Introduction

mmmm mmmmmmmmmmmmmmm WW��l�W>>WWiaWM>Mlll<>W�IW IIW I I MM�WltWlt�tM M WII>ll>�IWMWl>l�MII�i�IM�MIW��tfW* MANUAL OF HIGH SCHOOL B nBBHnwinpaniiMniwwMiMiifiwawMiMMiMM iMiiuiMiiiuiMmwiiiMiuwnnwwHWWWHii LIBRARY OF CONGRESS. Chap.Q-KiSCopyriglit ]S^o._ Shelf_-cC_(D UNITED STATES OF AMERICA. A LABORATORY MANUAL OF HIGH SCHOOL BOTANY FREDERIC E. CIvEMENTS, PH.D., Instructor in Botany in the University of Nebraska, IRVING S. CUTTER. B.Sc. Principal of the Beatrice High School. LINCOLN, NEBRASKA. rHE UNIVERSITY PUBLISHING CO. 19C0. 1 51603 SEP 25 1900 AH Copyright^ 1900, by Frederic E. Oewtemts and Irsdmg S. Cutter. r^his resented. PREFACE The present work is intended solely as a laboratory guide in connection with lectures or a text-book. The matter has, in consequence, been presented in the briefest and most compact form consistent with this purpose. The aim is to put the student to work quickly and to keep him at work intelligently. Explanation has been added only when it seemed essen- tial to the proper handling of the laboratory work. The material and the teacher have been regarded as the two important facts in the work. The laboratory directions, it is hoped, will bring the student into direct contact with the material, and will relieve the teacher of a large amount of drudgery, thus giving him time for real teaching. The Manual is an authoritative expression from the Department of Botany of the University of Nebraska upon the kind and amount of elementary botany that should be taught in the accredited schools and colleges of the state. It has been written with the idea of making it possible for schools to give at the same time the proper preparation in botany to those intending to go to college, and a broad and scientific view of plants to those who stop at the end of the high school. In consequence, it can not be used in part, if the best results are desired. The completion of the entire work as outlined gives two credit points. In those 4 MANUAL OF BOTANY schools which are not yet prepared to give the subject the full amount of time, a credit of one point will be given for a prescribed amount of work done in the different diyisions. The amount of work required for one credit point may be learned by communicating with the Department of Botany. University of Nebraska, August 1, 1900. CONTENTS General Directions 7 Plant Structure or Histology 31 Structurje and Classification 55 Phjtogeography 78 Synopsis of the Larger Groups of the Vegetable Kingdom 80 Physiology 85 Appendix 101 Glossary 102 GENERAL DIRECTIONS THE LABOEATOKY The laboratory should, wherever possible, be used solely for this purpose. When the class is not too large, the laboratory might be used also as a botanical lecture room. The laboratory windows should be high and wide, and should face the north or the east. West windows are serviceable only in the morning, while south windows are never satisfactory. The room should be furnished with regular microscope tables, having heavy tops and broad, solid supports, placed next the windows. Low deal tables may, of course, be used in their stead if absolutely necessary. The room should contain, also, a microscope case, material case, shelves for books, a set of lockers, a sink, and several A slop jars. good blackboard as well as a convenient place for hanging charts are essentials. THE MICROSCOPE The microscopes should be selected for compactness and serviceability. They should be furnished with two objectives and two eye- pieces, one containing a micrometer. If the microscopes are fitted with double nose-pieces, a great saving of time will result, and the objectives will w^ear longer. In buying micro- scopes, it is much better to buy several simple, me- dium-priced instruments that will do all that is : 8 MANUAL OF BOTANY required of them than to buy one or two high-priced microscopes which are altogether out of place in an elementary laboratory. The following microscopes are recommended by the Department of Botany for use in the high schools and colleges. Bausch & Lomb OA microscope with two oculars, one containing a micrometer, Vs, Ye objectives and double nose-piece, costing approximately f23. Leitz, Stand IV, with No. 2 and 3 ocular. No. 3 and 7 objectives, and double nose- piece, 122.50. The latter may be obtained of William Kraft, 411 West 59th St., New York. In the case of high schools, it is preferable to buy from Bausch & Lomb, simply for the reason that it is not necessary to wait for importation, as is the case with the Leitz instruments. There is practically no difference be- tween the two makes of instruments. LABORATORY EQUIPMENT Each laboratory table should be supplied with a set of drop bottles containing the following reagents alcohol, glycerin, iodin, potassium hydrate, sulphuric acid cone, anilin sulphate, safranin, gentian violet, methyl green, hydrochloric