©V §. P, pm pinrarg QHT05 kX*UH no BIOLOGY St years in the high ar school work in ires for the more ad- tic science, and the both civic and bio- ts, mammals, fungi. bacteria, fish, amphibia, and reptiles all find a place in this text and are treated in the light of their value or harm to man, in other words, their place 3n the community. Short chapters on the Prac- tical Laws of Life, the reliable sources for informa- tion, and the Progress in Discovery close this timely and stimulating volume, which is nationally repre- sentative. 1 1 • Date Due ^y;H If ■ ■ ■».,»■' iiML^ m~^m^ 1 ! ! A ■/ ■ _ / 1 I / / / ■ / i 1T614 ^ f HODGE AND DAWSON t CIVIC BIOLOGY The pedagogy of the book is excellent. Problems, exercises, questions - all are of the type that arouses interest, pro- vokes serious thought, increases individu- al investigation, and makes the work both in and out of the classroom effective and alive • Dr. Clifton B. Hodge is Professor of So- cial Biology in the University of Florida. Doctor Jean Dawson was recently Head of the Department of Biology in the Cleveland Normal School, and a member of the Depart- ment of Sanitation, Board of Health, Cleveland, Ohio. "s* M J II. ML i. A .MAN MAUI-: i-AllADiSL uK A .\1 A.N -.MADE Ul:.sKKT. U iliCH ? CIVIC BIOLOGY A TEXTBOOK OF PROBLEMS, LOCAL AND NATIONAL, THAT CAN BE SOLVED ONLY BY CIVIC COOPERATION T BY CLIFTON F. HODGE, Pir.D. I'UOFESSOR OF SOCIAL BIOLOGY IN THE UNIVERSITY OF OREGON AUTHOR OF "NATURE STLDY AND LIFE" AND JEAN DAWSOX, Ph.D. DEPARTMENT OF SANITATION, BOARD OF HEALTH, CLEVELAND FORMERLY OF MACDONALD COLLEGE, CANADA, AND CLEVELAND NORMAL school; author of "the BIOLOGY OF PHYSA " AND "BOYS AND GIRLS OF GARDEN CITY ,- *> It will teach only such uses of autlioritj (vs are necessary to secure cooperation of several or many people to one end; and the discipline it will advocate will be training in the dev^lopment of cooperative good will. — Char,les W. Eh^ot. GINN AND COMPANY BOSTON . NEW YORK • CHICAGO • LONDON ATLANTA • DALLAS • COLUMBUS • SAN FRANCISCO COPYKIGHT, 1918, BY CLIFTON F. HODGE AND JEAN DAWSON ENTERED AT STATIONERS' HALL ALL RIGHTS RESERVED 318.10 GINN AND COMPANY • PRO- PRIETORS • BOSTON • U.S.A. PREFACE Discovery is pusliiug forward in every direction as never before in the liistory of the world, and still it would seem that enough is already known to make living well-nigh ideal and the world almost a paradise, if only enough people kne\A-. In how many of our civic units does every citizen know enough to conserve effectively the valuable bird life, the trees, the soil, and water on his own premises, to exterminate the rats and English sparrows, the Hies, mosquitoes, and San Jose scale, the hookworms, diphtheria, and tuberculosis germs? If every individual citizen knows enouo^h to do these thinos, in how many communities do all the people know enough to cooperate, — to work together Avith efforts so timed and planned that the good work of one, or of all but one, shall not be rendered vain bv the failure of someone else to do his part ? The tides and currents, storms and floods, of living nature are too vast and powerful to be held within any dikes less se- cure than those built by the common, united effort of the wliolc community. The measure of our present need is seen in tlie wastage and loss that is streaming through our ineffectual defenses, — the probably not less than five hundred thousand valuable lives sacrificed annually to the currents of prevent- able disease, along Avith the several billions of dollars' \\orth of foods and other property swept away by rats, insects, weeds, and funoi. Mow nuich hicfher nuist the cost of livincj soar before we beo'in to awake from the dream that we are a scientific and elhcient people? As we are now organized iii 17614 iv CIVIC BIOLOGY (or, rather, disorganized J, who knows whetlier his next- door neighbors know what to do in solving common civic problems ? From the way they do and live he may conclude that they do not know, but they may all be passhig the same judgment upon him. So, instead of each one douig his civic part, and knowing that the rest are domg theirs, we are cauo'ht at every turn in the do-less net of '' what 's-the-use- ness." A would gladly protect his birds, but not to feed Mrs. B's cats. C could easily exterminate his own flies, but they continually swarm over from D's filthy premises. And so it Q'oes for the thousand and one civic ]3roblems, — at everv turn the deadly question, ''What's the use?" How can we extricate ourselves from this net ? Co()perative good will is the essential idea m civic biology, as it is in the progress of civilization itself. This means that civic biology consists of all those problems whose solution requires cooperative effort. In the nature of the case we cannot control many of the forces of livnig nature by any amount of uncoordinated individual effort, any more than we can turn back the ocean tides by haphazard sweeping with brooms. The problem of civic biology, therefore, is to make it possible for everyone to know what these forces are, for good or for ill, and to understand how to do his part for his own good and for that of the community. Cooperative build- ing of the defenses offers our only hope of success, and our education needs to be so organized that every citizen shall know enough to stop a breach the mstant he sees it. Acknowledgments in the text accompany pictures and other contributions, except in the following cases : The figures of ticks, in Plate IV, are rearranged from those published by the United States Department of Agriculture and the United States Public Health Service. The upper view in the frontispiece is taken from a photograph looking northward PKEFACE V down tlie Hood Kiver valley, Oregon, across the gorge of the Colnnibia, witli ]\Jt. Adams in the background. It is used by the courtesy of the United States Reclamation Service. The lower view is from one of Bailey AN'illis's photographs of Shingkung, China, and shows desert conditions, man-made within the short space of about the last two centuries. With complete deforestation of the mountains, the once fertile valley has l)een buried under the wash of floods, which, alternating with burning droughts, have made the country uninhabitable. We are indebted for use of the print to the Carnegie and Smithsonian institutions. The idea of the book is expressed at a glance in the fron- tispiece, the question. '' AMiich ? " being applicable to every landscape and home in the world. C. F. H. J. D. CONTKNTS CHAPTER J AGE I. Plan of the Course as a Whole 1 II. Equipment, Apparatus, .\xi> Lihrary 1(» III. The Insect Problem !>> IV. Birds L>:] V. Methods of Bihd Sti dv and Si'e< iai. ri; VII. Plant Problems : Preservation «>i \\'ii.d Flowers, Control of Weeds, jNIedicinae and Poisonous Plants <37 VIII. Home Planting a.nd Landscai-e (tardeninc ... 77 IX. Practical Biol!• XVII. The R.vt Problem 178 XVIII. Fungi: Bacteria, Veasts, Molds. Mm.df\n>. Pes is. Smuts, and jNIushrooms ls<> XIX. Fungi Continued: ^Mushhoo.ms, Poi>(»noi > am> Edible -'*•' XX. Fungous and B.vcteiiial Dlskasfs of I'lanis 207 XXI. Bacteria -'!« XXII. Bacteria Continued: LAMoh-AroRV Methods . . -"Jl vii viii CIVIC BIOLOGY CHAPTKR PAGE XX ill. ('<>NTi:<>I. <».'• ICVCTERIAL DISEASES 231 XXIW CoNTKUL OF A.MMAL PaKASITES 253 XXV. Civir PijoHLEAis Relating to Mollusks .... 271 XX\'l. Crustacea 285 XX\ ir. rnoBLEMS OF Fish and Fishing 295 XX^'JI^. Ami'huua : Sirens, Pkoteans, Salamanders, Frogs, Ti;ee Frogs, and Toads 313 XXIX. Reptiles: Crocodiles, Alligators, Turtles, Ter- rapins, Tortoises, Lizards, Snakes 321 XXX. Practical Laws of Life 330 XXXT. Knowing How to Know How 316 XXXI 1. Phogress in Discovery 355 INDEX 363 Working together will be one of its fundamental ideas, — of men with God. of men with prophets, leaders, and teachers, of men with one another, of men's intelligence with the forces of nature. It will teach only such uses of authority as are necessary to secure cooperation of several or many peo- ple to one end ; and the discipline it will advocate will be training in the devel- opment of cooperative good will. — Eliot, " Religion of the Future,'' p. 22 Physical forces^ or the exhaustion of purely physical resources never have, and for at least five million years in the future, so the astronomers tell us, cannot extinguish human civilizations. Floods or volcanic eruptions may cause small and local effects ; while biological forces are oceanic, subtile, all- pervasive, continuously active, ever ready, whenever a break in the vital defenses of knowledge occurs, to surge in and obliterate individual, nation, civilization. Even the great movements of human races, conquests and wars, are not so all-annihilating in their effects as the ceaseless struggle of man- kind against other living species. Disease, pestilence, plague, and famine have taken their millions to war its scores. These forces are so powerful, so vast in their sweep, that for one individ- ual to attempt to cope with them is like Mrs. Partington trying to sweep back the ocean with her broom. Our education must be so organized that each may know and do his part. It is not labor, not capital, not land, that has created modern wealth or is creating it to-day. It is ideas that create wealth, and what is wanted is more ideas — more uncovering of natural reservoirs, and less labor and capital and land per unit of production. . . . Muscular effort can be stimulated by the lash — intelligent supervision, intellectual production, never ! One single idea may have greater value than all the labor of all the men, animals, and engines for a century. The age of muscular human effort and of the lash is passing away, and the old morality with it : the age of supervision, of cooperative stimulus, is in full advance ; and with it comes a new morality, under which the Golden Rule can be ex- tended from the relations between individuals to those betw^een classes, nationalities, and races. ^-Emerson. '^ Twelve Principles of Efficiency," pp. X and xi CIYIC BIOLOGY CHAPTER I PLAN OF THE COURSE AS A WHOLE Motto of the course : "Tliat we may know enough to work together.'- United effort is the central idea in civic organization, and its extension underlies advance in livilization. Civic biology consists in that group of problems in the control of living nature to solve which requires that a community unite in working; together intellio'entlv. Tliere is a laro-e bodv of such problems which must be made a vital part in the edu- cation of every citizen, for in no other way can they ever be solved. We are suffering enormous losses, — in destruction of nat- ural resources, in unfruitful lab(^r, in damage to property, in preventable disease, — due to lack of proper civic organiza- tion. One ignorant or careless member of a community may kindle a forest fire, or clear a watershed that will cause a water famine over an extensive territory. lie may permit insects or vermin to breed, or allow fungi or l)ai:teria to grow, that will cause great damage to proj)crty. and disease and even loss of life among his neighVxu-s. It is a slight matter to extinguish a match or a camp fire ; it may require the strenuous efforts of thousands to cope with a burning forest. So with every memlx-r of a connnu- nity cooperating intelligently, slight effort may achieve great results, utterly impossible unless all work together. furonr ubrart H. C »«te CoUete 0 Cl\ iC BIOLOGY As an illustration, take the case of the common rat. These animals are probably costing the country $500,000,000 annu- ally in spread of disease, in damage to buildings, merchandise, and produce, and in cost of traps, poisons, and labor; and since bubonic plague has gained a foothold in America, they positively must be exterminated. A smgle pair may breed Fig. 1. Kats. where they all belong 1 250 rats in a year. As we are now doing. Smith attempts to rid his premises of the pests in October, driving many of them over to Jones. Jones undertakes the work in November, driv- ing them back to Smith, and in December both are practically where they were before. The same amount of effort, properly coordinated, might have proved effective. This principle ap- plies with added force to larger groups, and it is quite possi- ble that with even less expense and labor than is now almost PLAN OF THE COURSE AS A W IloIJ-: 8 wasted annually, the rat could be exterminated hoin tin- continent within a year ov even within a sinolc month. Civic organization applies not only to the control of injuri- ous forces, but ecpuilly to saving valual)le species from exter- mhiation. Lacking such organization, a numl)er of species of great value have already been extermniated from vast areas, and several more are in immment danger. A few of these, Fig. 2. Virginia deer Photograph by George Shiras chiefly among our game birds and game and fur-bearing animals, will receive attention in tlie appropriate chapters. At best, among the great nunil)er of such prol)lems, we shall be able to study only a few typical ones that touch the life of the comnnmitv most vitallv. Three or four insect tvpes are all we shall have time for, but tlu^usands of others may be studied by similar methods. The purpose of the course is thus to cultivate habits of observation, insights into the work- ings of living nature, and, above all, civir ways of thiidN'ing and civic methods of studyhig and of attacking sueh [)roblems : and 4 CIVIC BIOLOGY the highest product of the course will be citizens who know enough to work together. Select the problems that your community needs to have studied most. A single problem actually worked out to a definite civic advance will be worth more educationally than a hundred problems memorized from a book. With the school year arranged as it is, it will be neces- sary to start many different lines of work in the early fall. A store of material must be collected for use during the winter, and as far as possible this should be done by the class, — to give practice in collecting, insight hito problems, and at least glimpses of the various forms in their natural environment.^ In order to collect intelligently and plan and organize the work of the year, first run tlii'ough the book rapidly and copy into a pocket notebook the names of all the birds, insects, fishes, trees, and so on, described in the text. Estimate im- portance of topics and leave required space for notes between the names ; page and make an alphabetical index at the back of the notebook. This gives a place where every observation made during the year may be recorded and referred to in- stantly when wanted. Indent margins, date and space so that each note shall stand out clearlv. Records at the end of the year may read about as follows : ^ White Pine (Pinus st7'ohus) Sept. '■]. Noted on a trip into the conntry that the squirrels were cutting quantities of the cones from the tops of the pine trees and were feeding on the ripe seeds. The cones were closed and green, but the seeds were brown and ripe inside. Gathered nearly a bushel and spread on papers in the attic. 1 This outdoor work is such a vital part of the course that careful record should be kept of all types collected, and this should be understood to form the basis for a definite percentage or part of the pupils' required standing-. ^ A field notebook with printed index and topics is being planned ta accompany this course. 1*LA:s of THK C'i^lKSE AS A WHol.E Jan. 10. Found cones dry and wide open, with many of tlie .seed.s fallen out. Brought enough to laboratory to supply the clas.s.' Fkh. 22. Planted in a flat, 10 by 15 inches, -i inches deep, 200 seeds, with the wings intact. The flat was filled witli leaf mold mixed with sand, and seeds were planted alxuit ^ inch dr(|.. March 15. Seeds beginning to germinate (Lab. Book, [». 77). April 10. Made a seed bed according to directions in Forest Service Circular 67, and planted all the seed T had left. Trani^planted seedlings not used in laboratory into this bed. Fh;. .3. Type collection, white piue 1 It is supposed that this pupil undertook to .supply the chiss with speci- mens of the white pine, other members of the class doing the same for other trees. References co tlie laboratory book mean that on pages 77 and 78 will hr found drawings of the specimens, — the leaf bundle, with possibly a sketch of a tree, the cone, the cone scale with the .seeds in place, the seedlings in two or three stages of germination, and finally the flowers. He will also be able to tell the class about methods of collecting, storing, and planting the seeds. 6 ri VIC BIOLOGY May 7. Buds begimiing to shoot. Seedlings coming up thick. June 8. Collected blossoms, staminate and pistillate, together \Yith cones one year and two years old on same branches (Lab. Book, p. 78). Seedlings 3 inches higli. Estimated that there are 5600 in my seed bed. The Humming Bird {Trocliilun coluhris) Sept. 6. Seen daily about cannas, nasturtiums, etc. Sept. 12. Saw last birds, I think. One alighted for a moment on bare twig and flew south. Oct. 8. Found deserted nest while picking apples (Lab. Book, 1..14). May 14. First arriYal seen this spring, and first reported in class. Grape {Delaware) Sept. 9. Selected as specimen to study a Delaware planted by myself six years ago (Lab. Book, p. 42 ; sketch of vine, size of stock, area of trellis covered, drawing of cluster and leaf). (Tarnered grapes, 42 pounds in 12 minutes. Nov. 3. Pruned vine 15 minutes. Buried a bushel of bones about roots (Lab. Book, p. 43 ; diagram of vine after pruning). April 27. Buds beginning to shoot. ]\Iay 15. Placed a cane 6 feet long in trench 3 inches deep, for layers. JrxE 19. Blossoms open, new shoots about 2 feet long. Codling Moth (Carpocapsa pomonella) Sept. 21. Examined 100 apples and found i)2 wunn-eaten. Found 15 larva? in the apples; the rest had completed their growth and gone. Where did they go ? Sept. 22. In one hour's search, scra})ing apple bark, found 163 larvae in their cocoons under the bark scales. They must have gone there when they left the apples. Nov. 28. Observed a downy woodpecker at work on apple tree. From 8 to 8:15 saw liiiu drill into 5 bark scales and remove PLAN OF THE CULKSE AS A WiioJ.K T the larva'. Cliiulxd u[i and secured tlie punctured scales for my collection. At this rate how many mi^ht a woodjM'C'kcr eat in a year? Wish I could follow him and discover iiow many he actually destroys in a day. Put niai row hones and suet in the apple trees to attract woodpeckers to the orchard. Dkc. H. Ref(>r to Lah. I>ook, p. -11 (sketch of larva, etc.). April 12. Hunted one hour again for larvae; found only 8, l»iit have observed the woodpeckers working on the trees all winter, and counted 17!» [»unctured bark scales from which the larvae had been removed. Those found were still in the larval stage. May 1.5. Apple trees in bloom. Hunted one-half hour: found 1 larva and 2 ])U]>a' (Lab. liook. p. 42). June 11. A[tples about the size of marbles. 8 v.m., hung a lan- tern in a tree where apples were thickest. Caught a moth in act of laying an egg on an apple. As I raised my net to catch another, a bat flitted by and snai>ped it. Tried to catch bat but he was too quick for uie. The main laboratory for this course is the out-of-cloors, — the yard, garden and orchard, streets and roadsides, pastures, fields, woods, streams, lakes, hills, and s\\ani[)s. Thousands of interesting things are happening out there all the while, and it is there the student must go if he would really U-arn his lessons. AVith definite assio*nments of what to seek or to study and observe, most of this field work should ])e done either singly or in small groups of two or three. In addition to this tliere should l)e individual [)robk'ni-woi-king and lesson- learnhio" fur discussion and demonstration of the nu)re ueneral problems, such as the study of habitats: tlie struggle for life as seen in a dense woods; the distribution of a number of the types studied in the course; migration of birds; recog- nition of trees, birds, conunon plants. A numlu'r of s})ecial field tri})s also should be ari-anged. The success or failure (d' these will depend upon the teacher's know ledge of the locality 8 CIVIC BIOLOGY and of the times and seasons for the appropriate lesson.^ The course supposes at least seven tield excursions : two in the fall, for general outlines ; one in dead winter, for recognition of trees, study of animal tracks and doings, winter birds, hiding places of insects ; and four in the early and late spring. In these excursions plan to take in a model dairy, vineyard, orchard, nursery, tuberculosis sanitarium, fish hatchery, bird sanctuary, or other local institutions of mterest. Fall is the most favoral)le season of the school year in which to study insects and to begin the stud}^ of birds. The largest share of the time usually spent in " learning " lessons out of books or in the indoor laboratory will be devoted to collect- ing and studying specimens out of doors. Hunt particularly for the species required by the course. There are so many thousands of different insect species that you will soon find yourself bewildered and discouraged if you try to study them all. Any insect of special importance in your locality, however, may be substituted for those m the course, if de- sired. Collect, so far as possible, the complete story of the life and work of each species, — eggs, larvci3, pup£B and adults (male and female), injured fruit, eaten leaves, stings, galls, and the like. While working over the ground for insects it will require but little additional time to collect the materials for several other Imes of work to be done in the laboratory during the winter. Among the more important will be : Leaves aud fruits of forest trees. Fruits and seeds of common plants. AVeeds and their seeds. Common mushrooms and tree-destroying fungi. As many as possible of the parasitic fungi described in the text, — mildews, blights, rusts, and smuts. 1 It will often be necessary for the teacher to keep careful watch and go over the ground himself the day before a general field trip. PLAN OF THE COURSE AS A WIIDIJ' 9 Deserted Mids' nests for study of uesting sites, and aiialy5.is ui nuiLe- rials. Attach a label to each nest, statiuft- locality and ]>ositi()n. kind of tree, distance from ground, et<*. Fresh-water clams and snails, with duckweed, miliuil, stoui'wort. and other aquatic plants common to the locality, for use in stockini; aquaria during the winter. Fronds of all the common ferns, fruiting and sterile, 'i'hese should be pressed between sheets of paper and pr<^served dry. The ants' nests must be stocked as early as jiossible, and may br maintained through the winter. It is not advi.sable to try to keep frogs, salamanders, newts, turtles, snakes, or many fishes in the laboratory during the winter, since their normal period of hibernation will be interfered with and they ai-e not likely to do well. These may all be collected and .studied to betU'r adyantage in the spring. III general, the order of elia[)tei'S follows that hidicatt'd above: insects and birds with beginning plant lessons in the fall; fungi, bacteria, and animal parasites for nidoor work durmg the whiter; fishes and amphibia in early spring; and the emphasis on plants with the completion of bird and in.sect studies in the later s})ring months. A natural eoncdusion of the course is supplied by a brief statement of the principles and laws of life with an outlook toward the l)iological organ- ization of the nation. At best, with so many interests weav- ing a continuous pattern through the changhig life of the year, the text will need to be used as a reference book rather than as a series of consecutive lesson.s. CHAPTER II EQUIPMENT, APPARATUS, AND LIBRARY Laboratory outfit. Equipment for the more special problems will be described in appropriate chapters, but there are a few general needs which should be understood at the outset. First of all, the course demands more than usual individual storage room for students' material. Each student should have not less than 6 square feet of shelf, closet, or locker space. This will be supplied by a simple wall case 1 foot wide, 18 inches deep, and 3 feet tall, with three shelves about 9 inches apart. The student must be given time to label and store his speci- mens neatly, smce any appearance of "rubbish" about the laboratory is likely to prove fatal to the 7norale of the Avhole course. The laboratory should be provided \\\i\\ at least two good- sized aquaria and two vivaria. A convenient size for all of these is 24 inches long, 12 inches wide, and 15 or 18 inches deep. They may all be made according to directions given below for aquaria and then be used either as aquaria or viva- ria. Each student should have also a small aquarium, — about 12 inches deep, 10 inches long, and 6 inches wide, — which may be used nearh' dry, for insect-rearing cases; moist, for salamanders, toads, frogs, and tree frogs ; or filled with water, for fishes and other aquatic animals and plants. By partially filling such aquaria with loam, sawdust, or sphagnum, covermg the outside closely with black paper, tilting slightly, and plant- ing different seeds close against the glass, they may serve for mterestmg demonstrations in germination and the development of root systems. 10 EQUIPMENT, APPAKATL'S, ANi) LiJUiAKV 11 Individual apparatus. In cuMilion, the outlit of each stu- dent should contain the tollowhig: one insect net, one small scrim net for collecting in water, one cyanide hottlc <>ne paper of assorted insect phis, one do/cii insect-mount intr cuses (assorted sizes), and two notebooks (one pocket size for lield notes and data of field collections, the other lar^-er, unruled. Fig. 4. ]\Iaking insect nets for laboratory notes and drawings). 'Hiese should be [)aged and hidexed for quick reference from one to the other. A vital feature of the course is the making of simple ai)pa- ratus by the students themselves. Since lime in the fall is so precious for outdoor work, the necessary apparatus should be provided to begin \\ith, but after the iirst year it should ])e made by the })revious class ; that is, each (dass should take a turn at making apparatus during {\\v w inter in order that the laboratory m ly be well equipped for the work of the fol- lowing autumn. Since it is to be ho[)c(l that the students will u CIVIC BIOLOGY continue the study after the course is completed, it would be well if each could be given tlie chance to make at least the two collecting nets and a small aquarium for himself. Materials for making the nets. Flat-drawn spring brass or tinned steel wire for the frames for the air and water nets respectively ; the strong- est cotton tape (mill tape, such as is used in wra])j>iug- electric wires. Fig. 5. Easy construction of insect net 1, form of wire frame ; 2, slipping net on frame ; 3, net bound to handle with twine is good); then for the air nets, strong hobinet, light cheesecloth, or mosquito netting, according to preference. Mosquito netting, if the threads which cross run the long way of the net and care is observed to avoid water and briars, makes a fairly serviceable insect net. For the water nets use cotton" scrim. There are several ways of making the nets, but for nets detachable from the handles the writer has found the method shown in Fig. 5 most serviceable. Materials for aquaria. The aquaria may be made for little more than cost of glass, the materials being : EQUIPMENT, APPARATUS, AM) LH'.KAKV 13 Glass. Doublo-tliifk window glass lor sides and ends, and rilibed skylight glass fur bottom for sizes al)ove 20 x 10 x 12 inches. For smaller sizes, waste 10 x 12 in. negatives arc good and cost little or nothing. Angle or valley tin, sizes indicated Im-Iow. Aiiuarinm cement. Solder. (ireen or l>lack carriage paint and a little .spar varnish. Fig. (i. Making aciuaria From left to right, laying the cement; glass set in ..lie. with li.-iit .^reeu twigs to liold it in place; painting frames, and frames ef different sizes, 5x7x4 to 24x15x10; cutting the angle tin to measure: solderini; tlie frame hel-l in a square fa.stened to table Tools. Every laboratory should !•.■ provide.! with a few simple I.k.Is, among which the following will V)e reipiired in making atpiaria : Carpenter's sqnare,— to hold the frame perfectly scpiare at each angle while it is being soldered. .V three-way S(inare, ma.le by miiling two 5-inch boards of convenient length at exact right angles aii.l fa.-^ten- ing them to a work table, greatly facilitates getting each angle right at the first trial. 14 CIVIC r,lULOGY Tinsiinth's snii)S and square-nosed pincers, for cutting and bending the ani;le tin. A soldering outfit, — soldering iron and fluid or resin, and some safe and convenient means of heating the iron. If the tools are not at hand, the frames may be made at the tinsmith's ; or often a handy janitor can make them in his shop, or a good-natured one may let the boys use his tools, if they are very careful to leave every tool in its place and the shop in better order than they find it. Dimensions for the frames are given in the table below. " Three- cross " tin is heavy enough for all smaller sizes, and " four-cross " for % Fig. 7. Showing relations of frames, cement, and glass in aquaria, of different sizes a, for the larger sizes; b, for smaller sizes: c, arranacement at top and cover. Black lines, metal ; flashed areas, glass ; dotted surface, cement aquaria between 15 and 24 inches in length. The more slender the frame the trimmer and better the aquarium api)ears. For aquaria-dimen- sions in inches : 5 X 7 X 4 to 8 X 10 X 5 : use |-inch angle tin. 10 X 12 X 6 to 8 X 10 X 5 : use i-inch angle tin. 15 X 12 X 8 to 18 X 15 x 0 : use f-inch angle tin. 20 X 12 X 0 to 24 X 18 X 12 : use 1-inch angle tin (around base, and if the work is carefully done, |-inch, or even i-inch, is strong enough for the rest). Fig. 7 gives the relation of cement to the angle tin and the glass for large and small sizes. In the larger sizes the strip of glass, with the EQUTPMEXT, APPAKATrS, AND L1I•.KA1;^■ ].'> prism of cement behind it, strengthens the angh* and also i»r<)t<*cts the water from a large surface of cenuMit, Nvhich iiiiglit yield up cnoiigli of its lead to injure delicate animals. Lids may be made either of perforated tin, with the edges turned over to stiffen them, or of wire screen fastened to either wooden or tin frames. The lids will be needed when the acpiaria are used as insect-breeding cages and for feeding tests with toads, frogs, or otlier insectivorous ani- mals. Tlie hinges of brass or tin should be soldered to the frames when they are made. Tliese points are sufficiently illustrated in Fig. 7. Aquarium cement. The f(M-mula used l)y the United States Fish Com- mission is: by weight 0 parts whiting, 1 }>art red lead, 1 }>art litharge; mix thoroughly while dry, and as required for use make into a stiff putty with pure linseed oil. The oil must Ix^ free from any trace of adulteration with fish oil, or the cement is likely to remain soft and sticky. Do not expect the cement to "set" hard. If it did this, the expansion and contraction, under changes of temperature of metal and glass with which it is associated, would be likely to crack either the glass or the cement. It should remain as a tough gum, solid enough to support the pressure of water and })liable enough to accommodate itself to changes of temperature. Lay the right amount of cement in all the angles of the frame with a putty or case knife, and press the glass for bottom, sides, and ends into place in the order named ; smooth all joints on the inside, removing any extra cement ; spring plialde green twigs against the sides and i^iuh to hold them in place, and smooth up the outside joints. It is prefer- able to paint the frame, letting the paint dry well, before setting the glass. A coat of spar varnish along the angles on the inside will protect the cement from contact with the water and also insure against leaks. Leaks seldom occur, but if they do, mark them, dry the aquarium thoroughly, press a little cement into the cracks, and give another coat of spar varnish to the inside corners. After drying for a week, tlie a(piarium is ready to use. Note. It is easier to avoid daubs of cement than to clean them off tlie glass. The same applies to liands, clothes, tables, tloors. and everything else. A class in aciuarium-niaking can easily eks. Insects Injurious to Fruits. ScioDErw Everyday Butterflies. *S-MiTH. Our Insect Friends and Enemies. Birds *Ba 1 LE V . Han(11)ook of Birds ( )f rhe Western United States. *CiL\i'.MAN. Handbook of Birds of Eastern North America. *Reed. Bird Guides. Tart I, Water and Gam e. Part II, Land and Song Trees — Forest ri/ *Ai-(.Ai;. Trees nf the Nortliern United States. *Green. Principles of American Forestry. General Botany *Beuoen and Davis, Principles of *Osteriiout. Experiments with Botany. Plants. BitiTTON and Bhown. Illustrated *Stevens. Illustrated (iuide to Flora of Northern United States, Flow^ering Plants. *(ii{AY. New^ Manual of Botany. FHlUji ^^'estern Bird Guide (for west of the Rocky Mountains). *Trafton. ^Methods of ^Vttracting Birds, AVeed and Deakhokn, Birds in their Relation to Man, Sak<_.knt, ^lanual ot tlie Trees of North America. Atkinson, Mushrooms. *CoNN, Bacteria, Yeasts, and Molds in the Home. *DuGGAR. Fungous Diseases of Plants, GoituAM. A Laboratory Course in Bacteriology, *JoRiJAN. General Bacteriology. McIlvaine and Macadam. One Thousand American Fungi. Russell and Hastings. Experi- mental Dairy Bacteriology. THK LAr.()i;ATnl:\ l5(M)KSlli:iJ . \t/viruUun' *BrHKKTT, Stkvkns, ami llii.i.. Agriculture for Beginners. Cyclopedia (if American Atirieultuii-. \'()1. 1, Farms. *V()1. II, Crops. *V()1. Ill, Animals. Vol. IV, Farms and the Connnu- nitY. *IIoi'Ki.N>. Soil Fertility and I'ti manent Agiieulture. *KiN. WiiEKLKic. Ants. Joiirnnh Agricultural Department publit-a- ^American Forestry. tions. *Experiment Station Beeord. *Monthly List of Publications. *Weeklv News Letter. ^American Journal of Public Health. *Bird Lore. *Journal of Economi<' Eutomol.t^^y. *Journal of Heredity. *Journal of Agricultural Research. *School Science and Maihrm:itics. 1 " Civic Biology '" presupposes a knowledge of tlie problems stated in thi.s ■ MM IK. CHAPTER III THE IXSECT PROBLEM Work of insects in nature. Geologically the present is known as the age of man, but zoologically it is the age of insects. There is but one species of man, — Homo sapiens, — while over 300,000 species of insects have been described, and it is estimated that in all there are not fewer than 10,000,000 species in the world. The number of individuals of any one species may cover the forests and fields or even darken the skies over large areas. Compared with other animals insects are small, having developed, instead of size, refinement of mechanism and organ- ization and great reproductive power. This latter often sur- passes belief, but since it shows us the importance of natural checks to the increase of insects, it must form one of the central features of our insect lessons. A pair of San Jose scales could produce progeny in a season to the number of 3,216,080,400. A single female plant louse might give origin to 9,500,000,000,000 in a season (Forbes). The house flies of a city, if all tlie young survived and could find food, would bury it before the people could escape (Jordan). We are led from these facts to see the importance of insectivorous animals ; for example, it has been estimated that the birds of Nebraska consume dailv 86,000 bushels of insects durino- the warm months (B runner). No insects are used for food by civilized man, and it is remarkable that in so great a number of species so few^ pro- duce anything of value to man. Silk, honey and beeswax, shellac and cochineal, and cantharides virtually complete the 18 TlIK INSKCT 1M;(H'.IJ-:.M 1(» list of iin[)()rtant products. Many insects arc ol" great value to niau indirectly, because they destroy other hisects. The ui-j-cat- est service, however, which they perform in nature consists in effecting cross-pollination of flowers, and many of <»ur most valual)le fruits and flowers would be infertile without tlieir aid. Fortunately the honeybee is the most valuable insect for this work. In contrast to the value of tliese few insects, however, is the great injury done by others hi their attacks ui)on man and animals, causing annoyance, suffering, and often disease. 'J'he majority feed upon plants and thus compete witli man, directly or indirectly, for the vegetable food supply of the world, lie- cent estimates of the Department of Agriculture divide this damage as follows : Annual Loss of Agricultural Products causkd in Insects IN United States Cereals $-2:{7,S00,()n0 Ilay r,(i,()U0,0(M) Cotton (J 7,500,000 Tobacco (),900,OO() Truck crops (JS,000,000 Sugars (1,400,000 Fruits ()(),000,000 Farm — Forests 15,000,000 Miscellaneous crops 18,000,000 Animal products '2(>7,O00,0O0 Natural forest products l:iO,000,000 Products in storage 100,000.000 Total $1,OU>,50(),000 These estimates are conservative and relate to purely agri- cultural losses. They (h) not include the damage caused by common household msects, — clothes moths, carpet beetles, roaches, ants, and several human parasites, which entail great labor and expense in lighting them. Tlie annual cost of wire 20 CIVIC BIOLOGY screen to keep flies and mosquitoes out of houses amounts to at least §12,500,000 annually. Nor does the above estimate take account of the depreciation of property, loss of time, and cost of diseases like malaria or yellow fever, known to be car- ried by certain mosquitoes, infantile paralysis, carried by the stable fly, and typhoid, cholera infantum, dysentery, and many other filth infections which are transmitted by common house flies. With tliese additions it is safe to say that insects annu- ally levy a tax of not less than $1,500,000,000 on the people of this country, and this in addition to the annoyance and sufferino- which thev cause to human and animal life. Work for control of insects. Shice insects possess such power of rapid incrcLise, and since this increase is limited mainly by food supply, natural enemies, and artificial means of destruc- tion, any relaxation of natural or artificial checks tends to permit insects to increase up to the limit of food supply. AVith these checks entirely removed, insects would take practically the entire agricultural product in an incrediljly short time. The relative efliciencv of natural and artificial checks is well exemplified by a number of cases in which an insect has been accidentally introduced from some other continent with- out bringmg the natural enemies of the species. The cottony cushion scale of Australia swept over the orange groves of California Hke a consunnno- fire until its natural enemv, the Vedalia lady ])eetle, was imported. The gyp^y and brown- tailed moths in Massachusetts show even more clearly how ineffectual human effort is when pitted aganist such forces of nature. After expenditure of several millions of dollars and twenty years of futile effort we are l)rought to realize that our best hope of permanent success lies in the importation of natural insect enemies. The San Jose scale, accidentally in- troduced from Chma, is now rapidly exterminating fruit orchards and ornamental trees over almost the entire country. In 1901, Dr. Marlatt succeeded in importing a Chinese lady Tin: INSKCT n;(U;LEM lil beetle (^Chilochonis dmiUx), which is ('I'licioiU in kec[)iiij^f \\w scale in cheek in its native lioniu. li has not ms xcX proved, however, an equal success in Anii'rica. Other cases in point are the Hessian llv, cahija^r hniltTlh-, codling moth, ehn-lcaf beetle, iniporte{ ol' tivi* yoiiii;,' five days old — 2W insects, most of tlieiii lurq;e cal)!)!!!!:*' ratillars; time, 4.24 A.M. to 7.^}8 p.m. A pair of orchard oriides, from 4.:{() a. at. to (i.lo r.M., wen- ohsrrvcd to feed the nest, containing;- two nearly t'iill-lh*d,t>('d yoim.n. '»•' tinn-s, prohahly several insects at a feeding. .V [lair (»f jtlioebes, from 1.2(1 a.m. \<> T.l'J I'.m.. fed two young 'J«i'i times. A vonng ])h(el>e just out of tin- m-st rfi|iiin'd as liigli as '2i^*^ good-sized grasshoi)i)ers \h'v day.' A vonng rohin ahont three weeks ohl ate 7'> large cutworms on on«- day, and two and a half ounces of earthworms the next. A y<»ung scar- let tanager ate 150 cabbage caterinllars. liesides otlier food, in a .lay. A cuckoo on the tenth day ate 42 grass- hoppers, no woolly cater- jiillars, and:)l> cal)bage cat- erpillars. On the twentieth day the same bird consumed ()2 woolly cat- erpillars^ 12:} cabbagecater- ^,^^ ,^^ Bobwliite chick tliree weeks old. Usual occupation l>i liars, and 4:} ^, , , ., ., ^ , Photdiiraph l»v the author grasshoppers, amountinu- to tiiree ounces of food. An adult cuckoo ate 22.') cal»ltage caterpillars, or 1 .")() large woolly caterpillars, amounting to about five ounces of food daily. (From feeding t»\sts by Andrew .1. ricjinou.) From sucli actual data as these we learn that the estimates given above are conservative. Much more accurate ..bservation is rcpiired. however, before entirely reliable estiuuites can be made. Outdoor laboratory work. '1 bis siiouhl extt'iid tbr«)ii<;lH>ui the year, and also to coiiibhR' i)i(>l)li'ins irciuirini;- conlimums lAll the above data are taken from reports of students of the huliana University Summer School, Winona Lake, Indiana, for 100.-> and l'.>0«5 (O. P. Dcllingcr in charge of clas.s). 26 CIVIC BIOLOGY observations upon birds, insects, trees, fungi, weeds, native flowers, and common plants, elaborate the following plan as early in the year as possible. Let two students combine upon the same tract of land, in order to secure greater completeness of the f)ractical work, but each should make his own field charts in as careful detail as if he were working the tract alone. Select some readily accessible piece of land of limited area. On a farm, the home lot with the dooryard, garden, orchard, and grove will be most suitable. The village lot of an acre or two is exactly adapted to this work. In an open city the home lot, if well planted, may prove the best selection we can make, but probably the residential block in which the home stands will provide necessary variety and scope. For the crowded city we must have recourse to public parks and gardens, and to accessible tracts in the suburbs, for the study of which defi- nite permission can be obtained. The tract should present, if possible, a variety of natural features, — hill, meadow, ravine, brook or edge of pond, and especially variety in plant forms, — lawn, garden, orchard, field, meadow, woods. A variety of shrubbery and low-growing trees makes a tract preferable to one with very tall trees, which are difficult and unsatisfactory to work. By properly dividing the neighborhood among the class, however, all the important features of the locality may be covered, and this will add interest and completeness to the work as a whole. As a preliminary, draw an outline map to convenient scale, and with due regard to points of the compass. Within tliis, first sketch in standard contour lines and indicate location of water, marsh, swamp, rock outcrops, and all buildings and superficial subdivisions, — lawns, gardens, orchards, fields, pastures, woods. We are now ready to plot the details. Count and locate all the trees, vines, and shrubs, and indicate clearly the areas cov- ered by different plants or crops. Locate all birds' nests and STREET Maples / »■ 10 0 , Pear y ,. ^^ f^ ^ (^ ■^ C$ c^ Peach '^ 0? C* *» Of Q V ;.-i ! 1 ^ ,*^ -. .^ Martin House Quince -» n t Vegethbfes Gooseberries ■ '-i '^ '^ '^ * '"".< ^^ ■■ i ' * 'i •i*.^ V ♦ * •* 6» »^ > . ■ . .■ . /' , ■ ,« V r- i--^ -o v.^. r ■. .? , ... ... J ,, i ^ ._, .^. , ^ . ^Raspberries I Fig. 10. All ideal l)inl-.>liuly tract 27 28 CIVIC BIOLOGY determine the species as far as possible, mdicating them by some device, like the initial letter of the name, on the plat. This work should be completed as soon as possible after the leaves fall in November. By inquiiy it may be possible to locate nests that have been " collected " or destroyed by storms dnrino^ the summer, 'i'liis will o-ive a ''census" of the bird population of the tract. The main question which this investigation is designed to answer is, Are there enough birds in the area to hold the insects in check ? To aid in answering this question examine the district minutely for evidences of insect depredations, and make a list of important insect pests found upon it. Examine at least 100 of each variety of apple, pear, quince, possibly peach and plum, and tabulate the percentage of the different fruits injured by insects. Cjather similar data, if possil)le, for tlie earlier fruits, — strawberries, gooseberries, currants, — and also for the various garden vegetables and other crops grown in the tract. Add to the bill of damage the cost of materials, apparatus, and labor expended in fighting hisects. On the other side of tlie balance sheet record witli equal care any injury caused by birds. Note what kind of birds caused the damage. From all vou know and can learn of bird life try to discover what special features attract the birds to nest on the tract, — water, food, suitable nesting sites and materials. Suitable and accessible water for drinking and bathing will be found to be one of the main factors, and food supply and absence of enemies, other elements. Never lose an opportunity to see what a bird is doing, — what it is searching and finding for food. Clear observation on this point seldom fails to answer the question, Why is the bird here ? Study with equal care all the elements which can account for a scarcity of birds or the absence of particular species. What necessities of bird life are lackino- ? What natural lUKPS :21» enemies of tlie ditiereiil speeies are present ? M ncli of this side of the prob- lem will be worked ont natnrally in (.-onneeliun with nesthig habits, tlie study of nest building, and the fate of the differ- ent nests in the spring. Pay particular attention to the bird-food plants of the area with reference to abiuidance of food at dif- ferent seasons. Note the condition in this respect for the different months. Is the area strip[)ed of availal)le food by the time robins and bluebirds have miu'rated in the fall? ^Nlav this help to ex[)lain bird mi^•rations ? Note in detail w hat pro- visions have been made in your district to supply the necessaries of bird life, — l)ird houses, drinking' and bathing fountains, plant- ing of food trees. What is done to protect the birds from enemies? What in- fluence have these pro\ i- sions exerted on the l)ii(l po[)ulation as coinparcd Ki«.. 