplexa. 216. Sex, origin and signiflcance of, 32. Shimek. B., A theory of the Loess, 83. Perfect flowers in salix amygdaloides Ands. 89. Sirrine, Emma, and Pammol, Emma, Some anatomical studies of sporo- bolus and Panicum, 148. Slate near Nashua, N, H., Area of, 66. Slime-moulds, Nomenclature question among, 101. Sphctrium sulcatum. Anatomy of, 173. Spores of North American ferns, study of, 159. Sporobolus and panicum, anatomical studies of the leaves of, 148. Sporobolus. 151. Sporobolus cryptandrus, 153. heterolepis, 151. hookerl, 153. vaginseflorus, 155. Stewart, F. C, and Carver, Q. W., Inocu- lation experiments with Gymnos- porangium macrop\is, 163. Sulphuric acid, reduction of, 37. Thripida; of Iowa, contributions to a Knowledge of, 314. Thrips incequalis, 233. lactucm, 234. maidis, 319. pallida, 326. variabilis, 220. Tibiccn rimosa, 300. Tilton. J. L , area of slate near Nashua, N. H., 66. Notes on the geology of the Boston basin, 73. Unit systems and dimensions, 45. Weaver, C. B., comparative study of the spores of North American ferns, 159. Youtz. L. A., clays of the Indianola Brick, Tile and Pottery works, 40. Zinc mines, recent developments in lead and, 64. I e- I U i