acid. Probably all of these may be obtained from the local druggist, with the exception of the last four which may be bought of Bausch & Lomb. The salts used in making experi- ments with nutrient solutions should be obtained from this company also. Satisfactory laboratory work is impossible without good tools. For this reason it is unwise to use odds and ends in the way of razors, scalpels, tweezers, etc. : GENERAL DIRECTIONS 9 No work should be attempted without good dissecting sets, each set being assigned to as few students as possible. At the end of each working period, the teacher should see that the set is returned in perfect A condition. good hone and strop should be provided, and the students thoroughly instructed in their use and care. The botanical dissecting sets, yellow Bel- gian hones, and good strops may be obtained of Bausch & Lomb. Bessey^s "Essentials of Botany," 7th ed., and Pound and Clements' "Phytogeography of Nebraska," 2d ed., should be constantly at hand as reference books or as txts. In addition, every botanical laboratory should have a copy of each of the following MacDougal's "Experimental Plant Physiology," |1. Sachs' "Text-book of Botany," The MacMillan Com- pany, 66 Fifth Av., New York, |5. Strasburger's "Text-book of Botany," The MacMillan Company, |4.50. Bennett and Murray's "Cryptogamic Botany," Longmans, Green and Co., 15 E. 16th St., New York, $4.15. Britton and Brown's "Illustrated Flora of the Northern United States," Charles Scribner's Sons, New York, 3 vols., $9. Zimmermann's "Botanical Microtechnique," Henry Holt & Co., New York, $2.60. "Flora of Nebraska," Parts I and II. Botanical Seminar, University of Nebraska, Lincoln, f2. Webber's "Catalogue of the Plants of Nebraska" 10 MANrAL OF EOTAXY may be obtained from the Department of Botany for twenty-five cents. Besvsey's "Synopsis of the Vegetable Kingdom,'' a wall chart, may be obtained for fifteen cents. CAEE OF LAEQgATOEY EQUIPMENT The greatest care should be insisted npon in the use of the microscopes. The latter should be kept in a tight case as free from dust as possible. The student should be taught to clean the outer lenses of both eye pieces and objectives with lens paper when the instnuneat is taken out and put away. The lens paper should be clean and must be kept in a dust-free place, such as between the sheets in the back part of the student's laboratory notebook. If the microscopes are new or only slightly used, the student should be re- quired to clean the stand thoroughly with chamois skin or a linen cloth before returning it to the case. If the double nose-piece is used, the student must be taught always to find the object under the low power objective and then to swing the high power into position carefully. Without the nose-piece, the high power should never be twisted down upon the object while the eye is applied to the eye-piece. The objective should be lowered slowly until only a thin line of light remains between the front lens and the top of the cover glass, when it should be raised slowly until the object is seen in the field. In making tests with acids and alkalies, the work must always be done under the eye of the teacher and, as a rule, with the low power. Under no circumstances should any of the acid or GENERAL DIRECTIONS 11 alkali be outside the cover glass. It must be insisted on as an absolute rule that neither eye-piece nor objective be taken apart by any one except the one in charge of the laboratory. The glassware essential for microscopical work is slides, covers, and watch-glasses. In addition, there should be drop bottles for reagents and Petri dishes for materials. Water dishes of glass or stoneware should be kept on the tables. The laboratory should have at least one graduate ruled in cubic centimeters. A slide micrometer is necessary for exact micro- scopical measurements. Large battery jars should be obtained for aquarium purposes. For physiological work, there should be a supply of bell-glasses, beakers, flasks, bottles, test-tubes, cylinders, glass tubing and rubber tubing, the amount depending upon the size of the class. These supplies can be obtained of the Bausch & Lomb Company, Stewart Building, Chicago. BOTANICAL MATERIAL The materials necessary for laboratory work should be collected by the teacher as far as possible. Whereever possible, as much material as is needed should be collected during the spring and summer and preserved in the proper fluid. Ordinary histological material may be put directly into 30 per cent alcohol when col- lected, and trasferred a few days later to 60 per cent alcohol in which it will keep indefinitely. Algae, deli- cate tissues, etc., should first be killed in Flemming^s, the first for 10 to 30 minutes, the second for 1 to 3 12 MANUAL OF BOTANY hours. Algae are best preserved in a 1 per cent water solution of chrom alum, a