11. Bird ft»iintiiiii. Natural rocks laid in cement with deep chinks tilltd witli soil and planted with mosses, ferns, ami wild ri(nvers t^hut(>j,'ntpli I'v the iiatlim- 30 CIVIC BIOLOGY with neighboring districts in which no such provisions are made ? A\"hat is the practical value of such work as shown by your account of insect injury ? of losses caused by birds ? Other important lines of bird work relate to destruction of weed seeds and the control-by owls, hawks, and slnikes of nox- ious mammals, — mice, moles, rats, gophers, etc. Keep these matters in mmd throughout the year while domg the field work. Fig, 12. Bird house for study of home life ; windowpane is back wall of house Photograph by the author The birds in your district will change during different sea- sons. During the fall migration the " summer residents " will leave for the south, and many species whose breeding range is farther north will migrate through the territory. These species may be designated as ''transient visitants." They migrate by us to the northward in the spring and southward in the fall. After settled cold weather begins there will be left the '' per- manent residents," — about thirty-six species for the latitude lUKDS :\\ of New York (Cliai)man), — and '' winter \isitaiils,"* sc\ eniccii species of birds tliat come from the iiortli and spend part or all the winter. Make provision for the winter hirds. Snet and a piece of fat pork may be tied to a brancli of a ti-ee, with a irav also fastened to the trunk, in \\ hich si'cds (^niillei, corn, sunth)wer, pumpkin, or squash) aiul cracked nuts (bntt<'i-nnts ai-e espe- cially good) may be kept, and on the ground close bv a pile of chaff or loft sweepings. The pur[)Ose of this is to attract all the winter birds within range of easy o])servation. The tray may be attached to the living-room window sill, if on the south side of the house, an attractive l)ranch may be fastened at the side of the window, and the heap of chaff may be put under it, close to the house. This latter nuist be kept free from snow throuo^i the winter. The work of the year is intended to yield a complete i)ic- ture of the life and work of the birds in 3'our district. At stated intervals your observations should be carefully w ritien up under various heads. V^a suggest the following: Septf;mrei{ — ]\ry Uird Study Tract (giving chart and dt'scrii»ti<)ns of natural features). OcTOiJEij — To Avluit Extent do Birds prevent Insect Depreda- tions? KovEMBER — The Fall Migration of Birds. DECEMBEii — Winter Provision for Birds, — Permanent Uesidents and Winter Visitants. February — The Work of our Winter Birds. Makc II — My Pkins for Bird Work this Spring. April — Birds' Xests ; Xest Building; Nesting Sites of l)iftereiit Species ; Materials. May — P)ird Sony's and Xotes, and \vliat thev nienn. May — Feeding Habits of Birds. May — ]\ry Observations on Feeding of Young; Amount of Insect Food. June — Summary and Results of my l^ird Study for tlie Year. 32 CIVIC BIOLOGY Other more general topics, like the following, are suitable as assio'uments for different members of the class to work out and report upon toward the close of tlie year : The Enuiisli Sparrow in the Locality inav be subdivided into : Re- latioiis to Native Birds ; Damage caused by ; Methods of ExtHrniination. The Life and Work of the Bhiebird. (Substitute the name of any other common bird, if desired. It would be well if each member of the class could devote special attention to working up the life of some important species.) By a free interchange of notes these reports may be made more complete, and in this way each is made the summary of the Avork of the whole class upon the topic. AVe may vary and enliven the reports by casting them in the form of debates about bird problems that are in dispute in the neigliborhood. For example : Resolved, that the roljiu merits protection. (Substitute other birds.) Resolved, that the crow should be exterminated. Resolved, that there should be a bounty on hawks and owls. Resolved, that the bobwhite should be placed on the protected list for a [)eriod of ten years. Resolved, that spring shooting of waterfowl ought to be pr()hil)ite(l by law in all states. Resolved, that active lueasures be taken to establish a preserve for the breeding of grouse and waterfowl in this township. Resolved, that it is better policy to preserve native species than to import grouse from other countries. Resolved, that the killing of song and insectivorous l)irds for milli- nery purposes is legitimate. Resolved, that a person who allows his cats to kill birds should be sul)ject to the same fine as if he killed them himself. Resolved, that a law be passed making owners of cats responsible for the birds they kill. Resolved, that it is an unwarranted waste of bird life to make i^^^ collections. This list might be extended indefinitely. Birds are divided popularly into '' soft-billed," eating nuiiuly worms, insects, and berries ; and '' hard-billed," feeding upon 33 34 CIVIC BIOLOGY seeds. Both classes, however, feed the young mainly on in- sects. Our gardens, fields, and roadsides are weed}' enough, but who can imagine what they would be, were not thousands of tons of w^eed seeds destroyed annually by the sparrows, bobwhites, doves, larks, blackbirds, and others. About fifty species of birds are efficient weed destroyers. Compare and draw a few typical hard and soft bills to fix this distinction. Beal has estimated that the tree sparrows alone in the state of Iowa destroy annually about 875 tons of weed seed. Are both weeds and seed-eating birds abundant in your bird tract ? Hawks, owls, and shrikes render service in destroymg noxious mammals. Are the mice, rats, field-mice, or gophers numerous m your district, and what amount of damage do they cause by eating grain or girdling trees ? Dr. C. Hart jMerriam has estimated that a bounty act on hawks and owls, during its operation in Pennsylvania for a year and a half, cost the state not less than §4,000,000. The accompanying food chart shows about all we know of the foods of many of our commonest species. The blank squares in the chart indicate generally deficiencies in observa- tion, and not that any particular bird does not eat any par- ticular insect; hence they are in reality the most interesting part of the chart because they suggest further study. Observe the birds in your district, or, if you have a young or disabled bird, make definite feeding tests and record the results in your food chart. The chart will thus enable you to feed intelligently many birds that come to hand, and also to add to our knowl- edge of the subject. The probable diet of any bird not named on the chart may be judged from that of its near relatives.^ 1 The authors would be . grateful if those who make such feeding tests would send them any data secured. CIIAl^TER V METHODS OF BIRD .STl'DV AXI) SPKCIAL rKOI'.LK.MS I have no doubt, therefore, that the wild i»ii;('oii is still with u>. and that if protected we may yet see them in something like their iiniiilM-r< <.f thirty years ago. — John Buuroughs, 1906 In order to do the work outlined in the hist cluiptcr we, must know the birds. It is supposed tliat practical acMjuaiiit- ance with the commoner species has been begun in ihc nature study of the grades. The present course is planned as an " ad- vanced," and, so far as school life is concerned, a iinal vcar of bird stud}', which shall organize and comi)lcte previous knowl- edge, work out more thoroughly as practical jHoblcms the values and uses of different species, and licli) to answer the question, ''How may a community make the most of its l)ird life ? " If we are to have uitelligent progress, every one nuist know these things, because the ignorance of one tnav vitiate the best efforts of a connnunitv. After completing plans for individual bird-study tracts, dis- cuss in the class ^^'hat species merit a place in the year's course. Each member may present a list including liis choices, and from these the official list for the vear mav be seleite(l. The lists should be changed somewhat from year to vear, as conditions change and emphasis is shifted from one to anotlier grotip of problems. In this connection, as well as in the general problem of organizing our knowledge of birds, scii'Utitic classilication is of great assistance. Scientilic books ha\e (h'scrilu'd foi- tlie world 12,500 species of birds, and of this luimber 7(58 l>elong to North America. Tliis hu-ge number of species means tliat 35 .^-^ X cc r CO O ^ - Ns c3 a; .2 > r- T. .Xf- — < 36 METHODS OF lUJil) STIDV :y birds have become differeiiliated to iit all sorts ot" ciiviroiiiiuMits, — air, water, marsh, prairie, and forest. 'J'hose of similar activi- ties, like machines built and adjusted to their work, have come to have similar structures, — <»f Ixxly, wint;-, foot, and l»ill. Discoverv of these adjustments will add fi'csli interest at every turn and increase respect for scientific biid stndy. Fig. >! is (U'sio-ned to lix in mind the fundamental relations of the dif- ferent orders to cnsironment. Common names often var\ in Priiitarle.s Pritnar)/ Covert drPdfcr Covert MiHtUe Covert Tail Cnrprt.t Jiiiiiif) -> nark- Lfftxer Covert.'^' Ahi/(torSpuriou.r cnhtmhiduus. Canada goose — Brdnfft raii(i'n 1)^' |:i too small for fi is;] it. Tlic last record <>l" tlu' dodo was in ]i\S\. Jiotli of tliese r('inarkal)U' s[)e('i('s were iiiiwittiiiLclv cxtcnui- nated by llic introduction into the islands of hogs, which il.- stroyed their eggs and young. There are in Xortli America ton nfcnera and st'\ cntccn species and varieties of pigeons and (h>ves. Most of these are Western and Southern. The two namel valnaldo ut North American pigeons exi.sted less than forty years ago in Hocks which .stretched from horizon to horizon. It is now a .^erions tpicstion whether the last living specinu'n lias not been seen. 44 nVIC BIOL()(rV (For three years past rewards aggregating over $oUOU for discovery and report of imdisturbed nesting pairs or colonies of passenger pigeons, anywhere in Xorth America, have remained unclaimed, and no tangible evidence has l>een received of pigeons killed or even seen during this time. This is commonly accepted as proving the species extinct in the wild state. One old bird still survives in the Cincinnati Zoological Gar- den. If nesting pigeons are ever found, tliey should be most carefully safeguarded, and all protective agencies, private, state, and national, be focused on their ] n-eservation and increase.) Mourning dove — Zoiai- (Inm iinici'oura rdro/i/ic'/isis. Every effort is now being jnade to save this species in New P^ngland. It is abun- dant in the South and Middle West. Fui. 20. Young red-shouldered hawks Order Raptores {raptor^ " a robber ") — hawks, eagles, owls. 41ie hawks and owls furnish perliaps tlie most complicated and difficult problem con- nected with our bird life. By many of the best autliorities the majority are accounted among our most valuable birds, on account of the great num- V)ers of noxious mammals — held mice, gopliers, rats, etc. — wliich they destroys Most of the ha\\ ks, too, feed largely on insects when they are abundant, and take comparatively few birds, either tame or wild. In determiumg the value of birds in this class, however, it is always an open question whether the few insectivorous birds, — which may form only 1 or 2 per cent of the hawk's total food, — if allowed to live, might not have done much more valuable work than the sum total of tlie predacious species. We must leave questions of this kind to be worked out from practical experience and observation. METHODS ni- j;ii;i) .STUDY 45 Wlii'U (lepri'i cxclusiNcly on other birds and briniu;- prat'tically all tlic popular ill-repute upon tlie rest of the family. In addition (o tlicsc, tiie Anu*r- iean goshawk, a("anadian species ^^'hi(•ll cnteis the Xoithcrn States in winter, feeds largely on game and poultry ; and the rarer duck hawk, seldom seen far from the coast or lar^-cr waterways, feeds chietly on waterfowl. Some authorities are intdined to maintain that the smaller species, sparrow and pigeon hawks, may prove useful in towns and cities in destroying English sparrows. This is a good problem to assign, if some of these birds arc known to nest in the neighborhood. In the oidv case known to the author a pair of s|)arr()W luiwks which nested on one of the buildings of the Worcester Polytechnic Institute had linallv to be shot on account of serious inroads npon the \aliiablc bird lite ot the campus. Connnon tyi)es are: Marsli haw k — < 'Ircus hmlsi'miiis. Sliarj>-sluiin('d hawk — Accipiter nlnx. Coojter'.s hawk — Art-i/Hter codjuri. American goshawk — Asdir ti/ricd/n'l/us. Red-taih'd hawk — lli'tti <> hiu-Ki/is. Ked-shouldered hawk — liuteo linedtns. Bald eagle — II(ill(r('fns kticocephalus. Duck haw^k — I'Wro /xref/n'nus dtuiimn. Piii'eoii liawk — Fdl<-<> i-olmnhdrins. S)>arn»w liawk — Fdh-o s/xd-n'rins. Ajiu'rican osprt-w <>r fish hawk-- I'mulnni lialiv-tliroat(Ml liinnmiim" bird — ■ A rchHoclnis cdluhriK. Order Passeres (^passer, " a sparrow ") — perching birds. In this laro-est order, which contains nioru than ludt" tht- spcciL's t»i In* studied, the family names will be of assistance in distinLcnisli- ing the various grottps. Family Tyrannidcz — flycatchers. TyiR-s: Kingbinl — I'lirdnuux fi/rdnmis. Crested flycatcher — Mf/idrrlins crinitus. Phoebe — Sdi/drnis jdiulir. AVood pewee — Mi/ldc/Kincs r trots. Least flycatcher — Eiitjttddnels othin- species, generally warblers, vireos, and sparrows, smaller than itself, to brood and rear its young at the exi:)ense of their own. Cowbirds' eggii should be removed from the nests of other })irds w^henever found. P>obolink — Dollrlidnyx oryzworus. In the Xorth this l)ird is appre- ciated as one of our most fascinating meadow songsters, if it is- not at the head of the list. In the South it is the destructive ricebird. Bronzed grackle — Qntscalus qniscuUi (fiieus. Ked-winged blackbird — Ageldius phoeniceus. Meadow lark — Sturnella nidr/na. Baltimore oriole — Icterus ydlbida. Fig. 23. Junco's nest in the aviary of Mr. Herbert Parker, Lancaster, Massachusetts METHODS (H- I'.iL'i) >ri l>^ 49 Family FringilUdce. ( fringilla, "a finch") — sparrows, finches. 'I\|.ir,!lh's. Tree sparrow — Spizcda inontiru/a. Cliipping sjtarrow — Sjjlzrl/a /i n'mi. f] unco — Jihico /ii/fiiifi/ls. Song span"t)\s — Mc/osjjhfi hk loilin. Fox sparrow — J^<(s.-t( rc/hi i/itn-ii. Towhee, clicwink — Pij)ilo cri/l/iroj/I/l/Ki/mns. Kose-broastccl grosbeak — Zamrlndlti lin/oririiimi. Indigo l>unting — Ptifisrrlun ri/d/mt. The probU'ius in this grmip are the \aliiaM<' m'1-\ ice itmiIi'IimI l.y all the sparrows in weed-si^ed destruction; and, also, the dainag«' canst-d by the English sjtarrow. A single observation of the killing of a tn-r swallow or a bluebird by sparrows, or th<'ir eating the eggs from a rob- in's nest, is nsually enough to con^ ince a jterson of the advisability t»i' ridding' the neiiihborhood of these i)ests. The year after all a^re*', the English si)arro\v maybe banished from tiie continent into whieh it was so foolishly introduced in Is,")!, lutil all agre<', not niucli ln-ailway can be made against a species that has the j.ower to iuereas*- from a single pair to 27r),71(),98:3,0l)S in ten years. Family Tanagrida — the tanagers. The scarlet tanager — I'lr(in;/ti cn/- thrd/iK-lds. Why are not these l)eautiful Itirds moi-e numerous in y«»ur locality ? Family HirundinidcB — swallows and martins. Few more elhcient, and certainly no more agreealde, insect traps exist than the swallows. Tiiey shonld all ]>•' jtrotected until they increase up to the linnt of their insect food. The jnirple martin and tree swallow nest javferably in bird h»)uses, and provision about barns should not be lacking for tlu' clitV atul barn swallows. Differences in nesting hal>its in sj.ecies so closi-ly related are of general int(0-est. Types: Furple martin — J*r<>i/iir siihis. Cliff, or eaves, swallow — J*t fror/ulolini luiii/rni,>. Barn swallow — llinunld rrj/t/irdtfastid. Tree swallow — Irhldjirdctd In'otlnr. Bank swallow — }ii/i(iri(t rl/t(lriirds are valuable to control insects of garden and orchard, and, besides, are among our be.st musicians. House wren — Tro(/lot/f/t(s (il'
  • n. Every garden should be well stocked with this tireless insect destroyer. !Marsh wren, short-billed — ('istot/tdrus stelldris. Comi)are with house wren for habitat, foods, nests. Family Certhiidce' — creepers. I>rown creeper — Ccrl/iid fainHUirls (imni- cdnii. One of our winter birds that should be generally known and i»ro- tected. Family Parida — nuthatches and titmice. White-l)reasted nuthat<-h — S itta ca roliii ciik is . Chickadee — Pcnthe'sles afrirajji/lus. All are agreed that the chicka- lem of their economic value up to within recent years. A closer analy- sis of their foods has demonstrated that the birds prefer native wild fruits to cultivated; hence this prol»l:\ It should l)e ii'peatcMl that llic al)i>\(' list is suggested lor central Xew England, and that it should he freely niodilied to lit the species anil problems ol' othi'r seelions. One of tlie most inter(^sting civic problems in this Held re- lates to conservation of American game birds. To acctunplish this we need three things: (^1) national control of migratory species; (2) universal [)roperty right in all game reared by individuals; (o) study of methods of bree(bng and rearing under control all kinds of American game biids. The third factor will speedily follow fr(»m legal authori/a- tion of game breeding, ('2), which is being accorded by rr- cent state laws. Follow ley'islation in \(>ur own state and work for this at every opportunity. As long as the State claims owaiership in all game, peoi)le cannot attord to raise it, and often the lawless trespassing and annoyance of hunters on private land make the owners wish that the game were exterminated. As soon as we can secure the pro])er free(]om from laws which work against conservation, breeding of game birds wdll beeome one of the most profitable of occupations. Tlumsands of nests of wild ducks, geese, bobwhites, w ild turkeys, rutted grouse, and prairie chickens, are yearly broken up by various farming or logghig ojjerations. The eggs at an\ stage of incubation may be saved by carrying in the hat, as shown in Fio-. 25. If all these eg<>-s could l)e saved, thev \\<>ulv>-'V>-. ^-^s.i-'^: 'mm 'f<-4misi*»^" Fig. 26. Black Hills National Forest United States Bureau of Forestry 54 CIIAI'IKK VI TREE STUDY AND CIVIC EOliESTUY Why are there trees I never walk under but large and melodious thou.u'ht.s descend upon me ? — Walt Wuitmax IIow foolish does man appear to be in destroying the mountain forests, for thereby he deprives himself of wood and water at the same time. — Alexander vox Humboldt It is undoubtedly true that more pine timber has been destroyed by lire than the lumbermen have ever cut. — Gueex The problem. The aniiiuil grnwtli of all the forests of tlic United States is 7,000,000,000 cubic feet of wood, while our yearly consumption amounts to more than 20, 000. ()()().< 100 cubic feet. In addition to this, since 1870 forest tires, for the most part preventable, have caused a yearly loss of lifiy lives, $50,000,000 worth of lumber, and a dcsuudioii. cxfu oicaicr, of all younor m-owth and of soil fertility bv the burnintr of tlie veofetable mold of the forest floor. Floods in the lower Missis- sippi alone during 1912, due to unwise and uiuivic deforesta- tion, in the main, caused great loss of life, extreme privation, and damage estimated at $82,187J')70. W'liilc ibis torrential run-off is floodhiij: the lower ri\ cr vallevs, millions cd' woodland sprhigs and even wells back in the foothills and mountains are going dry. From one to two thousand niilli<»n tons of the finest and richest soil — enough to bury Kiiotle Island from one to two feet deep — is being washed yi'arly from tlu' farms, where it may be worth a dollar a ton. into our harbors, where it costs millions to dredge it out of the way. Increasing population and consiimpiion (d" woixl. decreasing forests, inadequate control of forest fires, increased washing o.> 50 . . ("IVIC I51ULUGV of soil, lloods rising higher each year — these are the main elements in the problem. Records of flood plane of the Missis- sippi atXew Orleans are as follows: • 1882 ~ l'")-'^ 1892 17.(i 1903 • 20.:; 1912 22.0 iH,. 27. Flood showing result of deforestation If the flood of 1912 had not broken the levees and poured over 17,605 square miles above the city, the flood might have risen to thirty feet at New Orleans. Vital civic cooperation must be developed in growing more wood, in holding the water and soil where they belong and can do the most good on every farm, and in prevention of forest fires. These are not matters of private individual right and con- trol : they are civic and touch the life of the whole people. tr?:e sT^I)^■ and cnic fokkstim •)i Every particle of soil that a fanner in IVmimsvIn aula. Miniiesota, or Montana allows to wash from his farm event ually raises the mud bed of the Mississi[)[)i, h('l[)s to cause llcxtds. taxes the nation to l)uild higher levees. The eleaiinn- ol a w alershed at the headwaters of the ()hio <»r Missouri is the i)usiness of every one whose spring" or well iiins dry l)el(»\\ it (»r whose Fui. 28. Deforested slope, Noitli C";u«iliiia. sliowiiitr erosin every hill and mountain side and aloii-- every o;ully and ravine, the rootlets of whieh will hind the st)il and liller the water as it falls, we slumld have the water leaving eveiy farm clear as crystal from perennial springs, ^^lst national projects are 58 CIVIC BIOLOGY afoot for building clains and impounding the flood waters of our streams and rivers. Much of this will be necessary on account of past mistakes in clearing watersheds and also on account of the original configuration of certain regions ; but first, and in connection with these plans, we should unite as a whole people in planting trees to conserve both soil and water on the farms. Otherwise, under present ignorance and mismanage- ment, how long will it be before our reservoirs are filled to the tops of their dams with mud ? Observe and study typical springs and streams, and learn the history of them for a number of years. Have they shrunk or gone dry ? If so, is it because Avoods have been cut above their sources ? They may be restored by replanting the water- sheds. Has it been necessary to deepen wells during periods of drought ? Has a man the moral right to clear off a woods that will cause his neighbor's spring or well to go dry ? Study in a practical way what the local streams are carrying, if muddy. Temporary streams will serve, if permanent ones are not available. After a freshet, are some streams clear and others muddy ? How do their relations to woodlands explain the difference ? Follow up a muddy stream and find where the soil is being eroded. Can ^^ou sketch a plan of planting with trees or permanent grass to prevent this ? Make a list and map of all the places in the district that are washing badly, or survey typical farms with this feature in mind. Sketch a plan of planting which will improve conditions throughout the district. After this has been perfected and thoroughly discussed by the class and with parents most con- cerned, arrange for publication of the plan in local papers or make it the subject of consideration in a community meeting. All can then arrange for saving or procuring the necessary seeds or young trees and for doing the actual planting. If not too extensive, possibly all of this work can be done in outdoor laboratory periods by the class. At least the seeds might be tim-:k sTri)\ and cinic F(HM:s'riM :,<» gathered and many of (lie yoiin^- trues bu rraic(l I'm- a yrar or two ill a nurserv in connection w illi tlie school r a inoiv valuable permanent stand. The following table suggests possibilities in handling the different species of Eastern conifers and hard woods with refer- ence to tolerance of shade or sun. Shade Bearers Intermediates Lkjiit Dkmandi.ks Conifers : AVhite cedar Loblolly i)iiie Loiin-lcaf \>'i]h' Sw^hv j.inc Si)ruces Virginia scrub i>iiu' Sliort-leaf jtinc Scrub |»iin* Balsam White pine liakl lyprt'ss Cuban pine Arbor vitae Tamarack V«'Ilo\v pine Hemlocks Jack i)ine Pitch pin«* Spruce pine Red ])ine Re*! cedar Rock [)iue JI(tru|>il, acconlim; to sui;ijes- tions for the White Pine, ]>. 1. Kach will then be resjK>nsible for seeds. 60 CIVIC lilOLOGY Nut trees. Hie rocky hillsides of Italy and Spain, planted to chestnuts, are said to produce witliout labor as valuable crops as our own best Avheat lands. We are importing annu- ally over 114,000,000 worth of nuts. How many, even then, have all the nuts they want ? Make careful collec- tions of all the differ- ent nuts in the district and prepare them for exhibition in class, keep- ing records of trees that produce the best. Pre- serve as many as pos- sible of the best for planting, exchange with other schools, and ar- range, if possible, to buy seeds or j^oung trees, or obtain scions from the best varieties of pecan, hickory, A\aliuit, and chestnut that can be had from anv ])art of the country. Organize ex- hibits of nuts in connec- tion with local horticultural fairs. I^y these means we may improve quality and increase yield of mits to any desired amount. At the same time the wood of our native nut trees, • — hickory, black walnut, chestnut, — for certain uses, is the best we can grow. flowers, seedlings, and otlier specimens of his tree or trees, when needed by the class. Have each pujjil study and be prepared to describe the method each tree has developed for scattering and planting its own seeds. ¥iG. 2U. Youiii; black-wahiut tree The nnts hang on a few days after the leaves liavf fallen TKEE STUI)^■ AM) CWU loKKS'i i; \ ♦;i State and national helps. Tlie luiiioiial liiuvaii of Korcstrv and your state forester prim a lunnlx'r n\' practical l)iillctins and forestry leaflets, which mav be obtaiiuMl trratis or at cost. 'I'hcsc ^^■ill give directions for galiu'ring, storing, and phniting different tree seeds, and ad\ice as to lu'st species to plant. Tier seeds and excn young seedling trees mav l)e obtained from state or (in Canada) from provincial depaitmcnts of forrstr\. Fn.. 30. C'l'up (if tit'c >li<>\vu ill Fiu. -1' ^^"c do uut luiM' to " wait '" tiftecn years i'or siicli a cn-i'; \\<' iu-i |«l;iiit tli.' init aiul jjo about our l)usinfs> Since the planting of trees is an important puitlic ser\i(M». states arc beginning to [»ass laws exem|)ting land so })lauted from taxation. Massachnsctts ami \»\\ ^ ork exempt tor thirt\-li\e vears all lands on \\liich not fewer than twtd\c hundred trees are idanled to the acre. Forest fires. In a hot. dry \\ iiili !)> Cliarlfs I. Kiro 64 CIVIC BIOLOGY Causes. Natural causes, lightning and friction, account for few forest fires, and as these occur during rainstorms, there is almost no damage from them. Study local forest fires and tabulate under the following causes : Forest Fikes in Massachusetts ix 1008 Cause XUMBEK l^rtilroad trains (Locomotives) 490 (38%) Sawmills : 12 (1%) Burning briis!i 1)0(7',) Smokers 111 {S%) Campers' fires 1 (0.1%) Boys (incendiary) .... 150 (11%) Unknown 314 (25%) ItEMAHK.S Usually cause about 50% of all forest fires. Can be stopped by proper use of spark arresters, or by burning oil, by turning hose into ashes before dump- ing, and by clearing roadbed of inflammable rubliish. Should have men organized, and be provided with adequate fire- fighting apparatus. I'vscape of these fires can be avoided bv burning when snow is on the ground or during a wet spell. Those Avho must smoke in the woods in a dry time should hv compelled by law to dive under water to light iip and stay down as long as there is a spark in their pipes or cigarettes. Boy Scouts may stop such fires. Probably mostly set by smokers and careless or incendiary boys. In all, for Massachusetts 1378 forest fires were reported in 1908, which burned over 40,327 acres of woodland, nearly 2 per cent of the wooded area of the state. In the whole of Prussia 1400 acres have been burned in the past twenty-five years, or less than 0.02 of 1 per cent a year. At this rate the TREE STUDY \SD ('I\'h l-()KESTK\ oo whole I'ort'ht area in Massaeliusetls would be ImniiMl ,.\,r in about fifty years, and in Piussia in 5000 ycius. Wliy tliis dit't'crenee ? The actual loss by forest lires, although great, is u<.l ihr worst feature of the situation. Forest tires diseourage tree Ki<;. 33. Safe burning of brusli I'nitod States Bureau of Forestry planting everywhere. Reduce or banish entirely danger of lires and tree planting will become a safe and profitable investnu'Ut. Note to Tkachkh. After working over the ground and witli sjM'cial reference to local problems ask tlie town fire warden to visit tli.' elass and explain the state laws and thr apparatus, eipiipnient, nu^thods, and organization of the state and town f..r ].reveuting forest fin-s and lor (piiek work with those tliat are started. 66 CIVIC BIOLOGY To sum uj) the whole matter have each member of the class write a brief outline of a plan by which he thinks forest fires can be effectively jprevented in the district, town, or county. The best of these plans may be printed in local papers or used as the basis for discussion in a timely neighborhood meeting. AVith every township safe and protected by a well-organized community, the entire country will be equally safe. Forest-fire laws. Secure the latest forest-fire laws in your state or province and familiarize yourself with tliem. These laws represent the best thought of your communit}^ on the subject. What can you do to help in making them effective ? CHAPTER \'II TLAXT rUOBLEMS: rRESERVATION OF WILD FLOW KKS, CONTROLOF WEEDS, MEDICINAL AND PoiSOXOIS j'LAXTS Groups of plants present civic problems oi no k-ss iiui)or- tance than those of birds and insects. For lu'iiutifnl lands('ai)cs the people of a locality must learn to co()peratc in prescrvint^ and planting native trees, shrubs, and vines. Additional study of these is taken u[) from this point of view in Lha|)ters on Forestry and Landscape Gardening. Conservation of native plants. ^Many of our most beautiful native plants are in danger of extermination. To educate ao-ainst wanton destruction a society of national memlu-rship has been organized,^ and if all can be induced to join in rea- sonalde conservation of these common interests, \\-e may have much more attractive and hiteresting woods, parks, and country roadsides. Do you have trailing arbuuis, fringed gen- tian, cardinal flower, maidenhair fern, pink lady's-slipper grow- ing in abundance ? I>y inquiry from parents, grandinirents, or older members of the connnunity, can you maki' out a list ot native plants that have become rare and need protection m 1 Society for the Protection of Native riaiits, Huston. Massaclinsctts. For leaflets, address the Boston Society of Natural History. This society urge.s that we all nse : 1. Morleration. Do not pick all that you lin.l. M:niy lluwi-rs must W left to develop seeds for future plants. 2. Care. Never pull up the plaut. for the roots are of no use in a bunch of flowers, and their destruction means the extinction of the plaut. ( 'ut wheji possible. 3. Jnnfftnenl. Many tiowers. such as wild roses, asters, au.l u'oldcun»d, may he picked with inii)unity. but when tiowers are few or rare d<. not pick them. Do not pick flowers which luust die before you reach home. n(.r jrreat fmantities of those flowers whose grace and beauty are better seen in a few than in many massed together. 07 68 CIVIC BIOLOGY the locality ? Discuss together as a class plans for bringing them back to their native haunts. Weeds. Fighting weeds is often the most laborious and ex- pensive part of gardening and of raising certahi staple crops. It was formerly said that weeds were the gardener's friends, because they made necessary the frequent stirring of the soil, which was considered beneficial to plant growth. Recent ex- periments in raising corn have shown equal production ^\'ith absolutely none of this laborious stirring of the s(nl. In fad, earlier experiments on the root system of the corn plant had proved that the farmer actually, and ^ ery materially, redticed his corn crop by deep cultivati(jn. Other crops await similar investiofation. The results so far have been to rate the damao-e cattsed by these '' robber plants " at much higher figures than formerly. If we could prepare the ground and plant our gardens and fields and never see a weed, the labor and cost of produc- tion from the soil might be reduced nearl}', or quite, one half. Damage caused by weeds. Weeds are defined as '' plants which persist in growing wdiere they are not wanted." Ko less than seven hundred such plants are listed for tlie entire United States. ]\Iake a list of weeds tliat are locally most noxious. Weeds reduce yield of crops by crowding, and by robbing the plants of water and food in the soil and of light in the air. 'i'hey injure seeds and flour, cause objectionable flavors in milk, and poison stock. A recent estimate by tlie Division of Farm Management of the United States Depart- ment of Agriculture places the total annual damage of weeds at $500,000,000. What part of this yearly tax is imposed on your own home, garden, or farm ? What is the annual damage and cost of fighting weeds in your district, township, county, or state ? ^ Can you propose a plan of cooperative work \)y which this may be reduced ? 1 Secure your state bulletins on weeds to assist in workiuii out the prob- lems sufjo-ested. Write also for the Weed Laws of your state. PLAN'I' I'KollLK.MS (i-.i Control of weeds. Select tlic laro-cst spccimons t<» he loiiiid ill roadsides and vacant lots, barnyards, and gardens, of pcr- liaps ten of the worst local weeds; dry carefnlly, thresh out and connt or estimate the nmiilxT (»!" seeds in ciicli. NO onr who takes j)art in sncli a lesson can cNcr he inchtVerent to al- low in^' such weeds lo ri[)en llicir thousands or e\«'n millions of seeds,! wlien a strokt^ of scytlie or hoe at tlic i-i<^lit tinit- would stop them. Failure to study weeds and get clear ideas of tlitir powers of re})roduetion and of effective metliods of extermiiuitiu^ tlieni is responsi])le for the fact that moic decisiv*' hcadwav has not been nuuh' in their control. I'liilhef topics in this coiniection are tlie following-: Dispersal of weed seeds. Along witli rats, English spiirrows, the San Jose scale, and i»v|)sv niotli, many of oui- worst weeds are innnigrants from tlie ( )ld AVorld. Thev come mixed with seeds and grains, in merchandise, and in all kinds of packing materials, ^^'at{•hing ports of entry has not succccflcd in kcep- ino' out tliese unwelcome LiUests. ()uronl\ hone lies in know 1- edo-e sufficient to recomiize and u'ive tlie alarm and unite in eradicating vicious im[)ortations before they l)ecome widi'ly established. The more widely a plant is aide to scatter its seeds, the bel-cer the chance of growth. Naturally wci'ds lead the world of plants in effective devices for dispersing their seeds. They are aided by different elements in the environment — winds, flowing AViiters, and animals. Make a collection of wciwl seeds ^ Tliis suirjrc'Stioii canicil mit in tlic Clovchinil Noniinl Scliu.tl vicMcil tlu' fnlldwiiig results : Milkweed — ^Lsclepias flies to graintields which have become seeded to chess, cockle, or ragweed. Pas- ture lands ''run out" to perennial weeds should be planted to annual crops. Thus a system of lield rotation and general management may be ado[)ted which shall give w i-eds the least possible chance to sur\ Inc. Chemical weed killers, herbicides. Salt or stnuig brine, arse- nate of soda, coal oil, crude sulphuric acid, carbolic acid, and sulphates of copper or mm are the chemicals usually employed and suggest interesting experiments for the lawn or garden. Medicinal plants. .Many crude drugs and aromatic herbs used as condiments are now iin]iorte CIVIC BIOL(Xn' the United States. The table ^ below gives the amounts brought in and the prices we pay for some of our most common weeds. Weeds Pa UTS USED Amoint 1M- I'OKTED IN Poinds Price paid IN Cents TER POLND Docks — i?i/mex species . . . Roots 12o,000 2-8 Burdock — Arctium lappa L. . Roots 50.000 3-8 Seeds 5-10 Dandelion — .Taraxnruin tarax- acum l\0(»tS 115.522 4-(> Quack or couch <;rass — Aiiro- pyron repjens L Rootstock 250,000 3-7 Mullein — Verbascum ihapsu.s L. Leaves 5.000 2.i-5 Flowers 25-75 Tansy — Tanacetum vulgare L. Leaves and tops 80,000 3-0 Horehound — Mamibium vul- Leaves and gare L tops 125,000 3-8 Jimson weed — Datura stramo- Leaves 100,000-150.000 2^-8 nium L Seeds 10,000 3-7 Poison hemlock — Conium mac- Seeds 20,000 3 ulatum L Leaves 10,000-20,000 4 Black and white mustard — Si- napis species Seeds 5,302.870 3-6 While the demand for medicmal weeds is not great, market- ing those that have useful properties would tend to check their spread, and might, in turn, pay at least for their removal. Other native drug plants. Clearing of the forests and the work of the drug collector have resulted in almost extermi- nating many of our native drug plants. To save these the Bureau of Plant Industry has undertaken the work of domes- ticating them with the hope not only of supplying the home market but also of exporting them. In the gardens at Washington some success in an experi- mental way has been attained in raising goldenseal, cascara 1 Compiled from Bulletin No. 188, Tnited States Department of Agricul- ture, "Weeds used in Medicine." This gives prices and methods of pre- paring for market. IM.ANT IMloni.KMS 73 sagrada, Seneca snakeruut, and [)nr[)le cnnillower. (iinsj-n^ has already been doniestieatiMl, the total yield in states east of the Mississippi River being abont (Uie niillinn dulhus aninndU. A considerable j)()rti()ii ol' ciiide drugs use(l in iln- Inilrd States is of foreign origin, 'id supply the lionic niarkcl and save millions of dollars now s[)ent on foreign (hugs, ilic Bureau has interested itself in the experimental culiurr *>{ these foreign plants in soil and climate similai- t<» tlicii' own. Plots of Asiatic poi)i)y, camphor trees, cinchona, belladonna, foxglove, and red pep[)ers have been planted in suitable parts of our country. Poisonous plants. Certain [)lants are p(»is(»n(ius cither when handled oi- eaten. For lack of statistics, no estimate can be li'iven as to the amount of damaiiv done b\' them. Complaints have been so numerous against various j)lants which poison man and animals, that the (ioNcniment has investigated them and has issiu'd a number ol bulletins on poisonous plants of the liiitetl States.^ (Sec JJniirh'ti .sv;, ''Thirty Poisonous Plants.") Of the thirty plants descril)ed. about one third are \V('e(ls : the others are fungi, herbs, shrubs, and iiees. 'The most poisonoits plants are nuishrooms {AnKUiittt iiiiisnirld and Anm- n(t«. jfh(fUoi(h's), the various species of w ater hemlock ( < 'irnf«*aver poison, musquash root, muskrat weed, cowbane, spotted cowi>ane. chil- dren's-bane, death-of-man]. Pokeweed — PiDjtolacca dtcandrn. Corn cockle — Agrostenima (I'lthugo. Black cherry — Prunus serotina [wild cherry, rum cherry]. Red buckeye and connnon horse-chestnut — .Ksculus paria and hippocastan um. Broad-leaf laurel — Krdinut hitlfo/id [laurfl (north of Maryland ). ivy (south of ^Maryland), mountain laiml, slict p laurel, jioison laurel, W(M>d laurel, small laurel, high laurel. AnuM-ican laurel, jtoison ivy. ivy btjsh, ivy wood, big ivy, calico bush, spoonwood, kalniia, w icky]. Xarrow-leaf laurel — Kahuia anffusfi/olla [sheeji launl, lambkill. sheep poison, lamb laurel, small laurel, low laun-l, dwarf hmrel, wicky]. Jimson weed — Datura stranioiiium and D. talula, the taller and purple-flowered species [Jamestown weed, common stramonium, thorn apple, apple of Peru, devil's ap])le. stinkwort, stinkweed, Jamestown lily, white man's plant (by the Indians)]. 76 CIVIC BlOLOdV Cciper spurge — Euphorbia lathyris [garden spurge, mole plant, gopher plant, wolf's-milk, spring wort]. Snow-on-tlie-mountain — Euphorbia inanjihutd. Other poisonous plants are : ])eath-cup mushrooms, of the genus Ain1:M N < ■ 7'.' public parks and buildings, the aljatonicntof snioki* and billlioard nuisances, conservation of llic natural beauties of forest, moun- tain, waterfall, woodland, s[)ring, glen, g<>rge, and ciinyou — for these real values to the whole people of a l)eautiful America. The appearance of a country, especially of its Ikmhc^. ailords the best index of the char- acter of a people. Some homes express taste, re- finement, good sense, and morals which warm the heart of the passer-by with a friendly feeling for those who dwell within. Some express pride and repel with ostentatious display of wealth. Alanv are mere nuuldles, accidents, com- mercial affairs of the nur- seryman. With the advent of the modern landscape gardener perhai)s the greatest present danger is the monotony of set [)1 anting — a bit of shrub- bery here, another there, '' just so," which is frankly more tiresome than nat- ural accidents. The practical biology of landscape gardening relates to effective planting of the home or street, park, town, or city. It consists in problems of forming pictures with adual trees, shrubs and vines, lawns and llowers ; and the lirst recpiisUe for success must be a clear knowledge of the living things with which we build. AVe must also bear in mind that we are Fig. 36. Lanciistei- elm, attt-r tlie .sionii 80 CIVIC BIOLOGY forming not only one picture but a series of pictures to be viewed from different dii'ections, and that planting is most effective which yields the most pleasing vistas. Then the Fi(. . 37. Lancaster elm Results oi neglect ami vandalism (the cavity had been burned out) pictures will come and go, from the red maples, pussy willows, peach and apple blossoms of spring, through the procession of summer bloom, the fruits and foliage of autumn, to the crystal fairy lands of ice storms and snow scenes of winter. Then, too. HOME PLANTLNC AND l.ANDM AIM-! ( i A l: I >1:M N< . >1 our bust I'ttV'cls \\ill lack aiiiiiuilioii and cliarni \\iili(»iit llic action and nnisic ot" l)irds : and to coinnlctc tlic w hole we musi luive fraj^rance — ci})|)lr blossouis. lilacs and syrinj^as (»! Mav, roses and ^'rapcs of .hnic, lioneysncklt' and niudnllnwcrs, cinnanioii \ ine and niii^iionetti* of sninnicr, and ilir spicv, health-giving aronia of [)ines, tirs, and spruces all the year. And liiuilly, our pictures \\ill grow iVoni year to year, .so thai when "we plant trees we nnist imagine alunid — ten, twenty, fifty, one hundred years. Trees. Given the ground, the first thing to plan is the posi- tion and grouping of the trees. In order to do this intcdli- gently we nnist know the biology of the different species — the soil hi which each grows best, and, esju'eially for our future pictures, tlie height and spread and general foriu and color of each. For outdoor laboratory work measure the height and spread to scale and sketch the general form of ten specimen trees of different kinds. These data will be neede r^ •— r-l •^ 2 5 S -S ■!?■ F IJ .X •1 . ^^ « ^ 5 c5 S 7 "C ci '^ -i 5 a, c: ^ O r» K rH O S *^ J £ i o H c a * ■*^ —, ^ — r", 3i c 5 ^ a; ■A o 2 ■3 a> -s S 1_- "*-■ -t^ !h ^ -r <; -5 "H S -2 3J 0 u • ' " a; — ■*" '^: en V ^ >^ '^ ni y; t> ;-i 0) tX) a; a> < tn ;h '^ 4J 5 c r 'A ^ ^ +j cS " o -d — , 0 ■*^ a: 1^^ -' OJ 2 • OJ cS ^ 1— I 'J2 X X , ^ • 1—1 ^ V Z) X -*-* X r^ 0 H F*-" «— • -U) 0^ -^ T^ -4-^ ^ 2^ 0 rr r^ r. r^ ^ fti r: a^ •--■ !f-l u ~. ^ 0 aj :e OS 1—1 --2 ~ St "-5 o -3 3 S .xi ^ a; ^ Z ■» - ? ^ s o « a; ^ a) - - I C X '~ Ij b c c = 55 •" 5 TJ I a c« o S P " > S i ■" '= S = - c o 0-1 I ■-3 CO ■J X 1* 1- © O o o l-H c o I-H I o I o o o CI I o I- o CO aj aj ^ - s -§1 ft f I 2 D fi. ^ s J3 I aj .i; ^ I ■^ e 5 g ^ e ^ s '^ § ^ S HOME IM.AMIXC AXI> LAN I )S( A I'K ( ; A I; I )1:M .\( , s;} trees; measure distances a[)art and draw the <^ruund j)Ian to scale, and sketch or photognqjh the groups. Rules for grou|)ing trees are sometimes given. The lollow- ini>' are modilied from different authorities as su*rLrestive and practical. 1. Specimen trees — those which stand alone — siiould Im- chosen for special beauty or cliaracter ; oaks, clicstnuts, hhick Fig. 38. A specimen of nature's plantinir walnuts, old pines, and cedars for massive strcnglli and dig- nity; hemlock, elm, larch, and spruce and tlir hiivhcs for graceful tracery of form and outline: ("oloiailo hluc spruce, purple beech, Schwedler, swamp and Japanese maplrs for ricli colorino-. 2. Groups should not l)e too compact, and on estates of limited extent are generally more effective if made up ol" trees of different characters. They should he imsynnnctricak irreg- ular, ''natural" in form. The taller trees slx^ild, of course, occupy tlic center, or form the 1)a('kground in l)oundary-line 84 CIVIC BIULU(tY groups. There is opportunity here for line contrasts in form, color, and character — oak and weeping willow or American elm, birches against white pine, etc. 3. Plant trees or groups to screen objectionable features of the landscape, and leave open spaces toward all pleasing vie\\s. 4. Plant deciduous trees on the south and west of the house for summer shade and winter sunshine, and evergreens along the northerly side to serve as stormbreaks in winter. Shrubs. Given the bounds and main features in tastefully planted trees, the shrubbery lets the picture down naturally to the ground, and supplies much desired color and fragrance. Shrubs, too, more than anything else form the setting for the house, fit it to the earth, and make it a part of the landscape, llie house being the center of the general scheme, we should place the choicest shrubs nearest to it. For outdoor laboratory Avork study throughout the fall and spring, at least, good specimens of all tlie different ornamental slu'ubs to be found in your local parks or neighborhood. ( )l)serve them in all possible relations to trees, buildings, and other shrubs, so that you will l^e able to choose tlie shrubber\" of a park or the home grounds with intelligent taste. A local planting table like that suggested for the trees should be made, giving size, form, preferred exposure, and color and season of bloom. A selection of shrubs may be made which will furnish bloom for cutting and fine color effects in either flower or fruit for not only the growing season but the entire year. If it is desired to combine use and ornament, - — a tendency growing in favor, — nothing in the way of shrubbery- can be more effective, either in bloom or fruit, than the dx^arf fruit trees, especially peach, apricot, nectarine, cherry, pear, and apple. Lists and descriptions of desirable shrubs for the locality can be obtained from any good nursery catalogue. " American trees and shrubs for American homes " is a rule with exceptions, but one that has much good sense in its favor. Fi«;. ;>'.». Mission irrape. Larirest grapevine in tlic world Planted in 1.S42, in 189") bore over ten tons of jji'^pes, Carpinteria. California Fi(i. 40. Delaware grape Livini; iltM.iratioii for a tlininj; poroli 85 86 CIVIC BIOLOGY What exotic is more beautiful than our mountain laurel or our rhoclora, or more graceful than our sumacs and elder- berry, or sweeter than our pepper bush and wild rose ? It is no slight matter that a plant has become adjusted to its environment on a large continent through the many centu- ries of its struggle for existence. Flowers. With shrubbery now as the background come naturally, in the finest landscape effects, the hardy perennials Fig. 41. The most beautiful back door in Worcester, Massachusetts Fiij. 4:2. An ugly back door Compare with Fig. 4L — peonies, lilies, irises, hollyhocks and phloxes, goldenrods and asters, and a host of others ; also the annual l)edding plants, the cannas and dahlias, sunflowers, marigolds and zinnias, nasturtiums, sweet peas and flowering beans, and by all means, here and there, a few tuberoses and a bed of helio- trope and mignonette. These supply the finishing touches for both color and fragrance, and should be studied largely as a matter of individual preference and taste. Here is the test, however, for harmonious and pleasing effects in color, and, since we must live with our homes so much of the time, the liU.ME PLA^TlN(i AM) LAMKSCArE GAIMjEM.Nj; sT whole effect shuukl be restful and uuinfortable and as far removed from fussiiiess as possible. Vines. Especially on the house and buildings, vhies ad that with proper support they may be carried to any reason- able height. A growth of sixty-three feet of vine from a single bud in a season proves how quickly any extent of wall can be shielded from the hot sun of sunnner 1)V pm})- erly trained grapevines. For cnNcriii^- snil'a((' im other \ iiie. Fi<;, 4.']. ("alit'oinia iriiiin.'s Pliott).>;rapli by GtM)rj;o (,'. Ilusinami. I'nitrd States Di'paitnu'iit of Ay;ri<.'ultuiv 88 CIVIC BIOLOGY excepting possibly the Actinidia, can compare with the grape, if well established. The fact that it climbs by tendrils makes it much easier to train, prune, and control than vines which twine around their supports. The grape thrives in poor soil, wet or dry, and can be depended upon to flower and fruit for centuries, renewing its youth often from the root. Varieties differ much in form and size of leaf and in vigor and rapidity of growth. iMake a special study, with sketch to scale, of at least one good specimen vine before it is pruned back in the fall. Note variety, age, size, and height of main stem and length of several of the most vig- orous canes of the season's growth. Record, if possible, the amount of fruit pro- duced. J>v each member of the class selecting a differ- ent variety, the grapes best suited to the locality may be compared and learned. Houses, even in crowded cities, might be transformed Fk;. 44. YXowevf^ oi Actlmdia . , , .• i i i mto bowers ot shade and beauty by the adequate use of the grape alone. Actinidia argnta is a close second of the grape. After be- coming well established it is a most rampant grower, speedily reaching the tops of the tallest trees, and about l)uildings is likely to require severe pruning. The leaves are clean and glossy, with red petioles. Fragrant and attractive flowers appear in June, and the fruit ripens in September and October. This is a dull green drupe the size of a small plum, with a flavor and quality quite unlike anything American. The Aftl- nidia comes to us from Japan and is hardy and well adapted to our climate. Along with other valual)le importations from HUMK I*LANTiN(i AM> l.AM»M Ai'K < i A l; 1 >1:M M . ■>'.» the same suiiree it lias llic a(l\aiilagi' ol in»l liciug atlaeketl by American insect pests. Ivis(( ntf/nsa^ the Japanese (piinee, and the Japanese sn(>\vball are other eases in pnim. FoUowing are some problems in lan(ls(a[)e gardening: 1. Make a series of sketches, to scale, of yonr home gronnds, — gronnd plan and at least one view, — naming and locating all trees, shrubs, vines, and bedding plots with their contents. 2. Draw a ground plan and view of your home grounds as you would wish to ha\ e them. 8. Can you suggest any improvements in the street tree planting of your town, city, or neighborhood ? Diaw plans and specilications for special local prol)- lems of this kind — the treatment of certain streets or roadsides. 4. Let each memljcr of the class sketch a ground plan and view of the school grounds, giving both specilications and (<'>i. 5. Taking a local public s(pnu-e, park, c(»nun(>n. or pla\- ground as a special problem fnr analysis and stndy, can \ ou suggest improvements in its planting? The simplest principles of landscape gardening are otten alluded to as the ''J* B, 6'" of the subject. Tluw are based upon the pleasing arrangement of trees, vines, and slnub> and Fk;. 4."). Arti)iidia diynta Two viiirs, three years fruii, tniiisplantiiij,', jiffonl dense shade for ;i punli 90 CIVIC BIOLOGY open glades as found in beautiful bits of natural woodland. A. Leave open glades for air and sunsliine. They make even modest grounds seem roomy. B. Plant in masses, like the forms of clouds, leaving open vistas toward sunrise and sun- set and all pleasing views, and covering unsightly features of the landscape. C. Avoid straight rows ; Nature never plants that way. Finally we may study home and city planting as an uiA^est- ment. If well done, probably no equal expenditure will re- sult m larger returns. Figure out increased value of property along well-planted streets and in the vicinity of public parks. Let each member of the class study and analyze his own home with this pomt in view — fio-urino^ into the account first cost, yearly expenditures, and upkeep against enhanced values. A shade tree in the wrong place may be a positive injury to a home, while the same tree in the right place might enhance its value a hundred, or even a thousand, dollars. And in these, as in all similar cases, it is not the money values we are studying so much as the human health and comfort which they represent. The planning and planting of a home or a country beauti- ful enough to inspire the love of a people is no unimportant matter. Compare Russia and Japan with tliis feature in view and in connection with the results of the recent war. Fig. 46. Actinidla arguta in fruit CHAPTER TX PRACTICAL lUOLOCrY OF ACRTCri/rm A I. PlIODrCTlOX AND CTVIC UTILIZATION OF LAND Public prosperity is like a tree : agriculture is its roots ; industry and c«>ni- merce are its brandies and leaves. If the root suffers, tlie leaves fall, tlie In-anches break, and the tree dies. — Chinese saying, fmni Hoi-kins, ''Soil Fertility and Permanent Agriculture " In filial analysis civilizations rest mainly u[)(>u agricullui-al efficiency. At least, tins must be increasingly true as civiliza- tion advances. Tn this vital matter it is high time to cast aside all pride and conceit and wake up to a sense of nur low agricultural elliciency as a pe()[)le. In 1907 a total nt 20,000 square miles of agricultural land in .Lqian supi)orUMl 40,977,003 people, or 2349 people to the s(pn\re mile, wiili less than one dollar per capita excess of agricultural imports over exports. Fertile regions of both Cliina and .lapan sup- port as high as 3840 people per square mil(>. Compare these fio'ures with those for Belgium, the most tlensely poi)ulatcd country in Europe ; here less than 300 pcoi)le per scpuuv mile are supported. The best farming districts of the Lniicd States support about 30 people [»er s(iuare mile. Further, in little more than a brief eeniury we have swe[)t over a continent rich in tlu^ aeenmula1e(l fertility ol nr.my thousands of years, and in ignorance have wasted and depleteci ("mincer' rather than '' cultivated ") the soil. As land in one region has been mined out, we have abandoned it and moved to virgin fields, but now, with practically no more lu'w land available, we are forced to turn toward the more civilizing and socially ethical task of pcM-manent American agrieultnre. THE EFFECT OF THOROUGH CULTIVATION UPON THE FARMER'S OWN MIND, AND IN REACTION THROUGH HIS MIND BACK UPON HIS BUSI- NESS, ISPERHAPSQUITEEQUALTOANYOTHEROFITS EFFECTS. EVERY MAN IS PROUD OF WHAT HE DOES WELL, AND NO MAN IS PROUD OF THAT HE DOES NOT WELL. WITH THE FORMER HIS HEART IS IN HIS WORK, AND HE WILL DO TWICE AS MUCH OF IT WITH LESS FATIGUE; THE LAT- TER HE PERFORMS A LITTLE IMPERFECTLY, LOOKS AT IT IN DISGUST, TURNS FROM IT, AND IMAGINES HIMSELF EXCEEDINGLY TIRED-THE LITTLE HE HAS DONE COMES TO NOTHING FOR WANT OF FINISHING. I HAVE SO FAR STATED THE OPPOSITE THEORIES OF "MUD- SILL" AND "FREE LABOR," WITHOUT DECLARING ANY PREFER- ENCE OF MY OWN BETWEEN THEM, ON AN OCCASION LIKE THIS, I OUGHT NOT TO DECLARE ANY. I SUPPOSE, HOWEVER, I SHALL NOT BE MISTAKEN IN ASSUMING AS A FACT THAT THE PEOPLE OF WISCONSIN PREFER FREE LABOR, WITH ITS NATURAL COMPANION, EDUCATION. THIS LEADS TO THE FURTHER REFLECTION THAT NO OTHER HUMAN OCCUPATION OPENS SO WIDE AFIELD FOR THE PROFITABLE AND AGREEABLE COMBINATION OF LABOR WITH CULTIVATED THOUGHT, AS AGRICULTURE. I KNOW NOTHING SO PLEASANT TO THE MIND AS THE DISCOVERY OF ANYTHING THAT IS AT ONCE NEW AND VALUABLE - NOTHING THAT SO LIGHTENS AND SWEETENS TOIL AS THE HOPEFUL PURSUIT OF SUCH DISCOVERY. AND HOW VAST AND HOW VARIED A FIELD IS AGRICULTURE FOR SUCH DISCOVERY' THE MIND, ALREADY TRAINED TO THOUGHT IN THE COUNTRY SCHOOL, OR HIGHER SCHOOL, CANNOT FAIL TO FIND THERE AN EXHAUSTLESS SOURCE OF ENJOYMENT. EVERY BLADE OF GRASS IS A STUDY ; AND TO PRODUCE TWO WHERE THERE WAS BUT ONE IS BOTH A PROFIT AND A PLEASURE. AND NOT GRASS ALONE, BUT SOILS, SEEDS, AND SEASONS - HEDGES, DITCHES, AND FENCES- DRAINING, DROUGHTS, AND IRRIGATION - PLOWING, HOEING, AND HARROWING - REAPING MOWING AND THRESHING - SAVING CROPS, PESTS OF CROPS, DISEASES OF CROPS, AND WHAT WILL PREVENT OR CURE THEM - IMPLEMENTS, UTENSILS, AND MACHINES, THEIR RELATIVE MERITS AND HOWTO IMPROVETHEM - HOGS, HORSES, AND CATTLE - SHEEP, GOATS, AND POULTRY - tree's, SHRUBS, FRUITS, PLANTS, AND FLOWE,-^S - THE THOUSAND THINGS OF WHICH THESE ARE SPECIMENS- EACH A WORLD OF STUDY IN ITSELF. IN ALL THIS, BOOK LEARNING IS AVAILABLE. A CAPACITY AND TASTE FOR READING GIVES ACCESS TO WHATEVER HAS ALREADY BEEN DISCOVERED BY OTHERS. IT IS THE KEY, OR ONE OF THE KEYS, TO THE ALREADY SOLVED PROBLEMS. AND NOT ONLY SO : iT GIVES A RELISH AND FACILITY FOR SUC- CESSFULLY PURSUING THE UNSOLVED ONES. THE RUDIMENTS OF SCIENCE ARE AVAILABLE, AND HIGHLY AVAILABLE. SOME KNOWLEDGE OF BOTANY ASSISTS IN DEALING WITH THE VEGETABLE WORLD -WITH ALL GROWING CROPS. CHEMISTRY ASSISTS IN THE ANALYSIS OF SOILS, SELECTION AND APPLICATION OF MANURES, AND IN NUMEROUS OTHER WAYS. THE MECHANICAL BRANCHES OF NATU- RAL PHILOSOPHY ARE READY TO HELP IN ALMOST EVERYTHING, BUT ESPECIALLY IN REFERENCE TO IMPLEMENTS AND MACHINERY. THE THOUGHT RECURS THAT EDUCATION -CULTIVATED THOUGHT- CAN BEST BE COMBINED WITH AGRICULTURAL LABOR, OR ANY LABOR, ON THE PRINCIPLE OF THOROUGH WORK ; THAT CARELESS, HALF PERFORMED, SLOVENLY WORK MAKES NO PLACE FOR SUCH COMBINATION; AND THOROUGH WORK AGAIN RENDERS SUFFICIENT THE SMALLEST QUANTITY OF GROUND TO EACH MAN; AND THIS 'again, CONFORMS TO WHAT MUST OCCUR IN A WORLD LESS INCLINED TO WARS AND MORE DEVOTED TO THE ARTS OF PEACE THAN HERETOFORE. POPULATION MUST INCREASE RAPIDLY, MORE RAPIDLY TH'N IN FORMER TIMES, AND ERE LONG THE MOST VALUABLE OF ALL ARTS WILL BE THE ART OF DERIVING A COMFORTABLE SUBSISTENCE FROM THE SMALLEST AREA OF SOIL. NO COM- MUNITY WHOSE EVERY MEMBER POSSESSES THIS ART, CAN EVER BE THE VICTIM OF OPPRESSION IN ANY OF ITS FORMS. SUCH A COMMUNITY WILL BE ALIKE INDEPENDENT OF CROWNED KINGS. MONEY KINGS, AND LAND KINGS. IT IS SAID AN EASTERN MONARCH ONCE CHARGED HIS WISE MEN TO INVENT HIM A SENTENCE TO EE EVER IN VIEW AND WHICH SHOULD BE TRUE AND APPROPRIATE IN ALL TIMES AND SITUATIONS. THEY PRESENTED HIM THE WORDS, "AND THIS, TOO, SHALL PASS AWAY." HOW MUCH IT EX- PRESSES' HOW CHASTENING IN THE HOUR OF PRIDE! HOW CONSOLING IN THE DEPTHS OF AFFLIC- TION ' "AND THIS, TOO, SHALL PASS AWAY." AND YET, LET US HOPE, IT IS NOT QUITE TRUE. LET US HOPE RATHER THAT BY THE BEST CULTIVATION OF THE PHYSICAL WORLD BENEATH AND AROUND US AND 'the INTELLECTUAL AND MORAL WORLD WITHIN US, WE SHALL SECURE AN INDIVIDUAL, SO- CIAL AND POLITICAL PROSPERITY AND HAPPINESS, WHOSE COURSE SHALL BE ONWARD AND UPWARD. AND WHICH WHILE THE EARTH ENDURES, SHALL NOT PASS AWAY. -ANNUAL ADDRESS BEFORE THE WISCONSIN STATE AGRICULTURAL SOCIETY, AT MILWAUKEE, WISCONSIN. SEPTEMBER 30, 1859. ABRAHAM LINCOLN, "COMPLETE WORKS," VOL.1, P. 579 FF. , 02 r.lOUKiV OF AlfKICULTUUAL IMM )l)l ( TK )N W,^ Agricultural efficiency. Wherever [)<)ssil)li' let eacli iiummImt (»t" the class choose some Icjcal plant (»r animal in Viii.n A\ i:i;A i:\ FKK ACHK VlKI.U KKFieiKxev Low Kl-FICIKNCV Potatoes 500 bu. 0() b\i. 10 fiiOO.OOO.IXKI Wheat 50 bu. ]4 lui. 28 |.U(I(),(J(M>.(KK» Cotton 1 bale 0.85 bale 35 I.IHKI.OOO.DOO Corn 1 100 bu. (icc(»r(l 231) bu.) 28 bu. 28 2.t;S().(ly the nu're addition of brains ( " cnltivati'il thouoht") to breeding' and selection of varietv, and scientitic precision in fertilizers and culture methods, this standar bushels of culls i)er acre. With the staiis I might say in America. To sp«'ak entin-ly within bounds, it is known that fifty hushcls of wheat, or one liuudred husluds of Indian corn, can he ^(roduced from an acre. Less than a year ago I saw it stated that a man, hv extraordinary care and lai>or, liad oroduced of wlieat what \vas e<[ual to two liundred husliels from an acre. Hut take fifty of wheat, and one hundred of c(»rn, to Ix* tlie j»ossihility, an throughout the United States; and this year an intelligent farmer of Illinois assured me that he did not Ixdieve that tlie land liarvested in that State this season had yielded more than an average of eight bushels to the acre: much was cut and tlien abandoned as not worth threshing, and much was abandoned as not worth cutting. As to Indian corn, and indeed, most other crops, the case has not been much better. For the last four years I do not l)elieve tlie ground ]»lanted with corn in Illinois has produced an averagt^ of twenty bushels to the acre. Lincoln admits too much for the sake of argument, however, ^vhen he says : Umiuestionably it will take more labor to [H'odiice fifty bushels from an acre than it will to ])roduce ten bushels from the saiiH' acre ; but will it take more labor to produce fifty bushels from one acre than from five? Unquestionably thorougli cultivation will recpiire more lal»or to the acre; but will it require more to the bushel? Recent experiments have pr(n'c. A siii*;"k' specimen nl plant oi' aninial nia\ ])r()(luee a pliciiniiuMial yield, l)Ut tlif pi-oo-eiiy may icnciI to loafefs and Koai'dei's. Pure-hreil strains liaNc hccii cart'lnlU sclcctt'd lor o'cnmations. iinlil all had liere(lity has hccn wciMh-d ont and the protrcnv can he relied upon to he tlioroiiL;hhre(ls, that is, to \ irld a ninform, standai'd Tesnlt. ( 'ollect reeoi-ds of \ afions pnir-hird strains in the neii^hhorhood and compare yi(dds, as hdow : Differ Kxci.s i\ Vii.i.i> Dik io ^'Al:ll.l^, l!\ I'l i:i \i i ni >i \ii«.\, KosTKKN, Canada Huron wheat Marquis wheat .... Kubanka wiieat .... Heeves' Ho.se potato . . Auieriiau Woii(h'r potato YiKi-D I WicKiirr Ti.mkto | Tx-Maukkt Pi.i! A< Ki: iiat BisiiKi. .\r\Ti icr. aim.i; 78 1)U. 70 1)11. :{7 hii. <;2;] i.u. 87 '"1 I.u. 107 (lay.s 98 (lays 107 (hivs tse is nnich infestef Seven Elements Essen t i a i. Plan r-Ft »< > i » Elkmknts Phosphorus rotassiuni Magnesium Calcium Iron Sulfur Nitrogen (vir2:in N.W. soil)i Nitrogen (in air over acre)i Pounds in 2,(J(J0,000 Poixnsixioo YkausSi p. I'olNDS OK Avr.K- Bt'MIIKLH OF TLV WILL Aimi|)1«* juinnds, or 2*2(10 pounds, a loss of S-j-50.(MJ wortii (•! introj^cn per acre. KKKiii-irv CoNiAiM I) IN Di III: i: I N I ]"\i:M ( i:<>i's (.Xpproximalc! uiaxiniiiin unioiints n'movahli- jn-r :nrt' HuimuUy; YiELn I'ol N 1>S I'll \ 1 1 1 ! < > 1 > I ( t Nitko<;i:n Piiosi'HoKis l*OTAS.SirM \ \ I.I 1 1 Corn, grain ... 100 bu. Stalk.s, cobs . . . 8 'I\ 100 50 17 10 54 .si(;.(;5 10.03 Corn crop . . . ... Wheat, grain . . 50 bn. Straw ' 2.1 'I'. 1 50 71 25 28.1 12 4 -•> 18 45 27.58 11.7'.» 6.57 Wheal crop . Alfalfa hay . . . Cotton lint . . . Cotton seed . . . Cotton .stalks . . 8T. 1,000 1b. 2.0001b. 4.0001b. U6 4001 3 68 102 1(18^ 63 47 59 6 112 ' 25 18 57 0.8 i<; A 11 18 58 102 1 111 50 is..8r, 72.<;n .7(1 10.0-J 10.88 Cotton croji . . ... Potatoes .... 800 bn. Apples (iOObn. Leaves 4 T. Wood growth . . .'^oftree 2!t. » 18 5 t 2 82 *.*(! 57 4 7 5 81. (K» 15.28 lu.r.-j 11. HH 1.2(1 A]>pU' cr(»p . . Fat cattle .... P'at hogs .... Milk Butter 1,000 lb. 1,0001b. 10.00011). 400 lb. 1 1 • > 7 0.2 lO't 1 1 12 «i.l 28.73.5 |)oun Fnriifr Fig. 40. Banostine BoUe de Kol Accordinof to above fio-ures, five such co^^ s would vicld the net i)r()duct of 25 of the })etter dairy cows, and their calves might be worth even more for breeding purposes. 'i"he highest dairy record for 1913 is 1073 pounds of buttt-r tat, scored by Mav Rilma, a Ouernsev. And so i)rogress in cM-rv brancli of agriculture becomes a game which, if well played, may ever '' lighten and sweeten toil." Poultry offers perhaps the most practicable field f(n' ele- mentary experiments in the breeding and care of animals, antl 104 CIVIC BJOLUGV any branch of the indnstry, from pigeons and chickens to geese and turkeys and native game birds, is likely to yield a sub- stantial profit from the start. One of the chief problems of present interest is that of breedhig for egg production, the accepted unit being the number of eggs laid in a year. Some recent American records are shown in the table belo\Y. A^ariations in crrowtli of flesli or fat are similar to those in milk and egg production. Tliis means that one animal may not digest or assimilate food as well as another, or one may use its energy in developing nervous activity (which is not edible) while the other is grow- ing flesh and fat. Experiments have shown that one animal may thus require over 30 per cent more food to gain a pound of flesh than another. Here selection and thorough breeding- are saving enormous losses and increashig productive efficiency. ri(;.50. Hen C. 521 Bred by Professor James Drydeu, Corvallis. Oregon Ami:i;ican Eoa Records Year Number of Eggs Description of Hex 1910 282 Barred Plymouth Rock, AcTicultural College, Giielpli, Ontario 1011 281 White Plymouth Rock, Lady ShoAA-yon, Illinois 1012-101:^, 30;^> Hen C. 521, cross hetween white Leg- horn and barred Plymouth Rock. Reared at tlie Oregon .\gricidtural , ' College, Corvallis, Oregon ^ 1 This is held to be the world record up to date. In attempting to make a record of this kind it is necessary to have official control to guard against any possible mistakes or falsification, if the records are to stand. BlUL(XiV OF AGKK'ULTL'KAl. PK«)I>1 ( 11<>N lo.) Special problems. Kccj) the lecunl of a cow and tigiin* jiiolil or Iom.h uu basis ol cost of feed and care. Traivnest a flock of hens and study variation iu eg^ production, making results tli«' basis for future bn-ediny and improvement of flock. Try different chemicals or l( ilili/crs in .stii|>s across tin- reci:il needs of soil or < rop. I'lo. ol. Cjfrowih and (»pi)ur- tunity One (»f the H cari'ots. tliimiefl to 4 to the foot, whieh w eijihe'2), and thin jdants to different distances (Fig. 51). Test seeds of all kinds before planting in garden or Held. l\\ blow- ing off the light, small seeds and jtlanting the o or 10 jK-r cent of the heaviest and strongest seeds, crops of remarkable vigor and <'venness an* 106 CIVIC BIOLOGY secured. Saving seed from strong, productive plants — potato, wheat, corn, cotton, timothy — has given rise to a large increase of production without other change or difference in method of cultivation. In order to unite the work of the school with the interests of the communitv, offer to test all kinds of seeds, especially corn, if in a corn- raising section. An increase of from 30 to 40 per cent in the corn crop of the district has resulted from such testing. A most remarkable fact has developed with reference to seed potatoes. Immature tubers, about half or two thirds grown or ripened, may pro- duce twice as many potatoes as dead or so-called overripe seed from the same field. Immature seed potatoes are specially raised and saved in Europe, and this one factor may account for the great difference in favor of European over American yields — more than 2000 bushels per acre as compared with less than 1000 as the best American record. This must be a matter of activity, or vigor, of buds, or of availability of the starch food supply. For information on raising seed potatoes, write your state experiment station. Work for record production of thoroughly cultivated, pure-bred, pedi- gree single plants — the world-record hill of potatoes, the best plant of corn, wheat, cotton, oats, sunflower, tomato, cabbage, currant, raspberry, blackberry, grape, peach, plum, cherry, apple, etc. More may be learned from intensive practical study of a few plants, each of which is a special experiment, than from any number of less intelligently cultivated acres. In all such problems, viiih both animals and plants, we need to learn all we can about the laws and forces of heredity, breeding, and breeds, and also all we can about favorable en- vironment, feeding, care, and treatment. The former topics are treated further in the appropriate chapters. The latter should be made subjects of special study whenever it is possible to have the care of either an animal or a plant, and to secure an authentic record. Any one, by applying " cultivated thought," may render a world service by whining a new world record. rTTAI*TEli X INSECT TYPE PROBLEMS: I.M I'OinAN'r 1 LIKS If each efrg of the CDiuinoii lioiise tiy should (leveh)i). and each of the larva? should find the food and temperature it needed, with no l(»ss and no destruction, the people of the city in which it happened would suffocate under the plague of flies. — Joudan and Kellogc;, " Evolution and Animal Life," p. 59 And as for the typhoid liy, that a creature born in indescribable tilth and absolutely swarming with disease germs should be practically invited to multiply unchecked, even in great centers of population, is surely nothing less than criminal. — L. (). Howaud What flies do. During the Spanish-American war typhoid fever wounded 20,738 United States sohhers and killed 1 r),SO. The chief means of spreading this infection were the swarms of flies which infested the army encam[)mcnts. '1\> cmphasi/.e this menace to health, Dr. Howard has suggested that we change the name of the house fly to ijipliold fly. This opened the way for thorough investigation of the insect, and its filthy habits were soon found to render it the possible distributor for many other filth-disease infections. Tuberculosis, cholera, enteritis (including epidemic dysentery and cholera infantum — the fly-time ''summer complaint" of infants ), spinal menin- gitis, bubonic plague, smallpox, leprosy, syphilis, gc.iiorrliea. oi)hthalmia, and the eggs of tapeworms, hookworm, and a iiuiii- ber of other parasitic worms — for all these and many more the fly has been discovered to be a ready actual or potential carrier. Since the fly is proved to l)e such an active agent of transmis- sion between all manner of lillh, on which it feeds and in which it breeds, and human foods. Dr. Stiles, of the Hookworm Commission, has proposed to call it the filth-diseiuse tly. 107 Fio. 53. Flytraps for barnyard or stable window 1, first model as found after being set one week ; 2, same, emptied hy lifting off top frame ; trap lifted from bottom board to indicate construction ; 3 and 4, larger window trap, sliowiug construction and in position. The small traps in 3 are merely to take off samples of the catch for analysis. These traps are made to fit the window about which flies naturally congregate, gunny sacks are hung over the other windows to darken them and to flap in the wind, and, when properly placed and managed, one trap will catch practically all the house, stable, horn, black, bot, and blow flies and even the mosquitoes that try to get in (U- out. or that either feed or breed about the stable 108 IMl'oKTAXT FLIES 1011 First necessary step in health conservation, lluj most sig- nificant fact in the situation is that only l»y cliniinating tin- fly can we form any notion of liow imuli present sickness it On this account Jicahli olhccrs ex cin w Ihmc arc is causuij«>sf(l to H'present a imxlt-l 12 iiichos widt-. 12 inches tall, ami 10 inches thifk — a cunvenient siz.e for onlinaiy use in a city yard. The speciti- cations will then be r two i-nd boards A inch or \ inch thick, 12x10 inches ; four strips for the top frame, Ix A inch, two I'i inches and two 9 inches lonjj; ; wire for top frame, 10x12 inches (raw edyes folded over ^ incli); two top shoulder strij>s IxA inch, 11 inches long; four bottom strips \ inch thick ami 12 inches lon^r, two \ inch wide and two 1 inch wide ; screen wire for sides ami bottom in one piece, 12 inclies wide and 41 inches lt)ng (allow 1 inch to fold over raw ends, .', inch each) roSgy:'aarrQA^/;^.-foIds in the sides, which do most of tlie catchini; wIumi the trap is set in a stable wimlow . P'old the wire squarely at the ani^U's indicated in the tiirure, .1, />'. ' ', /'. A". /■', '/. and at these ixtints sinp iii ■> indi. Fold the i-indi Haps to a rii;ht ani:le, tiirninir tin-ni in directions indicated by small hooks aloim the ce a sharp ".><>' aniud"'. not a rounded dome, or the tlii'S will not tind the holes.) Three holes are snfb- eient for the side folds. Pnneli all these holes after tin' wire is tacked in jdare. The traj) is really as simple as a box. With proper fools a boy ouixlit to <-ut out the end boards, rip Out the strijis, nail up. fold, and tack the wire, all in :il>ont one hour. The main feature of the trap is the {-inch crack opeidnj,' iijnranl to tin* bait sayino-, in eft'cct, "Clear tlic air of tiiis universal distrilmlor of filth, in order that we may he ahle to trace (dhcr uays of dis- ease infection." Thus cxtci luination **( llics cdnies to la- tin* necessary first step toward the effective prevention of disea.se. 110 CIVIC BIOLOGY The evidence we have indicates that abnost all dysentery and summer complaint (millions of cases and 56,000 deaths annu- ally) are caused directly by the bouse fly. One third of the typhoid (about 300,000 cases and 30,000 deaths) is estimated to be caused by flies, and an unknown and unknowable pro- portion of tuberculosis, spinal meningitis, and other filth mfec- tions. Thus it is quite possible that flies carry the infections which cause from 70,000 to 100,000 deaths annually. About 2 people m the United States die yearly from bites of poisonous snakes ; rabid dogs bite about 100 with fatal effect. Can you think of a more deadly animal than the common typhoid, or filth-disease, fly ? Spread of animal diseases. An additional factor is the prob- able causation of disease among domestic animals. As they are not even partially protected by screens, and flies swarm about their foods, epidemics of such diseases as fowl and hog cholera, bovine and fowl tuberculosis, and foot-and-mouth disease are almost certamly spread by flies. This matter has not been mvestigated as it should be, but we are likely to see a remarkable clearing up of animal diseases as soon as we exterminate flies from our farms. Futility of fly screens. Finally, a minor consideration is the (estimated) $12,500,000 we pay annually for screen wmdows and doors, which are not only expensive but disagreeable at best. These do not solve the problem, even if they did keep the pests out of our homes. We must prevent flies from contaminating foods on the farms and in the stores and mar- kets of our cities. Thus the fight against the common enemy must be community-wide, and, since one careless or ignorant household can breed flies enough to mfest all the houses within a quarter of a mile, positively every one must cooperate. Need of universal cooperation. The general situation, espe- cially the relations between country and city, is shown so clearly in the following case that we quote in full from the IMPOKTANT FLIES 111 Bulletin of the Indiana State Board of HcaltJi, July, llUri. The note is entitled THIS HAPPENED IN INDIANA A few days ago a |>liysiciau in Martin County called on tin* stat4* bacteriological laboratory for Flexner's antinieningitis scrum. Dr. Sinionds went to the case and fonnd a sevcn-nionths-old baby suffering from a very severe gastro-enteritis with the not infreciucntiy accom- panying meningism. The father of the child was a farnu'r living in a four-room honse with few or no modern conveniences. On th<' wall of the largest room was a family-hi.story chart done in brilliant colors, with three columns of lines for the record of marriages, births and deaths. The parents had been married ten years and six children had been born to them. In the death column were the names of four chil- dren, all under two years of age. Another name has since been added to this list. The cause of this sad story became evident on inspection. There was a shallow surface well in the back yard, a short distance from an open privy. A large i>ile of manure lay uncovered, almost against the side of the barn. If this farmer had attemi»ted so unthinkal)le a thing as transforming his premises into a fly hatchery for commercial pur- poses, he could not possibly have achieved a more brilliant success. The family and several of the neighbors were eating dinner on the back porch. Flies were swarming all over the table, but showed a si>ecial liking for a particular dish. They were so thick on this that it was absolutely impossible to tell definitely what it contained until one of the neighbors swung her arm over the table and cleared them away long enough for one, by looking quickly, to see that the dish contained cotr tasre cheese. The flies were so thick in the house that it was only witli difficulty that they were fought away from the field of the spinal puncture and kept from lighting on the instruments. On the death certificate the cause of the death of this child was doubtless given as "Gastro-enteritis." It would have been more in k. •«•))- ing with the facts to have said "Poisoned by Flies." Different kinds of flies. About 43,000 ditToront kinds <.f flies and related o-iiats and nios(iuitoos liave been descTilu-d. and Dr. Howard estimates that this trroui) of insects contains no less than 350,000 species for the whole world One larixe 112 CIVIC BIOLOGY family, the tachina flies, many of which look much like com- mon house flies, feed upon other insects and are among our most effective helpers hi holding certain msects in check. Tachina flies are being imported from Europe to destroy gypsy and brown-tailed moths. Syrphus flies are another large family which feed upon other insects. Tachina and syrphus flies are found about rank vegetation in which other insects abound. Of flies caught in and about houses the typhoid fly gener- ally numbers over 90 per cent. It is distinguished by the '' elbow '" on the fourth A^ein as it curves up to the third vehi near the tip of the wing (Fig. 55). The proboscis is an extensible trunk adapted for lapping up liquids, and cannot be used for either bitmg or piercing. The foot is provided with cla\As for climbing over rough surfaces, and also with two pads (pulvilli) covered \\'itli sticky, tubular hairs, which enable the fly to walk on ceilings and windowpanes. No more effective mechanisms Fig. 55. Wings of (a) house fly, (6) stable fly, (c) little house fly, (d) horn fly Photograph l)y I. A. Field for collecting dust could be designed than a fly's feet and proboscis, a combination of six feather dusters and thirteen damp sponges. The constant " cleaning " movements of flies are clearly designed to rub off' and scatter the adhering germs everywhere they go. The '' little house fly " (^Fmtnia canicuJaris), smaller than the common fly, is often seen in swarms hovering under chandeliers. In breeding and feeding habits it resembles the house fly. Other flies found about houses are the f ollowmg : Bluebottles, greenbottles, and flesh flies, or blowflies, which so frequently lay thek eggs on meat. These flies are scav- engers, but we can dispose of dead animals in nuich more I.Ml'oi; IAN r M.IKS 11:? sanitary ways than by Icax ing llu'in lo tlic hlow liics. Krlaird to tlu'se, and of importance in tlie sontlicrn states, is tlie scrrw- ANorni Hv (^Clirf/soinf/la innre.llnria')^ \\\\\r\\ on iposits (^ii wmmtls, tlie ma^'^'ots tVedint]^ upon ]i\ ini;" tlesli. Tliese are tiie tlies tliai sometimes lav their e^ws in nostrils oi' ears ol" children (tr ul' people it asleep out ol doors in the daytinu', the nuiLCirnts causing painful and e\i'n fatal wounds. 'I'lie stable lly {Sfoinii.rif^ (ui/cifrtfn.s ). which has soiiicwhal the ap[)earaiice of the hcaise fly, excejit thai it is pro\ ided w ilh a strong', })iercino- beak, sucks the blood of animals. This i\y is now con\ icied of inoculatinii' the germs of infantile paralysis with its bite. It also causes ofreat sufferinsf to cattle, riie smaller horn fly {Hi ways of attack, we nuist study natural eiuMnies trom every point of view. The ease with which mos(piitoes have been exterminated has suggested similar methods for dealing with flies. But mos(piitoes breed only in stagmuit water, which is easily drained, tilled, stocked with fishes, or oiled. Flies breed in decaying tilth, chieflv in hors(^ manui-e. but can bree(l in any Fk;. 0(5. Stablt* Hit's tluU a boy, witli an ins«*ct lU't. cauirlit 1<' IHK GVi'SV .MmIH 1, ei^c: clustor : 2, siiiule e<;,i; (enlar«.aMl ;U)ont four (liainetei"s) : :J. catcriollar: 4 and 5. female ami male pupa^ ; (\ ami 7. female and male moths : S. im- ported lion beetle devourinir a cater])illar. (All exeept 2 alxtut natural size.) IMFUKTANT FLIES 11;*) aiititiuated methods of storing, piliug, aud rolling. All staMc wnsUt should be hauled and spread on the land daily. It will generally become too dry for flies to breed in. The most expensive and disastrous I'allacy in lliis u hole pn»bl«Mii is the "fly-tight" pit or receptacle for stable wast<'. This has been ami still is recommended under the plausil>le excuse, "Make them flv-tight, so the flies cannot get in to lay their eggs." Eggs by tlic luillion an* laid in the material he/ore it is put into the pit ; the tight construction, nuikes it an artifi- cially perfected fly incubator, and when it is opened, as it must be dailv, the flies swarm out. By this method w'e actu- ally go to great labor and ex- pense to breed more flies. In cities, instead of fly-tiglit stable pits, we should have, by city ordinance, readily ac- cessible elevated hoppers or concrete-floored bins, and the city should arrange to empty these clean to the concrete at least once a week from May to October. It would be much better, for purity of air and Fig. 58. First model of outdoor fly ex- terminator has canirht 'JOK") tlics. It cauixlit "J (juarts (about ir),(NH») tlie tirst day, aiir tlics. Dcsii^iii-il bv thi- authur economy of fertilizer, to have This has been set fifty-eijilit minutes ami this done daily. By proj)er or- ganization of routi\s the city should be able to gather and dis- pose of the material at greatly reduced expense over scattering and irregular j^-ivate cleaning. It ought to be managed >. . .i> i.- p.ij stal>le keepers fertilizer value of material, less cost of handling, and still deliver it regularly to gardeners and farmers, as jdanned for. aiul for much less than it costs to collect the material privately. It tliis is not feasible, then the proper ofticers can license farmers and truck gardeners to collect from specified stables, under contract tt) remove the material in the cleanly manner 8|)ecified and at weekly intervals. Besides stables, the city should maintain strict supervision over all 116 CIVIC BIOLOGY stockyards and slaughter-houses, public dumps, aud all industries which handle materials likely to breed flies. It is utterly uncivilized and brutish that accumulations of filth, which allow flies to both feed and breed, should be permitted to vitiate the best efforts of thou.sands of good people, cover their foods and homes with filth, and cause not only annoyance but disease and even death.^ The eggs of flies batch in about eight hours into maggots Avhich feed actiyely and complete their growth in six or seven days. They then burrow into the ground under a manure pile (hence the need of concrete floors) and transform into brown puparia, from which they emerge as adult flies in three days. After comhig out as adults they fly about over an area not generally more than one thousand yards in diameter, and feed or drhik from two hundred to three hundred times a dav for from tm to fourteen cltn/s before maturing their flrst batcli of eff^rs. This actually delivers the enemv into our hands. It means that, with flytraps on every garbage can or swill l)arrel, and with everything most attractive to flies very carefully kept in these receptacles, not a single fly will succeed 1 In <\ large city the writer found, opening on an alley, and within a block of a great open public market, a pile of horse manure, entirely unprotected, at least thirty feet in diameter at the base and fourteen feet liigli. The outer layer of this whole pile was a solid, moving mass of housefly maggots. A moderate estimate for that pile would be ten barrels of fly maggots, which would make, when they reached their growth and emerged, from twenty to thirty barrels of flies. These flies were swarming black over the meat blocks and meats, fruits, fish, candies, cakes and pies of the whole market. The market people (some few had electric fans) were wearing themselves out shoo- ing those flies from one to the other and back again. The filth of that manure pile was being carried into thousands of homes Avith the market supplies. The flies were feeding in the market and in hundreds of kitchens in every direction and going back to the manure to lay their eggs. It is unfair to place on the inarket people the burden of trying to protect their foods from flies under such conditions. The horses in this large stable were kept on the second floor ; the manure could have been cleaned into a hopper opening downward into a dump cart in the alley, and every morning before daylight, by effective civic organiza- tion of the work, it might have been out in the country and at work In the laud, a paying proposition inste;ul of an insufferable miisancc. IMPoirrANT I LIES 1 1 ill feeding for two weeks witlimit grtliiig (•an<4;lil. In tliis ease no more eggs will he laid, and tlu' pests will vanish. Possible multiplication. Allowing ten days for i'\^^^s tn heconie adnlts, and, for conxcnience, It'ii days of frcMJiii^ hetween eniero-enee and o\ inosilion, fiL'nriin'- ilial a llv la\s one hnndi'ei] and fiftv eggs at a hatch and lives to l;i\- six hatches, eoni[)nte the increase of a pair of llies heginning to lay May first. Half the i)rogenv are snppose(l to l)e females. Test the following ligni-es: May 1(1 l.")-J Hi.-s I'd M)'2 tli.'s :;(i ll,7(rj tii«'s June 1(1 :}4,:{0L> fli.-s •JO !)ll,J>:)-2 Hies ■M) (1,484,700 flirs July 10 7-2,280,SOO rti.-s ' 20 :vjr),o:i:i,800 flies ;}() 1 :>,7}(;.(i70..')Oo flifs The common-sense cpiestion is. Why not let this pair of flies catch themselves in May ? This rapid ineiu'ase also means that anythingf short of extermination is hardly worth the etVori. A fly is possessed of no more ennning than shot rolling down a ])oard, and the last pair will run iiit(^ a trap as easily as the lirst. Why ]n)t let them all catch themsidves? Hibernation. Yovv few house flies snrvixc the winter in Canada and the northern states, and these hihernaie as young adnlts in cracks ahoiit hnildings. They come out ot winter (piarters ravenonsly hnngry and fee(l lor ahout a wt'ck. at least, hefore heo-innhig to lav. if at this critical tiuu- e\eiv household had some effective form of outdoor trap ready tor them, every earlv sju-ing hreeder would he i-aught, and the 1 This last figure would eiiual about 14:i(i7.> bushels of flies from one pair in three months. If we continue the breeding through Aupist and Septem- ber, the figure is 1.000.181. 240..310.720.O(M).oO0.(.)O0.(MH) fli.-^. 118 CIVIC BIOLOGY whole battle would be won for the season. The first commu- nity that does this with absolute thoroughness, and whose every member is intelligent enough to realize the 143,000 bushels that one pair might propagate in three months, will first be free from the world-wide, time-old plague of the " house fly, disease carrier," and from the diseases it carries. 1 2 3 Fig. 59. Outdoor fly exterminator as adopted for manvifacture 1, attached to garbage can {make hole in cover as large as inside of ring, to let in plenty of light) ; 2, on ring with which attachment is effected ; 3, on its own good-sized bait pan. Designed by the author Sketch a plan which shall prevent all flies — typhoid, stable, horn, and flesh flies — from either feeding or breeding about your own home. If the fight is carried out of doors into the camps of the enemy, this becomes one of the easiest problems to solve m the whole range of insect life, and its solution com- pletely relieves us of the need of screen windows and doors, as far as flies are concerned ; and, expense aside, screenless windows and doors in summer are a luxurv. i.MPoirr.vN r fliks 119 Study and experinit'iit with all the most likuly devices on the market for outdoor fly extermination, and invent better ones yourself, if you can. With the traps already availalile, outdoor lly extermination, as one man who tried it has said, ''is so easy as to he alnn)sl humor(tns and so etTeetive (tiie flies disappear so >;uddenly )as to he little short <>r the nncannv." Fig. 60. " Getthelastone " tiy nets The liaiidles are lonj; enoujih to rcarli the ct-ilini; w ithout stretchiiiii ami tlie t1y the tra|w and into the house. Make tliein of tiiier-niesh niosi-ol>al>ly be better to offer one cent a hundred, and be sure to avoid i)ayin<; for bluebottles, j^n-enitottles, or other lar;;e flesh flies. These will always be killed alonii: with the rest, but they l>e^dii active Ivreeding Huuii earlier in the sj>riiu; and, if not ruled out, iui;;ht easily swamp any treasury. The four flies whose wings are shown in Fig. 55 niay be included in the list to be j>aid for. Life history of the stable fly. During the summer of lltTJ a seriinis outbreak of stable flies occurred in grain-raising sections of northerii Texas, Oklahonui, Kansas, and \cl>raska. Cows fell off in milk and even went dry, ojierations had to l>e susi>en|>n»x- imatc order of iinj'ortance: in the wet, fermenting straw of oats, rice, bailev, and wheat, and in lioise and cow manure, esj>ecially w here nd\ed witli straw. Thus most of the trouble arose fiom decaying strawsta<-ks in the fields and from uncleaued liaiiiyars the winter in the larval or the pnpal stage :ind so are ready to enierge during warm spells in winter ans shown in Fig. ■'>:'>. Life history of the horn fly. The horn lly breeds t'\clusiv(dy in freshly dropped cow manure. The flies leave thect»ws and swarm to fresh ecially in the early morning h«»urs, and by following the herd a few mornings with a hand sj.rayer loaded witii kerosene or anv go<»d oil mixture used In keep the flies ofl from ani- mals practically all the horn Hies can be killed, ('(.vering the fresh droppings with lijue also ju-events the flies from breeding in them. Health statistics. Watdi bx-al licalth statistics and !•«•- purls, especially as to tyi)li<'i«l ami cases and dcallis hniu suinnier (-(uiiplaiiit, tiilx-ivulosis, and piicumoina. and any 122 CIVIC BIOLOGY other prevalent filth mfections. If the stable fly has been successfully dealt with, compare the monthly reports on cases of infantile paralysis with corresponding reports of previ- ous years. ^ Some people may object to fly campaigns on the ground that flies were created for a good purpose. Any such should refer to Exodus viii, 31 : And he [Moses] removed the swarms of flies from Pharaoh, from his servants, and from his people; there remained not one. All we ask is that " there remain not one. ?> 1 While the above is passing through the proof the discovery is announced that maggots of flies (species not determined) which develop in the bodies of chickens dying of limber neck infect animals to which they are fed with the germs of infantile paralysis, or poliomyelitis. All such fowls should be com- pletely burned up. If buried, the flies easily work their way to the surface and may spread the infection. (Latest evidence points to contact infection by human carriers, and excludes any influence of flies or other insects in spreading this disease.) CTTAPTET^ XI INSECT TYPE I'UOBJ.EM.^ : MObC^l ITOE.^ Mosquitoes and disease. Tlic tliscovury tluii luahuia and yellow fever are Uaiitsiiiitted. by certain mosquitoes slious liow Fi(i. (il. ^[}io2^h(Uft mosquitoes and malaria in a city A, Anopheles moscinitoes brcMMlinj? ; dots, lumsrs wIu'it malaria «><><'urs. Tiiere would 1)0 more dots in various parts if then' wv >"v li..iis,-v; important a role an insect may play in llic nlVairs of liuinan life. No obstacles have sd seriously IjIocIumI llic proj^n-ess of civilization in the tropics as these two diseases. The Panama 123 Adults Pupoe Fig. 62. Left, Annphfles (malaria) : center, C'ulex plpiei)'^ (common nuisance) ; right, Aecleff calopitfi (yellow fever) 124 MUSQL'ITOKS IJ.l Canal lias boi'ii iiiadt' [xjssihlc iiiaiiilv llirnip^li iln- coiiirol of malarial and yellow -tVvt'r nios<|iiitoc*s. Of tlic ten gi'iK-ra ot uios(|uiioi's ol Noii ii A nu'iica, , [ti'>j,/(, /i y, Acih's (Jie' dez), d\\i\ ( 'i(/r.i {-{nn-vvw us cliictly. riinc an- V\m- species of A//'7>/<- r/t's (listiil)ul('(l I h roll « 'lion I the fountrv, and it is important to remember that it is throuo'h these mosquitoes only that malarial t"e- \{'V is spread. 'I'his disease is not as fatal as some others, hut is important he- eaiise so \\idely distributed and iH'caiise in ma- larial countries from 2o to t5<> per cent of the people are al- Hieted. In tlie United States, according to the Kl(.. <»:'.. .l.|iiilM Ktr^i. l;ii\;i, pupa, ainl adiill estimate of Dr. L. (). Howard, there occur :;,(mu.(l(l0 cases, causin-; a l«».ss ol $10(1,000,000, annually. In India, where the fever assumes a fatal form, 5,000,000 people have succund)e(l to it in one year. Anopheles is particularly active durin*,^ the early part of the nioht. ll niav be distinoinshed from other mosquitoes at a 126 CIVIC BIOLOGY glance by its mottled wings and by its posture. It resembles somewhat a thorn in the wall, standing as it does at an angle of almost ninety degrees to the surface, with proboscis in line with the body, whether the surface is vertical or horizontal. Jan. Feb. Mar. Apr. May June July Aug. Se pt. Oct, Nov. Dec. 1 1897 1900 1895- - 551 \ 1890 Av. 4G2 1900- 1898- 1897- 189G - -1278 1897- - 828 / \ 1898- - 138 / \ 1899- - 102 J J ^^ J / \ 1900- -400 I ^ 1901- - 17 - - 5- \ / \ / / \ / / / , ,y \ -/. ^ - \ \ / / \ \ \ \, ^ /' / / y \ ^ N N :^^'" ! 189G /- / / ^ \ 1 J \ 1 ^"^ 1898- 1898- 1900-1901- Fig. 64. Yellow fever in Havana Aedes calopus. This is the mosquito responsible for the transmission of yellow fever, which in the memory of man has left its dead unburied in some parts of our country. Indeed, in the early part of the summer of 1905 a mosquito mfected with MO^ULITUES 1-2' yellow-fever blood ciiine uii a cargo from Central America ii. New OrleaiLs. The lever s[)read rapidly and by the mitldle uf September 2462 people had been attacked by tlie disease and 329 had died. Aedc^ is the connnon raindjarrcl moscpiilo lA the South; it is frequently referred to as the '' calie(j mos- quito*' because of conspicuous banding of its legs, ilutrax, and abdomen with black and white. 'Ihis moscpiito is unable to survive the winter of the JSorthern states (Fig. <>jj. Fig. 65. Outdoor laboratory work in a malarial di.strict of the city Culex mosquitoes. To this genus l)elong our most conuiion household forms. Thev are o-enei'allv l)rown and mav hv (lis- tinguished fi-om Anoj,]i,],s l)y the fact lliat tliey rest with body parallel to the })lane of supi)ort and liead and proboscis bent, giving a humi)backed appearance. ANdiile these mos(piitoes are not known to be injurious to liealth, tlu' annoyance and distress they cause furnish am]>le reason for the general move- ment to exterminate them. ('uh.r pip/nis is the common houRohold pest throughout the C( tun try. Howard says these mosquitoes will not llv far from thcii- l)i-eeding places unh^ss 128 CIVIC BIOLOGY they are carried by light and continued wmds. With the exception of two species of Oulex that breed in salt marshes and migrate for long distances, mosquitoes seldom go more than two hundred yards from where they are hatched. In a town or city awav from these marshes the woi'k of extermi- nating mosquitoes is simple and not expensive. Indeed, the class in civic biology can accomphsh the task as an interesting and valuable turn at outdoor laboratory work. Before begin- ninof the work, however, mucli more sliould be learned about the habits and life history of the mosquito; Habits and life history. ^Mosquitoes are nocturnal ; during the bright part gf the day they hide under leaves, in grass, in cellars, wells, cisterns, in barns, and in the dark corners of the house. Even the " day mosquito," Aedes, does not fly about or bite in the bright sunlight of midday. As winter approaches, the female mosquitoes seek dark, damp places in cellars, caves, hollo^^■ trees, and loose bark in which to hibernate. Can you find them ? Mosquitoes may be distinguished from gnats and other mosquito-like msects by the presence of a fringe of scale-like hairs on the margins of the wings. Like many other hisects, especially those that suck blood, they are strongly attracted or repelled by different people. It is a matter of common experience that some people are annoyed by this class of insects mlich more than otliers. Odors like a mixture of oil of tar, oil of pennyroyal, and olive oil are effec- tual repellents, as is also a mixture of cedar oil (one ounce), oil of citronella (two ounces), spirits of camplior (two ounces). If an odor could be discovered that is hitrhly attractive to mosquitoes, it might be effective in ridding a neighborhood of the pests if used in connection Avith a trap or some form of sticky fly paper. Mosquitoes seem to possess other likes and dislikes. They are attracted to dark colors and are repelled by lighter shades ; M()S(Mri'<>i> ^:« and certain musical sounds set'Ui tn possess a cliaim. i m- > (especially nighthawks, swallows, and w hippoorwills living at dusk), also bats and dragon llies, l'ec(l n[)on adult nioscpiitoes. One observer rcj)orts having fouiul six liuiimciit : instM-t lu-ts mid siiiiiUfr s. riiii nets for us.- in \\:it«T in the crop of a nighthawk. A miinilc red mile may often be found clino-ino- to mos(iuiloes, and it i- <;iid to un-«":>tlv re(hice their lunubers in some localities. Young mosquitoes are aquatic. Moscpiitocs lay then egg> on the surface of water, usually about three days after they have taken a meal of blood. The eggs are laioat-s]iape(l ma.sses. The larva-, better km)wn as wrio^ders, swim aetivelv about in the water. .•-if^ 130 CIVIC BIOLOGY feeding upon minute forms of animal and vegetable life which are swept mto their gullets by the constant motion of little brush-like mouth-parts. A long respiratory tube comes from the eighth segment of the body, through which the larva breathes by opening it to the air. After undergoing three different molts the larva reaches maturity and changes into a pupa in from ten to fourteen days. The pupa differs radically Fig. 67. Survey of mosquito breeding places by a normal-scliool class Equipment : bottles, tumblers, and saucers from the larva in appearance, and breathes from the ear-like organs on the thorax (Fig. 62). Except when disturbed the pupa remains at the surface of the water. After two days it splits down the back and the adult mosquito rises from the pupa skin. Anojyheles and Aedes lay their eggs scattered singly, those of Anopheles floating while the eggs of Aedes sink to the bottom (Fig. 62). The larva of Aedes resembles that of Culex, while that of Ano2jheles lies horizontally, just under the surface. MOSOriTOES 131 Its respiratory tube is short, its bmly black and spotted witli tufts of long bristles protruding from tlie sides (Fig. 02). The [)upie of the different species are not readily eiiiii;; iti- wanlthroiijihthethiueork 132 CIVIC BIOLOGY Watch for eggs, and examine the water for hirva'. I low many eggs were laid and how long did they take to hatch? AVherever yon have fonnd mosqnitoes breedmg, indicate it npon a map of the locality with letters, A denoting the presence of Anopheles; (7, Cnlex; and Y, Aedes. Fig. 61 shows the relation between malaria and the AnopJieles mos- qnitoes as worked ont hi this 'way by a biology class. Fig. 69. Yivariuin set up for studying mosquitoes Cheesecloth top with sleeved opening and glass dish of water in moss at one end Did yon hnd that, in general, AnopheleH breed by preference in spongy l)ogs and stagnant water, green with algic ; Aedes ui cisterns, tanks, buckets, tubs, rain barrels, flowerpots, sancers, flower vases, and water pitchers ; Cidex pijnens in ditches, stagnant pools, catch basins, or in any water near homes, indoors or ont ? Bnt algae may quickly change any neg- lected water into a green bog hole for Anopheles to breed hi. M()S()rii"()Ks 1 •{•> Methods of extermination. It is luiiuiiiiic Inr us in nur work of exterininatini;' iiiostiuilofs that tlicv pass tliL* fust ilirce stages of life in water, and that the achilts innst conic to water to lay tlieir ej^gs, that is, nios(niitoes are strictly dependent upon suitable breeding- waters, in all successful campaigns undesirable [xxils in which mosquitoes may brec^d liave been drained or tilled. Streams and ponds have had their shores cleane(l of weeds, bi'ush, and stumps, and haxc been graded so that ])ools were not left in which mostpiiloes could brei'(l aft(M' fi'cshets and storms. Tlien they have been stocked with lishes which feed u})on the young of mosquitoes. All water which was too tem[)()rary to drain or too polluted for fishes has been cov- ered with crude petroleum (one ounci- to fifteen square feet of surface). This treatment has been repeated as ohou as wrigglers have appeared. A mos(iuito can walk on the surface of water l)ut it cannot stand on oil ; hence, as all mos- ([uitoes come to the near-by water to lay their eggs, they soon perish, rrecautions liave been taken not to allow water to stand in tubs, barrels, or cisterns with- out being covered insect-tight. I'hrough systematic ap})licatiou of these methods, Tanama, Cuba, New Orleans, aiul many citifs in the north have effectually rid themselves of mosquitoes. The results of these campaigns ju'ove that the e.vierminalion of the mosquito from any locality is no longer a matter (»f doubt or experiment. 