few drops of formalin being added to each 100 cc. It is most satisfactory to keep algae constantly growing in aquaria, if the latter can be kept from freezing. If the water in the aquaria is aerated every day by allowing fresh water to fall into it from a height of two or three feet, the algae will remain growing for a long time. Wherever a greenhouse is readily accessible, fresh material should be used except in the rare cases where preserved material cuts more readily or shows some point not evident in fresh specimens. The greenhouse, if kept at all moist, will furnish an unfailing supply of Protophytes, in addition to the histological material. Cup fungi, mushrooms, mosses, liverworts, ferns, and horsetails may be readily grown in the greenhouse as well. In case it is impossible to get material for any reason, a complete supply of the materials required in the present Manual will be kept by the Department of Botany. These will be supplied to schools at the actual cost of collection and of preservation. In sending an order for material, indicate the plants desired and the number of students in the class. Address the Department of Botany, University of Nebraska, Lincoln, writing "Supplies" in the lower left hand corner. PREPARED SLIDES Prepared slides should never be used in the regular work under any condition. The student should be taught to make his own slides, the chief value of GENERAL DIRECTIONS 13 laboratory training being in the self-reliance which it develops. Demonstration slides may occasionally be used in connection with the text or lectures, but only in the case of those objects which it is impossible for the student to prepare for himself. In consequence, teachers are strongly urged not to use prepared slides for any of the regular work of the Manual. Slides showing karyokinesis, etc., for the purpose of demonstration, will be furnished by the Department to schools at cost. SUGGESTIONS REGARDING THE COURSE In the disposition of the time which is given to botany, it is recommended that the class-room work be reduced to a minimum. If five hours are given each week, only one or two should be used in the class- A room, and the remainder in laboratory work. single lecture a week, in connection with the texts and readings, will enable the student to follow the labora- tory work to the best advantage. The need of recita- tions may be obviated by frequent quizzes, either in the laboratory or class-room. The really important part of all scientific teaching is actual contact with the things studied, and, in conformity to this, everything else in the course should be subordinated to the laboratory. If the teacher or an assistant is constantly in charge of the laboratory, the lectures should touch upon different parts of the subject after the student has worked over them, completing and con- necting the facts he has seen for himself in the labora- tory. If the student must work alone part of the time, 14 MANUAL OF BOTANY he will usually work to better advantage if he has the lecture notes as an aid. When the amount of time given to botany is only sufficient for the laboratory work, the best plan will be to use the "Essentials of Botany'' and the "Phytogeography of Nebraska" as text-books, following the references to them given in the laboratory manual. At the beginning of the work, the student must be taught how to set up, use, and take care of the microscope, and how to make measurements with the mi- crometer. He must have impressed upon him the need of taking the best care of the instrument, especially the eye-pieces and objectives. He must learn to focus quickly and to find objects in the field at once. He should never be permitted to begin work until he uses the microscope readily, or he will always be handicapped by this inability. Fairly accurate measure- ments of an object may be made by keeping both eyes open when looking through the eye-piece, so that the object may be superimposed upon a pencil held in the hand in such a way that its length or width may A be measured. much more accurate and satisfactory way is by means of an eye-piece micrometer, a small scale usually fastened in the eye-piece. The value of one space of this scale is sometimes given by the maker of the instrument. If such is not the case, it must be determined by the use of a stage micrometer, a slide with one or two millimeters ruled in tens, and one of the latter ruled in ten smaller spaces. The value of a millimeter being 1,000 micromillimeters, the unit of GENERAL DIRECTIONS 15 microscopical measurement, usually designated by the Greek letter mu, /, the larger spaces of the stage micrometer will contain 100 micromillimeters or /, and the smaller, 10 /a. To find the value of a space of the eye-piece micro- meter, determine the number of spaces eye-piece mi- crometer in a certain number of spaces stage