'Hirough drainage of salt marshes whole I-K.. To. .lam hottlc iiiiii UiiiiltU'r arran«;f(l so ju* to secure t'i(^s of a single in(»si{uito Fig. 71. Connecticut salt marsh before draining Fig. 72. Connecticut salt marsh after draining - Photographs by W. E. Brittou 184 l^.SECT TVPK 1'K(h;li:ms 135 states are being freed liom luigrutiiiL;" luoscpiiiot's (^Figs. 71, 7*2). Incidentally, the yield of niai-sli liay is increased on tlicsc s\vani[)s, so that it more than pays Inr tin* cost of drainage. Locating Anoplides and Aedcs nioscjnitoes in a nciglihor- hood does not necessarily mean that malaria and yellow fever are present. These mosquitoes are not dangcrons lo health unless they have first bitten people sick with malaria or yellow fever. Planning a campaign. Yon may carry on a campaign against the mos(piito in a single neighbijrhood or yon may conduct it as a city-wide movement. In either case ofter your services as a class to the board of health. If malaria is present, your map showing location of breeding places of Anopheles might be offered to the board and cooperation secured in wiping out the disease. Arrangements should be made to have a doctor examine, free of charge, any one who has even a slight suspicion that he has malaria. (^)uinine is a cure for this disease, and every malarial [)atient should make use of this remedy (tuider the direction of a physician) and should be screened from mosquitoes to prevent them from becomhio' infected. Allow the newspapers to publish the results of your work, together with the accounts of mos(piitoes and the methods of extermhiating them. It is of the utmost importance that every one enter the campaign with enthusiasm, as a few care- less and ignorant people may continue to breed niosiiuiioes by thousands in all sorts of rubbish that can hold a small amotmt of water. CHAPTER XII INSECT TYPE PROBLEMS: CABBAGE BUTTEPvFLY {PONTIA RAPJE) Pontia rapct. This wliite butterfly commonly seen flitting over garden and roadside, has long been a serious pest. It gains its familiar name — cabbage butterfly — from I'avages of the larva upon the Crudfer family, especially the cabbage. In the northernmost portion of North America it is two-brooded, in the latitude of New England three-brooded, and farther south many-brooded. A butterfly lias been kno\^ai to contain over 500 eggs, and the progeny of a pair of cabbage butterflies in a season m the latitude of Boston is estimated as 31,375,500. The cabbage butterfly was accidentally introduced into America from Europe hi 1860, and twenty-five years later it had spread over nearly the lengtli and breadth of tlie land. This rapid invasion was due to the fact that its natural enemy, the ichneumon fly (^Apanteles glomeratns)^ was not present to hold it in check. This insect, however, was introduced in 1883 and is increasing rapidly. The cabbage butterfly may be collected in its different stages and the specimens kept in breeding cages (Fig. 73) for study. Larv?e thrive well in the laboratory if they are supplied with fresh cabbage leaves. Eggs and larvae. The small yellow eggs are deposited singly on the undersurface of cabbage leaves. Keep in water m the laboratory leaves upon which eggs have been deposited, noting how long it takes the eggs to hatch. Measure the young larva and note the time it requires to double in length. Does its color match that of the leaf upon which it is feeding ? What is the advantage of this ? 136 (.•ai;j;a(;k mTTKHri.\ \:\ > I Pupa. Larva. Parasites. Place some liiivu' in a cyaiiidr IxiUlc. Study and draw a specinuMi. Can yon lind llic six .singk- eyes {^ocelli) on the side of llic licadV Note the small feelers (fnifnivrr), and tlie strong teeth (nn(n/ Female. Male. Fig. 78. Insect case to show bioloiry of calj- bage butterfly 138 CIVIC BIOLOGY all that it does. It sips nectar from flowers, and does much to fertilize them. The female imago is distinguished by having two black spots upon its fore wing while the male has only one. From your specimens in the laboratory study the butterfly, noting its parts. Draw from the side and from above. Make drawings of the head from the side, one with the proboscis curled up, and another with it extended. (Place a little thin sirup near the head and watch the butterfly unroll its proboscis and sip it.) Compare the struc- ture of the body wdth that of the pupa. Mount, according to directions, the complete life his- tory of the butterfly (Fig. 73). Control of the pest. Artificial means of control are (1) Paris green, sprinkled over the leaves, killing the worms but not injur- ing the plant; (2) kerosene emulsion as a spray ; (3) water, heated to 130° F., may be used without injury to the plant ; (4) systematic '' netting " of adults. The most effective meas- ure, however, has been the in- troduction of its natural enemy, Ajjanteles gloineratus. This minute wasp-like insect deposits its eggs in the body of the cabbage caterpillar wdiere they soon hatch and feed upon the tissues of the host. They grow until they are about to pupate, and then eat their way out and spin their silken cocoons on or near the body of their enfeebled liost. The Fig. 74, Convenient arrangement for studying larvte Two tumblers with card between CABBAGE BUTTERFLY 189 cabbage larva that is parasitizefl by the ichneumon lly usually dies before it transforms into a chrysalis. J' he adult ichneumon fly emerges from its cocoon in a week or ten davs. It is not Fig. 75. Imported parasite of the eiibbiige buttertly — Ap(i)itcks glomeratus Open eocooii, adult inseet, aTid mass of cocoons near parasitizetl larva. llij^ldy magnilied known how long it lives or how many generations occur in a year. The fact that it is holding tlu' l)nttcrtly in check in some localities would lead to the belief that it nuilti[)lies more rapidly than its host. 140 CIVIC BIOLOGY The larvjB that are infested with llie parasites are usually a paler green and are not so easily bent. Exanime a number of larvse, keeping in a closed vivarium those suspected of be- ing parasitized. How many parasites are found in a single larva ? The parasitic larvse begin to spin their cocoons as soon as they emerge from their host. With the aid of a lens watch this interesting process and note the length of time it takes to complete the cocoons. Apanteles does not escape without its enemies. Two small chalcis flies prey upon it, but tlms far have not been effective m checking its ravages upon the cabbage ^^•orm. CITAPTEK XIII INSECT TYl'K ri(()r»Li:MS: AXTS No other group of animals presents such a maze of fascinating problems to the biologist, psychologist, and sociologist. — Wueeler, "Ants,'* p. 11 If 1 had to choose the iorni in which 1 would prefer to live again, I am not sure that I should not like to be an ant. You see that little insect lives under the conditions of perfect political organization. Every ant is obliged t(. work, to lead a useful life; every one is industrious. There is perfect subordination to the good of all, discipline and order. They are happy, for they work. — Bismakck Economic importance. Over a thousand species of ants have been described, of wliich about two hundred belong to North America. ^Vs a group they are generally considered distuictly beneficial insects, though among so many species it is not strano-e that a few are iniurious. Forel counted 28 dead in- sects per minute brought in by the foragers of a large colony, and estimated that this colony collected 100^000 insects per day. In China live ants are an article of conuuerce and are regularly used to control injurious insects in gardens and orchards. The Department of Agriculture lias recently tried the experiment of importing a (iuatemalan ant. the kelep, in the hope of discovering an effective enemy of the cotton-boll weevil. Observations of ants attacking in jurious insects should be carefully recorded and reported to tlic class. Many species burrow deep into tlie carlli. opening up the soil to air and moisture and preparing it for easy penetration of roots, and l)ring cjuantities of fine subsoil to the surface. In this way ants supplement the work of earthworms in the formation ot" vei''etal)le mold. 142 CIVIC BIOLOGY Three species, the red ant, little black ant, and pavement ant, are common household pests which can easily be looked up in state or national bulletins if they are locally important.^ Serious damage is sometimes inflicted by the corn-root louse (Aphis maidi-radicis). The eggs of this aphid are cared for over winter by the common brown ant (Lasius hrimneiis). They hatch early in the spring and the ants carry the young aphids to various oTasses and weeds in the field, and later transfer them to the roots of the corn. Concerted work of farmers over an infested area by early spring plowing and repeated disk har- rowing, so that no weeds are allowed to grow before the corn is planted, effectually controls both ants and aphids. This topic is well adapted to laboratory demonstration and experi- ment in infested districts and where education is needed to secure general cooperation. The chief interest, however, attaching to a study of ants is their seeming intelligence and wonderfully perfect civic organization of the colon}^ The colony. Ant colonies are composed of queens, males, a I. workers. Queen ants are usually larger, are wingless when mature, and sometimes live fifteen years ; the males are smaller, always winged, and never live more than one year. The wor.^ers may be distinguished readily from the queens and males by their small size and lack of wings. They do all the work of caring for the queen and her young, gathering food, building and de- fending the nest, caring for plant lice (aphids)^ and wagmr "^ar. Before mating, the queens have wings. In the summ ^ early fall clouds of young queens and males leave the ent colonies, flying in thousands. The flight over, the queen is either adopted by an old colony or establishes a new one. When once established, she removes her wings and never leaves the colony. While there is usually but one queen in a colony, there may be as many as thirty. ^ Hodge, Nature Study and Life, p. 80 ff. PLATK III. LIFE HISTORY OF THE BKOWXI'AIL MOTH 1, ejig cluster ; 2, sini^le etrir (enlarired five diaineters) ; 8. winter nests (rediir 1 about one lialf) ; 4. caterpillar : o. \m\y.v, male at riixlit. ventral vie : female at left, dorsal view : 0 and 7. female and male moths ANTS 14:3 Food. Ants feed upon l)utli animal and vegetable matter. Their loragiiig- raids extend over a radius of forty yards from the nest. They often take food into the nest, ami in cold climates they hihernate duruig the winter. Much of the food of the queen and larviT3 is eaten by the workers and rcgurgi- tated from the crop when they return to the nest. Ants have a preference for sweet food, such as juices of fruits, sugar, honey, and honeydew. Aphids secrete honeydew, and on that account are cared for by the ants, taken into the ant nests over winter, and in the spring carried back to the plants upon which they feed. But the aphids are among the insects most injurious to vegetation, and their protection by ants may l)e of great economic importance to us. Watch the problem in your own locality. Special senses. The organs of sight and hearing are very slightly developed in the ant, but the sense of smell is espe- cially keen. This sense is situated in the antenna^. The ant travels from its nest and finds the way back by the odor of its own tracks. If a portion of the path the length of its o\\ n body is disturbed, the ant is lost and wanders al)out until it picks up the trail again, but a path left dry and undisturbed can be followed by it hve days later. Experiments show tliat its own nest is evidently detected at quite a distance by odor, but the odor of other ants is supposed to be recognized only by touching with the antemit'e. Each species of ant has a disthict, characteristic odor. Different colonies also of the same species differ slightly. In general, the odor of one species of ants is offensive to those of another species, and causes aversion and hostility. This is shown by well-defined warfare and slavery. Slavery. While most ants will capture and carry away the young of another species whenever llic o[)portnnity is offered, there are three species in America (^Fonnicd ifdnynl- 7iea, JRoIj/en/fdi rKfescoin, and Toniognaflnia (Dnrriranrt^^ that plunder the nest of their enemy and rear the young as slaves. 144 CIVIC BIOLOGY The slaves undertake the work of the new nest much as they woukl that of their own. Can you find ant colonies with slaves ? Warfare. jNlany comparisons have been made between ants and man because of the diA^ersity of their activities. Ants are said to indulge in games and athletic sports and to cany on war. The folloAving observations are recorded that they may incite some young Lubbock or jNIcCook to find the cause and purpose of these wars. On the morning of June 20, 1883, 1 observed numbers of large black ants wandering excitedly over a back piazza of my house in Boxford, Mass- achusetts. More careful observation showed a dozen of their dead bodies scattered around, while two living insects were struggling in a desper- ate conflict. In some places dissevered legs and antennse M^ere thickly strewn, while in retired nooks living ants were resting, either exhausted or skulking. I gathered over twenty corpses from the piazza and the tiround. Some of these warriors, having mutuallv inflicted mortal wounds, had never relaxed their iron embrace, but lay dead in pairs. The conflict was not vet ended, and I watched one of these Homeric encounters. An ant had his antagonist's feeler in his jaws. The com- batant, thus held, twisted and turned to get his own mandibles upon feeler, leg, neck, or waist of his antagonist. He was, evidently, much unnerved bv the other's hold, for these antennse seem as sensitive as the eyeball, and he was dragged about, resisting and struggling in every way, but all in vain. Finally, the antenna came off near the base and the two warriors parted. Single combats like this iirobablv went on through the dav, and a few occurred the following night, for in the morning I found more dead bodies. One wounded soldier died in my custody, and many, doubtless, in cracks and nooks, but the level floor seemed to be the main battle- field. Altogether I collected from the fight aliout seventy complete bodies or dissevered heads, which I preserved in a red pill box — the rather gaudy tumulus of this AVaterloo"! In the same place on the morning of July 7, following, T found traces of another battle which was not yet finished. Again, July in, there had been a battle during the night on the bare floor of a chamber at the opposite end of the house and upstairs. One morning in August, of the same year, I found traces of a similar battle in the cellarway of a neigh- boring house. — W. P. Alcott, Bulletin, Essex Institute, 1897, p. 65 ANTS 14o A S'rri»v of Ants i\ iiik Laikm; a roi.-v The nest (formicary). Most species of ants readily adapt tlieiiiselves to an artilicial nest. After tlie lirst few weeks they become accnslonicd to their snrroniulinLi-s, and may live for years working- and rearini^" tlieir yonn^*, nnnli as tliey do in their natural enyironnient. Kelloo'u" in his ''American Insects" describes several of the more commonly used formicaries. The large-sized insect- mounting cases serve admirably in this capacity. The case should be partitioned off into two or three rooms,- by glueing strips of wood that reach nearly across. On the top of tlu^ walls of the case glue strips of Tnikish towtding, so that air may pass to the rooms after the up})er glass is in [)lace. Choose two pieces of heavy glass of unequal size for the roof of the formicary, so that one piece will cover two rooms. Excludt' the light from these rooms by placing blotting paper over the glass, and keep a Avet sponge (finest texture) in each of the darkened rooms. .VU food should be kept in the light room, and should consist of small pieces of sponge cake, moistened with sirti[) or honey, ap[)le, mashed nuts, dried fruit, and insects. Kee[) the sponges wet. In cool weather the food nei^l not be changed oftener than once in two weeks. How to obtain an ant colony. J)ig up an ants" nest and take lar\;e, pu[»a', and workers. If you eamiot find the queen, release the captives and try other nests until success- ful. Carry the (pieen by herself in an en\tdo[n\ and the young and workers \\\\\\ some earth in a cloth oi- [)aper bag. Upon reaching the laboratoiy, empty the earth and ants upon a board afloat in water; pick out the ants and young from the earth and placid them with the (pieen in the nest.^ 1 An easy way to niana«;e this is to scrape a hollow in tin- conter of the pile of earth, i)nt the queen in this, and cover it with a chip. The ants will then collect all the egpjs and larvie into a pile, and they may be lifted int<» tlie nest with a spoon. 146 CIVIC BIOLOGY The carpenter ant (^Camponotus j)ennsylvanicus) is one of the most satisfactory species to study. The colony lives in wood, and hibernating queens may be obtained under the bark of stumps or logs in the fall or during a winter thaw. In general the logs and stumps in which they are found are not badly decayed. Most frequently queens are hiding beneath bark that may without difftculty be removed with the Tig. 76. Ants' nest This is made of an insect-mounting strip, 5 by 7 inches, \ inch deep, glued, with the two partial partitions, to the bottom glass. The top glass is cut so that one piece covers one, and the other two, of the compartments. A braided cotton twine is glued along the top of the frame and partitions to insure ventilation. The sponge, in the middle compartment, is kept moist ; and the living chamber, to the left, is kept dark when not under observation. Designed and photographed by the author fingers. The queen is curled up in a cleared space under the bark and may be alone or accompanied by several eggs, larvse, pup^e, or workers. Having secured a queen of Cainjwnotus lyennsylvanicus^ jDlace her, together with her young, in a nest and carefully observe the beginning of an ant colony. Observations should continue for the remainder of the year and careful notes made to reen- force those taken upon ants in the field. Eggs. The queen may not lay for a month or more after ANTS 147 she lias hocii hn)iigliL iiilo llic lahoniton . Note the iiiUTvals duiiiiL;' ^^■liicll eggs are laid. Dcscrilx* tlic action of tlic <|ii(M'n and workers in re<>-ard to tlic eui's ^^lK'n llic nest is distnrbt'd. lluw soon do ants become aecustonied to the carefnl interfer- ence of being observed ? Fill the sponges w ith w atcr, one day hot, another day cold. A\'hat effect upon the ai)parent care of the eggs has a difference in nioistnre, temperature, and light? Larva. The time taken for the eggs to liatcli depends upon the warmth and humidity of the atmosphere. The time of in- cubation is about twenty days. The larvie are soft, footless grubs, the smaller end being the head. The presence of hooked hairs upon the bodies of the larvae explains how they are car- ried in bundles. Note that the larva' are helpless. They are not only fed by the cpieen and workers, but are carried about to places of proper temperature and humidity. AVith the aid of a lens observe how the workers ami queen feed the larvie. The queen has food stored m her body, which enal)les her to live and feed her first brood without lierself takino- food. This fact probably accounts for tlie small size of the first brood, which is composed of workers, as compared with subse(pient broods. The queen is relieved of all work when the workers appear. They feed her and the larvie and assume all work of the colony. Note that the larvie are of different aues, and that thev spin cocoons as soon as they become full-grown. Aie the lar- vie and pupa' kept together? Ants have no regular places for their young; even in the natural nest they are carried to places which offer suitable conditions. The pui)a stage like the larval lasts about twenty days Avhen the temperature is alxnit 80°. Observe that the cocoon turns yellowish lu-fore the young ant (callow) appears. How long before tlie callows assume the duties of adult workers? CHAPTER XIV SPECIAL PROBLEMS OF IXSECT CONTROL The life histories of insects lie at the fouiulatiou of the Avliole subject of economic entomology, and constitute, in fact, the principal part of the sci- ence., for until these are clearly and completely made out for any injurious species, we cannot possibly tell when, where, or how to strike it at its weakest point. — S. A. Forues Control of insects by a communit}^ or nation nnist depend upon each citizen knowing the inipijrtant species and actually dohig his part. Insects are so small, tough, and hard to kill, and, above all, possess such powers of rapid dissemination and increase, that the problems of insect control are probably the most difficult in the whole field of living forces. However, in the life history of a species from the egg, through the actively feeding larval stage, in the quiescent pupal condition, or in the adult, egg-laying period, it is generally possible to discover some weakest jx/int at which it may be successfully attacked. To work out these life histories, discover these vulnerable points of attack, and devise best ways and means is the function of our scientific experts ; but, in order that these discoveries accomplish their purpose, the people nuist learn and use the results. Organization for both research and information is so perfect that if any one \\^ishes to know aljout an insect he has onlv to inquire of his State Experiment Station or of the United States Department of Agriculture at Washington. If the answer to liis question is known, it will be sent to him prac- tically l)y return mail. If not, a special research may be ordered to solve the problem. 148 SPE("lAi. lM(()liIJ:MS OF INSKCT CO.NTKoL Ui) As a nalioii w i' are paying about $25,0<.)<),U(M) ainiually lor the (liseoverv and disseniinatirtn of just tliis sort of infonna- lioii. If we are not "getting" our moneys wortli," it is our own fault. ( )ue trutli witli reii^ai'd to an insect wliieli causes disease or levies a tax of often hundreds of millions of dolhirs on some staple crop may he worth the entiri' annual cost of the seientilie tlepartments of the government, as soon as the knowledge is put to use. With hundreds of ex[)erts working at these problems, knowl- edge is growing so fast that statements are likely to he super- seded before thi' ink of a 1)ook is dry. In order to keep up to date, every biological laboratory should have available for all students two important publieations, the MontJily Lid of Pnl>- Jirations and the Ejyeriment Station Record^ both issued bv the I'nited States Department of Agrieulture. These ^^ ill keep the student informed of every advanee in our knowledge of insects, as well as of a great many other matters of interest. ]\Iake a list of the most important insects of the neighbor- hood, or those about which vou wish to learn, and follow them through the indexes of the U.qyerime^it Station Reconl. Send to your State Experiment Stati(^n or to Washington for the bulletins you need, and, after studyino- them and collectinu" and observing your specimens in the Held, mounting them so that they will tell as com[)lete a story as possible, be ready to report your results to the class. Working independently and without consultation, let each member of the class prepare ;i list of the insects which Ik^ tlu'n]^s every member of the conumuiity ought to know in order to prevent annoyance, s})read of disease, damage to household goods, stock or cro[)s. 'I'his should be done after woi'king through the la])oratory types given in Chapters X-XIII, read- ing bulletins and books assigned, and studying the lists given below. After comparing and discussing individual lists, pre- pare a class list which shall include the most important local 150 CIVIC BIOLOGY problems, and one ^yllich the class can reasonably cover dur- ing the year, and then write the names on slips and let each draw a certain number, or distribute by individual preference, as the class may elect. As these studies progress they should be reported and freely discussed. Thus the biology class may be the organizing center for a better understanding of local insect problems, and enlist cooperation of homes and of boys and girls in the lower grades for more effective effort and. better local control. The problem of insect classification. It is recognized that for an elementary and practical course the complete classification of insects is too difficult and would take too much time. The vast number of species, more than three hundred thousand, are commonly grouped mto nineteen orders, and any student who is specially interested can find the subject full}' treated in manuals. For all elementary purposes it will be sufficient to learn the names and characters of the seven more important orders. Every one ought to know what we mean by a ''fly," a "bee," a- ''bug,'' a '' moth or butterfly," a ''locust," a " beetle," a " lacewing." Since classification consists in gathermg mto groups forms with similar structures and parts, we need to learn something of the way an insect is constructed. To begm, take any large insect, a beetle or grasshopper, and work out all the apparent subdivisions of the body. Note the three main subdivisions — head, thorax, and abdomen — and locate the breathing pores (^spiracles) as indicated in Fig. 77. Insects, spiders, and myria- pods, instead of having one pair of nostrils, a windpipe, and lungs to which the blood is brought to be oxygenated, circu- late the au directty to the tissues by means of fine, elastic, branching tubes. These are known as trachese, and these ani- mals are known, since this is a character of great significance, as traeheates. Contact insecticides — oil films on water for mos- quitoes, oil-emulsion or soapy sprays — depend upon clogging these fine breathing pores and thus smothering the insect. SPECIAL PKOBLEMS OE INSECT CUMlii)L 151 Water will not do this, because the openings are protected agaiiist its entrance by oily secretions. Compare the effect of dipping an insect into water and into kerosene. Next, beginning at the head, study all organs and mov- able parts {(ippendages) : the eyes, feelers ( antennas rci)la(ing Head Prothorax Mesothomx Metathorax Abdomen Comppiind Ey^ \ I / / Simpt^ Eye/ | ^^.^ ^,.^^^ / / ^/„,; j,^„j, / Ear / d* Spiracles 'Trochanter Mandible Maxilla 'Femur ■.Tibia '■ .Tarsus Labium Oripositor Mouth-Farts Fi<;. 77. External anatomy of the grasshopper ears and nose as sense organs, at least partly), moulli i>arts (very complicated, consisting typically of an upper and lower lip (labrum and labium) and two pairs of jaws (mandibles and maxilhe), which move sidewisc instead of up and down). Watch a caterpillar or grasshopper eat a leaf and see if you can discover why the jaws move side wise. A study ol mouth parts is again important with ref(M-ence to methods of destroy- ijicr insects. Tliose that bite and chew can be killtMl by spraying 152 CIVIC BIOLOGY poisons upon their food plants or by mixing poisons with foods which attract them. Those whose mouth parts have been modified into an apparatus for piercing and sucking can be reached only by insecticides which kill by contact. The thorax is divided by rather conspicuous sutures into three parts named prothorax, mesothorax, and metathorax. Each carries a pair of legs ; that is, all insects have three pairs of .legs. Wmgs may be present or absent. If two pairs, they are attached to the meso- and meta-thorax, and a single pair is usually attached to the meso-thorax. The insect wing is the most perfect flying mechanism in existence, and until man can match its structure for lightness and strength, he can hardly hope to solve completely the problem of flight. Note that insect wings vary in texture from the hard, shell- like structures, as in the fore wings of beetles and the leathery or parchment-like wings of grasshoppers and many bugs, to the transparent membranous wings of bees and flies. The abdomen is made up of a series of similar rings termi- nated by various organs concerned with reproduction, ovipos- itors, etc., sometimes modified into sharp stings. The life history of an insect also gives characters for classi- fication. With many insects the egg hatches into a worm-like maggot, grub, or caterpillar wholly unlike the parent, and later passes through a quiet stage (pupa or chrysalis) before becoming like the parent. In these cases the insect is said to show a complete metamorphosis Qnefa, " over " ; morplie^ '' form" — '' change of form*'^. Name insects that you know% of which this is true. In other insects the egg hatches into something like the parent. To study this point, watch a nest of grasshopper or squash-bug eggs hatch. These insects are said to have an incomplete metamorphosis. In the case of a few insects — the San Jose scale, aphides, and some of the flies — the eggs hatch within the body and the young are born alive. SPECIAL I'Kor.LE.MS oF LNSECT (ONTKUL lo3 Of IIr' iiiiK'tot'ii orders lliu .st'veii most iniportciiit are: I. Diptera {di-, "two"; pteron, "wing"). Two nn'iiiltniiious wings, nioiith I'iirts lor i)k'rcing and sucking or for laj.ping; nn-tanior- pliosis conqik'te, larva; various in form and lial>it l>iit always foot- less; maggots, wrigglers, etc. >:xami)les: Hies, mos([uitoes, gnats; 40,000 known si)ecies ; estimated iiimil>er, :jr)0,000 (Howard). II. Coleoptera {koleos, "sheath"; pteron, "wing"). Flete, the larva a grub, with usually six legs. Examples: beetles, potato beetle, June beetle, lady beetle: 100,000 known species (Galloway). III. Hemiptera{hemi-,''hdi\V'\ /)feron, "wing"). F<.re wings membra- nous, i)archment-like or with horny ])ases and membranous tips; hind wings membranous ; many wingless forms ; metamoridiosis incomplete, the young resembling the adults, but wingless — the true " bugs." Examples : plant lice, scale insects, cicadas, lice, water l>ugs; 20,000 know^n species; probaldy 80,000 in all (Howard). IV. Orthoptera (orthos, "straight"; pteron, "wing"). Fore wings parcli- ment-like, net-veined, hind wings almost always mend)ranous; mouth parts for biting ; metamorphosis incomplete, the young resembling the adult, but wingless. Examples : -grasshoppers, crickets, cockroaches, walking sticks; estimated more than 10,000 species. V. Lepidoptera (lepis, "scale"; pteron, "wing"). Wings auW( »nu — Ifi/phantrin cunea; cankerworms (sjtring — Paleacrita ventata\ fall — Aiiisoptt-nix pometaria) ; yellow woolly bear — Sj)ilosonin rirf/inica-, curculio beetles, w^eevils (apple — Ant/iofionms lum — Conofnic/it las iiinu- ])har\ quince — Conotrarhelus cmlnuji; grape — Craponiua infifjualls; borer beetles ; round-headed apple-tree — Saperda Candida; flat-headed apple-tree — Chnjsohothris femorata (also attacks the plum); i)ear-blight V)eetle — Xiilehnrua pyri', pear-tree borer — yl-Jf/eria pyri;, cherry-tree borer — Dicerca dicarirata; peach-tree borer — Sa}ininoid('a exifiosa; apple-twig borer — Amphicerua hicaudalus)] s)»hinx moths ("humming-bird" moth) (pbim — Sjdiinx drupiferarum ; green grapevine — Aniptlvpluuja mi/ron); 156 CIVIC BIOLOGY scale insects (oyster-sliell scale — M//ti!(is/)/s jioinoriu)! ; scurfy scale — ■ Chionaspif! furfuriiSj San Jos6 scale, Chinese pernicious scale — Aspi//i- otus perniclosus, the worst fruit-tree pest on the American continent; cottony cushion scale — Icerr/a purchasi); apple-tree enemies (yellow- necked apple-tree caterpillar — 'DaUina viinistra; red-humped apple-tree caterpillar — Q^demasia concinna ; apple sphinx, or hawk moth — Sj)hinx f/ordius ; apple maggot, " railroad worm " — Rharjoletls pomonella^ ; enemies of small fruits (strawberry crown borer, weevil — T//loderma Jragrarke ; strawl)erry root borer — Anarsia Vmeatella; currant borer, American — Psenoceriis supernoiatas; currant borer, imported — yEr/cria tipniifonitis; grapevine root beetle — Prionus laticoUis ; grape-berry moth — PolijcJirosia hotranci] grape, gartered plume moth — Oxi/ptilus periscelidacfijlus] rose chafer — Mdcrodariylus suhsplnosus); plant lice (ajdiids, gra[)e — Plujl- loxera vastulrir ; woolly apple louse - — Scliizoneura laniyera : cherry louse — Mt/zus cerasiy Vegetable, Grain, and Cotton Pests : Colorado potato beetle — Doriiphorn lOdlneata ; striped cucumber beetle — Diahrotica vittata ; as- paragus beetle — Crioceris aspara" tlic liiolit, and steam cars and trollcvs iians- port these pests. liesides tlie injniv to oicliard, sliade Wcv, and forest, the brown-tail caterpilhii- inllicts serious pain iipon nnmy persons. This is caused by line hairs which pierce the skin, the irritation })ecoinino" severe enon<>-h in sonic cases t<> cause illness. A free use of \aseline Avill s^'ive relief. The l)rown tail cannot be controlled by an attack ujx)!! the eggs, since they are usuall} on tlie leaves and for- a short time only. S})raying is em- ])loved to destroy the swarm- ing cater})illars, but the most effective methrxl is destruc- tion of the winter nests. These are conspicuous on the tips of liranches between August luid April. 'Hiey may then be cut with pole shears, and must be can'fu/Jj/ colU'ctciJ and Inonu'd. Parasites. '11 le great aim in the attempt at control of any pest is to discover its nat- ural enemy. In the case of insects like the gypsy and ])i'own-tail moths, a .sv/vV.s- of para- sites is necessaiT, for the parasitic insects restrict themsebcs to one stage only in the (levelo[)meiit of their host. 'VW inscci which attaeks the Qgg takes no notice of the caterpillar, and the insect whicli attacks the caterpillar is never found upon pupjie. Several native parasitic insects are known to attack these pests, and many liave been imported ; but as yet the series is not complete and has failed of effective control. Fi(.. 7'.'. lirown-Tail Mollis Four Piry; masses and two moths layiiiu, July H>. Photoijraph by Katliariiif K. Dolliear 162 CIVIC BIOLOGY Comparison of Gypsy axd Browx-Tail Moths . Gypsy Moth Eggs. August to May. On the trunks and branches and everg- ivliere, especially on undersides and inner surfaces of objects. Masses. Light brown, long, broad, about the size of a silver quarter. 300-1400 eggs. Caterpillar. May to August. On wnJerside of leaves. Night feed- er's. Cluster in shelter during the day. Win ter form . Egg. Full-grown. Two and one-half to three inches long. Rows of con- spicuous spots on the back — blue near the head, red on posterior part of the body. Hairy tufts on the sides. Pupa. Late July. Found in some places as egg masses. Dark brown female larger than the male. Motlt. Female, white with brown markings. Spread of wing, from two to three inches. Xever goes far from pupa case. Male smaller, brown. Brown-Tail Moth Eggs. July. Seldom on trunk or branch. Generally on underside of leaf. Masses. Smaller than the gypsy, more elongated, brighter, red- dish brown color. Al)out 300 Caterpillar. Hatched in August. On upper side of leaves in clus- ters. Day feeders. Winter form. Caterpillar in nest. Nest four to six inches long, composed of leaves and silk, contains about 250 caterpillars. Emerge in April, attack bud, blossom, and foliage of fruit trees, and then move to others. Full-grown. One and one-half to two inches long. Broken white stripe on each side of back, two red spots near posterior end. Hairy tufts on the sides. Pupa. Late June. Five eighths of an inch long. Dark brown, with yellowish hairs. Moth. Pure white. Female slightly larger, with conspicuous bunch of brown hairs at tip of abdo- men. Spread of wing, one and one-half inches. Night flyer, attracted by light. ^ 4 .* 9 # * * # f f t iV^j: Olive?: dnl. &■■ ■-4 5 oa 6 # 6" a PLATE IV. AI>L'LT FEMALES OF F1\E LMi'OKTANT TICKS* CHAPTER XV ARACHNIDS. PROBLEMS OF SPIDERS, MITES, AND TICKS Prices would be higher, the demand greater, and the odium attached to ticky cattle at the stockyards removed. Pure-bred >.'urthern cattle could then be brought into the South to improve the native breed, without danger of death from Texas fever ; Southern cattle could enter the show rings of the North without restriction ; and the total cost of tick extermination would be far less than the amount saved in the first year after it had been accom- plished.— John R. Mohler, 1914 Closely allied to insect problems are those of the arachnids. This group includes scorpions, spiders, mites, and some of the ticks. Interesting as they are, scorpions and spiders are far sur- passed in economic importance by the insigniiicant mites and ticks. Among the latter are the cattle tick (carrying the germ of Texas fever), the sheep scab mite, mites which attack poultry, and the red spiders and harvest mites which infest vegetation. Since arachnids are often mistaken for insects, compare any common insect and spider, noting their similarities and dif- ferences. Make a diaGj-rammatic sketch of each. Similarities. Both insects and araclmids are ringed or jointed animals. Both are tracheates, though a few of the arachnids, particularly spiders, have also pulmonary sacs. Differences. These will be found in the relation of head and body, the number of legs, presence of antenna% com- parison of palpi. * Five species are shown, enlarged and natural size. 1 and 1 a, adult female cattle (Texas-fever) tick ; 2, growth stages and variations in color of this tick ; 3 and 3 a, Rocky JNIountain spotted-fever tick, adult female ; 4 and 4 a, female dog, or wood, tick ; 5 and 5 a, female European dog tick ; 6 and 6 a, female chicken tick. (Reproduced from plates issued by the United States Department of Agriculture and the United States Public Health Service.) 163 164 CIVIC BIOLOGY The larger aracliiiids, in spite of their bad reputation and terrifying appearance, are comparatively harmless. Even those of the poisonous A'arieties, tarantulas and scorpions, make no attack upon man un- less frightened or mo- lested. Their economic importance is not con- sidered great, though since they are insectiv- orous, they may be dis- tinctly beneficial. The smaller arach- nids, mites and ticks, cause great destruction of vegetable and animal life. They are charac- terized bv an unseof- mented body, the abdo- men as well as the head being joined to the tho- rax. While we must not overlook the service of some species as scav- engers, we are con- cerned nnich more with them as parasites upon livino" animals and plants. Red spider — Tetra- nychid(£, " four-clawed." This greenhouse pest is found both indoors and out, and on various plants and trees. It is one of the commonest families, containing sixty species. The red spiders are most trouble- some in times of drought and are found chiefly on the underside Fig. 80. Harvestmen clearing the plant lice from a grapevine Photograph by the author TKOliLKMS OF SPIDKKS, .M ITKS, AND I'K KS li;.") (if leaves. So mimilc ai'c tliuy that a single oiu' is scarci-ly visible to the naked eye, and they are ullen not noticed uniil tlie plant is badly infested. They pieree the snrfaee of the leaf and suek its juices, and very soon the plant beoins to appear yellow and sickly. A\'hcii it is practicable the garden hose will exterminate these pests. I'jider other eonditions spraying with fish oils or soap solution is effective. Clover mite — Bryohia pratensis. As t he name indicates, these mites are found chietiy n[)on clover, but also on apple and peach trees, cottonwoods and arbor vit;e, and even on boards, st(mes, and fences. During the fall and winter they ai)pear also on [)lum, almond, po[)lar, and elm trees, and frequently leave vegetation entirely and become very troublesome in houses. Of species found upon animals, there are some which can- not be considered a real menar })laiit .slutuld Ijc looked uiion as an experiment in iiiakiim- a inachine which shall best tit its eiiviroiiiiieiit and most effectively do the work re" the youn^^ ^vith milk. Among the more important problems relating to American mannnals are the following: 1. Extermhuitiou of predacious forms as the continent has been opened up to settlement — panthers, bears, lynxes and wild cats, wolverines, wolves, minks, skunks, and weasels. 2. Utilization of native wild animals — bison, elk, moose, deer, antelope, mountain slun^p and goats, hares and rabbits. SEALS, SEA LIONS, WALRUS BEAVEllS, SQUIRRELS, RATS AND MICE MULES AXD SHREWS AUSTRALIAN Itl (KlilLL oi-ossiMS AM> KANGAROOS Fig. 82. Orders of inainnials, with habitats 170 AMEKK A.N .MAMMAi. I'KoJli.KMS 171 These have been an important source of food (huing- the early settlement of the country. 3. Tra[)ping fnr-hearinor mammals — Ix'avcr, ottci-. marten, sable, badger, muskrat, moles, and others. 5. Efforts to prevent the total extinction of valuable species. This last feature of the American problem has been late in developing. Our destruction of animal game resources is connnonly spoken of as wanton, and in many instances tliis is undoubtedly true. Still the problems are not so simple as they often appear ; for example, thousands of bison were shot for the mere sport of shooting, and the species is now i)ractically extinct in the wild state. This seems a great waste, but it is impossiljle to use the same range for both bison and domestic cattle, and cattle are mucli more valuable. The bison herds swept the rancre cattle with them in their mio-rations and strewed settlers' fences over the plahis. When full-grown they are not amen- able to ordinarv means of control and pr()bal)lv could ncjt be profitably domesticated. Even tame buck deer and bull elk are dangerous animals. Kearing the bison in specially feuc-ed preserves is quite a different matter, and has proved — at present fancy prices for robes and heads — a profitable indus- try. Both the United States and Canada have undertaken to thus safeguard the species from extinction, and the American Bison Society has been recently organized to make sure that the largest, and in many ways most picturesque, American mannnal shall never entirely disappear from the earth. Those in charge of zo(')logi('al parks and private forest preserves, as well as ot" the extensive national forest reserva- tions, are all making preservation of native animals a strong feature of their work. ]\Iany states are also ])eginning to legislate to prevent extermination of valuable animals. Sev- eral states derive considerable revenue from hunting licenses, and, in order to attract sportsmen, nuist maintain the supply 172 CIVIC BIOLOGY of game. Wild deer are beginning to be seen in eastern Mas- sachusetts, the state allowing but a single week for hunting them and paying all damage which they cause to crops. These damages are increasing, however, so fast that it is a serious question whether such an animal should be allowed to range at large in a state not possessing extensive tracts of waste land. State forest reservations, private hunting preserves, and spe- cial parks will probably solve tlie problem in such a manner that the species will be preserved and the people permitted to see and enjoy them in their native haunts, while promiscuous damage is prevented. The preservation of tlie fur seal has come to be an inter- national problem which is engaging in its solution the best ex- perts of England, Russia, Japan, and the United States. There is thus a good chance of savhig a great industry to the inter- ested nations and a number of fine species of seals to the world. As the animals have been trapped off, tlie price of furs has steadily advanced, until the rearing of fur-bearing animals — notably the silver fox — is l)ecoming a paying industry. At present prices it ought to be possible to rear many of our fur- bearing animals at enormous profit. " The beaver,'" says Pro- fessor Shaler, " particularly the North American form, offers a most attractive opportunity for a great and far-reaching experiment in domestication. On this continent, at least, the creature exhibits a range of attractive qualities wliich is ex- ceeded by none other in tlie wliole range of the lower mam- malian life."' Here is a new h(dd of biological interest, experiment, and human adxance in control of animal life which ought to appeal to boys who live on farms affording opportu- nities for such work. Methods of caring for the animals in confinement or under control may be learned to advantage from zoological gardens ; and anything in the w^ay of local '' deer farming "' or '' fur farming " should be studied and reported on by interested members of the class. rilAPTER XVII THE KAT PROBLEM The rat is the worst nuiuiinaliaii pest known to man. Its depredations throughout the world result in losses amounting to hundreds of millions of dollars annually. But these losses, great as they are, are of less importanc«' than the fact that rats carry from house to house and from seaport to sea- port the germs of the dreaded plague. — David Lantz, "The Brown Bat in the United States," p. 9. Bulletin No. 33, Biological Survey, United States Department of Agriculture The smell of mice shall be in their nostrils and they shall die. — Old myiufj To pay $1,000,000 for the last pair of rats on the North American continent, after the Panama ('anal is cut through, and every harbor is properly sea-walled, might be money well expended. The warfare which has been going on for thou- sands of years mioht then be terminated in at least one conti- nent — and may not all good Americans unite hi the hope that ours may be the first conthient of wliich this is true ? The failure of all attempts to deal witli tliis vile enemy may be traceable to lack of a vivid realization of what the '' last pair " may do in the way of increase. The brown rat may breed five times in a season and have from 6 to 23 young at a litter. Allowing 8 young, the iiu-rease from a single pair in a season may amount to 880 ; and if we liguri' 10 in a \\\{v\\ this number is hicreased to 1250. In three years with only (J young in a litter Lantz has computed the possible hicrease at 20,155,392. From these data it is clear that any scientific method of dealinu' with this pi-oblcm in any home or loijditv must catch the last pair, and also, under existing conditions, insure catching the first pair as soon as ii comes. 173 174 CIVIC BIOLOGY Damage annually caused by rats has been figured for several countries as follows : Denmark $3,000,000 France 40,000,000 Germany 50,000,000 England . . • .' 73,000,0001 United States 100,000,000 '^ This estimate of |10 0,000, 0.00 worth of grain is based on the amount actually eaten by rats, and Lantz maintains that they destroy and pollute '' fully as much as they consume." But a Fig. 83. Common brown rat and mouse , Photograph by the author damage tax of $200,000,000 levied annually on cereal crops is by no means the whole story. The poultry industry yields $600,000,000 annually, and rats take an enormous toll of eggs and young chicks. '' I have known them to take nearly all the chicks on a large poultry ranch, and in the same neighbor- hood and over a large territory, to destroy nearly 50 per cent of the season's hatching " (Lantz). The writer learned of an instance of a large rat killing and carrying away an entire brooder lot of over two hundred newly hatched chicks in a single night. Ducks, turkeys, pigeons, game, and song birds 1 Great Britain and Ireland, rural damage, and does not include losses in towns and cities and that inflicted \\])o\\ shipping. ^ For destruction of grains only. Till-: ILVT rnoiJLEM 1 anlz esti- mates the yearly damage at $700,000; and foi- cities in the United States of over 100,000 inhabitants these studies would indicate an annual loss of $20,000,000. Black death, the bubonic plague, beginning hi China in 1334, swept westward ()\('r Furope, and in that single epi- demic killed, it is estimated, 25,<)""^"^' Bait a JL §; ■'■//////////////.k KV//////////////////////M Bail i—a- /^////////////////////////v//^^^^^ Fig. 88. The poison box The inner box. where the bait i.s put, should be about 4-6 inches smaller in hori- zontal dimensions. The strip o, i X 1 inch, is nailed all around the bottom of the larger box to prevent scattering of poisoned material. Bait with pieces too large to be carried out. Leave holes in lower corners small for rats to enlarge in numbers may be seen dying and dead around it. Tliey even lose all fear of man and crawl to the water to drink in broad daylight, and commonly remam at the water until they die. To destroy rats on farms. Each evening when the cows are milked place a little fresh milk in a shallow pan where the rats can get it. Continue this for a week or more until the rats get bold and impatient to get at it. Then mix arsenic with the milk and await results. This plan is said to entirely clean a barn of rats. — Quoted by Lantz from E. H. Reihl, in Colmaii's Rural World, January 29, 1908 Strychnine acts so quickly that there is danger, when used about buildings, that the animals may die in the walls. In other places ii may be uslmI veiy effectively, and still, uii account (^f its intensely bitter taste, it seldom cat dies the sly old ones. ►Strychnized grain used in poisoning s[)arro\vs is equally effective for rats and mice (\- oz. stnehnia sul- ])hate dissolved in i pint of boiling water, thc)i-()ughly stirred into - quarts of cracked corn or wheat, dried and labeled and stored safely for use). The ^\ liter has been told of clearinof a barnyard and larp'e stable bv lirst feeding the rats with raw, unbroken eq;<_rs, then substitutino- eoos heavilv charged with strychnine, the crystals of the poison ])eing pushed through small holes in the shells. 