micrometer, reduce the latter to />t, and divide by the spaces of the eye-piece micrometer. If 6 spaces of the eye-piece micrometer equal 1 space of the stage micrometer, then x, the space of the eye- piece microm- eter, equals 1 multiplied by 100/^, divided by 6. _. IXlOO = X 7i =16. DW, O The value of the eye-piece scale is found in the same way for both high and low power objectives. The number of diameters of magnification of the high or low power may be found by projecting, with both eyes open, the eye-piece scale upon a millimeter rule placed upon the table alongside the microscope, and by determining the ratio between the two. The ratio between the eye-piece micrometer and the millimeter rule being determined, to find the magnification of high or low power, reduce the spaces of eye-piece micrometer and of millimeter rule to /* and divide the latter by the former. If 5 spaces of the eye-piece equal 6 of the rule, then ijj the number of magnifications, will equal 72. v= "^ 5czx..1-6ia.6n =^'^ diameters. 16 MAXUAL OF BOTAXY In order to draw accuratelv, it is necessarr to know the magiiified size of the object in millimeters. The magnified size is fonnd by reducing the number of spaces of CTe-piece micrometer to mnltiplring the /^s result by the magnifying power, and diriding by 1,000 in order to reduce to millimeters. 10X16.6X72 =11.9 mm. 1000 If each student is required to make out a table such as the following, and to keep it in his laboratory notebook, much time will be saved in working out the ralue of measurements. SPACES 1... 2... 3... 4... 5... 6... 7 8 9 10 ACTUAL VALUE 2-3 2-7 . . . 16.6 ^ ... 33.2 ' ... 49.8 " ... 66.4 ' 2.7 ytx 5.4 . 8.1 , ,10.8 ... 83.0 ' . . . 99.6 " U6.2 ' 132.8 ' ,13.5 ,16.2 ,18.9 ,21.6 149.4 ' ,24.3 166.0 ' ,27.0 MAGNIFIED VALUE 2-3 ANT) 2-7 m 1.29 ni. 2.58 3.88 , 5.17 . . 6.47 . 7.76 9.06 . ,10.35 .11.65 ,12.94 If the object measures between one and ten spaces, its actual and magnified size will be found at once. Above ten, the number of si:)aces may be factored at a glance and the factor referred to the table. The be^t method of work is first to examine the object in the gross, then under the low power, and finally under the high power. As the results of the observation, the notes, are written up, the meas- GENERAL DIRECTIONS 17 urements should be made and recorded. In all eases, the student should be encouraged to write up his notes without the questions and suggestions given after each experiment. He should be taught to observe and think for himself, though at first suggestion will be found absolutely necessary. The drawing should never be begun until the student has made all the ob- servations required. Having found the dimensions of the magnified object by reference to the table, the exact size may be measured upon the drawing paper and the student is ready to begin his drawing. In schools where no adequate instruction in drawing is given, the student should be instructed in making straight lines and curves with a sweeping stroke, and A in fine stippling. poor line or an incorrect one should be erased at once : a second line should never be drawn until the first one is out of the way. The drawing sheet should be loose in order that it may be turned readily in any direction. This is necessary since a sweeping stroke is more easily acquired if the line is always drawn in the same direction. The teacher should supervise, in so far as possible, the making of the first drawings so that the student may not lose any time in having to redraw a completed drawing. After a time the student may be trusted more and more in making independent drawings, always with the understanding that a poor or careless drawing must be redrawn. In those schools in which botany is taught for the maximum time throughout the year, ink drawings may be made with good results, 2 18 MANUAL OF BOTANY but in most schools the extra time demanded by the inking makes it out of the question. The ink used is Higgins' Waterproof Black Ink. It may be used undiluted, giving a black line, or it may be diluted with water fifty parts, making a gray ink, called outline gray, which is especially good for drawing tissues, outlines, etc. Outline gray flows more readily than the black ink, also. The stippling should generally be done with the black. The only good drawing pen is Gillott^s Crowquill Pen, 659. THE NOTE BOOK The laboratory notebook should consist of a history cover TfxlO inches, filled with alternate sheets of drawing paper and note paper. It may be obtained of H. W. Brown Co., 127 South 11th, Lincoln, Nebraska. The drawing page should be arranged to the left, the note page to the right. As a rule, only two drawings should be made on each page. Generally, the notes on each study will require a page so that the drawing page should be followed by two note pages. Nothing should be placed upon the page in addition to the drawings, except the necessary lettering. In the histological work, the notes may be written up without regard to any fixed arrangement, but in the study of plant forms, a definite scheme saves time and aids in making the notes more easily accessible. In the following sample note page, the classification of the plant is given first, followed by a short description of the plant, giving measurements, and then by answers to the questions suggested. GENERAL DIRECTIONS 19 Gloeocapsa arenaria Branch Protophyta : Gr. protos, first phyton, plant. ; Class Schizophyceae : Gr. scliidzo, split; pliykos, seaweed. Order Cystiphoreae : Gr. cystis, sack; phora, bearing. Family Chroococcaceae : Gr. chroos, color; kokkos, berry. Genus Gloeocapsa : Gr. gloios, glue ; kapsa, chest. Species arenaria : L. arena, sand. Plant mass mealy, light blue, 1-3 mm. long; cells globose to elliptical, slightly granular, blue green, 5-7 H; furnished with a lamellose colorless sheath, grouped in colonies of 2-4-8. Growing upon flower pots in the greenhouse. The cells are all vegetative and alike, varying in shape only during fission. The cells are globose for the most part and are nearly homogeneous within, neither nucleus nor plastids being visible. Increase takes place only by fission, each cell elongating from globose to elliptical and constricting at the edge until pinched into two new cells. Compared wdth the ordinary cell of parenchyma, the cell is much simpler, lacking apparently nucleus, plastids, and other cell contents. The etymologies of the names of the various groups, which will be found in the glossary, should be given each time a name is repeated, as they make the names much more serviceable, though they may be left out entirely if they are found to require too much time. 20 MANUAL OF BOTANY DIEECTIONS FOR CUTTING SECTIONS The importance of keeping the razor always sharp can not be over-estimated. The time lost in vainly endeavoring to make a dull razor cut thin sections is much more than enough to keep the razor in excellent cutting condition. The teacher must see to it that razors are kept constantly sharp. The material to be sectioned must be as fresh as possible. With rare ex- ceptions, preserved material should not be used when fresh material is available. The material, whether fresh or preserved, should be kept in cold water when in use. The specimen from which sections are to be cut should be held firmly between the thumb and fore- finger, the latter a little lower, affording a support for the blade of the razor. The edge of the specimen and the razor edge should be kept wet with water in order that the razor mav take hold readilv. The stroke should be started about an inch from the heel of the razor and the latter should be drawn with a long sweeping motion clear through the specimen. Sections should alwavs be cut at a sinsrle stroke, un- less verv lar^^e. The sections are removed from the razor and placed in a drop of water on the slide, and a clean cover is dropped over them. Care should be taken in a temporary mount to avoid bubbles, and water outside of the cover. From time to time water must be added at the edge of the cover in order to pre- vent drying out. The best practice in section cutting is to cut a dozen or two sections into a watch-glass of A water, and then select the thinnest ones. great deal GENERAL DIRECTIONS 21 of time is consumed in stopping to examine each sec- tion as it is cut, only to find that it is too thick. If the sections are intended for permanent mounting, in addition to being thin and complete, they must also A be uniform, i. e., equally thick throughout. com- mon fault of sections is that the edge is turned. This is often due to a dull razor ; sometimes it arises from the fact that the razor is pushed against the epidermis or bark instead of being drawn obliquely. Finally, a thick section should never be used. Thin sections are made only by practice. PERMANENT MOUNTS Permanent mounts of tissues are best made by removing the water by means of alcohol and mounting in balsam. Thin uniform sections are cut into a watch-glass of water. If the tissues are delicate, the sections should be started in 25 per cent alcohol and then changed successively to 45, 60, 75, and 95 per cent alcohol, remaining only a few minutes in each. They are then placed for one to two minutes in 100 per cent alcohol, cleared in bergamot oil for five or A ten minutes, and mounted in balsam. drop of thin balsam is placed in the center of the slide, the section placed in it from the bergamot, and the cover laid upon it. The cover should be started at one edge of the drop and lowered slowly to prevent air bubbles. If the latter form, the cover should be removed and a new one used. As little balsam as possible should be used. If sections of hard tissues, such as woody, stony, etc., are to