'J'he groiuid near these eggs was described as '' strewn with dead rats."' Phosphorus pastes conunonly sold as rat and mouse poisons cannot be reconunended, as they are too likely to cause ffres. The other ingredient, glucose, is likely to be leached or weath- ered away, leaving the phosphorus strong enough to ignite spontaneously, and lumps of the material may be carried by rats from perfectly safe places — in a cemented cellar — u}) into the nests anywhere in the building. Even fields of grain have been lired in this way. Fumigation with poisonous gases is perhaps the most eftVc- tive method of dealino- with vermin that burrow. It is such sport to absolutely exterminate rats from fields, dumps, [)oultry yards, and cellars that the game is worth the expense. Carbon bisulphide is the agent most conunonly uselants. The green plants build up this entire food sup- ply from the cheuiii-al elements by the energy of suidiulit AAorking tlirough leaf green, or chlorophyll; nn repri'sents free nitrogen from the air, drawn into combi- nation by symbiotic bacteria in the root tubercles of clovers, beans, etc. The non- nitrogenous foods — starches, sugars, gums, fats, and oils — are built up along Avith the proteins .and are tinally oxidized to carbon dioxide and water. MJietljer in tbe animal or plant body or by rotting or burning 188 CiXK' BIOLOdY Functional subdivisions, saprophytic, parasitic, and symbiotic fungi. Saprophytic fungi are those that hve upon the dead bodies or waste matters of animals or plants. Parasitic fungi attack living animals and plants and injure or kill them. They are the causative agents in the larger part of contagious or infectious animal and plant diseases. Symbiotic fungi live w ith other organisms, to the advantage of both. Bacteria in root tubercles of the legumes are familiar examples. While convenient, these lines of classification are not hard-and-fast, because it may be difficult, or even impossible, to tell whether an organism, or any part of it, is really dead or alive. The rouoli bark and tlie heartwood of a living tree are as dead as they ever will be,- so may be the hair or cuticle of a livhig animal, or the rind or pulp of a ripe fruit, or the food material of a seed or egg. Who can say whether the sap of a plant or the blood or milk of an animal is dead or alive ? So there are all degrees of liveness or deadness, and a usually beneficent saprophyte may attack a half-dead pjant or animal, A\liich we would call alive, but tlie fungus may know better. Accord- ingly we have JiemiparasiHc and hemisaprophytic^ or, so-called, facultative parasitic or saprophytic, fungi that attack the living or the dead according to degrees of vitality or variations of external conditions. Botanical position of fungi. All fungi are devoid of chloro- pliyll, but not all plants that lack " leaf green " are fungi. Dodder and the Indian pi})e are flowering plants that have adopted the parasitic haljit, and with this degenerate life they have lost the mechanism and the power of making their own food. So we find from a study of their ways of growth and methods of reproduction that fungi have developed from the alg?e. Flowering plants reproduce by seeds, which are embryo plants provided with food for the start in life. The ferns, mosses, algse, and fungi reproduce by spores, which, compared with seeds, are almost inconceivably small. jMan'y seeds are FL'NCI 189 provi(le(l with hairs or wiii^s to cariy them in winds, and many lioat in tlie water in oich-r to he wi(h'ly scattered ; hnt the spores of the fun^i are so lio'lit and small that they float invisihle in either air or water, and so they far ontstrip in dis- tribution the hest de\ ices ol' the higher [)lants. As a I'esnll, wliile the flora of seed plants is very ditt'erent in different countries, the molds and nnishrooms, yeasts and bacteria, are more likely to be the same species the world over. (Nmipare seeds and spores as to size and nnml)ers pro- duced. For spores use the dust from a i)atch of mold and from a puffl)all, and try to see, feel, smell, and taste them. The fino-er ti})S mav be black or green with millions of mold spores, but how nnu*h can we feel them? We can see the cloud of '' smoke " from a puffball, but as the spores scatter, can we see them in the air (unless in a ray of sunlight in a darkened room), and have we ever tasted them in food ? Some people enjoy the tastes of certani molds and bacteria in cheese, — Camembert, Roquefort, Stilton, Limburger, — and they may be as wholesome as any other vegetable. How do the different kinds smell? How many spores may we be breathinir in with every breath in a ninstv room? How dues the number of seeds of a grain [)lant or weed compare with the spores produced by a puffball? Size and power of growth. .V baby grows to doul)le its weiirht at birth in live months. A yeast ]>lant or bacterinm may double in size in twenty or thirty minutes. The fungus thus has from seven to ten thousand times the power of growth of the babv. Whv this difference? Food, anl(l not be worth oui while if it were not for the fact that they are associated in the (hist with Ics> reputable bacteria. There is just one point that we should learn in a wav we can never foro-et. 11 ic skins of fruits, of course, art' c(»vcrc(l Fin. 1*4. Kxpi'iiiiu'iits in mnwiiii; yi'ast 1, yoast i)liuit parts, kt>i)t at iiioiu iriupfiiiiurr : '_', same, kept in dark: •>, i)laiitt'(l in tiltercd, Ixiilrd, or distilit'il watir: \. ««;niif as 1, not i)lanttMl : "t, sanu» as 1, kept in crafkfd icr witli yeasts and with spores of molds. This fact is rtdatcd it» one of the large industries of the world — the picking, hand- ling, and marketing of fruits. K\ I'KKi.MKX r 1. Have llic class collect a iniinl»fr of tin- fruits aviiil- alilf at tiic season. Scrape the sui-face lightly with a sliar|i. clean scalpel ]t(»iiit oi- kriife-ueedle (or wash with a tine l>nis!i iiiln a , a lunsli- rooni siiowing a, the pileus (or cap), h, the velum (or veil), which has torn from the margin of the cap and remains as a ring around the stem. aii«l c, the remains of the volva, which forms a cup the mushrooms l-oUccKmI for winter study bv drvinLi'; cxcn many of the softer ones may l)e preserved in this \\ ay it they are dried in a current of hot air. Amanitas. Iiefore collecting' nnishrooms, li\ dearly in mind the characters of the deadly =^ Amanita. Other varieties of fungi may interfere with digestion, l»iit to I lie Anianitj^ all tleaths from toadstool ]Knsouing are traceable. Its subtile alkaloid is absorbed by the system, and in most cases lies unsuspected 202 CIVIC BIOLOGY for from six to twelve hours, then its iron grip holds to the death. For centuries it has defied all remedies. — McIlnaxe, }>. 5 The amanitas are the most conspicuous, beautiful, and, too often, the most abundant mushrooms to be found in the woods from frost to frost. (3f the t\yenty-eight species nine are deadly, ten are doubtful, and nine are considered edible. The three characters which infalliljly mark an amanita are white spores, a rm^, and a volva, or eup. In order to understand these terms and others that we need to know, study an amanita as a type. Fig. 98 shows all the constituent parts and all the characteristic stages of growth of Amanita j^haUoides. The parts in order of growth and formation are Mycelium : extremely fine white threads, uniting here and there to form larger strands — the nutritive, or vegetative, part of the fungus. Buttons : white knots or balls in the mycelium, the beginnings of sj)ore-forming bodies (mushrooms). One button cut lengthwise shows the parts, which will be more clearly differentiated later on. Note especially that the mushroom proper at this stage is completely enveloped in a sac. Not all mushrooms have this sac. Sporophore, consisting of 1. Stem : the part which springs directly out of the mycelium and supports the pileus. 2. Pileus, or Cap : the umbrella-shaped part which carries, on its under surface, radiating, leaf-like structures — the gills. 3. Gills : the organs from the surfaces of which the sj^ores are set free. The shape that the spore-forming surface assumes is a prime character in classification. It is j^roduced into gills in the Af/aricacece, into spines in the Hydnacece, into tubes in the Boleti, and into fine pores in the Pobjpori. Spores : Place a cap from which the stem has been removed, gills down, on a piece of white or black paper, and cover tightly with a tumbler or bell jar. Leave for an hour or so, and examine the spore print and, if a microscojie is available, the spores. • VoLVA, or Sac : the membranous sac which may envelop the entire sporophore in the button stage ; also applied to the portion which, after rupture, remains as the cup at the base of the stem. FUNGI 203 Warts : irregular flecks, or piitehes, on the surface of the cap, formed if the volva ruptures about the equator and the upper portion is carried up and remains adherent to the growing pileus (not the case with Amanita phaUoidcs). Velum, or Veil: a membrane which, in some forms, attaches the margin of the pileus to the stem. When, in growing, the cap tears away from the velum around its margin, the velum re- mains attached to the stem as the annulus, or ring. The presence of the three characters, white spores, ring, and cup (which may be reduced to a scaly, bulbous base to the stem), mark the specimen as an amanita. In collecting, why should we be sure to have the base of the stem complete? AVhy should we never mix buttons with edible mushrooms ? Classification. Sort the mushrooms collected, using the outline given below. If 3'ou place tlie dried specimens in a jar packed with wet paper the day before beginning the work, many of them will absorb moisture and become approximately like fresh specimens: 1. All forms with gills underneath the pileus may or nuiy not have stems — A garicacece. 2. Hedgehog mushrooms : forms whose spore-forming surface is i>ro- duced into spines which hang downward. They may be umbrella-shaped or irregularly tuberculate or branched — Ili/dnacece. 3. ]\iushroonis with a honeycomb structure of tubes in i)lace of gills ; soft and with the tubes readily separable from the cap — Doleti. 4. Fungi with fine pores underneath the pileus. ^lany species become corky or woody, the bracket fungi of the woods — Polijpori. 5. Coral mushrooms : may be simple, erect clubs or large, branehing masses, the branches being erect. The spores are produced over most of the exposed surface — Clavariacece. 6. The morels and cup fungi. Some of these have stem and cap, but produce the spores in pits or irregular depressions on the outer surface of the conical or cylindrical cap. Other forms are cup-shaped or saucer- shaped — Discomj/cetes. 7. Puffballs and earthstars : mushrooms in which the spores are pro- duced within a closed cavity, wdiich may open by an apical pore or by the irregular breaking of the wall ([leridium) — Lijcoperdacea'. 204 CIVIC BIOLOGY 8. Stinkhorns, mushrooms which, once smelled, can never be mistaken for anything else or forgotten. The immature plants, known appropri- ately as witches'-eggs, resemble ]Duff balls externally ; but as one matures, out shoots a long, hollow stem bearing pendent from the tip a small pileus, and this carries the spores in reticulations of its outer surface — Pludloidece . 9. Trembling mushrooms : soft, gelatinous fungi (witches'-butter) in color varying from white to orange, red, or brown, generally found grow- ino" on wood or parasitic on other fungi — Tremellacctp.. The first purpose of these lessons should be to learn to recognize the deadly genus Amanita. Then let each student acquaint himself with as many as possible of tlie abundant edible mushrooms. An excellent plan is to have the class unite in making a neat card cataloo-ue of the most abundant and valuable nnishrooms found growing in the locality — this catalogue to be left in the laboratory as part of its biological equipment during the year. A sample card might read about as follows : 0 1^ Di: R : A GA li I CA CEA^: CxENrs : Ldctarius Spkciks : (leliciosus S PORKS : White Delicious Milky Mushroom Edible, excellent (first taste a little acrid) Space for Color Picture 8-10 cm. high; 5-18 cm. broad; funnel-shaped. Color : orange, in concentric darker and lighter zones around ca]>; becomes hghter, often green- ish, with age. Gills: decurrent, saffron vellow. Milk at first reddisli orange, qiiickly turning to dull greenish — char- acteristic of every part of plant when bruised. Odor: aromatic. Taste : delicious. Habitat : damp coniferous woods. Season: July to October. Notes: Have found it abundant since our first field woi-k — Sep- tember 10 up to October 28. Frx(;T 20.1 Tabli: or (ii.xi.KA i>i' A(,aricaci:.e (( iii.i.-r.KARix*, Mimikooms)^ IMI.r.rs DISTINCT Ki{0>r KI.KSHY STKM SroKics JjKCvdsi'iiit.i-: (White) liiinnosfint: (Pink) O-iiiiosroltf-: (Yellow-brown) Poll I'll iK'tsr'iH *: (Purple-brown) AfKliKoaroiiA (Black) King aiul volva Amanita- AmanitojtsLs* Tjcpiotn* Volva, no ring f'olraria'i Arvldhuhtnn Chitiniia Ring, no volva Affarimx* Cnpriviis* No ring PI a hits /{ol bit ins J'ilosfire 1 I'lI.ElS CONTINl'Ol'S WITH KLKSIIV STEM King Annillaria* Phnliofn * Cortinarius* Strophariu" ' (lomphidiu Sinnate gills Trie ho lorn a* Kntoioma 3 Ilebelomn ^ Hijplioloma * Pnnxolus^ Lacfarins'^ III or II he Am Unrin (milkv) Jiussnld* (brittle) Ill/qrophoriis* (Jills often decnr- Clilnpllus* Flaiinuulit rent Clitoci/ht'* Cant ha re 1 1 as* Xerotus Xyctalis Paxillus* «i rowing on wood. Lcnzites Claud oj) IIS Crepidtttus Stem usuallv ec- LentiuKs centric, lateral, or PleiirotHs* wanting (fleshy) Panus (leathery) Trof/ia » m (gills crisped)' Schizophi/Uion PILEUS DISTINCT KKOiM CAKTI LAGIXOL'.S STEM ^Margin of pileus iinoUed in yovnig plant Colly bia* Lepton'ia ' Xaurorin 1 P all or 11 111 * Marasmius* /feliomi/i-cs /'siitlii/ra ^largin of pileus straight in young plant Mj/ci'iia Hiatula XditiK II I'.iiil'in I'liiti nlii^ Caler I I'siithiirflln Gills decurrent, pileus usually uni- bilicate OmphiiHK Tiibaria /)i roilirft Montarjiittrx 1 AiTa]i,i;ed by TIu-mkIuU' L. Siuilh, I'li.]). - Contains deadly yoiHon species. No spfvieii of Atnanltn .should In- ditni irithout identification by an expo't. 2 Contains stispicious sp(HMeK or tlidsc liavinu- niiimr ]>()isoiis, 4 Contains edible species and none knimni t<» be poisc.noiis except those £-;iven below : Lepiota morgani has green spores; it is one of tlie linost edibles, but makes ill about one person in six. JiHSfiuhi emetlca causes nausea in some in-oplc. but is liarndess for others. Tricholoma siiJphureuf^ smells like illuminating gas and is reputed poisonur prol)lem in its world-wide 207 208 CIVIC BIOLOGY scope, and may be prepared to conclude that its final solution must depend on intelligent, world-wide cooperation. Irish famine. It was the great famine in Ireland in 1845- 1847 that opened the eyes of the whole Avorld to what a fungous disease of a plant might mean to a people, and the awakening that followed marks the begmning of modern plant pathology. The case illustrates, too, the apparent suddenness of the attack, and also the total destruction of the crop the second year if rotation is not resorted to. Ireland had become densely populated, a large part of the people were almost wholly dependent on the potato for food, and the fungus that caused the famine Avas the late blight, or rot, of the pot'dto — Fhi/tojjhthoni iiifesfcai.^. Tlie harvest of 1815 proiui.sed to be the richest gathered for iiiauy years. Suddeuly, in one short month, in one week it might be said,, the withering breath of a simoom seemed to sweep the land, blasting all in its path. T myself saw whole tracts of ]>otato growth changed in one night from smiling Inxuriance to a shriveled and blackened waste. A shout of alarm arose. But the buoyant nature of the Celtic peasant did not yet give way. The crop was so profuse that it was expected the healthy portion would reach an average result. Winter revealed the alarming fact that the tubers had rotted in ]>it and storehouse. Nevertheless the farmers, like hapless men who double their stakes to recover losses, made onlv more strenuous exertions to till a larger breadth in 184(3. Although already feeling the pinch of sore distress, if not actual famine, thev worked as if for dear life ; they begged and borrowed on any terms the means whereby to crop the land once more. The pawn offices were choked with the humble finery that had shone at the village dance or the christening feast; the banks and money- lenders were besieged with appeals for credit. Meals were stinted, ])acks were bared. Anything, anything to tide over the interval to the harvest of ''Forty-six." O God, it is a dreadful thought that all this effort was but more surelv leading them to ruin I It was this harvest of Forty-six that sealed their doom. Not partially Init completely, utterly, hopelessly, it perished. As in the previous j^ear, all promised brightly up to the close of July. Then, suddenly, in a night, whole areas were blighted; and this time, alas! no portion KU^GOUb AM) I'.ArTEKiAL DISEASES lK)".! uf the crop escaped. A (M-v ut' agony and desjiair went up all uNcr the land. The last desperate stake for life had lircn played and all was lost, riic doomed people realized l>ut too well wiiat was hcfori' thcin. Last year's pii'iiionitorv siilTfriniis li;id <'\haust<-d tlirm and now? — they must die. ^^'e rai.sed a ])u1)lic .sult.serijitioii, and employed two men with ii(ii>e and cart to go around eair at Ardnahraiiair Al>l»ey and dro]»}ied through tilt' hinged l)ottoni of a trai»-<*otlin into a common grave below. Tn the remoter rural districts even this rude sepiUcher was impossible. In the field ami by the (lit 1^. Frrz.MAii;i( i: and d. II. 'I'm i:si ii;i.i». in Larned's "History for IJeady Keferenee," Iifland, Is l.'t-ls I7 Here we have our prol)h^in in the laro-c and in concrete form. An enemv lias kilUnl l)v starvation nearly a million people.^ What is this enemy? A\'^ho sa^y it come or c^o ? How does it o})erate ? ^^hy did it do this? How can we prevent fntui'e calamities of this kind? 'rbc world had to await alleviation of fears and sni)erstitions, (Hscovei'ies in many fields, and <'"rowth of the science of hotanv before many of these questions coubl l)e answered. Nothing can surpass in human \alue and interest, liowever, the (piality of mind that works out solutions for such [)rohlems. In tbe lio'lit of the Irish famine, what ma\' he the bnnian vahn^ of such asons, or during certain weather conditions, and pour clouds of spores into the air to infect surrounding trees. These disease breeders should be the first to be made hito lirewood in animal cuttinir from the wood lot. The sporophores slnnild also be destroyed as soon as they appear, lly a little intelligent cooperation a connnu- nity could bring these pests under control, and liowever valuable the trees may be in themselves, the sttidy will be worth while as an example of spread and preven- tion of disease. Koot rot of fruit trees is a matter that will call for special attention in certain sections. Two con- spicuous mushrooms, Cli- tocyhe parcifiitica and the common honey mush- room (Armi/laria mellea), show strong parasitic tendencies when brought into contact with the roots or crowns of apple, peach, or cherry trees. In clearing- land for orchards it is advisable to remove all stumps and roots that are likely to harbor these fungi. Invite the local forester or tree surgeon to discuss these jiroblems with the class. Learn from him the best treatment for tree wounds. (A^'ounds of any size made in [nnining should be sealed with paint or gas tar.) As laboratory work let. the class, in convenient groups, make some experiments in tree surgery where most needed about homes, school vard, or streets. Civic types for study. Duggar describes, or mentions, in his book " Fungous Diseases of Plants," 238 fungi that attack the common plants and trees of forest, orchard, garden, and field. Tie also gives a most useful Host Index Fig. 100. Apple inoculated, at pin, with spores of brown rot from nuunmied plum. Control apple As instructive as a case of smallpox 212 CIVIC BIOLOGY (the host is the organism that supports a parasite), hi which he hsts 174 plants, with the fungi that attack each. From this we see that everything Ave try to raise has its fungus enemies : alfalfa has anthracnose, leaf spot, root gall, European root disease, and root rot ; the apple has 2-i, among them anthracnose, or l^itter rot, tire blight, crown gall, rust, and scab ; beans have 7 : corn, (3 ; cotton, 9 : the grape, 9 ; potato, 6 : tomato, 8 ; wheat, 7 : violet, 6 ; phie, 6 ; oak, 7 ; and so on through the list. The following Ijacte- rial diseases are common : Pear and apple blight. Leaves turn l^rown as though burned with lire. The germ was supposed . to be carried by bees to the blossoms, but it is probablv inoculated b\ aphides. Limbs that show sj^mptoms of the disease -should l)e cut l)elow traces of the blight and burned. Wilt disease. This disease affects tomatoes, cucumbers, melons, cotton, and Irish potatoes, and causes the plants to wilt rapidly and die. Black rot of cabbage. Hie germ attacks cabl)age, turnips, rutabaga, and cauliflower. Leaves turn black and the plant dies. This disease is common hi America and Europe. Try, at least, to make a preliminary survey, and then choose for intensive study the local types that are most im- portant, and especially those that require general knowledge and united effort of the community to control — the civic Fig. 101. Loose smut of oats {Ustilago avence) and normal heads FlXGOrs AM> liArTKKlAl. DISEASES >i •> 21 typea. It may be possi])K' for eiicli pupil i«> uuikc a table giving for each fruit, vegetaljlo, and farm (idp ih«' loss caused by fungi — that is, to answer tlic (piestion, What jjart of the half-biUion-dollar tax (hx's my Ikuih* ]>:iy? A su(j:gestif -VH) Ai i;k8 1 i NUMBKU OF AOUKS Yield tx IJisnKi.s 1 Pku Cent , iN.riHKO PlJHE S.MITTKI> Total Loss Wheat . . 280 47 17 %\ .80 S.H.', SH,^<4a.yo ( )ats . . 40 :5(i 10 .40 140. S(l Com . . 10 7') / .7"» 4:^.(1(1 Potatoes . !i 4^ ( -1 . •')( 1 144.00 ( )rcliar(l . 4 20.50 - Total . . fi»,li>7.10 National and world problem. Tlic general situation is aptly expressed by the complaint heard on every hand : The woi'ld is not fit to livf in any more, and it 's Gf«4tinq; worse and worse every year. We never used to lu-ar al»oiit all tlies.- new-fan.uled diseases all the tinie^ and everytliing did n't nsr to rot and >ninl and l)light wlien 1 was a u'irl liaek on tin- old farm. This is literally ti'uc and for several good rea.Nt)ns. People did not then ktiow what was eatino- tlicm out cd" house and 1 Wheat is supposed to be affected witli stinkini^snnit, whiih Diigpfar says sometimes takes "from one half to two thirds of a crop" of some sections. Loose smut, corn snnit, and early l)li<,dit are the funiri sni)|)osed to have attacked tlie oats, corn, and potatoes respectively. Estimates are not ex- cessive. The percentatres for tlie wheat, oats, and corn are fii^ured by coinif- inij 100 stalks taken at random in ten different jiarts of the lield. (Save several of these bundles of wheat or oats for demonstration in tlie labo- ratory and at neighboriiood meetings.) The potatoes are estimated from u.sual results in case of sprayed and unsprayed field ])lots. The cost of treating the wheat and oats with formalin would liave been a triflini,' insurance agaiiLst the loss incurred. 2 Cost of three sprayings and one i)runing f^r bJiLdiC liiti.r y,,\, .•(.•. 214 CIVIC BIOLOGY home. They called it Providence and did not talk about it. Again, modern commerce and travel are rapidly mixing Fig. 102. Tree (on the right) infected with peach yellows Peach yellows is a contagious disease, exterminative of the peach in northeastern United States, that has baffled all attempts to discover its cause. The tree shown on the right is in the last stages of the disease ; the one on the left is healthy the bacteria, f nngi, and insects of all the world, and these are the forces that have often determined both the floras and the faunas of continents. More American Indians have been FUNGOUS AND IJACTEUIAL DISEASES 215 killed by European bacteria lliau by bullets. Measles struck the Fiji Islands like a deadly pestilence. So we inspect and quarantine against the importation of such germs as those of bubonic plague, Asiatic cholera, and foot-and-mouth disease, but they slip by in s[)ite of all precautions. The canker, or chestnut-bark disease, appeared about ten years ago, coming probably from Japan. Working as it does, between wood and bark, it cannot be reached by sprays, and there are not men enough available to prune and burn the diseased trees. It is said to have destroyed over $30,000,000 worth of chestnut trees, and predictions appear to be well founded that it may not leave a single one alive in eastern North America.! A third reason is that we are planting large areas to the same crop, with lield against field. This is like [)iling up kindling for a fire, when a disease gets a start. Control measures. ^lethods are improving continually, and the only safe course to pursue in this field is to correspond with our nearest experiment station and secure their latest s[)ray calendars, take the monthly list of publications, and keep abreast of discoveries. The underlying principles, how- ever, should be generally understood. 1. Be sure to plant lipalthy, uninfected, free-from-disease seeds, tubers, bulbs, or nursery stock. This refers to germs of disease inside the seed, tuber, or stock, and applies, of course, to buds and scions. Peach yellows, while the germ has not been discovered, is known to be transmitted from diseased trees in seeds, l)uds, or scions. Wilt dis- ease of sweet corn, or Stewart's disease, sometimes destructive to from 80 per cent to 100 \)vr cent of the croj), is transmitted on, and prob- ablv in, the seed. Seed should not be saved, or distributed to uncon- taminated land, from infected fields. The same is true of anthracnose of beans and cotton: l)ean blight; bacterial blight, or wilt, of jiotato: ^ Tlie species mi^dit be saved to the continent if nuts from sections as yet uninfected could be sent to suitalile i)laces on the Pacific coast and planted and reared beyond probable reach of infection. The United States Bureau of Forestry would probably be glad to supply safe seeds to biology classes that would agree to follow out directions for planting and culture. 21t) riVIC BIOLOQY late blight, or rot, and dry rot, or stem blight, of potato ; and crown gall of grapes, berry bushes, and fruit trees. So, too, pear and apple blight have often been scattered broadcast from nurseries because disinfec- tion of j^runing tools was neglected. In general, disease shows \\\< clearly in the nursery or field, while it would require bacteriological and microscopic methods to find the germs within the seeds or stocks. Go out and hunt over local nurseries or seed farms. Ask experts from them to come in and demonstrate and discuss their methods. All wh.r) Fig. 103. Covn smwt {Ustilago zew) propose to distribute these important supplies to the puljlic ought to know their business by this time. The best firms employ trained ex- perts to see to it that stock is free from disease, and then they may send it to branch farms, far away from any possible contamination, to have it propagated for the market. 2. If spores are alive on the seeds or tubers, ready to attack the embryo plant when it germinates, kill them before planting. Scab of potatoes and smuts of grains are examples. Soak seed potatoes for two hours in formalin solution (1 ounce to 2 gallons of water) or in mercui'ic chloride (corrosive sublimate) solution (1 ounce to 8 gallons of water). External spores of the smuts on wheat, oats, and barley are killed by soaking for from ten to twenty minutes in formalin solution (1 pint to 30 gallons of water) or by warming up the seed in water at 110°-120° and then holding it for ten minutes in water at 182°-133^ F. FUNGOUS AND BACTEIUAL DISEASES lilT 3. If liviug si>oros iiro coutiuuuUy Milting down from the air, wo must keep the surface of leaf or fruit covered with something tlial will kill them as they germinate. If we wait till they get in, tiie crop will be ruined. Various Bordeaux solutions and lime-sulfur washes an- effective for this purpose, and, iiatiii-ally, while leaNes are unfolding ra[>idly or fruit is growing, we must sjtray (•\fry few days. 1. If the s[»ores are alive in the soil, there is nothing to oii — sonu'thing that will starve tliem out; there is no other way of killing them out of the ground. 5. Seek continually for resistant varieties and strains. With every- body on the lookout for these valualde variations, we may liojte for more rapid progress in the control of fungous diseases of [ilants. 0. ( )bserve general soil and plant hygiene. A\'it!i the soil mellow and well drained we may minimize danger from root rots and damping-ofV fungi ; with plants W(41 spaced to let in sunlight and allow free circu- lation of air, or pruned with this iu view, a!ul with fruits thinned so as not to touch, we may greatly reduce danger from aii'-boi-iie spores. Every comiimiiity organization, rural or suburban, oiiLcltt to have a conmiittee on funo()us diseases of })lants and tlieir practical control. The local class in biology mioht widl be the laboratory right arm of smdi a coinniittcc. \\y \\()iking out cooperative plans, tliorougldy agreed upon, which niighi spread from neigliborhood to neighl)orhood as tlicy were de- velo[)ed and perfected, uuuiy of our worst fiuigus enemies might be completely stamped out. Xo real estimate of the loss caused l)y them has ever been even attempted. We do not know enouoh about them. I)uo-(rar's guess of ^r)00,()()0,()00 a year is ^■erv low, and, w hile it mioht a])pi'oximate the lossi's to th(^ larirc markets and chaniuds of trad(\ we nuist certainh adoses. 220 CIVIC BIOLOGY Reproduction in bacteria. Bacteria multiply by division, which is even more simple than the budding of yeast. The cell, when mature, divides transversely into equal halves. Under favorable conditions a bacterium may divide every twenty minutes to half an hour. Can you calculate the progeny of a single bacillus for twent3^-f our hours ? Bacteria do not grow and reproduce without food, and their astonishing power of multiplication helps us to understand the altered condition of milk and meat if kept in a warm place for even a few hours. Some species develop spores withm tlie cell and these are much more difficult to kill than the bacteria themselves. Conditions favorable for the multiplication of bacteria. Like other plants, bacteria demand food, moisture, oxygen, and warmth for growth. Remove any one of these conditions and they w^ill either cease to multiply or die. Moisture. Bacteria grow only in liquids or moist sub- stances. Dry foods and those containing less than 20 or 30 per cent of water they cannot attack. Drying weakens and kills many bacteria. Spores, however, are much more resis- tant to continued drying than the vegetative or growing cell. Why should houses not be allowed to. become damp? Why is meat salted and dried? Why is canned fruit sealed? AVhat influence has sugar in preserving fruit? AVhy are such foods as molasses, condensed inilk, flour, seeds, and grain bacteria-] iroof? Temperature. Temperature affects growth of bacteria. As in higher plants, there is a temperature known as the optimum at which each species thrives best. A tubercle bacillus grows within a range of 5 degrees, while a few other species can grow anywhere within a range of 50 degrees. Bacteria do not multiply during the time they are exposed to low temperature, but their vitality is not affected ; the tu- bercle bacillus has been exposed to a temperature of liquid air BACTEKIA '2-2\ ( — 190° C.) for periods varying from six hours to forty-two (lays without killing it. The retardation of haeterial growtli in low temperature is of importance from tiu* })ul)lic-healt]i standpcunt, since it makes possible the s!iip[)ing and temporary preserving of perishable foods in cold storage. Heat in sutfieient amount kills all bacteria whether in the spore or vegetative state. Steam heat is more etTective than dry; a few minutes of steam heat at 1:2(1° ('. will kill spores that would take 1S0° (". of dry heat to destroy. Light. Contrary to the effect jjioduced U])on green [)lants, light has an unfavorable action upon bacteria. iJright sunlight serves to kill the vegetative cell and weakens the spores ; diffuse liii'ht retards g^rowth ; in the absence of all light thev grow best. This destructive action is intensilied by moisture and fresh air. Oxygen. Pasteur was the tirst to demonstrate that some bacteria live without free oxygen. I le divided all bacteria into three classes: aerobic, those species that can grow only in the l)resence of air: anaerobi(% those that can grow only in the absence of air; and facultative, those that can grow either with or without air. liacteria that grow in the iiuier tissues of the bodv of a plant or animal are examples of anaerobic species; they do not grow without oxygen, but get a supply by breaking down organic substances that contain it. The majority of bacteria are aerobic, as evidenced by the many cases of decav whicli begin on llie surface and woi k towarutatioii is as unjust to the 999 CIVIC BIOLOGY saproj^hytic bacteria as it would be to condemn all higher plants because a few of them are poisonous. In general, sap- rophytic bacteria do no more harm than dust if breathed, or than vegetables if eaten. Nitrifying bacteria. Certain bacteria of the soil are spnbi- otic upon the roots of leguminous plants, such as clover, alfalfa, beans, and peas, and cause tubercles to form. These bacteria gain entrance throug^h the root hairs of the plant and cause smooth young roots to as- sume a nodular appear- ance (Fig. 104). Experiment shows that if a legume, notably clo- ver, is grown upon soil of known composition, a part of which has been ster- ilized (baked), the crop upon the unsterilized soil will be notably larger and the soil will have nitro- gen added to it. These bacteria are important, since they can fix the free nitrogen of the air and give it to the soil in the form of nitrates. The benefit to the soil result- ing from clover cropping was discovered and practiced by farmers long before the cause was known. jNIuch experimental work is being done with these nitrifying bacteria, and pure cultures are being sold to inoculate soil that does not contain them. To prevent extravagant and mis- leading claims of dealers, the United States government has issued the following statements : " No beneficial results can be Fig. 104. Clover plant with many bacterial nodules on roots BACTEKIA 223 expected for a piirtieulur ('i()[) it" -the bacteria for the cn^) are already in the soil, liut little, if any, benelit can be expected from the use of these bacteria if the ground is decidedly in need of other fertilizers, such as phosphates, potash, and lime. But little, if any, benefit can be expected Iruni inuculalion if the soil is already ricli in nitrogen." Carefully wash the roots of different clover plants. Are the nodules of nitrifying bacteria present? Are they found upon alfalfa and peas in your region? Are pure cultures of these bacteria sold iu your state? Read the state and government bulletins upon these bacteria. CHAPTER XXII bactp:ria coxttxued: laboratory methods Apparatus and material. To grow bacteria in the labora- tory the following apparatus and material are necessary : a steam sterilizer, hot-air sterilizer, two platinum needles i; test tubes, Petri dishes, absorbent cotton, litmus paper, sheet gela- tin, agar-agar, extract of beef, potatoes, caustic soda solution, and hydrochloric acid. Gelatin medium. Dissolve in lOUO cubic centimeters of distilled water 10 grams of peptone, 5 grams of common salt, 2^ grams of beef extract, and 100 grams of sheet gelatin, and place in the steam sterilizer until dissolved. ^ Let the mixture cool to 55° C. (you can hold it in your hand) and add a teaspoonful (.)f albiimen dissolved in cold water, or the whites of two eggs. Boil until the liquid looks clear.^ Line a funnel with wet absorbent cotton or with filter paper designed for gelatin or agar-agar filtration. Pour the gelatin mixture into the funnel and catch in a sterilized flask. Place in a steam sterilizer. If the funnel is kept thoroughly warm, the gelatin will pass through the filter in about an hour. Test the gelatin with litmus paper. It will be found to be acid. Add a weak solution of caustic soda to it, drop by drop, until blue litnuis paper does not change 1 Cut platinum wire (No. 27) into two-inch lengths. P'use one end of each into a glass rod, and bend the free end of one of the needles thus made into a small loop, to be used in measuring drops in liquid cultures. • 2 A portable sheet-iron oven and an ordinary steam cooker may be used if necessary. 3 A fact that nuist be borne in mind in preparing gelatin is that its gelat- inizing power is injured by prolonged heating during the process of prepa- ration or sterilization, and is lost immediately when heated to 140^ C. . 224 BACTElJiA 225 color. r<>ur about one and one-lialf inches of gelatin into each test tube and plug with cotton. Sterilize the tubes tAventy minutes for three ('(Hisccutivc days, so as to kill all spores. Agar-agar medium. Mix the same as the gelatin medium, usiiu»" 15 o-rams of ao-ar-aiiar in phice of tlic ItM) o-ranis of gelatin. 'I'he })re[)aration of agar-agar medium, however, is more troublesome than the gelatin. .Agar-agar does not dis- solve easily and is ditlicult to lilter. To obtain a (pi irk result it is best to perform the filtration in parts. If the funnel, lined with absorbent cotton, is well heated, about one half of the agar-agar mixture will have passed through the filter in fifteen minutes. Remove the funnel and reboil the remaining agar- agar and pass tlu'ough a fresh filter, liepeat the process until the mixtuie is filtered.^ Potato medium. Pare the potatoes and cut \\'ith a cork borer of suitable size for the test tube. Divide the cylinders into two-incli lengths and then cut diagonally across. Place the "' potato slants " thus prepared in water for several hours, to extract the product which turns them black when exposed to air. Put into test tubes, slant side uppermost, ping, and sterilize in a steam sterilizer for twenty-five minutes at 1<>0 C. for three successive days. A small piece of glass rod placed in the l)ottom of the test tube holds the potato above the condensed steam. Rules and methods of manipulation. (1 ) i.earn as early in the course as possible that all dishes should be washed and sterilized in the hot-air sterilizer before using. All micro- orofanisms are killed when thev are heated as follows: three hours at 150° C, or until pai)er is brown : one half hour at 160° C; one fourth lumr at 170°C. ; one minute at 190° ('. (2) Before sterilizing, wrap the Petri dishes in paper and 1 If time is limited, obtain the prepared p;elatiii vr agar-agar from a local hospital laboratory or board of health, or order from a regidar ilealer in such supplies. 226 CIVIC BIOLOGY plug the test tubes. To make plugs, tear a strip of cotton about two inches \yide and as long as needed, fold length- wise, and roll into a plug. Insert this not more than half an mch into the test tube. Cotton plugs are quite generally used in bacteriological work, since they allow a free circu- lation of air and prevent the entrance of germs. If material Fig. 105. Preparing culture media Photograph hy the author is properly sterilized and plugged with cotton, it will keep indefinitely. (8) Do not open the hot-air sterilizer until the temperature is down to 40° or 45° C. It is preferable to leave the dishes undisturbed in the sterilizer until used. Before planting (inoculating) your culture media with bacteria observe the followinof: Unless otherwise directed, always inoculate media with platinum loop or needle. (1) Heat the wire in the flame just before and immediately after using. (2) Avoid having BACTERIA 227 currents of air iii the room. (3) Upon opening a euliure medium for inoculation, pass the mouth of tlie tube through the flame (flaming) ; if it has stood for some time, flanu; the cotton before opening the tube. (4) Never allow the tube end of a plug to come in contact with anything while re- moved from the tube. (5) If a plate culture is to be made, melt the gelatin in a test tube (placed in warm water) and pour into a ster- ile Petri dish. If I'ctri dishes are not available, test tubes may be substi- tuted, provided the gelatin in tlicni is allowed to cool while they are lying- in a nearly horizontal position. (6) In- oculation should not take place before the gelatin hardens, unless germs from a liquid are to be grown. In this case the gelatin is inoculated in the test tube and then poured hito the Petri dish. (7) Unless otherwise directed, all cultures that have been inoculated should be kept in the dark, or in dif- fused light and at room temperature. (8) If possible, duplicate each experi- ment, using Iwtli potato and gelatin media. Note appearance of growth in each case. Label and keep careful records of each experi- ment. (9) After your experiments are finished, do not allow the media to dry; place all dishes in water and l)()il for fifteen or twenty minutes before cleaning them. Experiments for bacteria of the air.^ (1) Expose a Petri dish of gelatin for five minutes in the laboratory before the class enters. (2) Expose another for the same length of time Fig. 100. Exposing Petri dislies Photograph by tho author 1 Each member, or group of members, of the class should perform one or more of these experiments. 228 CIVIC BIOLOGY in the same room just after the class has left. (3) Expose a Petri dish of gelatin in a room for five minutes immediately after wiping up the dust with a dry cloth or after using a feather duster. Compare this plate with one that was exposed for the same length of time in a room immediately after it had been dusted with a damp cloth. (4) Expose a plate in a living room for five minutes and compare with the air in the yard. (5) Compare the number of bacteria in the air upon the ground with that of the first and fourth stories of the same building. Is it true that a child breathes less pure air than a man ? Is it more desirable to sleep upstairs, as far as air is concerned ? (6) Expose a plate of gelatin in a busy street before and after it has been sprinkled, or before and after a rain. (7) C'ompare the number of bacteria in a well-cleaned street with the number in one that is not cleaned. What do you thmk of the system that cities are using for flushing their streets ? (8) Compare as to number of bacte- ria the air before and after a snowstorm or rainstorm. Inocu- late plates A^'ith rain or fresh snow. Keep these experiments hi a drawer in tlie laboratorv. In a day or so count the colonies of bacteria and record results. (9) Sweeten and cook fruit, such as apples, in a test tube. Plug with cotton. Does canned fruit keep if air is present and bacteria are excluded ? (10) Discuss the desirabilit}^ of having children's playgrounds upon the roofs in large cities. Experiments for bacteria of water. (1) Make a culture of water from a stream (dip your platinum loop three times) and compare with the same amount of water from the reser- voirs and lakes of the locality. (2) Compare the water above and below the point where the sewage is emptied. (3) Com- pare the different drhiking waters of the locality. (4) ]\Iake cultures of water that is rich in organic debris and compare with the same water that has been boiled for fifteen minutes. (5) Filter some of the Avater used in the above experiment ILVCTEKiA ■2-2^) through several inches (twelve or fifteen) of clean sand. Is a sand filter effective? (0) Make cultures of milk. How does fresh milk compare in the numl)er of its bacteria with that which has stood for some time? (7) What is meant hy Pasteurizino" milk? If possible, visit a milk station where milk for babies is sold. What measures render it safe? Fig. 107. Inoculatinii- gelatin tubes with platinum loop Note the way in wliich cnttoii phijjs are hehl between the fiugers Additional experiments. (1) Scrape the surface of a silvi'i coin with a sterile knife and make a plate culture. Compare with cultures made from cop[)er coins and paper momw. No l)aper money is used in the Hawaiian Islands because ot the danger of transmitting disease. (2) Make plate cultures from the surface of a pencil that a child lias used for some time : from the eds^e of a common drhdving cup, door handle, straps 230 CIVIC BIOLOGY in a street car. (3) Make a culture from a dishcloth that is washed and boiled once a day, and from one that is not. (4) Compare the number of bacteria in rancid and fresh butter. (5) Allo^Y a fly to ^Yalk across a plate of sterile gelatin ; record results. (6) jNIake a stab culture by running a straight platinum wire, with germs upon it, down through several inches of sterile gelatin in a tube. Upon removing the wire the gelatin closes around the germs left in its track, and serves to cut off the air supply except at the surface. Do you find three classes of bacteria growing in the culture ? The excretions of bacteria render the most favorable medium unfavorable. In general, bacteria do not grow as Avell upon acid as upon slightly alkaline media. (7) ]\Iake a culture from the dust of a dark corner of a room ; from a surface in diffused light; from one in bright sunlight. Can you think of more favorable conditions for the growth of bacteria than that offered by the mouth ? How can you keep your teeth from being destroyed by them ? (8) Inoculate a plate with clean- ing of a finger nail, dandruff, single human hair, cat hair. (9) Breathe into a gelatin tube without .touching the lips to the glass; make a plate culture. Can the breath carry bac- teria? (10) ]Make a plate culture of some of the substance that has gathered upon the back of the teeth. (11) A bacillus has a characteristic growth upon a culture medium. From the appearance of the colonies do your experiments show that you have grown different species of bacteria ? Can you- see that by selecting a species of bacteria and inoculating a fresh cul- ture with it, and then from it again selecting and inoculat- ing a fresh medium, you would soon obtain a medium with a "pure culture" of that species of bacteria? (12) Can you now explain the need of such rules and precautions as are given in the early part of this chapter ? CHAPTER XXIII CONTROL OF BACTERIAL DISEASES Aristotle (384-322 n.c.) instructed Alexander the Great to have his sol- diers boil their water in order to prevent epidemics of disease in camps. Possibly to this bit of practical biology Alexander owes his conquest of the world. Advertendum etiam, siqua erunt loca palustria, et propter easdem causas, et quod (arescunt) crescunt animalia quaedam minuta, quae non possunt oculi consequi, et per aera intus in corpore per os ac nares perveniunt atcjue efficiunt difficilis morbos.i — Vakro (b.c. 110-27), '' De He Rustica," Lib. I, 11-12 (Keil, 145) Already in his studies on silkworms, Pasteur's first experience in the domain of disease, the dawn of a new era in the contest of man with con- tagion opens up before him. He says: "II est au pouvoir de Thomme de faire disparaitre de la surface du globe les maladies parasitaires, si, comme c'est ma conviction, la doctrine de la g^n^ration spontan^e est une chim6re."2 — Fkanklaxd, ''Life of Pasteur,"' p. 123 Bacteria and disease. The majority of bacteria are harm- less or beneficial. A few are venomous, as are a few species of snakes, fishes, trees, or mushrooms. The venomous bac- teria strike plants, animals, and man just as really as do lead bullets, and wound and kill in essentiallv similar wavs. The notion is current that bullets hit the fittest, while l)iR'teria seek out the untit, but tliere is not nuich ground for this 1 "One should be on guard, if there should be any swampy places, both for the same reasons and because there grow certain minute animals, which the eyes cannot perceive, and which, permeating the air, enter the body through mouth and nostrils and cause serious diseases." — Professor S. F. DiNN, Lniversity of Oregon, Translator 2 '' It is within the power of man to cause to disappear from the surface of the globe the parasitic diseases, if, as is my conviction, the doctrine of spontaneous generation is a chimera.'' 231 § 120 <:i* 110 ^ 100 S 90 g 80 '^^ 1^ VU g 60 s 50 Q 40 30 20 10 ^ >^'' T*'-^ ~Z^ (under or^""* \ ^--*fe*fxr A poplexy 3T* 1 I 1 Cerebral^ ffemorrhaq^ *7 / X fgOO 1901 1902 1903 1904 1905 1906 1907 1908 1909 1910 1911 1912 Fig. 108. Death rate per 100,000 population in the registration area of the United States From the Census, Moi-tahty Statistics, 1912 232 CO^'TROL OF BACTERIAL DISEASES '238 idea.i Ignoranco aside, there is no more reason for allowing ourselves to l)e ])itten In* bacteria than by rattU'snakes. About two people die from snake venom annually in the rniti'd States; 20,000 die yearly in India from snake l)ite, because cobras are accorded superstitious protection. A\'e religiouslv preserve our bacteria, with the lilth hi which they thrive and the Hies that distribute them; the Hindus, their relatively harmless snakes. A few of the more familiar germs, with ihe disease and death they are causing, are presented in the table on page 2^34. When we all know how to kill and avoid these bacteria, as well as we know how to deal with rattlesnakes, we may be as free from them as we are from the smdvcs. All must know and each must do his })art, for one ignorant i)erson can scatter bacteria by the million from Maine to California. The table is hy no means cuniplete. In the lu-xt c-ha})ter we sliall study a siiuihir list of diseases caused by parasites of aninud origin. There is another list, known to be infections, — smallpox, yellow lever, scarlet fever, measles, spotted fever, and footrand-mouth disease, — the specific causes of which have battled all attenii)ts to discover. Still another class of ailments, noninfectious, chronic and organic, — of the heart and arteries, brain and kidneys, — of heavy and increasing fatality, may have to do with organs weakened by parasitic attack. Finally, we have no statistics of tlie number (»f the wounded, the weakened or crii)})led, anrol)ably not less than 2(»0,000,(MI0 of them a year. A\'hen we aneumonias. white diarrhea of chicd^s and foul brood of bees, 1 "Neither regularity of life nor bodily strength was any preservation against it. The strong anil the weak were equally struck down ; and death spared not those of whom care was taken, any more than the poor, desti- tute of all help." (The fleas of that time bit all alike.) — fJ \-«^rKT. "Tlie Black Death." p. 12 234 CIVIC BIOLOGY < < ;h 1 «+H 1 t>5 cc 0 1 ft o • I-H +3 o ?-H 02 ft 0 IT— ' a q; •I-H '^ ,-H f-H -(J a> fa- 0) 0 0 ^ > O o 03 o 53 •CH o o • 1— 1 o o ^ 'S 0 ■ 1^ •I-H 0 -^ ,-5 0 I-H • rS +^ ,-H t-H a» _ft f— < ,-H 0 CO 0 0 • ^H CD ;h ft 03 <-< III C ft • I-H o; ■^ Tr X •- o> - 1— 1 o o o o 0000 0 0 I— 1 0 0 1— 1 S " I^ -^ o o o o 0000 0 0 I-H 0 I-H - ^ "- ut; CM ^ ut CO I- 0 0 ■M r^. 0^ CO^ *- g ;^ 2 ;i^ '^^ CM CO ^.ta/ 0 CO Ci ^ CM CO t— " co" '^ cc T— 1 T— 1 t^ 1— 1 T— ( i-H CO t^ '^ I-H I-H 0 H fe t>. t>. _t^. K r--< ^7-* J^ H ;:; >> 1 0 0 0 0" 0 0 ClJ o o o 0 0 0 0 p^ ^ ^ o cm" 0" 0 (M 0 0" 0 CO ^^ ^ ^,^ ^ ^ 1 a: ^ .2 ce d 2 O) *-3 s ^H OJ Oi 0 .-H Ul X 0 5 ■2 g sc rH S '■5 > • ^H c5 0 ^ ft "I-H 5r! "^ "^ (Do;! — oT >H 'j3 ?H 5^ -H aT • f-H -1-5 • I-H 'X ^ 0 0 < aT ^ ft O) G 'A J3 ce ^ r^ 3 ?-( -1-^ 0 32 1— ( ft 2 ^ xP +-3 .-H ;-H rH ft e3 «- .2 5 ft 0 Th s s 'ft 0 of <^^ ft •^H ^H 0 of 2 C O ^t >> S C t. a; rv^ r-Ti r^^ "^ 1— 1 ^^ ^ ^ 0 0 "*"' C^ X q; 9 '0 S o ?H P H 1— C2 hJ rA ^-^ Q 0 ^ ^ >--*^ ^— *^ S^. Cv. c^ •ti ^ ^ CO 5C 8 •|S> Is • =0 0 to liii Hit 1;:) 0 -0 ^0 O 1 1 ■SO to to 0 0 to 1- ■*o ^■0 Si -to 1 1-^ 06 to Si 5t 5t ■♦0 • 1 -H -1^ ft; Ki k; p; ^^^^ k; pQ «; ^ ^ CM T-H ;h o 03 O -t-5 O) +3 a o 03 I-H '■+3 03 03 -« 03 ^ '^ a. > - s + :3 ce rH (^. C3 ft 0 >^ ft -i-i F— 0 r* i^ -l-i 0 ;-, r, 0 0 *— 1 0 03 0 0 -'-' ^H ;:; t^ = ^- w CC T 0) ^ C/. 13 CS X5 ® COXTKOL OF BACTEIUAL DISEASES 235 anthrax and glanders, and many others) and the long list of bacterial diseases of plants, already briefly considered, we begin to realize that the very edge of the struggle for existence lies between mankind and the bacteria. The three questions. The following questions apply to the parasitic diseases — bacterial, protozoan, vermian, and all the rest. When Pasteur was '' wasting his time " disproving spontaneous generation, one of his friends wrote: ''He makes me uneasy, he does not recognize the limits of science, he only loves insoluble problems." Now that we know that " la generation spontanee est line cldmere^'' the problem of the control of disease becomes the comparatively easy one of preventing the spread of the living germs from the sick to the well. In every case of contagion or infection the germs escape alive from the body of tlie sick, are carried to the well, and gain entrance. Therefore the three fundamental questions are : 1. How do the germs of each disease escape from tlie body of the patient ? 2. How is each kind of germ carried ? 3. How does each kind of germ gain access to the body? Paths of escape. Parasitic germs of the lungs, nostrils, throat, or mouth (of diphtheria, tonsillitis, pneumonia, tuber- culosis, rhinitis, bronchitis, and influenza, as well as stomach and intestinal diseases that involve vomiting — typhoid fever, enteritis, and cholera) escape with any discharges from mouth or nose. Careless coughing and sneezing may scatter the germs over anything or anybody within a distance of about six feet. Spitting in any public place is an abc^mination, and laws against it should be rigidly enforcetl in the interests of public education as well as health. Bacteria from the digestive and renal-reproductive organs pass out with the dejecta — dysentery, choleras, typhoid. Typhoid bacilli have also been found in the perspiration. Job CIVIC BIOLOGY Germs circulating in the blood are usuallv drawn off bv blood-Slicking insects, ticks, or mites ; malaria and yellow fever, by mosquitoes ; typhus fe^•er, by body lice (and per- liaps by fleas and bedbugs) ; plague, b}^ fleas (possibly also leprosy) ; typhoid, by bedbugs ; Texas fever and spotted fever, by ticks; infantile paralysis (?) and anthrax, by the .Micrococci Bacilli S|>irilla bi.flnmmaCLoa (Pneu ni'jii'i'J, Rheumot.isrn, S'jvc.-i. Boils) Inflarivrnation (rt'lppC Diphthena Fig. 109. Pathogenic bacteria modeled to scale in plasticene (niicra = centimeters), magnification of models being 10.000 diameters A suggestion for a laboratory oolleotion. INIount in inspot cases under glass. Photograph by the author stable fly ; and sleeping sickness, by one of the tsetse flies. Diseases marked l\y lesions of tlie skin — measles, scarlet fever, smallpox, and probably dandruff" and eczema — may escape with the scales of cuticle or the contents of blisters or sores. How living disease bacteria are carried. Tlie greatest barrier to the learning of truth is apt to be a firm belief of an error. Xo set of ideas has cost the world more misery, suffering, and loss than false notions, prejudices, and superstitions re- garding the transmission of diseases. First they were carried C02sTKUL ()!• UACTEIUAJ. DISEASES 237 by angry gods, demons, and witches; next, b}' the air as miasms and eflhivia; then, by fomites in dust of clothmg or merc'liandise ; and, iiiially, we liave come down to the sure exidence ot" science that contact infection, chiefly by tlic liands, accounts for ahnost all the spread of common diseases, and insects, by contacit or inoculation, for most of the rest. Air not an important carrier. Just now the air is rapidly losing all its terrors, smallpox being the only disease which may possibly, though not probably, be carried from house to house by this agency. (This does not mean that hisects that Wy may not transmit many infections by contact.) Cha})in puts the case carefully and sensibly as follows : Only a lew authorities now assert tliat disease is carried liv tlir atmosphere outside of dwellings, and this assertion is made only in regard to smalliwx. . . . Infection hy air, if it does take place, as is commonly believed, is so ditficnlt to avoid or guard against, and so universal in its action, that it discourages effort to avoid other sources of danger. If the sick-room is jfilled with floating contagium, of what use is it to nuike much of an effort to guard against contact infection? Jf it should })rove, as T firmly believe, that contact infection is the chief way in which the contagi(JUs diseases spread, an exaggerated idea of the im})ortance of air-borne infection is most mischi<'V(Mis. It is impos- sible, as I know from experience, to teach people to avoid contact in- fection while thi'v are tirmlv convinced that the air is the chief vehicle of infection. . . . Without denying the i>ossibility of such infection, it may be fairly affirmed that there is no evidence that it is an a}»preciable factor in the maintenance of most of our common contagious diseases. Wt' arc warranted, then, in discarding it as a working hypotliesis ami r York- Mr,l}r„l .1, ,„,•>,<, I. WA. LXXXI (1005), j.. .'.-!1 Men detaileniifd the dutv of cmiitving liedpans, seen to go dii-('cily to tln-ir iiiral> without washing their hands, and even U) distrihute food to tln-ir comrades.^ — ('iiaimn, \k TJl* Thus, at one of the Huest hospitals in this country, with separate wards for scarlet fever and diphtlieria, a considerahh' iiiunber of cases have arisen in the general wards. The germs were supposed to he air- l)<)nu% as it was said there was no other possible a\eiiue of infection. When T saw the head nurse lick her finger to facilitate turning the bed- side charts of dijththeria ]>atieuts, [ suspected that the jirinciph-s i>f medical ase]tsis liad not been entirely mastered. — -Cii mmx. p. Iti.'i The superintendent of another hospital invited another visitor and mj'^self to eat ice cream from the same spoon with himstdf, whi(di .spoon was then rei»laGed in the freezer which was to supi)ly the wards. 1 w as mo.st of all impressed with the fact that at the International Congress on Tuberculosis in 1008 a large number rotest. — ('iiai-in. p. Iti.' The followino' observations were iiia. I 'aid for it and threw it away. ;i. Called for glass of milk .at railway-station lunch counter; swarthy foreigner removed cap from (piart jar, put his dirty hand (tv(n- bottle, turned it bottom up and shook it violently, scra|ted jialm of hand on mouth of jar, and pourefl out tin* glass. lie was tohl to driidc it himself. 1 From a description of an army typhoid ejtiileuiic. 242 CIVIC BIOLOGY 4. Observed ^ flies swarming on crates of raspberries and black- berries, absolutely open and unprotected (caught about sixty flies with. one sweep of the hand over such a crate). Carriers and contact with food. Typhoid Mary was dis- covered by Soper in 1906. She was apparently healthy, but wherever she served as cook typhoid fever was sure to fol- low, and she was found to be alive Avith virulent typhoid bacteria. She had already caused several small and at least one large epidemic. From 1907 to 1910 Mary was detained in the isolation hospital of the New York Board of Health and then was released upon her promise to change her occu- pation. Early in 1915 an epidemic of 25 cases broke out in one of the New York hospitals, and there in the kitchen, under an assumed name, was found Typlioid INIary. About 4 per cent of those who recover from the disease remain as typhoid carriers, either continuously or intermit- tently, and some may not even know that they have ever had typhoid at all. For some unaccountable reason there are about five Avomen carriers to one man. A typhoid epi- demic occurred at Hanford, California, INfarch, 1914, the study of which by the health officers proved most instruc- tive. A church dinner, of which 150 partook, resulted in 93 cases and 3 deaths. The infection was traced to a Avoman Avho had cut the bread and prepared a dishpan of Spanish spaghetti. She had nursed her daughter through typhoid thirty-fiA^e years before, but did not knoAV that she herself had CA^er had the disease. In order to test the matter a dish of spaghetti, not so large, was similarly prepared, and, although baked much more thoroughly than that served at the dinner (until the top Avas broAvn, the points on the sur- face Avere charred, and the edges were boiling furiously) living typhoid bacilli Avere found Avithin half an inch of the 1 In a public market, Washington, D.C., July 3, 1915. CONTROL OK llACTKlilAL JJlSEASES 243 surface and at the center ol" the nuiss they were swarniinc^, and the • temperature there was only 28° C. Tin's proN rd that '' ordmary hakinstance, which were not destroyed by heat. Jordan says of this : " Many of the epidemics of 'meat poisoning 'etc. are now known to be due to infection with a specific microorganism rather than to the action of a formed poison."- Milk is a most favorable culture medium for bacterial growth, and naturally many epidemics are traced to it. Cha})in gives the follow- ing figures : 315 outbreaks of typhoid, 125 of scarlet fever, 51 of diph- theria, and 7 of tonsillitis (e^tidemic sore throat). Immediate report to the board of health of the milk route on which a case of illness occurs nuikes it possible to nip nuiny an epidemic in the bud, a visit to the dairy generally revealing the source of the infection. Recent outbreaks of typhoid on two milk routes in Hartford, Con- necticut,— 12 cases in September, 1914, and 34 cases in November, — were traced to the same carrier, an occasional milker, who had moved from one dairy to the other. All the typhoid, 21 cases, in a ^Minnesota town for five years was traced to one carrier in a dairy. ^ An epidemic of dii>litheria in Lincoln, Nebraska, of 110 cases and 2 deaths (07 received antitoxin promptly, and none of these died) was traced to a di]»htheretic "sore throat " of a milker. The numey cost to the community of this "trilling sore throat " is estimated at $10,000, in addition to the suffering, labor of nursing, and the 2 deaths. ■* ^ Sawyer, Journal of the American Medical Association. 1".»14. p. 1537. 2 Jordan, General Bacteriology, p. 101. 8 H.^V. Hill, American Journal of Puhlir Ihalth, Vol. IV (11»14), p. OCT. * Wait, " Report of Milk-borne Epidemic of Diphtheria,'' American Journal of Public HeaUh, Vol. IV (1014), p. 418. '2U CIVIC BIOLOGY Clean milk. For many, possibly for all, coiuinuiiities no better health- conservation work could be undertaken than solving, each member of the class for his own home and the whole class for the home commu- nitv, the problem of safe and clean milk. Milk is safe when all disease "•erms are kei>t out of it, and it is clean when free from filth of all sorts, usually indicated by numbersof other bacteria. As secreted by healthy cows, milk is pure, and by ol)serving hospital-operating-room precau- tious it can Itc kept so.^ A'on Behring's statement that milk should not l»e used for infant feeding if it contains more than 1000 bacteria per cubic centimeter is rarely lived up to. Boston's standard of purity (which Spargo thinks is worse than no standard at all) allows 500,000 bacteria per cubic centimeter, and "certified milk " may run as high as 10,000 bacteria per cubic centimeter. Secure copies of specifications for local certified dairies. ^ If jwssible, have a committee of the class, or each member, work iqt the technique of making the bacterial co\mt and examine local milk supplies.^ We have been too long scoring dairies according to l^uildings and e(|uipment, and nothing could be more convincing for the truth of Dr. North's contention that dirty milk is 90 per cent due to dirty or io-norant dairymen than his demonstration in ten Kelton dairies. Ten trained Oxford dairymen were shipped over to Kelton in time to do the evening luilking in ten of the dirtiest Kelton dairies, with the result shown t)n the next l)age : bacteria in the milk reduced from inillions to less than 10,000 per cubic centimeter, in all but No. 0, a most in- structive exception.^ Four things necessary to production of clean milk : 1. Milking with dry hands into covered pails. '2. Proper washing and sterilization of milking })ails and milk cans, :>. Cooling milk by placing cans in tanks of cold water or ice water. 1. Regular laboratory testing of milk for bacteria, and payment based on the laboratory tests. Pasteurized milk. Dangerous milk can be made safe by heating to (JO' for twenty minutes, and this does not seriously injure its nutritional value. This treatment kills all non-spore-forming disease germs of ^ Kosenau, The Milk Question, p. 7o. (Tells liow Mr. S. L. Stewart, New- burgh, New York, produces milk free from bacteria.) 2 Rosenau, Kequirements for "Certified Milk," pp. 151-lGO. "^ Pussell and Hastings, Experimental Dairy Bacteriology, p. 122. ■* North, "The Dairyman versus the Dairy." American Journal of Public Jlcalth, Vol. V, pp. .511V-52.5. CONTKOL OF BACTERIAL DISEASES 245 Uactkiual Ti.sts of Milk rRoDUCKD in Kklton Daiimkr (Bactkkia I'Kk Cubic Ckntimetek) Bv Kklton Daiuv.mkn B \' Ox F( ) U U J )A I K \ .M K N Ajiiil o: April fi : 1,830,000 3.300 l.r/20,000 3,101) 4,830,000 4.000 4,000,000 7.OO0 1,450,000 1 4.100 3.000,000 i ♦51,000=* 00,000 1 80(J 9,000-2 2,500 70,000 I.OOO 500,000 5,000 tuberculosis, typhoid, dysent«*iv, (li]>htlii*ria. tonsillitis, cholera, and thi- virus of scarlet fever. This does not make the milk any cleaner, nor drx-s it kill tlie more resistant hacteria, hut it it is dangerous, it rtiiders it safe. Flies, vermin, house pets as transmitters of contact in- fections. After the lnuiiaii hand coine other active ovriii carriers, and aniono- these the lionse flv ]»r(>])ahlv stands first not onlv in transmitting' sferins (A' tihli and disease to foods ])nt in combining air-carriage \\iih contact. '1 his prol)- h'm has l)een treatecl in a previons cha})ter. Roadies and rats and mice slionhl he iniiversallv recooniziMl as t(»o lihliv to eat with, and shonhl be comph'tely exterminate(l, ahmg with the ilies, from every honseliohl. Cats, on account of their rd'ten intimate contact with chihb-en, liave been responsible for innumerable infections, especially of di[)litheria. Since this germ attacks cats virulently, tliev assume the doubh' rol«' of irresponsible patients and mcclianical carriers in the family. 1 This dairy, on April 3, liay swoepimr at niilkiuL'^ time. 246 CIVIC BIOLOGY Every case of '' cold " or " sore throat " in a cat should be considered diphtheretic or tubercular until proved otherwise. Serious epidemics of diphtheria have been traced to cats, and these have had to be killed or rigidly excluded from homes before spread of the disease could be stopped. Cases of scar- let fever are sometimes traced to cats as passive carriers.^ While dogs may act as mechanical carriers of bacteria, and are responsible for harboring several animal parasites, which we shall have to consider later, they are almost immune from bacterial attack. Recent civic advances due to acceptance of contact infection. Public drinking-cups and common towels have vanished as if by magic. Sanitary regulation of dishwashing and bed linen in hotels and restaurants, sanitary protection of drinking- straws and cleansing of glasses in soda fountains, wrapping and boxing of bread, other foods, and candies to prevent contact in handling, liquid and individual soaps, and many other items of modern improvement are active steps in the direction of rational prevention of contact infections. As with the dairies, when we all realize that intelligence in per- sonnel is of more importance than equipment, we shall see to it that only the healthy and cleanly and those who know are allowed to work in dairies or take care of foods in markets or eating houses. No man who does hot know better than to put his bare hand over a milk bottle, or Avoman who does not know better than to take candy from a tray Avith her bare fingers, has any right to serve the public. Our mil- lions of preventable infections and our more than 500,000 deaths annually are the measure of our need in this direction. Resistance, susceptibility, and immunity. Possibly every American chestnut tree on the continent is susceptible — 1 Caroline A, Osborne, M.D., "The Cat a Neglected Factor in Sanitary Science," Pedagogical Seminary, 1907 ; also ''The Cat and the Transmission of Disease," Medical Recorder, Chicago, 1912. ) 17 CONTROL OF BACTERIAL DISEASES "24 unable to ofi'cr resistance — to the fungus of ])ark disease. In lliiil ease, unless sonu^ specimens can l)e taken Itt-ynnd r(»acli of tlie spores, every cheslnnl tree in America will \)v. killed. If innnnne trees can be found, it may be ])ossil)le to propa- gate from tliem a strain ol' inniiune trees and so save the species to the continent. It is possible, tliongli not i)i-o])al)le, that something may be discovered which, injected into the sap uf the tree or fed into the tree from the soil, will enable it to resist the fungus, that is, give the tree an arlilieial ur aecpiired immunity. It is concHuvable that we might inject some of the sap from an imnuine tree into a susceptible tree — \ aeei- nate, or inoculate — and so inununize it and save its life. Every animal or plant offers some resistance to being eaten alive bv a i)arasite. 'J'his resistance may be natural or ac- quired; it may be mechanical (skin, bark, cuticle, too resist- ant for parasites to break through) or, as is more common, it may be chemical (some poisonous, toxic substance is pro- duced that weakens or kills parasites). As a nation stung by foreign attack begins to make anununition, so cells of the host may be stimulated by the toxins of a parasite to produce defensive substances — antitoxins or antibodies. In this case the acquired resistance, or immunity, is said to be active. If the defensive sul)stance, antitoxin, is injected from some other person or animal, as if a foreign nation sent in its army and anununition, the imnumity conferred is said to be pas- sive, and this is not likely to last so long as active innnunity. Recovery from certain diseases (whooping eough, measles, nnimps, scarlet fever, smallpox) generally leaves the body armed with acquired innnunity against a second attack by the same germs — that is, leaves an experienced army that can prevent another invasion. 'I'his, in a true sense, is the case, the white blood corpuscles (phagocytes) often gaining the power to eat the germs. prol)ably alive, instead of being eaten by them. The process is nut always as simple as this. 248 CIVIC BIOLOGY The Avliitc corpuscles may not be able to ingest some bac- teria unless there are certain substances in the blood to help them. These are called opsonins (Gr. o-i/roji^eo), I prepare food for), and their amount in the blood as compared with a nor- mal standard is known as the opsonic index. The injection of killed bacteria of the exact kind that are causiJig the trouble (made with cultures taken from the patient — autogenous bacterins) often results in a sharp rise in the opsonic index and with this a quick defeat of the invading germs. Great prejudice has existed against the use of these vac- cines, antitoxhis, bacterins, and serums, and one accident attributed to them, perhaps falsely, is often made to out- weigh in popular prejudice the literally thousands of deaths caused by the natural course of infections. Beginning with vaccination, discovered by Jenner, in 1796, we now have safe and effective vaccines, antitoxins, bacterins, and serums for rabies, diphtheria, tetanus (lockjaw), pneumonia, boils, pimples, and inflammatory fevers, cholera, bubonic plague, bacterial dysentery, cerebrospinal meningitis, and typhoid fever, and, among animal diseases, anthrax, distemper of (logs, hog and fowl choleras, blackleg, and tetanus, with many more that are on the way toward perfection. It is claimed by some high in authority that the present great war \\'ill result in lengthening the average of human life by as much as fifteen years, by breaking down apathy and ancient prejudice aud demonstrating the value of modern bacterio- logical science. Typhoid has been banished from our army by preventive inoculation. Let some pupil volunteer to look up the story of this and report to the class. Asepsis, antisepsis, germicides, and paths of entrance to the body. Blood wells from a wound, carrying out the germs that may have entered, rendering it germ-free, or aseptic, and then it clots to seal it over. This is nature's primitive aseptic surgery. The saliva is somewhat antiseptic, and the acid CONTROL 01' BACTERIAL DlSEAfSES 249 gastric juice of the stomach is strongly germicidal, these behig nattire's provisions for turning tlie food over to the absorj)- tive organs gcn'm-frcc. T'rcaks in the skin and mucous mem branes and the mouth an* the great clianncls ol' niirancc loi- germs, and tlie fact that there arc so many prevental)lc in- fections proves that under modern conditions of lite miture's provisions need constant reenforccmcnt. In normal bicathing throuyh the nostrils the iicrnis arc cau<»'ht before thcv reach the lungs, so that even pulmonary tuberculosis is coming more and more to be considered a moutli infection, reaching the lungs cithci' by \\iiy of inllanicd tonsils or by way of stomach, intestiiu% tlioiacic duct, and circulation. When the role of bacteria in causing disease was lirst dis- covered, chemical poisons were sought which might kill the germs without quite killing the patient. Carbolic acid (phe- nol), mercuric chloiidc (corrosive subhmate). and formalin were the germicides first used most extensively, and the gov- ernment standard of efhciency, " the phenol coetficient," is the germ-killing power of phenol. Later came the delicate, specific, exact antitoxins and resistance serums that kill the particular germ and have no poisonous action on the cells of the body. Other mmpoisonous germicides, especially the hypochlorites, from general use in purification of drinking- water and sewage, are being adapted to dairy, home, and personal use. Here oxygen is the active germicide, and tlu' end products of the reaction are harndess calcium chloride in case of hypochlorite ot lime, and, with sodium liypo- chlorite, sodium chloride, oi- common sah.^ ^ "Three ^^-aiiis df a practically harmless suhstance will kill the myriads of germs in a barrel of water. To do the .same work with the poi.sonous cor- rosive sublimate would recjuire at least one ounce, or of the e(iually poison- ous carbolic acid tive pounds (p. 23). . . . Ilypochlorous acid is one of the most powerful oxidizing- a.uents known to chemists. The 'acid mixture" will, within a miiuite. kill spores which resist 5 per cent .solution of carbolic acid for weeks" (\\ 54). — Ilofjker. CMdniidc of Lime in Sanitation. I'.M.". 250 CIVIC BIOLOGY Keeping abreast of discovery. Bacteriology is a young science, and luuidreds of students are pushing discovery forward so rapidly that we must " step lively " to keep up. Have committees of the class invite members of the state and local boards of health and public-spirited physicians to come in and discuss their problems. Try to gain clear ideas of just those problems in dealing with which the community most needs to develop '' cooperative good Avill," and make a test of what a biology class can do to help. No matter where it is, or how large or how small it may be, any com- munity that can, by intelligent, united effort, demonstrate accomplished control of such infections as tuberculosis, grippe, common colds, pneumonia, diphtheria, typhoid, and summer choleras of infants, may "go to the head"; and the class of young men and women who help to attain this result Avill have a story to tell that the sick and tired old world has waited thousands of years to hear. Problem summary. AVhat do we mean by " clean hands " ? Are our fingers generally clean enough to put into our own mouths or into the mouths of other people, that is, to handle our own food with and that of others ? Tests : Touch finger tips, unwashed and washed, to agar plates, incubate, and compare growths. To determine how many germS we may collect on the hands in a half-day's work, wash the hands with- out soap (cleaning the nails thoroughly) in two liters of sterile water. Inoculate a plate with 1 cubic centimeter, incubate, count colonies, and estimate total number. — Read " Dirty Hands and Typhoid Fever," American Journal of Public Health, Vol. IV (1914), p. 141. Study conditions in local stores, bakeries, and candy shops. Are foods and confections that go directly into the mouth handled with the bare hands? Can you devise practical ways and means of doing away with all such handling? Look up thoroughly , hygiene of mouth, throat, and nose, and adopt a definite plan that shall insure perfectly sound teeth, uninfected tonsils or nares, and absence of adenoids. Arrange a campaign to see that ordinances against spitting in public places are obeyed. Report infractions to board of health. C.O>TK<>L (M" r.Au j.lau to take sole care of a case of tyi'li«>i"l (to injure ai^ainst catchinj,^ it yourself or pennittini,^ it to sjn-ead to others)? of tuberculosis? of .UTij.j.e? of pneumonia? of diphtheria? of dysentery? of erysipelas? of leprosy? of scarlet fever? of measles? of pella-ra? of smallpox? (Refer t(» best available manuals for trained nurses.) What pi^ecautions would you take if you were a ty].hoid carrier? if you were a dii)htheria carrier? if you were infected with tubercu- losis? if you had the grijipe? if you had tonsillitis? if you had a cold? Is the Schick reaction used in your district to test immunity to clij-h- theria? Look n[> use of Widal reaction in detection of typhoid carriers. I^Iake out a complete list of diseases of man and other animals for which we have reliable antitoxins, vaccines, or liacterins. Discuss their use in your district and get reports from those who have tested them. File this list in the laboratory and note changes and growth from year to year. It is estimated that in 191 4 diseases of farm animals caused damage to the amount of $212,0()(),()()(). Can the class work out plans of coojh eration by which any of these diseases may be brought under control? Compare the merits, for various purposes, of different disinfectants, antiseptics, and germicides on the market. Study especially the liome and dairy use of the hypochlorites. Get the reports on all these things from the United States Public Health Service, Washington, D.C. Collect and discuss national, state, and local quarantine and health laws and ordinances. Visit as many of the local dairies as possible. Obtain the official score cards from your dairy inspector and study the scoring he has given. Are the dairymen included in the scoring? In the liu'htof all vou have learned alumt bacteria, discuss the prob- lem of washing dishes properly. Slioiild we banish the "common dish- towel " along with the "common roller towel." .Make plate tests for nuudx'rs of bacteria in ''dishcloths," in "dish-towels," in "dishwater," and on the dishes after different methods of washing and drying. How- do these tests compare with Wm^i- made on dishes after actually boiling for five minutes in the rinsing water? after treating with hypochlorite^ in rinsing water, without wiping? It is being claimed that spread of infections in families, especially of colds, grippe, and tonsillitis, might be greatly reduce-d by steriliza- tion of dishes. Can the class find a test for this in their ..wn homes? ^. - J. w , ^ c 5 1 '-♦-^ r-* 0 '~~^ X o 0^ ^ ••^ i-H 'C rf, o o -4-5 ■»-> 0 ^ 'bit o 'x X ■*^ 3; ^^^ > ' ,^ ^v' — a; c. ■1- < r. X if ■^ ^ c 2 s X = o t^ F-H 7 .—1 7. s /-* 0) +3 c; fer :=^ C ^^ HI -*- (-^ >. . a; 13 0 1—1 ^4-H P^ t/j O c/^ cc rrf r/> • r-* .^ CI ^ ctf c;J P- t> r-< cS O) cc -r O >. O rr M 2 "^ rH cc C 0 Ul o; r ;-i S-^ r- ^ c; 0 k "*~ rj 14-1 •^ c S i-H ^ 0 ^ <^ ^ (V -4-3 +J r "^ 7i ^ f -t-> a; 7 B«^ ■^ .-H •^ < 0 O) ^ m c HO be =+ ;l) >^ rt 0 1 ;i -^ rt 1 c2 0 =4H t c 5i ■Jl , r/: r^ "^ «3 ^ f~4 'w) 0 'H ^ 0 % d •— a; rH 0 :3 0 2 252 CHAPTER XXIV COXTKOL OF AXIMAL PARASITES 1. To what i.s liookworin disease due ■• Describe the worm. 2. What are the symptoms? 3. IIow is the disease spread'? 4. Give the life histoiy of the hookworm from the time the egg is hiid until tlie worm is back in the intestine. 5. Can the disease be cured ? Which is better, cure or preven- tion ? 0. How can it be prevented ? 7. Suppose you had charge of a hook- worm patient, describe your treatment and precautions. 8. Wliat can school rliildren do to eradicate, the disease in Essex County? — From a (juiz given in a Virginia high school With this as a part of public-school work for boys muI girls, one might be tempted to call the disease a blessing ; for what else could have brought the old "education"' on such a long journey toward connnon sense? Of course it will not stop with this particular subject. It will deal more and more with the kinds of subjects that have to do with healthful living hen- and now. IIow whimsical Fate is, that we should be mightily lielped to the right kind of schools in the United States by an intestinal parasite that poi- soned tlie Pharaohs! — Walter H. Pa(;k, "The Hookworm and Civiliza- tion,'' The WorhVii Work; Vol. XXIV (P)12), pp. 515 ff. But that the nKASipiito bite not only annoys but may kill, l»y infecting the punctured tissues with the germs of malaria or yellow fever or lilaria.sis. three of the most wide-spread and fatal diseases of man. — tiiis alarming fact is a matter which has come to be really recognized only recently, and the general recognition of which has given to the i)ractical study of insects an importance which years of warning and protesting by economic ento- mologists have been wholly unable to do. ... In addition 1 may simi»ly say, when in malarial regions avoid the bite of a mosciuito as you would tliat of a rattlesnake. One may be (piite as serious in it^s results as the other. — Kkllooo, "American Insects." pp. 80.S. (580 Importance. Tlic world ovci, it is (|iiite wiiliiii tlic miigc of possibility that animal parasites arc sappini^- half the life- blood and strength of the human lace, and many other plant and animal species are similarly alllicted. 'Hiis one parasite, the hookworm, belts the Wdrld between '■W>° north 253 254 CIVIC BIOLOGY latitude and 30° south, influeDciug, more or less, the lives of 940,000,000 people- — more than half the population of the o-lohe. " In Porto Rico the disease has reduced the average etliciency of the labor on the coffee plantations to 50 per cent of normal efficiency, and in some cases to 35 per cent." ^ Theory of control. Precisely the same argument applies to animal parasites as was developed m the preceding chapter with reference to parasitic bacteria. All must know the facts in order tliat each may be able to do his part for the safety of the whole community. A case in point is the following : The caretaker of an expensive plieasant farm was recently observed laboriously twisting the gapeworms out of the windpipes of his young pheasants and scattering them on the ground of his breeding pens. They were killing hundreds of his birds, but he did not know the life history of the parasite. It would have saved him time, labor, and worry, and cost him nothing, had he simply wiped them on a bit of newspaper and burned them. It may be easy to prevent outbreaks of trichinosis, hook- worms, tapeworms, malaria, yellow fever, and all the rest, as soon as each one knows exactly what to do to prevent multiplication and spread of the organisms. Stiles's argument in regard to scattering hookworms applies to all infections.^ We have the parasites concentrated m the wastes of the patient, and we can kill them by the good old Hebrew " cleansing by fire," or with chemical disinfectants 1 Thus there is a distinct loss of 10 to 20 per cent in the wages and a cor- responding loss in crop returns. In some places (this refers to our own South) I should estimate the loss at even a higher percentage, say an aver- age of 25 per cent, while in several families which I have examined I should say that uncinariasis is reducing the laboring capacity, hence the produc- tiveness, of the family to as low as 30 to 40 per cent, thus entailing a loss of 60 to 70 per cent. — C. Wardell Stiles, ''Prevalence and Geographical Distribution of Hookworm Disease," Hygienic Lahomtory Bulletin No, 10 (Wasliington, 1903), p. 96 2 gtiles, loc. cit., pp. 93 ff. CONTROL ()!• AMMAL PAJiASlTHS 255 (clilori(l<' of lime), before they become scatterecl in sewage or water or in the soil, or are earried, no one ran know where, by liies, earthworms, or other livini.,^ agencies. This is an effective method and can be delinitely workiMl into tlie habits and sanitary regime of every liome, and will eventnally free us from all (huio-erous infections; whereas tlie most intelli- gent and conscientious of us cannot possibly kee[) our hands clean enough, boil or filter all our driiddng water, or con- sistently and always observe all the precautions necessary to prevent infection if the oi'ganisms are scattered every- where in soil, water, and food. Practical problems. The field is so vast and dillicult, and knowledge is growing so fast, that the only course for the student to follow is to make connection with the best sources of information, — local boards of health and the scientific de- partments of each state and of Washington, — so as to keep abreast of important discoveries. In this way all will be able to help themselves and one another. Apply the quiz at the beginning of this chapter to all the parasitic diseases — of plants, animals, or man — of local importance. r>raun^ has described nearly 400 animal [)arasites of man — ol protozoa, 40 liatworms, 43 threadworms, 39 ticks, and over 25(1 insects. The mere fiofures nidicate how little we know al)out what is literally "eating" us most of the time. Our present knowl- edge marks little more than a l)eL!'inninr ANIMAL I'A l; ASlTKS 2nT from 40^ north latitude to IfP south, — ifUfh-rint; uuinv «•! the most fertile vall«\vs uniuhahituMe. Manson doclares that lualarial parasites cause more death, anarasite is carried to man l»y the bite of an anopheline mosquito. The minute vcrniicitles, or sjntntzoites, i^nU'v the red corpuscles and p-ow until the substance of the corpuscles is absorbed, when they divide asexually into, generally, from 1(5 to 24 spores, inerozoifrs. These burst out of the corpuscles, and this, probably on account of their poisonous waste prolasuui the para.sites of our com- mon, temperate-zone malarias (/'. n'vax and /'. nKihiritc) may be killed by heavy doses of (juinine. The i)arasites of the nuili.^nant malarias of the tropics are not aifected by this drug. ( )iir common malaria is caused by P. vivax, which passes through its life cycle in the blood every forty- eitrht hours — the usual time between chills. This is also known as tertian malaria. (Quartan malaria, the other temperate-zone type <»f the disease, caused by /'. iiily sexually within the anopheline mosquitoes. Kea.soning from the above data, we see that there are thre«' ways by whieh malaria may be banished from a locality: 1. Exterminate the mosquitoes (see Chapter XI). 2. Prevent the mosipiitoes from biting healthy i)eople. :{. Prevent mosquitoes friuu becoming infected by lilting malarial patients. As soon as every responsible member of any community beconu^s able to grasjt these sinq>le facts, that lom- munitv mav free it.self completelv from the most vicious blood parasites that afflict mankind. The Piroplasmas ; Texas fever, or bovine malaria. While the cattle tick acts as carri»'r, the parasite of Texas fever is I'lmj^lasina (Latin pints, '^a pear") hlffcnilnitm, which attacks the red blood cells of cattle. Tick extermination is banishing this costly jiarasite from our South- ern states (see Chajiter XV). Horses, sheep, dogs, and other animals 258 CIVIC BIOLOGY have malaria-like diseases caused by different species of the genus Piroplasma — P. erjui, P. oris, P. canis, etc.; and birds, frogs, turtles, and many other animals serve as hosts for blood parasites of other kinds. Yellow fever, Xo one has been able to demonstrate the parasite of yellow fever, although many investigators have hunted for it diligently. It is so snudl that it passes through the pores of a Berkefeld filter and is therefore siqiposed to be too small to see with a microscope. This may be true, or the organism may be soft and elastic enough to squeeze through the pores of a filter, and so transparent and unstainable that no one could recognize it in the field of the microscope. It is generally agreed that the organism is a j^rotozoan, biicause it is proved to have a life cycle in a certain species of mosquito (Aedes calojyus, formerly named Stegomijia fasciata) and is transmitted solely by its bite. It has been transmitted experimentally by injecting into nonimmunes a few drops of blood (or the serum of such blood after passing through a Berkefeld filter) drawn from yellow-fever patients during the first three days of the attack. After filling with yellow-fever blood the mosquito is not infective for at least twelve days, indicating a definite life cycle, and then the mosquito remains infective as long as she lives — fifty-seven days in one case. (For discussion of this topic in relation to mosquito extermination see Chapter XI.^) Few stories of discovery are more instructive or fuller of insi3iration and hope for the future than this work upon the cause and prevention of yellow fever. Will some member of the class volunteer to look it up and report? Smallpox. This is clearly a parasitic disease, the germ of which has eluded discovery, as have the organisms that cause measles and scarlet fever — epidemic disorders of the same class. We have, however, gained control of it by vaccination. About 1770 Edward Jenner happened to hear a woman say : " I can't take smallpox, because I have had cowpox." The idea was common at the time in several countries. Jenner studied the problem of immunity among the dairymaids for twenty-six years. On May 14, 1700, he made his first exi^erimental vaccination, upon James Phipps, son of one of his friends. On July 1 he vaccinated James again with virus from a case of smallpox, at the same time vaccinating a 1 Sternberg, "The Transmission of Yellow Fever by Mosquitoes," Popu- lar Science Monthly, Vol. LIX (1001), p. 225 ; Kelly, Walter Reed and Yellow Fever, New York, 1007 ; INIcCaw, Walter Reed Report, Smithsonian Insti- tution, 1005, p. 540. CONTROL Oi- ANIMAL J'AKASITES ^oO noninnuiiiH' man witli the same virus. The man took sjiialljiox as usual ; Jami'S did not. Crude methods at first, imikiut,^ iuevitaldc mixcil inocu- lations with other germs, raised vioh'ut ohjeetion to va<-cination, hut at that timt' the disease itself was so much mnic sriious than any such coni[)lications, that the ]»ractice spn ail raiiidly over the worM. MimIith bacteriological methoi)ositi<»n has persisted, ami this has resulted in many serious local epidemics. Tin' same is true of our own country ami Canada. A new ditliculty has also ari.sen. The di.sea.se has heen so nearly exterminated that even the most con- scientious people are saying: " ^^'hy vaccinate our children against a disease to which they will never be expo.sed?" This argument is suf- ficiently answered by the nniny local ej)id<'mics of recent years. Study carefully the history of at least one such eiademic.^ No less than eighteen other cities and towns in New York State, ami several more in other states, were infected with smalli)ox from Niagara Falls in 1014, and Canada was ()l)liged to (puirantine against the city. Is it right for one person, or one city, to endanger the safety of others in this way? Look up the prevalence and mortality of smallpox, and methods of "inoculating" from mild cases, before l-SOO, and compare with present conditions. Study also the story of the introduction of smalli»ox into America by the Spaniards. Tt is said to have killed ;;..")()( ),()()() natives in ^lexico. The trypanosomes (trypanon, "auger"; soma, "body"). This genus contains al>out sixty known .species, which live as free-swimnjing juira- .sites in the blood plasma of many vertebrates, from fishes to num. Their primary ho.sts are probably bloodsucking Hies, which, at any rate, act a.s carriers. Surra, a disea.se of cattle, horses, and cannds in India and the Philippines, is caused by T. rransli; and nagana, ov tsetse-fly disease, whi(di long made impossible the introduction of Kuro])ean cattle, horse.s, and sheep into Last Africa, is caused by a similar bl.x.d jiarasite, 7'. hnicri. Xearer home a serious di.sease of horse.s, dourine, long known in Europe, and more recently reported from western Canada, is caused by 7'. etiuipfinhtm. This forms a notable exception among diseases of this class in being spicad exclusively by breeding, and has no known connection with biting insects. 1 1)1. ].. M. William.s, "Smallpox Kpideiuic at Nia-ara Falls,"* Amrriran Jnunud <>t Pahlir Ihnlth. Vol. V (I'.nr,). p. 4l':b -260 CIVIC BIOLOGY TJndulating ^ '/Membrane Flagellum )BJepharopIast Trypanosoma gainbiense, which has long been the scourge of the west coast of Africa and is now spreading rapidly up the Congo, is the para- site of sleeping sickness in man. It is found in the blood of a number af native animals and is carried to man by the bite of one of the tsetse flies, Glossina palpalis. The flatworms, flukes, and tapeworms — Platyhelminthes {platySf "flat"; helmintheSy "worms"). The flatworms comprise a group of diverse forms which vary in size from almost microscopic Nucleus flukes to tapeworms 60 feet in length. Two large classes, the trematodes (to which the flukes belong) and the cestodes (to which the tapeworms be- long) contain only forms that are par- asitic on or in other animals. Two hosts are commonly re- quired for one of these parasites to complete its life cycle, which depends on the practice, com- mon among animals, of eating one another raw. So, in parts of the world where fish, pork, beef, and other meats are com- monly eaten raw, man comes in for his full share of these parasites. People with raw-flesh-eating habits, coming to us from the ends of the earth, bring their internal pets with them^ and proceed to take up a collection of American forms. The eggs are minute, and flies swallow them and Fig. 112. Tnjpanosama gambiense, from a case of sleeping sickness, different forms After Manson 1 A tapeworm has been known to live in man for thirty-tive years. — Bkaun CO>'TKOL OF ANIMAL PARASITES 2til Man pass them uninjured or may carry them to liuman foods as dust on their feet — eggs of eighteen worm parasites have been found on or in flies. It is estimated that a tape- worm produces 12,000,000 eggs a year, and the flukes may l)e equallv prolitic Such powers of reprochiction demand a number of different liosts, or host and parasite would (he toefether. One authority states the })roblem thus : It" a liver fiuko were to de- posit its million or so of eggs in the bile ducts of the sheeji, and these were to devplop in situ, the host could not with- stand the increased drain upon its vital resources, and host and parasites would perish to- gether. Hence it is clear that the infection of a second host by trematodes is hiuhlv necessary. Egg Bovine ^cysticercus\ Kk.. 118. Life cycle of human tape- wunii : infection from raw beef So, while many of the bacterial parasites " don't know any bettier" than to kill their hosts outright, these animal parasites, as a rule, sap and drain slowly and are the cause of prolonged misery rather than of death. Reasonal)le cleanliness in i-earing of farm animals, proper in- spection of meats, and, above all, j)ruper cooking of meats on tlie part of everyone will iinally relieve us from these disagreeable pests. Tlu' life history of one or two types should be generally known, and any of the following that may be of local interest should l)e worked out to practical conclusions in nature and in the books. Liverfluke — Fasciola hepatica. The adult is most commonly fouuil in the liver of tlie sheep, l)ut may occur in the horse, deer, camel, ante- lope, goat, pig, rabbit, kangaroo, beaver, s(|uirrel, and, rarely, in man. 262 CIVIC BIOLOGY The eo-o-s pass out tlirougli the bile ducts and hatch into minute, free- swimming embryos (the miracidia), which bore into fresh-water snails. Witliin the snail the parasite develops into a sporocyst, which produces still another form of the worm, known as the redia. The redise, in turn, produce asexually other redi?e or still another form (the cercaria). The cercarise are tadpole-shaped, and, passing out of the snail, swim about in the water until the tail drops off and they encyst upon the leaves of plants. Here they are eaten by animals and make their way up the bile ducts, and so the life cycle is re- peated. The adults in the liver are hermaphroditic. A large 'Species (DLstomum mag- nurn), jjrobably imported from Italy, may become a serious obstacle, especially to sheep-grazing, in portions of the West. The main rem- edy is avoidance of low pas- tures during wet seasons. Tapeworms — cestodes {ces- tos, "a girdle")- ^^ idea of the general form of a com- mon tapeworm, adult and bladder stages (^cysticercus^, is given in Fig. 111. In the adult the head is a small knob provided with four suckers and a circlet of booklets. This head has no mouth or sense organs, but serves merely to anchor the worm to the wall of the intestine. The neck is the short, unsegmented por- tion close to the head, and behind this the characteristic segments begin to form. These grow by absorption of the digested food through the skin; hence there is no need of digestive organs, the entire con- tents developing practically into reproductive cells, eggs, and sperm; and finally the joints {proglottides) break off and pass out, containing each its many thousands of minute fertilized eggs. In 1861 Leuckart Fig. 114. Tapeworms After Leuckart CONTROL OF AM.MAL VAKASITES 263 fed the ripe jiro^lottides from 111:111 to calves, ami was thus ahlc to dis- covt'i- how man aoiniircs this tapeworm from eatin^^ measly beef. The tiiiv egg hatches in the stomach of the cow, Imrrows tliroiiL;h the wall of the intestine, and in from tlirce to six months lias grown to a bladder, or cyst (the cysticerctis), tlie size of a small bean, and is then found in the muscles. After the cysticercus passes through the human stomach, the head everts (l)Ops out like turning a glove-finger), bringing the hooks and suckers to the outside; these anchor in the Man intestine and begin a new life cycle. AVhile the beef tape- worm {I'd Ilia sdf/iiKitd') may cause some irritation, anryos are picked up by the l)irds, and the direct life cycle is repeated. Trichina worm — Trichinella spiralis. The presence of this parasite in man causes the well-known disease trichinosis', and our constantly re- curring epidemics prove that, with all the publicity given to the matter, we have not reached a solution of the problem. Has proper attention been directed to extermination of rats from premises where swine are raised? The course of infection is indicated in Fig. 119. The adult worm, the size of a very fine hair 2-4 millimeters long, lives in the wall of the small intestine, where the female gives birth to from 1000 to 1500 ^ Fig. 118. Gapeworms, female with small male attached 1 The Cambridge Natural History (Vol. II, p. 146) estimates 12,000. CU^'TKoI. ol' ANLMAl. I'.VliASiTES L^iT Rat living young iil)()iif 0.1 luilliuiftcr long. 