be mounted, they may be started at 22 MANUAL OF BOTANY once in 95 per cent alcohol. It is usually necessary to leave them in the latter for several minutes, or sometimes even for hours or days, in order that all air bubbles may be removed from the tissues. Such sections should be stained by placing them from 95 per cent alcohol into an alcoholic solution of some stain, preferably safranin, for five to ten minutes. They are then washed in 95 per cent alcohol until clouds of stain cease to be given off, run through 100 per cent, cleared in bergamot, and mounted. Nearly all tissues should be stained if permanent mounts are to be made of them. For woody tissues, safranin is the best ; for cellulose or soft tissues, haematoxylin or methyl green. An excellent double stain may be ob- tained in sections containing both woody and soft tissues by staining them for ten to fifteen minutes in safranin, washing in 95 per cent, staining in dilute methyl green for ten to fifteen seconds, washing quickly in 95 per cent, running through 100 per cent, clearing in bergamot and mounting in balsam. Spores, pollen grains, etc., may also be mounted in balsam, though usually without staining. Algae and delicate parts of plants are best mounted in glycerin jelly. The algae are run through 10, 20, and 30 per cent glycerin and then placed in a drop of jelly on the slide. Glycerin jelly is solid at ordinary tempera- tures and must be kept warm while in use. It is well to keep both slide and cover warm also. The jelly solidifies again on cooling and the slide does not re- quire sealing. GENERAL DIRECTIONS 23 -- PERMANENT MOUNTS PARAFFIN IMBEDDING Paraffin imbedding and sectioning on the microtome require considerable apparatus and are inconvenient without gas burners. In consequence, they can not A be carried on in many high schools. brief outline of the method will be given here, however, for the sake of those schools where it is possible to make use of the paraffin process. The different parts of the process are known as killing, washing, dehydration, clearing, infiltration, imbedding, sectioning, and mounting. Killing stops the activity of the cells quickly and fixes the cell contents so that the subse- quent processes will not change them. Washing re- moves the killing medium in order that it may not prevent ready staining. Dehydration substitutes alcohol for the water of the cell cavity and makes it possible to clear the specimens in bergamot oil preparatory to transferring them to paraffin. Infiltra- tion consists in warming the sections in a mixture of bergamot and paraffin in order to make it possible to imbed them in melted paraffin without harm. The material to be imbedded should be killed in Flemming's solution, a mixture of acetic, osmic, and chromic acids, the length of time necessary depend- ing upon the size of the specimens and the kind of tissue. The root-tips of the hyacinth are killed in 4 to 6 hours, while stems and harder tissues require 12 to 24 hours. The amount of killing solution should be at least ten times as much as the bulk of the material. Washing may be effected by leaving the 24 MANUAL OF BOTANY specimens in slowly running or dripping water for a time equal to that in which they were killed, or by putting the specimens in a large bottle or beaker and changing the water every hour. Root-tips should be started in 10 per cent alcohol and then run every half hour or hour through grades 5 per cent apart, i. e., 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95, and 100 per cent. In the case of harder tissues, the specimens should be started in 30 per cent and run through a series of alcohols 10 per cent apart, remaining in each for Ito 3 hours, depending upon the size of the specimen. When it is found necessary to interrupt the process, the material may be left without harm in the lower grades of alcohol. As a rule, ma- terial should not remain in a grade above 90 per cent over night ; most tissues become hardened and brittle if left in 100 per cent for more than 8 to 10 hours, while root-tips should not be left in it for more than 3 to 4 hours at the outside. CLEARING In clearing, the material is placed in a mixture of equal parts of 100 per cent alcohol and bergamot oil, or part of the 100 per cent used in dehydrating may be poured off and the bergamot added directly to the remainder. With delicate tissues, root-tips, ovules, etc., the specimens are run through four grades containing respectively 20, 40, 60, and 80 per cent of bergamot, remaining 1 to 2 hours in each. The latter should clear in the bergamot over night, which is also sujBficient for harder tissues unless the specimens are quite large. GENERAL DIRECTIONS 25 INFILTRATION Infiltration must be carried on at a temperature of 30� to 45� C. This may be done best by using a water bath, preferably number 3535 of the Bausch & Lomb