'These Imrrow tlu-ir way, or are carried l)y the blood, into the niuscle.s, wliere they feed actively and grow rapidly. They go to all parts of the Itody, l>iit gathrr in greatest nunilier.s in the r<'S[»iratory muscles, intercostals, and diaphragm. TIk' females live and produce young in the intestine foi- from five to seven weeks, and the first young begin to reach the muscles iu uiue days after infection ; hence the disease is pro- longed, and, from the nature of the attack, is extremely ])ainful. After thus feeding in llir mustdcs for an undetermined time the full-grown larva encysts (Fig. 120) and may live for years (thirty-one in man, accord- ing to Braun) or until the flesh is eaten raw by some other animal, when the life cycle is repeated. The rat is continually eating its fellows, and since this is the most common host of the parasite, infection of these pests is continuous. The pig eats the dead rats, or the cysts in filthy sties get into its food, and so it becomes a common host. Cats, naturally, are often badlv infested. Cooking all pork thoroughly is the safeguard of man, Init we should always remem- ber the dish of spaghetti and the typhoid epidemic (p. 242), and real- ize that the center of a roast, a p(n-k chop, or a cake of fried sausage nniy be scarcely warmed through when the outside is browned to a erisp. Here is a fine problem in civic biology. In eonnection with rat extermination, why not examine the diaphragms of all rats and mice killed, and tabulate and jdot on a nnii) the results obtained? Then examine diaphragm an«l intercostal mu.scles of all lu)gs slaughtered in the district, and tabulate and map the results. Placing this map over the other, note whether there is more trichina in the hogs where rats are numerous and badly infested. File all these maps and tabulations in the school library, so that when the rats and mice are exterminated, the next year's class can examine the pork and thus record progress. / Cat . Rat \ . Hog I Man Fn;. 110. Life cycle and host- relations of trichina worm 268 CIVIC BIOLOGY The first school able to report complete freedom from this parasite should write up the story for the benefit of other communities. This one job might be worth the total cost of the public schools in some communities. Hookworm disease, uncinariasis — Uncinaria americana. It only remains to add a word as to life history and mode of infection. The adult worms live in the small intestine, where they gnaw holes in the lining membranes and suck blood. Besides this the patient is likely to bleed liadly from the wounds. How long the adults may live in the intestine, if the case is not treated and no new infection occurs, is stated by Stiles to be certainly six and a half years and probably from ten to twelve years. A\^ith this rich food supply, eggs are })roduced in great numbers. These hatch in about twenty-four hours and feed and grow in the soil for about five days. The microscopic embryos may then be swallowed with polluted foods or water (carried to foods espe- cially by flies), or, on coming in contact with the skin, most commonly of bare feet, they bore in, causing "ground itch," and make their way to their final destination in the intestine. Stiles says that the embryos live in the soil " probably eight to twelve months." This is a sectional problem, and every school (especially every high school) in the South should have in its school library the latest information ob- tainable from the Rockefeller Sanitary Commission for the Eradication of Hookworm Disease,^ and also the bulletins of the United States Bureau of Public Education, notably Bulletin No. 20, " The Rural School and Hookworm Disease," Washington, D.C, 1014. Knowledge is growing so fast that the latest and best should be secured from year to year. 1 Address, Washington, D.C. ^: 'fcrf Fig . 120. Trichina worm embry( > cysts in human muscle and adult. female from intestinal wall After Leuckart CUNTIIUL OF ANIMAL PARASITES 2t'»".» Wliile the study of these piinisites of disease may seem disaoreeable at first, where eaii we lind keener inspiration than in tlie thont;iit of their eontrol by human (•()i)p('ratinii Fi<;. 121. Class with state inspector ; nit-ats in cold storai^^e and intelligence ? By this ruad unly can mankind Uvv itself from these time-old and world-wide tormentors and sappers of human life. So may even the parasites of the Pharaohs help to teach us lessons in cooperative good will. 270 ( llAPTKR XXV CIVIC I'Kor.LHMS lii:LA'lL\(. TO .MOLLC^KS It is doubtful whether there is any fanning land in the United States which yields as great a profit to the acre as the bottoms whicli are us«'d for oyster-planting in Khode Island.— W. K. Bkooks, "The Oyster," p. K^-j The sea nuissel (Mytihis edulis) is one of the most important food re- sources of the ocean, and as yet France, Belgium, and Holland are the only nations that appreciate its real food value No shellfish grows so rapidly and abundantly. Natural beds often contain as many as 8000 bushels to the acre, and planted beds yield at the end of three years from 4000 to 6000 bushels per acre. At present prices this means from $1000 to ^2400 per acre every three years. The high nutritive value and low cost of sea mussels make them the most economical shellfish on the market. The same money will buy four times as nuich food in nnissels as if spent for long clams, and ten and twenty times as much as if invested in oysters and lobsters respectively. They are also most palatable and easily digested. As these facts come to be better under- stood it is hoped that the American people will no longer neglect this vast source of food supply, but convert it into the wealth of the nation. — Ii;viN(; A. FiKM) Possibilities of marine food supply. " Four feet scjuare of the ocean is capable of producing ft)o(l cnougli to .su[)port a Imnian bein_o\" ^ This statement, made in a public lecture by an cnnnent authority, may seem incredible, l)ut it may also serye to indicate that we have scarcely l)co'un to realize the wealth of life in the waters. Of the r)lS,90() species of animals known, <;l,000 are mollusks, almost all acpuitic. In regard to how many of these do \m' kii(»\v anything? Oriental peoples utilize a considerable number of them, and Europeans, since remote anticpiity, have feasted npou deli- cious mollusks, conunon but unknown to us. 1 Statement by Major McGee in an address at the University of Wis- consin, 181>-J, 271 272 CIVIC BIOLOGY Sea mussels. These most abundant mollusks of our coasts niio'ht supply the soup and fish courses for every dinner m North America without strahi upon their reproductive pos- sibiUties. How many have ever heard of them ? How many have tasted them in prime condition, or even at all ? Some may have heard from irresponsible sources that sea mussels are poisonous. So are oysters or clams that are taken from sewage-polluted waters or that are dead and half decayed; and stale lobsters, crabs, cliicken, veal, and even milk may be poisonous. ' Mussels taken from pure water which has free circulation have never been known to produce injurious ef- fects. .\ New York dealer who has been selling mussels for years has never known of a case of poisoning from them. Neverthe- less, too much emphasis cannot be laid on the fact that care must be exercised in choosing proper localities for the culti- vation and collection of mussels for market. They must be sold to the consumer in a perfectly fresh condition or serious results will be likelv to follow."" ^ It would ])(i an interesting problem for any community unit to figure out its aquatic resources and possibilities, ana- lyze the different elements, and estimate the percentage of present utilization. For the United States as a whole this is roughly attempted in the following table. 1 Irving A. Field, '' Food Value of Sea Mussels," Bulletin No. 742 of the United States Bureau of Fisheries, 1911, p. 125. Fig. 123. Cleaning sea mussels commercially Photograph by I. A. Field CIVIC PKuBLEMb KELATi.\(i TU MoLLC^KS ■21'.\ A.MOiNi ANi» Value OF Mulluscan Tkoducts in tiil I'xitkd .States' 1 Present , ro.s.siiiLE 1 1 1 Yiehl, pounds Value Yield, pounds: Valiif Clams, hard 7.805,000 81.317,000 Clams, soft 8,054,000 553,000 Clams, razor 25'.>,000 25.000 1 1 Clams, surf 205,000 21,000 Sea mussels 8.542,000 12,000 S35.0(K>- f5,(>00.000 ' Fresh-water nuisst-ls . . 81,800,000 002.000 Abalones, shells . . . 1,005,000 1(5.000 Abaloues, meat ■ Cockles, conchs .... 140,000 35.000 - ( )ysters, Atlantic . . . 281,146,000 15.020,200 Oysters, Pacitic .... 2,103,100 003.500 Oyster shells All other shells .... 952,000 8,400 Squids 2,502,000 43,000 Scallops , 2,432,000 1 ' ' 317,000 1 The most instructive factor in such problems is hkely to be the causes that work to depress actual l)clow possil)h' resources. Here we shall Hud ignorance of a alu?s, lack of knowledge as to life history of forms and hence of practical means for development, and, above all, in ;niy development of a(|uatic resources, the old, uncivic spirit of piracy, handed down from the times of natural oyster beds, which still holds that anything whatsoever under water belongs to the one who can get it. " Oh yes, this is a tine location for oysters, and I did go to considerable expense and planted a lot, but 1 Statistics furni.shed by the United States Bureau of Fisheries for 1008. At present the Bureau cannot supply any estimates of possible yields. Fill out the table and keep it up to date as fiirures become available. Make a similar table of actual and possible yields for local waters. - Dr. Field's estimate of value of sea nuissels produced in 1015. •5 Dr. Field's estimate of iH)Ssible value of sea nuissels i)roduced in any one year. 274 CIVIC BIOLOGY I never got an oyster. As soon as tliey grew to amount to anything the oyster pirates came along and cleaned them up in a night. So I had to give it up." ^ Classification. Our common mollusks may be classified iuto three main groups : 1. Lamellihranchs (lamella-gilled) : Clams, mussels, oysters, scallops, — bivalves, — all are aquatic (marine and fresh-water). All the great food mollusks belong in this class, because their gills enable them to filter out and feed upon the inexhaustible supply of algai and other organisms floating in the water. 2. Gastropods (stomach-footed) : Snails, conchs, periwinkles, aba- lones, — typically coiled univalve shells, — and many shell-less forms (garden slugs) are marine, fresh-water, and terrestrial. Most gastropods are carnivorous, but a number are vegetarian, like the edible snails, the slugs, and the periwinkles and abalones, which feed upon the algaj and seaweeds of the bottom. 3. Cephalopods (head-footed): Squids, cuttlefishes, devilfishes, octo- puses, nautilus, are all marine, the molluscan over- (or under-) lords of the ocean. The cephalopods are all carnivorous, and many of them are used for food by oriental peoples. Our common squids, used now for fish bait, are good food mollusks. Typical problems and life histories. While schools along the seacoasts have the advantage, the mollusks of our' rivers, lakes, and ponds, and even of our woods and gardens, offer problems of no mean interest. Oysters. Oslrea virginica is the native oyster of the Atlantic coast from Cape Cod to the Gulf of Mexico. It has the reputation of being the finest edible oyster in the world. A small, starveling variety, the " coon oyster," forms extensive natural beds throughout the salt-marsh sedges and mangrove swamps of the Southern states. A small but delicious species, 0. lurid a, is native to the American Pacific, and young 0. virginica, since 1870, have been shipped across the continent to grow and fatten in the favored coves of the Pacific coast. Almost the entire Pacific coast line, however, from Puget Sound to jNIexico, is a waste of desert sand, unindented and open to the ocean front, with line after line of huge beach combers out as far as the eye can reach — terrific instead of "pacific," and not at all suited to the oyster. The United States Bureau of Fisheries has made repeated experiments in colonizing Atlantic oysters iit favored places along the Pacific, but, 1 Experience of a shore owner on the Chesapeake. CIVIC rUUl5LEM.S iiELATkNii TtJ .MnLJ.USRS liTo while they evidently find food and coiiditioiis generally favorable to growth, there has been ditiiculty in getting them to spawn. It is claimed that they have now become acclimated and are spawning freely in some of the inlets of the ^^'ashingt()ll coast. It this is true, such oysters ought to be used exclusively for seeding ull a\ aihible coves of the Pacific coast, which are few at best. To usi; them otherwise, until this is done, would be monumental foHv. I'acitic-coast schools should give special attention to this proith'in. Oatrea edulis is the native oyster of the European Atlantic, and, like 0. lurirld, is herma[>hroditic, while (K rlrf/inica is bisexual. For a nnn- munity interested in oyster culture a good to[)ic would be a comparison Fig. 124. Ostrea virglnlca Left, old shell covered with yoniii; oysters: middlo. shells of four hw^r specimens about G iuelies long; right, shell uf an old oyster riddled l»y borinir sjionucs of local with European methods. Possibly France has attained nearest to 100 per cent efficiency in the use of her available oyster beds. The French attend not only to the rearing of the oysters but to the j»ropa- gation of certain kinds of alg;e which impart desired colors anercent efficiencv as possible. ^lueh as we have already done in this direction, probably not more than '2 per cent of the possible production of American waters has been attained. How we can develop to 100 per cent efficiency in each community is the [»roblem for each community to solve. Sea mussels — Mytilus edulis (and other species). The range of MiilUu:i is ciicuiiipolar, fringing the iioitlicrn coasts from .Taj>an around to the 276 CIVIC BIOLOGY Mediterrauean and from North Carolina around through the Arctic Ocean to San Francisco. In depth it ranges from halfway between tide marks to probably 100 fathoms. Under most favorable conditions, in American waters, the mussels may grow to an average length of from 2 to o inches in a year. In England, hj the bed system of cultivation, they require two and generally three years to attain a length of 2 inches; but in France this size is secured, by the huchot method, in a year and a half. A female mussel has been observed to lay 12,000,000 eggs in fifteen minutes, almost the entire substance of the animal, except the heart and gills, being transformed into eggs or sperm, which are thus quickly shed once a year. The spawning season varies with lati- tude and with the temperature of local waters, extending from Feb- ruary to Sei)tember ; and since the mussels are in prime condition when full of reproductive products, the beginning of the spawning season should be determined for each typical bed in a locality, to the end that the yearly cro]:» may be harvested at the right time, that is, just before spawning occurs. Thus mussels may be made to fill the gap in the markets from May to August, when oysters are out of season ; and, in fact, according to the extended investigations of Dr. Field, sea mussels may be found in fair or prime condition every month in the year. Of course, as long as no one knows how good they are, this vast food supply will continue to go to w^aste. As a matter of practical biology, then, why not arrange for a course of mussels in class banquets or other entertainments, and agree to call for them frequently in local restaurants and hotels. When once mussels have been tried, the de- mand for them, and consequently the supply, will grow until the whole country is benefited. Soft, or long-necked, clams — Mya arenaria. Tliis is popular for clam- bakes along the New England shore and far inland. Mya ranges from South Carolina to the Arctic Ocean, but, unlike Mytilus, has not as yet reached the Pacific by that route. It was, however, introduced into San Francisco Bay in 1870, and spread rapidly. It appeared in AVillapa Bay, Washington, in 1880. was transplanted to Puget Sound a little later, and has become abundant at many points in the Sound. Pacific-coast schools may well lay emphasis on this problem; for in this l)urrowing clam we may possibly huve the form best able to transform the endless barren sand wastes of the Pacific into productive sea gardens. Mya can be much more easily, cheaply, and quickly raised than oysters, coming to market size in a year, under favorable conditions ; and the young, in passing from the free-swimming, larval stage to the adult stage, often CIVIC PKOBLEMIS KELATI^G TO MULLUSK8 -111 gather in solid masses in tide pools, a siugle find of this sort often suf- ficing to plant acres of barren beach at almost no cost. Antiquated and utterly destructive beach laws and customs, remains of piracy, are keei> ing barren and totally unproductive thousands of acres of New England beaches and flats that might, under enlightened civic management, be yielding per acre from ^WO to $500 worth, or more, of these delectal>le mollusks. These places aif uot adajitcd to the culture of either sea mussels or oysters. Hard, or little-neck, clam (quahog) — Venus mercenaria. As relations now stand, Venus ranks second in eomnu'rcial importance among th«* Atlantic-coast mollusks. It is par excellence the chowder clam c»f th«' country, and when 3'oung it is also relished on the half shell. In range Venus is a southern form, thus supplementing Miiest on soft, muddv bottoms from Itetween tide lines out to ^^•;^te^ ten fathoms or more in depth. ^ Scallops — Pecten irradians and P. magellanicus. Kj)icures have assured us that " tlie scallop is tiie daintiest of all foods the waters produce. "- The smaller pecten, ]*. irradians, occurs in the shallow, eel-grass waters south of Ca])e Cod, down the southern Atlantic, aud in the Gulf of Mexico. AVhile jiiratical methods are exterminating it from its north- ern range, fartluM- south there are (pumtities, totally unknown and unutilized, which might support profitable fisheries. The northern, or "giant," scallo]< {P. ma (jell aniens) lives in water from 40 to 60 fathoms deep, over rocky bottoms ditlicult to dredge, which 1 Kellogg figures the crop from an acre, one year after planting with small seed little-neck.s, at GOO bushels, worth at least ^8 per bu.<;hel, that i.s, SI 800, the net profit being probably about ^1000. " Preseut prices for this baby clam are high, the clammer sometimes receiving four dollars a bushel for his catch, while one who orders them on the half shell at a lioston or Nt'w York restaurant pays for them at the rate of fifty dollars a bushel." Kklloog, Shellfish Indu.stries, p. 220 2 Denuiri'er tiled in favor of Mytilus^ taken iu prime coiulitiitn aud fried or roasted brown in cracker crumbs. To make a practical test anil settle this controversy, have both scallops and nms.sels prepared alike and served ftt a biology-cla.ss banquet. Decide by ballot at end of banquet, and print result, with discussions that may arise, in local papers. 278 CIVIC BIOLOGY makes it scarce in the markets except along the Maine coast. This scallop reaches a diameter of 7 inches, and the sexes are distinct, while the southern pecten is hermaphroditic and seldom grows over half this diameter. The life history of P. irradians has been studied carefully and has a direct bearing on its practical utilization. These pectens are spawned in midsummer, grow rapidly, and spawn when a year old. They continue to grow, but rarely survive to. spawn a second time, most of them dying in the early spring of their second year. It is thus clear Fig. 125. Dio-giug soft clams 'oo United States Bureau of Fisheries gain to utilize all of these pectens over one year old. This will not cause any decrease in the species if all those under a year old are left on the breeding grounds. The fine Pacific clams, the geoduck, or giant clam {Glycimeris gen- erosa), that grows to weigh 6 pounds, the gaper clam (Schizothcerus nuttalli), now becoming rare in the western markets, the western little- neck {Tapes staminea), and the butter clam (Saxidomus nuttaUl), along with the western species of Mytdus and the closely similar, and equally edible. Modiolus, are all fine subjects for study in western-coast schools. The Pacific has also two valuable scallops. Life history. In general outline, the life histories of all the marine bivalves described above are similar. Eggs are produced by the millions, and hatch within a few hours into free-swimming embryos entirely CIVIC PKOIU.EMS liEl.ATLN(; TO MolJJSKS 279 unlike the parent. This free-swininiing period eniil)les the species U) be distributed widely by tides and currents, and it also offers opportu- nity for the culturist to increase his stock almost beyond belief by mak- ing conditions more favorable for the young. The embryo oyster, for example, swims for from one to six days, liy the end of this time the shell begins to form and it must sink to the bottom. If it hajtpens to land on a clean, hard surface, it may survive ; if it falls in an ooze of slinu' or silt, it is (quickly smothered. So the oyster culturists scatter clean Fig. 126. Pearl fishing in the Mississippi Hiver Photograph l)y the author shells — "cultch" — over the bottom about the beginning of the spawn- ing season. If too nuiny of the young oysters succeed in attaching to these, they must be dredged up and the clusters broken apart and re- planted evenly over the bottom, so that all nuiy find food and have room to grow. The left valve of the oyster, which is spoon-shaped, always makes contact with the sujiport and is (luickly cenu*nteUL;h its .L;ilis jx-r hour, auns daily y»'ar in and year out. Fig. 128. Fresh-water mussels, female, male, and side view, showin-; growtli lines Set up two ])erfectly clean ,:ilass aquaria exactly alike, put a iim-« s«d in one of them, and note the difference in clearness of the water. What may this mean in keeping reservoirs and }iark waters clear and wholesome? Glochidia (£?/oc/j/s, " arrow point ") /-//; /n'storif. The eiigs st American commnnitics. For all we know, nmy not our big, fat garden slugs be food delicacies? Compare garden slugs with marine or fresh-water snails, which they may be seen to resemble, except in respect to the rudimentary shell. These slugs are often as destructive in gardens as any in- sect, and, 1)eing nocturnal, are little known. Collect the eggs (translucent, yellowish, about the size of buckshot, in masses of thirty or more, found in damp }>laces nnder boards) and keep them in a glass jar or aquarium to watch their development. If the life history of these pests were better known, we might control them more effec- tively abont our gardens and greenhouses. In connection with other field work, make a collection of common marine, fresh-water, and terrestrial gastroi>ods. Keep them in suitable acpiaria or \ i\aria, to study habits and foods. Note that som<' snails are 'Meft-handepening uj* and spii-c pointing away from you, tlie dextral shells have the opening to the right, tin- sinistral, to tiie left.) The commonest and most interesting arc tin* pond snails, belonging to the genus PJi//ssea forms reach enormous size ; we hear thrilling stories of their encounters with whales, and they probably furnish whatever basis there may be for sailors' yarns of sea serpents. Fig. 132. Atlantic squid CHAPTER XXVI ciu sta(i:a The tislie.s in a school of mackerel are as miinerous as the birds in a flight of wild pigeons. Goode, in his " History of Aquatic Animals," tells of onv school of mackerel which was estimated to contain a million barrels, and of another which was a windrow of fish half a nuh' wide and at least twenty miles long ; but while the pigeons are plant eaters, the mackerel arc rapa- cious luuiters. pursuing and devouring the herrings, as well a,s pterojujds and pelagic Crustacea. Herring swarm like locusts, and a bank <»t' herring is almost a s(jlid wall. In 187U three Imndred thousand river herring were landed in a single haul of the seine in Albemarle Sound ; but the herring are also carnivorous, each one consuming myriads of copepods every day. In spite of this destruction and the ravages of armies of medusa; and siphonophores and pteropods. the fertility of the copepods is so great that they are abunilant in all parts of the ocean, and they are met with in luimbers which exceed our powers of comprehension. On one occasion the CUalloujer steamed for two days through a clensf cloud formed of a single species, and they are found in all latitudes from the Arctic regions to the equator, in masses which discolor the water for miles. "We know, too, that they are not restricted to the surface, and thai banks of copepods are sometimes a mile thick. AVhen we reflect that thou- sands would find ample room and food in a pint of water, we can form some faint conception of their universal abundance. Modern microscopic research has sIkjwu that these simple jilanls [the alga- in the water], and the globigeriuic and radiolarians which feed \ipon them, are so abundant and prolific that they meet all the demanOS Lobsters . . . Blue crabs . . Shrimps, prawns I'acitic crabs . Crawlish . . . ACTCAL VALI E ^1,031,000 012.000 404.000 1 -J 7.000 82,000 Pt)SSIBLK VALCE' Classification. The Crustacea an^ (livide(l into two main groups, the Entomostraca ( inostly microscopic or small, iiiclnd- ing the ostracods, co[)epods, and barnacles) and the Muldms- tracn (the lobsters, crawlish, shrimps, prawns, and crabs). Entomostraca. Although inconspicuous and little known, these minute Crustacea are of the L-reatest biolotxical si^jniti- cance. If we had them all gatluM-ed into a ball, and all the rest f)f the animal matter of the world rolled into another ^ Kstiinates not obtainable 288 CIVIC BIOLOGY ball, it is quite possible that the Entomostraca would be the heavier of the two.^ They form the main food of the young of fishes and many other aquatic animals, and also of the adult fishes that are provided with gill rakers — the herrmgs, smelts, shad, and others. They are thus the connecting link between the vast store of floating, microscopical plants and animals (the primitive food supply) and all higher life in the water. Baphiia and Cyclops are examples that may be found in almost any fresh-water aquarium or in streams, ponds, and pools everywhere. The fairy shrimp (Branchipus) is also found in the icy pools of early spring. The Lobster (Homarus americanus). Of the invertebrates used for food the lobster ranks next in importance to the oyster, and of all marine animals, for the past thirty years, it has been in the greatest danger from overfishing. The reason for this is seen in the following table, the supply having been drained to the utmost on account of soaring prices. New Kn(Ilani) Lobster Fishery Year 18S0 18110 lUOO 11)08 1013 Pounds 10,836,233 30,440,603 15,567,081 14,734,000 11,504,257 Value $473,341 833,746 1,362,962 1,855,000 2,254,486 Price per Poum) ^0.024 0.027 0.088 0.125 0.196 1 The writer has thought, as he steamed through a veritable slush of copepods tliat colored the ocean for hundreds if not thousands of miles, that here must be the greatest of all untai^ped and unthought-of sources of supply of animal matter. If the ship's engines could be geared to some effi- cient filtering machine, a cargo could be secured as fast as hoisting and stor- ing machinery could handle it. The material might prove as good, or better, than lobster for salads (but the microscopic spines and bristles would be likely to Interfere with human edibility). It might prove of value for poultiy and swine, for oil production, and, at any rate, for fertilizer. Perhaps it would solve the problem of food in fish hatcheries, especially for marine s])ecies, and make possible the roaring of young lobsters in any quantity. CKL'STACEA 280 Range. The American lobster ranges along the Atlanti. seaboard from Labrador to North Carolina. Possibly no ven- ture in the held of maruie a(|niculture would prove of greater eronomic value than the hitroduction of this species into the Pacific; but although egg-bearing l()l)sters have been shipped across the conthient by thousands and in carload lots, up to this time all attempts of the United States Bureau of Fish- eries to colonize the Pacific have failed. While hiding among the crevices of rocks would seem to suit the habit of the lobster l)est, it apparently thrives as well on sandy and even muddy bottoms, and it ranges from the tide pools to water 100 fathoms, or even more, in depth. ^ Size, growth, and life history. Female lobsters spawn once in two years; the eggs as laid are cemented to the swirnmerets underneath the abdomen, and here they are carried during the long incubation period from July or Auoust of one vear till ]\[uv or July of the next. Tlie liatchlings — delicate, transparent creatures about one third of an inch in length — swim feebly, or rather "tread water," and so tenly not one in ten thousand, under natural conditions, suryiyes its accidents and dangers. At the third molt the young assumes adult I'orm. and the liny l»»b- sterling tends to seek the bottom and may eycn Itcgin to burrow for greater i>rotection. It is now a little over half an inch in length, still a helpless morsel for every shar^veyed minnow, ^^'hen it is about twenty- five days old, the fourth molt brings the lol»strrling to the fifth stanc ' Barnes, Methods of I'rotectin^' and I'ropagatjutr the Lobster. K. L. Freeman Co., Providence, Khode Lsland, 101 1 . Refer to this for further data on the habits and natural history of the h^bster. Al.so, if undertakini: special work on this problem, write to Kxperiinent Station. Wi(kf to the thirtv-tliird year at which time the lobster is almost 2 feet long. If a lobster lives forty years and produces twenty batches of eggs, averaging 10(),(M)0 each, an adult pair would produce 2,000,(100 eggs. This would mean, with the species holding its own in the struggle for existence, that under natural conditions only one eg^^ in a million grows to Ix-coine adult. If man kills the one. that nature has preserved out of the million to keep up the species, eggs and young will fail and the lobster will beconie extinct. Our laws are leased on the totally inadetpuite assumption of the fisher- men that if a lobster is spared until it grows to be 10 inches long and lays only one batch of eggs — about 10,000 — the population of the species will be maintained. Botli theory and experience prove the fallacy of this idea. Brooks's law. ^^'e must work out a biologically correct solution of this problem or lose our lobsters. Dr. AV. K. lirooks^ has given a dis- cussion of the problem as applied to nnuine fislies. This might well be 1 Khode Island has led the way by making a clo.sed .season, from Novem- ber 15 to April 15. All the states except New York tine from :^5 to SUHJ for killing an egg lobster, but the eggs are easily bru.shed off. Short-lobster laws differ. In Maine a lobster nm.st measure 4| inche.s, body length (eiiual to 10^ inches long) ; in New Hampshire, 10| inches; in Mas.sachusetts, S> inches; in Rhode Island, 4| inches, body mea.sure ; and in New York, 0 im-hes. According to the biologfcally correct view of Dr. Field, of the Massachu.setts Fisheries and Game Commission, all these shortdobster laws protect the wrong end of the animal's life. A lob.ster 10 inches lonir jinxhu'es 10.000 eggs; one 12 inches long, 20,000; a lO-inch lobster, lOU.HOO. The old lob- ster is thus ten times as valuable to the species for egg production, and, being coanser and tougher, may not be as valuable for food as the legal- limit lob.ster. According to Field, lob.ster pots should be made with open- ings too small for the large lobsters to enter, 3{ or 3i inches in diameter, and with slats open enough to permit all lobsters under a certain size to escape. -Brooks. "The Artificial I'ropau^ation of Sea Fishes," Popular Science Monthly, Vol. XX.XV (1880), pp. 35".»-.3r.7. •^ «7 arf CIVIC BIOLOGY called " Brooks's Law of Extermination of Species by Man." Stated in his own words, this law is " To marine food fishes man is a catastrophe, not a natural enemy:' This means " Man takes the adults which natural enemies have spared to con- A Adult per iod,40{^) \ years ; 2 individ- uals, o7ie pair Lobsterling period, i; years: 200 — > 2 individuals Larval (critical) period, 1 month; 2,000,000 — > 200 individuals Fig. 135. Diagram representing the indi- viduals at different stages in a generation of lobsters This is auother form of expression of Brooks's law. The typical form is a pyramid, with a broad base of eggs aud younj; maiutaiued by a small apex of adults. Each species of animal or plant has a form of its own de- l)ending on number of eggs and duration of the diftereut stages. The large number of eggs, the long life of the adults, and the extreme reduction of numbers in the short critical, larval stage reduces the typical pyramid in the case of the lobster to a monument with a broad base of eggs Mhich shrinks suddenly during the larval stage to a slender spire representing the adults tinue the species." Figs. 138 and 135 show this law diagram- matically as it applies to the lobster. It is applicable to every species that man attacks, from oysters and lobsters to whales and pine trees. When man disturbs the nice balance of nature he must assume control ("have dominion") or lose the species. Blue crab — Callinectes sapi- dus. This common crab of the Atlantic-coast markets ranges from Massachusetts Bay to Mexico, and. while it is taken by millions every year, shows as yet no alarming signs of decrease. Two facts in the natural history of the si)ecies may largely account for this : the eggs are minute, a female average more laying on the than 3,000,000 at a batch ; and, while molting, each female is protected l)y a hard-shelled male. Pacific crab — Cancer magister. Tins robust crab, 7-0 inches broad by 4-5 inches long, ranges from Alaska to Lower California. In the markets of the Pacific it supplies the place of both the lobster and the blue crab of the Atlantic. State laws are beginning to Cia'STACEA 2"j:; protect those crabs by making closed seasons aiul by si.>ecifviug size limits, but the natural history <»t" this si)ecies has not be«*n adequat«'ly studied. Crawfish — Astacus (Pacific); Cambarus (Atlantic). .Many sj»eci«'s «>f these two genera inhal>it North Aiiifri< an I'rrsli watt'rs and lowlands, several of them growing to (i imln's in K-ngtli. They arc extensively iisid for food ill Europe and are growing in fa\<»r in soint- parts of this eouiitry. The t1«*sh is delicate and sweet, like that of lobsters and crabs, ami there is no good reason why they should not be much mitie widely Fto. 180. Female and male crawlisli. the female with eirgs ai)preciated and utilized. In the waters they often form the chief fo...! of our game fishes, especially of the black bass. Crawfish are found in tlu; fresh waters of the temperate /.ones of all the continents except Africa, and it is evid«Mit that they have developed from a number of different marine forms. The largest crawfish in the world is Astdcopsis /ninllinli, found in the small streams along the north and we.st coasts of Tasmania. The.se often weigh as much as 9 pounds; and if they could be safely introdtu'ed, they might give us an industry for our fresh waters that would rival lobster culture. The land crawfishes, known as "chimney builders," dig holes in soft ground, generally down to water. These are about an inch in diamett-r and are surrounded by a chimney of excavated earth. This burrowing habit makes them serious pests in embankments and levees. They are also, in part, vegetable feeders and are often destructive to young plants of field or garden. \ few Irops of carbon bisulphide in a burrow will 294 CIVIC BIOLOGY kill the occupants. The Biological Survey has designed a special droi> ping can to deliver the proper amount, so that extermination of craw- fish from land is now quickly accomplished with slight labor or expense. Crawfish are also excellent food for poultry. The female crawfish, distinguished from the male by her broader abdomen," carries the eggs attached to her swimmerets, as do the lob- sters and crabs (Fig. 136), the young passing through the nauplius, or^ free-swimming, stage within the shell. Even after hatching, as tiny crawfish they remain attached to the mother until after the third molt, when they scatter to take care of themselves. One or two pairs, kept in an aquarium or vivarium during the hatching period (March to June), will afford most valuable opportu- nities for observing the instincts and habits of a crustacean. Per- haps some member of the class will volunteer to do this. If so, he must study carefully to make conditions as normal as possible, and must feed well, or they may kill and eat each other, and the females may even devour their own eggs. CHAPTEU XXVII PROBLEMS Ol" I-ISU AM) FlSIIIXCr You might have tlie rivers as pure as the crystals of the rock, beautiful in falls, iu lakes, and in living pools — so full of fish that you might take them out with your hands. — Rlskix Now what happens if, after each one of the natural enemies has claimed its victims, a new enemy not provided for by Nature sui«.i,.i.a.i" Fig. 137. Extenninatins,- sIurI from a N'iririnia river Largest seine in the world, 9600 feet long. The seine was hauled by steam power iuul the hihor of 80 men, and was drawn twice daily, at ebl) tide, throughout the season. As many as 3600 shad were taken at one haul, and 126,000 in one season ; 250,000 alewives Avere caught at one time. The season's yield of shad fell to 300, and the fishing was consequently discontinued in 1905, after having been carried on for a century. This seine was a source of eggs for the Bureau's shad hatchery on this river, Stony Point, Virginia. United .States Bureau of Fisheries of increasing floods in the river valleys. Waste hollows and ravines might be turned into the most productive areas of our farms, acre for acre, when properly stocked with fish. Mas this been adequately "worked out for the district?^ ^ Johnson and Stapleton, "Fish Ponds on Farms," Document No. 826, I5ureau of Fisheries, Washington, 1915. PROBLEMS OF FlSll AND FISHING 29' If for any district in the United States or Canada the above qtiestions can be answered in the airnmative, there remains still one thino- for the class in civic bioloo^v to do. Writ*- up the story to tell how the connnunity lorin;:; a new l»ank dIT the c«)ast <>f Alaska. United States Bureau of Fisheries I> it clear or uuuldy ? Do snun-es of pollution exist? IIo\\' uiight these be remedied? (C'on- sult state laws in this connection.) Kecord all lishes seen, and gather records, from neighbors and local lishcinien and markets, of the numbers and \alues of the different lisln^s taken during the past season. 'I'his should result in a com- plete list of tlie fishes of market value, with their iclative 298 CIVIC BIOLOGY importance, and from these data we should be able to con- struct a table showing the crop of each kind of fish for the entire district. We may then figure per acre production and percentage of effective utilization of each water unit.^ In making the survey, seek to arouse the interest of the coniuiuuity. Ask your fish experts — the fish warden, the one who has charge of the nearest hatchery, or some of the best local anglers — to visit the class and present their views for stocking the district. Study the publications of your state fisheries commission and of the United States Bureau of Fig. 139. Topography of a fish (Yellow perch) 1, spinous portion of dorsal fin ; 2, soft portion of dorsal fin : 3, caudal tin; 4, anal fin ; 5, ventral fin ; 6, pectoral fin ; 7, opercle ; 8, branchiostegal rays ; 9, mandi- ble, or lower jaw; 10, premaxillary ; 10 o, maxillary ; 11, snout; 12, eye ; 13, head ; 14, lateral line ; 15, series of scales, counting from front of anal fin upward and forward to lateral line Fisheries. Ferret out all such bulletins in private collections and induce their owners to loan or donate them to the school or public library ; and write to Washington or to your state department for any others that may be needed. 1 ''It is difiicult to estimate the capacity of ponds for the various stages in the growth of fish. It depends for the most part upon the amount of ap- propriate food available. ' A 2-acre pond producing 10,000 one-year-old black bass from 4 to 6 inches long would be a remarkably successful enterprise, and 20,000 one and one-half to two inch yearling crappie or sunfish to an acre of water would be likewise notable. These numbers have been realized and in some instances exceeded, but the average results are doubtless much smaller." — Johnson and Stapleton, loc. cit., p. 25. PROBLEMS oi" FiSJl AM) li>Ui.N(i liDi) Finally, dmfl a plan I'ur .stuckint^^ and maintaining llic waters of the district at their inaxiiimiu production, ;ind have this printed in tlic local pa[)crs. Fishes Day.' \\'e have liiid Day and Arlx)!- Day and A[)[)lc Day. Wliy not have Fislics Day? \\'»' ought to know otir fishes better. We oui-lit to know tlicir lial)its and habitats, their foods, and especially tlieir nesting and spawn- ing seasons; and if we did, it would come to be considered as much an outrage to take a tish from her nest as to kill a mother bird on hers. When we all know these things and come, as a whole people, to have a right feelino- for them, we may then combine in- telligently to have onr waters teemhio* with all the best fishes they are capable of supporting. Aquarium manage- ment, d his may be nsed as a key to the solution of onr problems. A ''balanced aquarium" is one in which just the right pro})ortions of animal and j)lant life are maintained, witli tlie right amount of liglit, so that the \vater remains clear and sweet. This means that there are plants enough, under tl»e light admitted t(^ th(» a(pKi- rium, [)ro})erly to oxygenate the water for tlie animals, and ani- mals enough to supply the carbonic acid and nitrogenous wa,stes ^ An,ijler.s often wonder why tlie fishes do not interest the public as do the birds, as they are also attractive and their habits interestiuir, indeed, fasci- nating. The reason, possibly, is. that birds are always in sight, while it takes searching to find the fishes. — Hoi.nr.u and Jouk.vn, "Fish Stories," y. '1'1^\ 1 \ \c • Fig. 140. Hluegill snntish — best tish for pond culture Photograph by Kcighard 300 CIVIC BIOLOGY which the plants require for healthy growth. The common mistake of beginners is to overcrowd the aquarium with both animals and plants; more waste matters are produced than are contmuously used, and bacteria develop and foul the water. Too much light is the other common danger : this results in the excessive growth of algte, which green the water and overgrow the glass. A pond receives light only from above, while the aquarium may be lighted from the sides as well. Hence aquaria do better in north or east windows, and even liere must be provided with cardboard shades to shut out almost all direct sunlight from the sides. South and west windows may be used if three sides are shaded and the top partially shielded from direct sunlight if algce become troublesome. Great care must be exercised not to overfeed, because uneaten food will decay and quickly foul the water. In an aquarium properly planted with good oxygenators — temperature of the water not allowed to go over 15°-18° (60°-65° F.) — two fishes 3 inches long per gallon is the rule. Large specimens cannot be made comfortable in small aquaria; consequently small ones must suffice for schoolroom demon- stration and study. Predacious fishes (pickerel, basses, and sunfish, eels, and all except the smallest catfishes) should ordinarily be kept, each kind and usually each size, in a sepa- rate aquarium; and it will be necessary to watch them and to remove any vicious specimen or to partition it off with a pane of glass. In equipping a laboratory or in planning an exhibition it is better to liave a considerable number of small and medium-sized aquaria — easy to set up and each with its own distmct and clearly labeled exhibit — than to have a few cumbersome aquaria with impossible or difficult combinations mixed up in them. The temptation is to make aquaria too big. Taking the dimensions given on page II, we have the following data for approximate capacity PROBLEMS OF FISH AND FISHING :Jol in gallons and vreight of water. Any size ran lie figured, 2'M cuVnr inches (weighing 8.34 pounds) being a gallon. Sl/l (JAM.oNS POLNH.S Number KKgiiitKn rv»K a T'iax*. or Immctv indth Ih\(,lit Th ich)H'SS 5 X 7 X 4 ] 5 r () J .66] 1.7 > ;;. J 5.5 "1 r40 (1 apiece), used l«.i m- > i>. 8 X 10 X 10 X 12 X 12.8 25. . ► •i fungi, and feeding tests with .small animals. 20 X 12 X 11 11.4 78.4 4-12, used fordemon.^tratiuns 24 X 18 X 12 22.4 180.8 2, used for demonstrations Demonstration a(inaria arc usually l>uilt into iIk- w;ills ><> as to !"• lighted from alxjve and \i<'\ve15), p. 181». (From remarks before the Pacific Fisheries Society. Seattle, on the plan of establishing a school of fisheries in connection with the Tniver-Mty of Wa.shin.i(ton — on a par witli schools of forcstrv and airriculture, minim: and conunerce.) 302 CIVIC BIOLOGY and danger of a stoppage of escape jDipe, and consequent flooding of building, is too great a risk. The absolute rule should be that one j^erson shall take the sole responsibility for an aquarium, and no one else be per- mitted to put anything in or take anything out of it. As long as the aqua- rium is properly balanced and managed, the water need never be changed. Water is always water, and as it evaporates, clean pond or brook water Fig. 141. Biological Laboratory, Cleveland Normal Training School A^'iew of the. west end, showing three of the four large aquaria built into the wall under the windows, and a small greenhouse opening out of the laboratory i must be added to keep the level about constant. If adding any consider- able quantity, allow the water to stand in the room a day, or until it is of the same temperature as that in the aquarium; for even small changes of temperature, if sudden, may be injurious, or even fatal, to some fishes. The hand should never be put into the aquarium ; it carries too many troublesome bacteria. Use the proper tools — dipping-tubes and siphons, dijvnets and scrapers. A spirit of good-natured rivalry should be 1 The architect overruled the location of these aquaria in the north wall and changed their specifications. They should be two feet, instead of about one foot, deep, bringing the bottom two feet from the floor and giving double the depth of water. The glass roof, if present at all, should be raised to the middle bar of the window, and the flap, which can be lowered to shut the space above the aquaria from the room, should be two feet wide. PROBLEMS OF FISH AND FIS]IIX(; :]03 encouraged, to see who can have the most beautiful aqtiarium and th« most instructive one, and iiold it longest without chang*' of wat«'r. A d««- iiH lit mark is deserved, and may he given, for t-very time a ]»ui»il |»«'rmits tilt' water in his aquarium to ht'eomc foul I'lioiii^li to n'(|uire chajiging. In this way, by gaining experience tlirou-h the year, the students may keep the acpuiria running in fine balance, each with some specimen of native fish,' and so afford a most instructive exhibition. This may be held in connection with ai)propriate lec- tures by specialists and a general discus- sion of the plans which have been worked out for the adeipiate stocking of local waters. Whether we call it Fishes' l)av or make it a feature of more general exer- cises will dejtend on community interests and preferences. A few important features of such an exhil)ition may be 1. Species of value antl relative inqior- tance of each. 2. Habits and proper hal)itats of each species (so far as these can be shown Ity arrangement of aquaria). 3. Table of si)awning seasons; pre- served specimens of eggs and fry : plioto- graphs and other pictures of fish nests; diagrams of local waters, with distribution of nesting places of difi'erent species. 4. Eggs actually being luitched (Fig. 142) and fry Iteing fed and reared for distribution. 5. Foods of different species, with natural food supjilies. 6. Extermination of Mios(|iiitoes by fishes, with data from t'eeding tests in the school acpiariaand from ))ark or pond waters |ir()j>erlv stcH'ked. 7. Data of growth of different fishes, •fed in different ways. -S. Diagrams and records of production of home lish ponds. (Whv not have fish projects and fish clui»s as well as corn elubs and pig clubs?) 0. Enemies of different fishes, and means of their control. 10. Fish course, composed entirely of local varieties in .season, prepared by domestic-science classes for the exhibit luncheon. Fi«;. 14l'. Tunibk'r liatciiory Water runniiii; tln-i>ii<;li fumiel keeps eggs aerated. .Xuthor's tlesigu 304 CIVIC BIOLOGY 11. One or two of the most wonderful curiosities of fish natural his- tory : a nest of sticklebacks, " nothing short of marvelous " (Mornaday), or a paradise fish with his nest of bubbles ; or exchange with coast schools and devote one of the large aquaria to artificial sea water and marine forms. Classification and species. About as many different kinds of fislies as of birds are known to science (13,000, Galloway), but more than four times as many fishes as birds are found in the inland and marine waters of North America (3263 species). 1 Any list (published by your state fish commission or by the United States Bureau of Fisheries) giving the dis- tribution of fish and fish eggs for the preceding year will contain about fifty of the more valuable food and game species, and from this w^e may choose the most instructive types for study.'-^ Ponds as balanced aquaria : foods and overstocking. The work with aquaria may be made to help in understanding how to keep park waters and reservoirs in good condition. Lack of proper balance results in fouling the water, and is accompanied with offensive odors and appearance. The fishes die, beginning with the more overcrowded or more sensitive kinds, and ending with the catfishes, w^hich can live in fairly wholesome mud. Probably in most such cases the prime reason why the fishes die is because they lack proper 1 Jordan and Evermann, Descriptive Catalogue of North American Fishes, 8313 pages, 392 plates. "The work has been carefully devised to be of no use whatever to anyone save an ichthyologist" (Hornaday). 2 The list recommended for pond culture is as follows : black basses (small-mouthed and large-mouthed), crappie, calico, rock, and warmoutli basses, the bluegill sunfish, and the cattish, or bvdlhead (either Ameiurus nebulosus or A. n. marmoratus, a variety known in the South as the marble cat). Strong local prejudice and lack of outward beauty are against the humble catfish, but for edibility Dr. Jordan has placed it above all the basses, perches, and pikes, and just below the trout, salmon, and whitefish. The bluegill is the only sunfish recommended for use by the Bureau of Fisheries, " and it is believed to be the finest pond fish available for private culture." — Jonssox and Stapletox. loc. cit.. p. 18. PKOBLE.Mb Ui ribll \Mj ii.^lil.NLi lUu'i food; that is, if they were thriving and growing, iliuy winUd resist attacks of saprolegnia or other disease germs. A variety of plants and animals is essential in a halancctl {mukI it" it is to snpply food continuously to all its inhal)itants. As with similar pi'ohlems on land, the most necessary tiling is an abundance of {)lants, to sui)ply food for snails, mussels, in- sects, worms, Crustacea, and vegetable-feeding lishcs; ih.-n mussels should be present in sullicient numbers to strain ont any excess of floating alga? and fungi : and, Hnally, there nuist be enough carnivorous forms to prevent exces- sive nuiltiplication of the vegetarians. Of course this natural bal- ance of lakes and ponds is a more complex mat- ter than tliat of our aquaria, since these are never required to pro- duce all the foods of the fishes. ^^^ 9 Fi(i. 143. Tiuy (»t \\ilul eijfjfs, with in»>s- (|uito net and moss in wliirh they were packed I'nilc'd States liiircau i«f FiNlicrirs Even good-.si/t 1 1 hikrs may lose balance, and cer- tain species may suiter. The white bass in Lake !\biidi'i;i, W'isounsin, in the summer of ^889, died in sucli iiiinibfrs that windrows of them were washed upon the shores, necessitating; thf rmioval of over *Jno wa^onloads from the mile or so of beach in Madison. They iiad iM'comr overcn>wd»'d and weakened by starvation. T>ake Louise, in Pt'imsylvania, was stureau of Fisheries, which advised fishing out the surplus black bass and transferrincr them to the 300 CIVIC BIOLOGY Susqiieliamia River, where there was abundance of food, and introducing food fishes (percli, minnows, and crawfisli) and aquatic insects. The starved black bass very soon grew to proi)er form when well fed. Food being practically the limiting factor, self-sustaining ponds are said to be capable of producing from 5000 to 6000 pounds of fish per acre.^ This yields a cash value, at 10 cents per pound, of from $500 to |600, " and this with no expenditure for food." Xo figures are available for limits of possible production in well-planted and aerated ponds if the fish are given adequate variety and quantity of food. Estimates might prove more amusing than instructive. For example, in a self-feeding pond of one acre, 3 feet deep, we have 130,680 cubic feet of water. At 5000 pounds per acre, we should have 1 pound of fish produced in about 26 cubic feet of water. Sui3pose, by proper care and feeding, we could produce 1 pound per cubic foot (7.48 gallons) ? Can anyone so feed and care for a bluegill or a catfish, in a five-gallon aquarium, that it will gain 1 pound in a year? Successful combinations in aquaria may suggest similar treatment of ponds. That is, can anyone manage and feed a bluegill and a catfish in the same five-gallon aquarium so that each will gain a pound in a year ? Thus we see that by learning the habits and preferred habitats of different fishes we may have all parts of our pond occupied and so in- crease production. The pout will choose the stagnant holes with muddy bottoms ; the perch, the deej)er channel, where there is some current ; the crappies, rock bass, and sunfish, the shelter of stumps and brush and weed patches. The water will be purified if the bottom is well stocked with the best available mussels, and crawfish (if there is no danger from their burrowing) may do the scavenging and turn waste matters into food for the fishes. Frogs and toads, if allowed to breed, may further help in the balance of life ; and, finally, a few pairs of mallards, teal, or wood ducks might fit in, both for ornament and for j)rofit.^ 1 N. K. Buller, "What an Acre of AVater Will Do," Bulletin No. 10, Pennsylvania Department of Fisheries, 1914, p. 7. 2 In a project of this kind, like working for a record production of corn, potatoes, or poultry, we open a new field of interesting possibilities. Who can produce the largest and best-balanced and most varied crops from an acre of water ? Water cress, water lilies (of many rare and beautiful kinds), cowslips, gentians, and cardinal flowers, the fishes, frogs, crawfish, possibly fingerlings for distribution, perhaps a ton or so of highest-grade mus- sel shells, and a fine flock of wild ducks for distribution and propagation — will results from such a home-pond project bear out the statement that "an acre of water may be made to produce as much as five acres of land " ? PROBLEMS OF FISH AM) FISHING 307 A record iit the end of a .successful year iiii^^lit read sonu'what as follows: ReCOKD I'liODl CTION 1 KO.M a I'OM) Ol (>M: A' UK, 1 KOM One to Ten Feet Deep 0000 pounds cattish $;.300.00 80UU pounds bluegills 8U().(M) 5000 linuerliug cattish, removed in fall to thin stock .... .')<). 00 5000 hugerliug bluegills, removed in fall to thin .stock . . . 25.00 12 dozen frogs (5.00 50 dozen crawfish 10. Oo 1 ton yellow and green .striped nuicket shells HO.(M) 50 wood-ducks' eggs, early 12.50 3 pairs wood ducks 45.00 1000 bunches water cress — from clean, fenced intake .stream 5o.oo 100 dozen water lilies lo.OO 100 dozen cardinal-fiower .spikes lo.(M) 10 bu.shels cowslip greens 4.00 1000 pounds basket willows — from margins and island . . . 50.00 Total S052!50 Seeds, tubers, bulbs, and [dants of ac^uatic duck foods, any of whicii, if present in excess, might be made to iucrea.se the account, are quoted in a price list as follows : Duck potato, or wapata {Sagittaria latifolia): bulb.s, 15 cents each ; $5 per 100. Wild celery {Vallisneria spiralis) (must be wet): 35 cents per pound. Water cress {Nasturtium officinale): plants, 10 cents each ; $4 per loO ; $20 per 1000 ; .seed, 50 cents per ounce ; $5 per pound. American lotus lily {Nelumbo lutea): tubers, $1 each; SIO pt-r dozen; .seeds, $1 per 100. AVild rice {Zizania aquatica) (nm.st be wet): seed, 85 cents jm r ]...uiid. Potamogetons (mixed): $1 per (puirt ; $20 per bu.shel. Wild .sago {Potainogeton pectinatus): $1 per ijuart ; $25 ^ler bushel. Mu.sk grass (Chara) (mixed or .single species): $7.50 per crate. Duckmeat (Lemna): $1 per (luart ; $10 per dozen (piarts. Anacharis, or Elodea {Philotria aniadensiH): $(> per crate. Coontail, or hornwort {}ri/riuphyllum) (various .species): S7..'.o pir ,raie. 'f To tliis list we might add : Cardinal flowers {Lohelia cardinalu<), .seeds and plants. Water lilies {Castalia or Nclumho) (various species), seeds and rootstocka 308 CIVIC BIOLOGY Professor Forbes of the University of Illinois has made a special study of the foods of fishes. He has found that wdth most fishes foods change with age, the life of a fish being, in fact, divided into two and often three distinct periods. In the first, which we may call the " fry " period, from hatching to one or two inches in length, all species feed on small Crustacea. In the fingerling stage, from one or two to four inches, they feed largely on insects but begin to devour their smaller fellow fishes as well. Wlien adult, tlie larger s])ecies feed chiefly upon Fui. 144. Visiting Municipal Fish Market, Cleveland, Ohio Class learn to distiuguish fresh fish by the red gills and the unsunken eyes smaller fishes, while the smaller species continue to feed mostly on insects. Adult fishes possessing fine gill rakers continue to strain out the minute Crustacea ; those with heavy, blunt teeth feed largely on niol- lusks; and worms play but a small part in the food of fresh-water fishes. Spawning habits and seasons. Brooks's law, as stated in its application to the lobster, with the diagrams illustrating it, applies with equal force to food and game fishes. With the powerful machmery at his disposal, man strikes all species as a catastrophe and not as their natural enemy ; and he must make good his attack by intelligent dominion or lose PKOBLE.M^ OF FISH AM) FFSHLNG :;()i) ■T. 1^ 2 < S5 fa O < D fa X « X h5 o V. < •A 02 >»^ Cl- ^rt S^ 09 X a « ^ r c i^ ^ < K ^ g o - /; 2-3 = -< •P : c u -r 2 «^i: ^ ^ ^/ '/"- '-* -i ^ o: W' X aj^"~ = •£- I' X H X ? r- :^- c " I ? z -^ X ^ if. /• - ^- - c — - *- 5 ij "H X -^ -"^ - ~ X -r ~ -i 5 - ^- > - ~f = ■'^ = - ti i ^ > ^ — " .' -• i. — - 5 r i^ ■= i: L' -= ^ ~ >.^ r- > X = - T. ■/. Z. f- \. X 3^ K 'X ^ 5 c ;x^ ^ ei O -J c I- I- I I M I 'x >-. >■. a:' > 0; X .::; % > - r. '-a z. X X >l>t='l ■J. JL I ■r t: -^ r- X ji ? :Hf? ?L^ X 5 'i: 5 ■^i. ^ ~ ; ,- «- X C SC-^w ^ c • ^"^ T'-2 =; 5- ->: ;, 310 CIVIC BIOLOGY the species. The large numbers of eggs produced by fish indicate ho\Y quickly we may have our waters abundantly stocked, as soon as we learn enough to cooperate in leaving a sufficient number of adult spawners and in insuring protec- tion of eggs and young from their natural enemies. The data in this field must be worked out in connection with the local surveys suggested above. The table above is offered merely by way of further suggestion. The biology class in each district should have its own table, developed to give local dates and precise breeding places, so that all may know how, when, and where to protect effectively all valuable species during their spawning seasons. This knowledge may be of advantage in extermmating pest species, such as garfish and dogfish. Economic and civic values. To doubt the value of fish culture would be as absurd as to question that of agri- culture. For the United States, including insular posses- sions, an invested capital of $79,000,000, with about 165,000 people employed, results in gathering a food product amount- ing to $91,073,000 annually. The fishes do most of the work, foraging in the boundless food-wealth of the ocean and then, like the shad, salmon, and others, bringing it up our rivers and to our very doors. As the cost of food advances, we are beginning to ask what are the possibilities of supply from our waters. The brief table on the next page may serve to indicate the problem for the species named. Sport fishing also carries civic values and yields annual returns, not only m catch but in health and pleasure, of possibly no less importance to the country as a whole than the commercial fisheries. It gives employment to thousands in the manufacture of tackle and boats, stimulates travel, and supports many special outing resorts. Is not good fishing an asset to any community, well worth careful study and conservation ? TKor.LKMS or 1-lSiI AND l'lSillN(; :;ii Valite of Puksknt Yearly Catch VALt?E OF PogMIMI.K VEARLV PROlU't-rio.N > Sliiul, Atlantic $2,085,200 22,000 :^,700 ;^,842,70(J 12,000,000 Shad, racitic . . Salmon, Atlantic tii Salmon, Pacific . Total f resh- water sh . . . . 1 This table was submitted to the United States Bureau of Fisheries, but no estimates were available. Dr. George W. Field estimates that under proper management the marine and fresh waters of Ma.s.sachu.sett,s might be made to yield $50,000,000 worth of products annually. Fig. ]45, Toad catchiiiii aut.s Photocfiaph by Newton Miller Fio. 146. Toad exposed in its liibernation cavity Note protective coloration and granulation of skin in relation to earth. Photograph by Newton Miller 312 cllArTKIJ \\\ III AMPHir.iA: siKKXs. rK()ri:AN>. > AL AM AM)i:i:s. rK()(;s. tim-j: i'K()(;s, and toads Fur ail iii.sectivuroii.s animal which coiituniis to every nMiuiroiiieiit of thf situation — ease of control and rai)i(l increase, noninjnrious in any nunilK'i-s. an active feeder in alnindance and a patient faster in scarcity — the toad stands i)rol)ably first on the list ainoni; American insectivorous a/iimals. — MiLLEK. " Biology of the American Toad."" A nuriridt Xtitunilisf.yiA \IJI1 lilt' aiiipliil)ia mo a relalivcly small okjuj, ,,|" alj/'-friniis and Ju//-o-n(/ns of the bullfrogs in late June and early July. 'J'he i^gg^ are most interesting forms with which to follow endjryological dev(dopment. and their numbers indicate possi- bilities of increasing val- uable species, when we learn to provide favor- able conditions. The toads' eofo-s are found in strings ; the green frogs' and bullfrogs', in loose, floating films ; the wood frogs', leopard frogs', and pickerel frogs', in globu- lar masses of jelly ; and the peepers', shigle or in small clusters. Ol^serva- Fki, 140. Toad tadpoles as sca\ f iigers, eat- ing dead pout at margin of pond Photograph hy Newtou Miller tions by the class may yield a table for local s[)ecies some- what like the one shown on the following page. The feeding test. Ani[)hil)ia afford most convenient ani- mals with which to study foods and feeding hal)its. Imitate natural habitats in the arrangement of terraria and a(iuaria — moist earth, moss, or sod for toads, wood frogs, and land salamanders, with a forked branch and a small pool for tree frogs, and a larger pool, with a bank of nntss at one end. for aquatic frogs and salamanders. Then, for the tests, introduce all sorts of insects, spiders, millepeds, crustaceans, slugs, and worms, countincr the numbers and kinds eaten. Xo single laboratory exercise shows so convhicingly the vahu' ot the 816 CIVIC BIOLOGY < 2 1^ -5 < '■J O < O 9 e Tr. <-* n a thick disk elly ■f. 5r (4- c 2 X c5 be ^- - o bf. of b/j be mg from roofs of cavi- nnder stones or logs and So as - o" o ^ O o O CO O S o ^ CO CO >, aa o 1 1 '^ c: --4-1 J) 1 7 O 2 1 '^ — '{- o o s ^^ — 2? o O '-C o o S~+- o c w^ -^ 0 i o o S 'O o lO 3^1 •^z 1 'i^ CO (M o? CC (M 1—1 CO 1— 1 '"' uC ■j: o: K Jl a; cc r,^ ^. ^, >~. >: >: >5 ^ 7- 11 O CO *-* r— o i; O :-.. < 'j: 1 1 1 o T 1 T ^ -M t- ^ ^ I- ^ 1 X. - ;r o ^ >^- 1 1 o 1 og 1 i 1 1 T O ^ < ,^ QC ct *' -+i CO CO ^ »■-? »— ^ r— .c^ <— ■M «* -^ 1 1 d" ^00 , — . ^ o o o r— 1^ CO i^ F-H O '— 1 >1 1— i ^^ -t-J ^~ ^— < ^**s ■^ >, ^ 05 2 >. "^^ C' 1 1— 1 1 cr. I— 1 1 o CM 3 1 p— ' r bC s 1 1— i 1 — 1 1,0 — ^ ^^ :z3 7Z^ 1— i CO " "^ >-. o ^ 13 ?-i ^ >^ t-^ ^ ^ ^ ;-! Ph r— 1 >r- 5 ^ , ce c3 c3 < ^ ''th ^w ^ r; *■ § ^ § "-1 ^ f^ , a: 2 ^ It H O ■+3 ■■H o o fc£) ^ ct ? -^ o +^ 1-4 1-^ 1—1 05 O o 1 1 oo ■>: 1 ^,^-.^ >^-~^ ^-"^ 1 ' A O •-* Si. 5^ O c3 ^ y. • 1 "i 1 5 " •-< S f-^ fcC " ' fcf. • ^ '". 3 S X be o ^ 0) '^ EC ^ o 'a; be 2 CO bfj ^ P rH S-l CD ^— ft ^ Jp . ^ -" O) ^ ^ 1 &H ^ H P4 c^ 2- o a. v CO CO -r^ r-( o © I— 1 O ■^■^ I— +j y^ +S o y. £o "n 'VJ ?-( > o 4-) o • ■— < p— ( >— ( r-^ CU 0^ S =4-1 k; -u t-3 •"^j rt c ^ c. '^ 2:5 o o •■^ I— 1 *^ ^ o PI 2 ID ^ bn ce rt l-l p s •"^ a; ce "ce r/3 -t-j Ul ce ce Cl) 03 ■^ 0 > ce c +J 1 ^u -M • rH -^ ,*J +J a; 'j: (~* O ^^ l-H Z> cS 1— ( 0 -4-3 bD .2 'br 13 /-^ O a; t~* C ■-+H O ce O tf: 0 =4— t .-1 r^ ?^ 0 +J c^ ^^ o ce i^S '■ ' ce ^3 a; > o ^-> : t ?-f ci ■-0 0 tM 0) fin 0 0 cS -t-j ^^ «4-l =+-( •" a> n (■■) ^ 02 be be ■Xi O w— 1 l-H r-i C^ 2; K AMPHIBIA 317 work of a species. DifTercnt nionihers of the class may lake different species, and tlie daui obtaincMl slioukl be applied to solvini;- tlir insect jtroljlenis (tf the Incalitv. Alnujst all insects come to llu' ground at .sonn- linn-, and we have, especially in the toads, a possilde force of insect police that onu'lil to he better known and utilized. Commercial values, 'i'oads arc r(.'gularl,v sold in tin- niarkris ui huruiK-, l)eiiig used I'V gardeners to control insect i)ests.' I> there any local mar- ket for them? Could sucli a market he developed as a result of studies and demonstrations to prove tlieir value? The following' nunihers of insects have l)een eaten by a toa«l at a m»al or were found in a toail's stomach: 00-100 rose beetles (Klh-n M. Foskett): '>'> army worms, 77 myriajiods, do gypsy-moth cateri»illars (A. il. I\irklan«l. in three stom- achs): 21 gypsy-moth caterpillars (fourth moh ), taken in ten minuti's (Wilcox); S() house Hies, snapited up in l»'ss than ten minutes (Il«»dge). From examination of 140 stomachs, Kirkhmd- estiuuites that a toaove all else, ni>on other frogs. This is tin- great obstacle to frog culture — exc.-pt on pajHT. Xo matter how many we .succeed in bringing through the tadjK.le stage, we have few big frogs in the end. 'I'lie ditlicnlty in f.-.-ding frogs arti- ficially is that they take only active, nn.ving. hmrr livin-. food. It woidd 1 Kirkland .states (Farmers' JiulUUn A". /•'"', \>. M) that Kn-li.-^h gardmei-s pay S2') per hundred. 2 Kirkland, Hatch ExperinienL Statit.n, liulktin 4ii (181»7). p. I'T. 3 Miller. " Tlie American Toad,*' Aincrkan Naturalht, Vul. XLIII (1'.hH»), p. 008. 318 CIVIC BIOLOGY seem entirely possible to solve the problem of supplying such foods in quantity and variety that would largely prevent even the bullfrogs from eating each other. AVe might have lighted insect traps to deliver their catches of moths and beetles all night long into the water beneath them ; i'lG. 150. Toad tadpoles (broad, dark margin of pond); young toads emerged and moving landward (irregular gray edge of shore) Photograph by Newton Miller sweeps designed to catch grasshoppers alive ; blowfly maggot hatcheries, made to drop the maggots into the w^ater as they ripen ; or, if all these should not suffice, crawfish and the smaller species of frogs could be added. Meehan^ states that "30,000 tadpoles have been safely carried 1 Meehan, "Possibilities of Frog Culture," Country Life in America (1908), p. 315. A.MIMm'.IA :]10 ^^^^HS^^^fT mm HHB P vH H£^^Htf( •i Yf^i 15 • ''■>:-Sm j" ^« ^Bi^ 1 :^iH ^^^K^ ^ ^^H •% ^ ^^ Fig. 151. Coininon tree f rocr Photograph l)y Millett T. Thompson to frogdoin in a i)ond :>(! feet l>y l."», havinj; a (jssiltilities of ]i\('-fot>d jiroduction. Ill addition to their uses, actual and l»otential, as insect trajis, frogs hav** com- mercial values which threaten their exter- mination in many localities. In souie jdaces small ones hring from Si to S'J..')(I per 1()(» for fish l>ait. The frog is the animal luost commonly used for laboratory studv the world ovei- ; frogs used for this purpose hring from .")() cents to $o per do/.en. More- over, while they were rarely used for food a few years ago, frogs' legs have now he- come a well-known delicacy. "The meat is white, delicate, and very wholesome and palatable." Hence catching frogs for mar- ket often yields good profit, and it affords a mildly humorous form of outdoor sport. As these values come to he recognized, valuable sj^'cies can ]>e protected by closed seasons (from the opening of spring until after they spawn), local waters can be kept stocked to their full capacity, and an abundant crop can be secured each year. Some special problems. 1. in a pond stocked with bullfrogs, how can we feed so as to prevent cannibal- ism and thus secure the greatest numl)er of large specimens from a given area ? 2. IIow^ can the largest number of toads be reared from a pool a foot square and a foot deei)? (^^^■ have one record of :{1);JS from April to August; the main foods were alga% dog biscuit, and fresh fish.) ^3. Are toads beinc: exterminated from agricultural districts bv drain- ing their breeding pools, by farm animals, and by the operation of fariu Fig. 162. Pair of si)otted salaiuanders Photojjraph by Millett T. Thompson 320 CIVIC BIOLOGY iiiacliinery ? Could this be prevented? If so, how? Might it be worth while, as a measure for insect control, to try the experiment of stocking a farm with them, and comparing the damage done by insects on such a farm with that on a similar farm where there are no toads ? Elementary classification and distribution. The names at the head of this chapter present the main groups of amphibia in ascending order. They are placed there to serve as handles bv which any form that is of local interest or im- portance may be looked uji in the dictionaries, natural liistories, or zoologies. Jordan's " ^Manual of Ver- tebrates " describes eighty-one species of salamanders for the United States. So little is known about their habits, foods, s])awning seasons, and general natural history, that they offer an almost virgin field for young American nat- uralists — a field that needs w^orking the more on account of senseless prejudices con- cerning the venomous char- acter of these harmless and valuable aninuils. The mud puppy (Necturus jnaculosiis) of the upper Mississippi and (xreat Lakes basins destroys the spawn and young of fishes, but this is the only one of the tailed amphibia that is considered harmful. Recent books describe fifty-three species of the tailless amphil)ia as native to the United States — the frogs, tree frogs, and toads. Of the fourteen species of toads the greater number occur in Texas and south- western United States, indicating this region as the i)robable center from which the group has spread over the continent. Fig. 153. Coast newt depositing eggs in an aquarium Photograph by Loye Hohues INIiller REPTILES: CROCODILES, ALLK^ATOltS, TL'K'I LKs, TERRAPTXS. TOUrOTSES. LIZARDS. SXAKFS However, the Reptilia take up u \eiy central i»t»siti<»ii in the evolution ot the main classes of the Vertebrata. (-)n the one hand, there is n«»t the slightest doubt that they are evolved from some branch of the St<*frocephali, whilst on the other han and fear, tlut (;hil(h-en of ignorance, have (himinaird ihr lifkL As venomons snakes have been almost exterminate* I troni iidial)ited parts of ihe eountrv, we are eomin<;- to Im- alile tn appreeiate the beauty and aeknowk'dLr(. the iXoor and ;}21 ^gm||w^«fr»^ Fig. 154. Rattlesnake coiled to strike After Ditmars Fig. 155. Copperhead After Ditraars 322 iM:i'riij:s ;>:>;; snake-skill b^allicrs. tlic tortoise slicll of (-•omniorco, and tlie flesh of some ul' ilic niaiine turtles and fresh-water terra[>ins. Here is a wicU', ahiiost new, lidd. and anyont^ who will make careful studies of haliits and life histories, espeeiallv of feedinj^ tests with snakes, lizards, or turtles, and even tests of ('(lihilitv in case of likely forms, lias a j^iuxl ehame of advaiicin;^ the cause of valuable knowledge and common sense. Crocodilia. Tlie warm regions of the world contain nin»'te«*n .s|M*cii*s of Iti;;, hiirly, hony-annori'd reptiles, with Ioiilj tails, powerful jaws, and tt'iniiers as ugly as their own rough hacks. — II<»i;n \ i. \^ . To see a Vwo AlantosaKnis imiiKinIs ll.'> ftrt long — said to 1m* the "bigge.st and l>ulkiest of all animals" ((iadow) — wouM make us real- ize that our hirgest 20-foot crocodiles are mere pigmy survivals of the huge reptiles that ruled the world during the Upi>er Jurassic. Accord- ing to Ilornaday only three of the nineteen species are dangerous man- eaters — the ^Malayan salt-water crocodile and two African forms. 'Die two that are natives of America, Crocodilus acudts and AUhintor niissis- sippiensis, are not man-hunters. Still, to keep such hulks in food — con- sisting of fishes, waterfowl and poultry, i»igs, and other animals such as they can catch — is expensive and must eventually limit their ran-jf to zoological gardens and alligator farms. Turtles — Chelonia. Senseless waste and even cruelty have too often characterized man's treatment of these defenseless and valuahh* crea- tures. Tlieir nests have been i>lundere»l for the egi^s, whose value is slight compared with that of the turtles which they might have j»rt>- duced; the mother turtles, when they draw out of the sea to lay, have been turned on their backs in iiuiiibers that could nof l>e utilized, anin { Aspiihmectcs firoj) is said to he tin- hrst of all the fresli-watt r forms, t^xm tin- shell, properly cc^jked, heing eonsidered a ossil)le edibility. The cojumon box tortoise (^Cishnln ctintliiifi) makes an interesting pet, and its apjietite for slugs renders it a vahi- able assistant to gardeners. The goj^her tortoise {I'tsfw/n jtnlt//>/<' nms) of the South may attain a weight of 1.") jtoumls. It is eonsidered edible. The annual eateli of food turtles, terrapins, and tortoises amounts to about l,l(i(i.ooo pounds, valued at SllT")(M), What it might be if these re- .souroes were })ro}>erly haiuUed has never been estimated. Lizards — Lacertilia. Tbc Kk.. i.'.h. Cninuion li/.anl lizards are an i-ffectiM' in- sect police for hot, dry habitats not covcrtMl by ani[diil»ia. 'IMiey are ditficnlt to kcc}) in a laboratory, l)ut if wf have a .-iunny window, in wliicli we can imitate desert condition.^, we may make valnable feedinu' tesl.s with a nnndn-r of the eonnnoner fonns — the Idne-tailed lizard, or skink {, F.itiiinux Uisfiutux), the fence swift {Sccloporus uii'/iihif}fs)^ and one of the liorncMl toads, or the eluiineleon ( Aii'ilis rtfrolinriisis). This may bidp us to realize the im[)()rtanee of tin- o-ronp in nature. Li/ar7 species of small, aorile lizards are in any way harmful or dangeroits. The Gila monster (Hehxlenna .'rtuniiiL'ly nuiie of (uir vcihuiious snakes tend It) infest houses, as does the ho(Mh'(l (-(dini (»f India. Ill eoiisecnieiiee, snake bites are extremely rare with ns, and i)ro])ahlv not nioro than two (h-aths occur annuallv from this cause (I lorna(hiy). < M ihc 17 venomous species lo are rattlesnakes, beloiit^iiiLr to the (genera Crotnhis and Fi<;. ItiO. Blowing viper, trying to make room fi»r one mor»* Pliotograj)!! Ity tlw author Sisfno-Hs (tho massasaugas), so well known, so (dearly dis- tinsruished hv the rattles, and so nearlv extind iVoni all settled regions, that they recjuire no description, li i> proba- bly safe to say that a rattlesnake strikes only in self-defense and that it never oives chase. AVhen coiled it cannot strike more than one thii'd of its length, and nnicli less if the neck is drawn into an S-shape(l loop, and its ras[>ing buzz gives a warning that is readily understood by both animals and man. Closely related to the rattlesnakes arc tin- two inoceasins — the npland moccasin, or copperhead {Anrisfrotlon rntitortrir), ans ;j2i) Snake venoms and the treatment of snake bites. l)r. Caluicttc, of tlie Pasteur Institute, succeeded iu proving that snake venoms act ui>on the body and are reacted against by the tissues like any otlier toxins. From this it has followed that antitoxic sera may b»' develo|K*(i for different snake poisons, — the aiitivenins, — which are able to neutralize the poisons and thus confer certain degrees of passive immunity. When this subject has been thoroughly worked out, we may have .specific and sure remedies for all snake poisons, and this will d(» away witli the old, ineffectual remedies — whisky, sucking the wound (very dangerous unless the mouth is perfectly sound), or instant ligature above the bite and quick excision of the poi.soned ti.ssue.s.^ 1 NoGOucni, '' Snake Venoms," Publication J 11, Carne,i,de Institution. Washington, 1909. CHAPTER XXX PRACTICAL LAWS OF LIFE Gp:o>rETKicAL Inx'kease and Struggle eor Life. Vari- ation. Selection and Survival of the Fittest. Heredity. Genetics. Eugenics It is good thus to try iu imagination to give to any one species an advan- tage over another. Probably in no single instance should we know what to do. This ought to convince us of our ignorance on the nuitual relations of all organic beings ; a conviction as necessary as it is difficult to acquire. All that we can do is to keep steadily in mind that each organic being is striving to increase in a geometrical ratio ; that each at some period of life, during some season of the year, during each generation or at inter- vals, has to struggle for life and to suffer great destruction. AVlien we reflect on this struggle, we may console ourselves with the full belief, that the war of nature is not incessant, that no fear is felt, that death is gener- ally prompt, and that the vigorous, the healthy, and the happy survive and nniltiply. — CnxitLKS Daiiwin, " Origin of Species," p. 00 An exact determination of the laws of heredity will probably work more change in man's outlook on the world and in his i^ower over nature than any other advance in natural knowledge that can be clearly foreseen. — Batesox, '^ Mendel's Principles of Heredity," 1902, p. ] To imravel the golden threads of inheritance which have bound us all together in the past, as well as to learn how to weave upon the loom of the future not only those old patterns in plants and animals and men which have already proven worth while, but also to create new organic designs of an excellence hitherto impossible or undreamed of. is the inspiring task before the geneticist to-day. — Walter, "Genetics." p. 5 It is as impossible now to take the ideas of descent and of natural selec- tion out of the world as to take a star out of the sky. — Cramer, " Method of Darwin," p. 61 Mankind is slowly discovering the laws of life. Ignorance cannot, in the nature of the case, bring exemption from the consequeiices of breaking laws ; hence failure even to try to 3.30 iMiAcric Ai. LAWS oi' IJI-1-: :i:n leani the laws iiiidcr wliidi wc lixc mav ainoiuii lo ciiiiiiiial carelessness. Wv, discoxrr ami Icani laws in (udcr thai we may be able l<> obey thciiu thai is, brini^r nwy \\\cs into har- mony with tluiii. (harlcs Darwin, by litdonL,^ application and saciilicc, niaikccl the L;rcatest advance in discoNciy of tht! laws ol lite that the world has known. These are not far-awav abstractions of thonirlit, and not him'- can bo of more intense practical valne than a knowled^^e of them. Work done or life lived in accordance with them is always etVective and successfnl, while that done (n- lived in ()p[)osition t(» thcni is always fntilc. While it may be snihcienL that a few specialists learn how to control the chemical and i)h3^sical forces of nature in accordance witli the laws of physics and chemistry, the forces of living nature are so numerous, affect tlie lives of all alike so intimately, and are so powerful that common welfare re- quires of every member of a civi- lized community that he know enough about them to do his part. Law of geometrical increase. A// HviiKj iliimis frii in- erenae In geometrical r<(ti>. 'i'his is the })roblcni of the hniner who promised to pav the blacksmith one kernel of wheat for the first nail in his horse's hoofs, two for the second, bmr lor the third, and so on. The sixty-fourth nail al(»nc would cost him 6,141, 4r)l,r)r)(;,():i-2 bushels of wheat — more than the en- tire wheat crop of tin- world for 1^n 332 CIVIC BIOLOGV and in many other ways. Fig. 168 expresses this relation to the eye, showing how quickly the world may be covered or any limit be reached, whether of space or food supply, by the o-eometrical increase of a living species. Each species has its own formula or equation of increase, its terms depending on the number of eggs, seeds, or offspring and the length of life of a generation. Every species that we need to control or extermmate, or which we wish to save or increase, finds expression for its power of good or evil hi this law of increase. The mythical labors of Sisyphus typify humanity struggling with these problems. He was condemned to be eternally rolling a heavy stone up a mountain, the stone slipping and rollmg down again when he had almost reached the top. Flies, rats, mosquitoes, or some other plague, become unendurable, and the community tries to rid itself of them. It rolls the stone almost to the top of the mountain. A little more effort, and extermination would be complete, the stone would be rolled over the summit and disappear; but those who do not know this law say, " Never mind these few, they can't do much harm." In a short time the Avork is all to do over again. So effective control or conservation can- not be developed until we have clear ideas of these equations of increase. Work out formulas of increase for all sorts of types, good or bad, and develop clearly their significance in solving local problems. The native American oyster-shell scale produces one generation (about 50 eggs) a year. Its equation of yearly increase is 2 (a pair) = 50. The Chinese (or San Jos6) scale brings forth about 500 living young in a period of 45 days, having four or five generations a season. Its equation of increase for a year is 2 = 3,216,080,400. What bearing has this upon thorough spraying of trees? The native insect rarely injures a tree perceptibly. The imported scale threatens to exterminate many species of trees from the continent. The bobwhite has been known to produce 100 eggs in a season. Suppose each pair rears 10 young a year ; how long would it take, if PRArTICAL LAWS (»1' LIFI-: 888 everyone cooperated, beginning with present niunbers, or witli ten pairs, to increase them to limits of insect and weed-seed food supitly ? Figuring the numl)er of buds prochiced l»y a grap«*, j>each, ai)pl<'. strawberry, or other fruit, the number of eyes Ity a )>otat(), tlie numlxT of seeds by a grain or vegetable plant, how long would it take to supply every farm or garden with a favorable variation? This introduces us to the second practical law uf life. » Law of variation. No ttm liritif/ f/ihit/s arr. cvactly alike Can we liiid two forest leaves, blades of o-rass, or luiiiiaii faces exactly alike ? Living organisms are too complicated for it to happen, even by chance, that any two slionld be alike. So this universal law of living nature has given us all our different kinds of plants and animals. Domesticated plants and animals early attracted Daiwin's attention as showing variations most clearly.^ Horses, cattle, sheep, dogs, pigeons, and all manner of cultivated plants have varied in the brief centuries of human control, and are still varying, in most wonderful fashion. We have horses, from C/lydesdales and Norman Percherons U) Shetland ponies, all produced by human breeding and selection. Ages before man appeared on tlie eartli little Eoliippus, not nuich larger than a fox, with five toes, four of them hoofed, trotted over the bogs of the tunes; and we can now trace in successive strata of rocks how the modern horse developed from ibis earliest form. The story of other animals and even of man himself we have not as yet been able to trace so clearly. The great practical values attaching to variations in relation to agricultural productions are touched ui)on in CliapUT IX. Since these dei)end so largely upon the possibilities of increas- ing and pro[)agating favoralde variations, we nnist considei- this stibject further in connection with the greatest of all biological laws. 1 Darwin, Variations of Animals and Plants under Domestication. 334 CIVIC BIOLOGY Law of heredity. Organisms tend to produce offspring like themselves. Variation is as destructive as it is constructive. It may give us the Spitz enburg apple, and the seeds of a Spitz- enburg may revert toward the original wild apple. Heredity is the force that enables us to conserve the gains supplied by variation. Organic reproduction is of two kinds — asexual, or vegetative, and bisex^lal. The asexual process is seen in growth and simple division, as found among the bacteria, or growth with budding, as in the yeasts. and in plants generally and in many of the lower animals. In all this reproduction we virtually have continuity of the organism, and this can go on indefinitely with little or no variation. So buds, grafts, cuttings (of stems or roots), layers, runners, Ijulbs, bulblets, tubers, and, in short, all purely vegetative parts of plants capable of reproduction carry the variety true to name. This means that every bud on a Spitzenburg apple tree, rooted in the ground or grafted into any kmd of apple root or branch, will produce a true Spitzenburg tree, while not a seed from all the Spitzenburg trees in the world might be able to do this. Tliere is some talk, but little evidence, that varieties tend to run out, or grow old, under bud propagation. Still bud variation does occur. A branch of an orange tree may bear lemons, or a bud of a peach tree pro- duce nectarines or apricots. Buds may also be weakened by association with disease organisms (as in diseased potatoes) or, possil)ly, by lack of proper nutrition, and so give rise to weakened stock. So we are beginning to hear of pedigree selection of seed potatoes from healthy, vigorous, productive hills, and of buds and scions from healthy and fruitful trees. If these pomts are attended to, there seems to be no reason why any variety may not by Vjud propagation be held true to type indefinitely. All higher plants have adopted bisexual reproduction as one method of jnultiplication (all seeds), and all animals 1M;A( TIC Al, LAWS ol" lAVK :i:i' (i^-r^ liiqluT than till' worms and soim* iiisft-ts have cuiiil* to (h*- peiid upon it entirely. In st-xnal iv[)ro(hiction each indi- vidual is huilt n[) hy the niini»-linL; of the j^^crniinal rlcnimls of two parents, and nol only that, hut of fom- L^randpareiils, eiyht great nrand[)arL'nls, and so on. This niin'^lin*^, hv pre- poteiiee of some characters and recession of others, causes active variation, an() per cent of Ins characters from his ^^^^^ ^^ parents, 25 per cent (£^hHp from his grandpar- ents, and tlie rest from more remote an- cestors. (ii\en all the forces of increase, va- riation, and heredity, another law comes hito play, the discovery of which was Darwin's great contribution. The law of natural selection. Xttfurr srirrfx fhc fittest tn survive. From the becfinidno-, man has imitati'd nature in selectino- the i)lants and animals that suit his need or fanev, and this is connnonly distiiiLiuisluMl as ((r(.'fict\t/ .srhctiou. Combination of tliese two ])rocesses has resulted in \]\o sp(»- cies and varieties, strains and breeds, that we nnw .sec in the world. Progress has been made in the [tast chielly by pick- ing up chance variations as they have occurred in nature and accidentally among domesticated j)lants and animals. ( )nly within recent years haxc we begun to learn how to sidi'ct the parents in order to cause desired vaiiations. \\\ eight years of most accui-alc :nid ]iainstaking experiments in cn^ss- ing and rearing \arietics of garden ju-as, the Austrian monk. (dd) @)~T~@) ^^ ^® abviuf. Vu,. 104. Diaiirani illustratiiiLr Mt'iidel's law of (lihybrids. white lu-iiii,^ (l(»iniiiiiiit and black recessive 336 CIVIC BIOLOGY (iregor Joliann INlendel, discovered a law of heredity, claimed to be equal, for biology, to the law of gravitation in physics or to that of atomic equivalents in chemistry. Mendel's law. Characters are represented in germ cells by units which tend to segregate or combine in definite jjropor- tions, the residt of mating together first crosses falling in the ratios IDD + 2DR + IBB for characters D and /?. Illustration. A tall and a short pea are crossed. The seeds resulting from the cross produce only tall plants. When the seeds (self-fertilized) of these plants are grown, they are found to produce 75 per cent tall plants and 25 [)er cent short, or 8 tall to 1 short. Here tallness is dominant (character D) and shortness recessive (character R). A dominant character dominates the outward form of the plant or animal body, while a recessive character has its units persisting unchanged in the germ cells. When male and female germs again combine, they do so according to the law of chance (like dice, or any other free units) and so fall out IDD + 2DR + IRR. Since we cannot distinguish the DD i)lants from the DR plants, except by planting the seeds and analyz- ing the progeny, we have 3D to IR. All the RR plants are found to be as pure and to breed as true as if they had never been crossed, and so are all the DD plants when we propagate them. Tlie DR plants will continue forever to produce IDD + 2DR + IRK. A hybrid can never l>e fixed so as to breed true. The above is the law for monohybrids — forms in v,hich u single character or pair of characters is involved, and instead of assuming the presence of a unit (determiner) for a character (for example, shortness), the tendency is to assume merely the absence of the germi- nal determiner for tallness. In cases of two characters being involved in each parent, that is, in dihybrids (characters Dd and Rr), there is IDd-Dd and IRr-Rr, that is, 1 pure dominant and 1 pure recessive in Ki. In case of trihybrids only 1 offspring in 64 is pure dominant or [)ure recessive. If ten characters are involved, the offspring of the sec- ond generation would fall into 1,018,576 different kinds, of which only 1 would be pure for eacli set of characters. When we consider that this law of inheritance applies to fixation of all kinds of characters, from tallness of peas to tallness of men, from rust resistance in wheat, egg production in poultry, or milk production of coAvs to feeble-mind edness or normal intelligence in men, we begin I'h'AC'ncAL LAWS (>!■ I.IFK 837 to ie;ili/c what Meink-l has doiut lor tlic woild. A> \\'all<*r suin.> uj> tljr ease: "Tims in a few generations at j>ro|i<'rly ct«'(l crosses there can be obtainrd c-onihinations of characters united in one strain that formerly were never obtained at all or were only hit iiimmi by merest chance at lonj;' intervals. Herein lies the scientifi<- conti-ol of lienMlity which the trinity of Mendelian i»rinci|iles, naniely, indejH-ndent unit characters, se^Teijation, and doiuiiunice. has placed in human hantis." ' Historical. Mendel jtresented the re- sults of his era-making experiments before the Natural History Society in Brilnn early in 1805, and they were published in the Proceedings in 18, 1884, bitterly disappointed that no one could be found to share his vision, and his discovery slumbered for sixteen years longer. In 1900, three men, working inde[>end- ently, rediscovered ^Mendel's hnv almost at the same time. These were De Tries in Holland, Correns in Germany, and Tschermak in Austria. The time was ripe for its appreciation, an«i it immediately transformed the subject ami, from a matter of abstract disquisitions, made heredity the most intensely practical concern of the experimental breeding plot and pen, of the hunt for variations in nature, and of even sociological analyses and surveys. " I'he practical breeder of animals or plants, basing his methods on a determimition of th«' Mendelian units and their properties, will in many of his operations be able to proceed with confidence and rapidity. Lastly, those who as evolutionists or sociologists are striving for wider views of the past or of tlie future of living things may by the use of Mendelian analysis attain to a new and as y00. i>. 17. Fig. lOo. Diagram illustrating relation of germ plasm (straight lines) to somatopla.sm (circles) in bisexual reproduction 388 ^'iVlC BIOLCXiY Evolution, mutation, and Mendel's law. In his scheme of evohitioii Darwin emphasized the influence of slight variations continued through long periods of time. He realized at the outset that in heredity, in the i)Ower to pass on variations, lay the heart of his problem, but he went far astray in his own theory of heredity, pangenesis,^ and so failed to attain the goal he might have won. Xo one realized this more keenly than Darwin himself. De Vries found that from the same seed capsnle of Lamarck's eve- nino- primrose he could rear as many as nine distinct kinds of plants, so different that, liad they occurred consistently in nature, they might have been named as separate species. On the basis of these and similar experiments he advanced his recent theory of mutation. This theory supposed that evolution goes forward by leaps and sudden changes. It now tnrns out that this evening primrose, (Enothera JaniarckUma, is a Mendelian cross, a hybrid; and this suggests that all mutations may be merely cases of segregation and recombination of nnit characters in the germs of plants and animals, that is, outworkings of Mendel's law. Weismann made a solid contribution when he distinguished sharply between germ plasm and body plasm, or somatoplasm. He called atten- tion to the fact that the germs are all formed in the embryo lonf/ before the body; the egg-germs, and many more than a hen can ever hope to lay, are all set aside at almost the very beginning of incubation. 1 Pangenesis {pan, "all,'' or '''the whole,^' and genesis, " origin '" — that is, "from the whole body") is the theory that the germ cells are built up by the streaming together, from all the organs of the body, of minute parti- cles (gemmules, or pangens) — an infolding or involution of the body into the germ. Then when a germ unfolds or develops, each pangen reproduces the part of the body from which it came. This theory implies an active influence of the body upon the germ plasm, and if parts of the body or brain should be specially developed by exercise or training, or if parts or organs should be removed or lost by disease or accident, we should expect to find such additions or subtractions reproduced when the germs from such bodies developed. This we never find. There is no evidence that any acquired character is ever inherited. Lambs' tails have iTeen bobbed for thousands of years, and lambs are born with tails as long as they ever were. Galton disproved pangenesis experimentally by exchanging the blood of animals. Since the blood is the only means by which the pangens could possibly circulate from the body to the reproductive cells, if we exchange blood between white and black animals, we ought to get some of the pangens mixed. Galton's experiments disproved the theory absolutely, as does every case of budding and grafting. rKACTKAJ. LAWS ( H' IJFIO 8:^9 (it'vm plasm forms <,'enii j-lasm aiwl I. nil. Is ii|. th.- I.o.ly, l.iit th.- ImhIv cMiiiiot f(.rm or rrprodiicc a siii-ic i.au-^cii or niiimirst partich. ot* germ plasm. Organized study of genetics. Wliai is \..iir (.wn ((.iiiiimnity doiiior to improve its t)lams and luiiinals? .Manv investi- gators iiiul students in our universities and colleges, our atnon^ our nildin^S The next ftin^ to do waS to fmd ; tke best and earli£5t grape for ^eed and IniS 1 ioimd in i an accidental seedling at iKe foot of llie liill . TKe cyop was atundant ripe in August and of very pood auality for a uild grape. I ^owed \\\e ^eed in tlie autunm of 1843. Amonp them the Concord Ma5 the only i one worth 5av:n^. Fio. 166. Quotation from Mr. Epliraim Bull (Ui tlu' wooden tablet markim: tlie original Concord grapevine at Concord, Mas.sacliusefts Agricultural Department and experiment stations, practical seedsmen, farmers, and independent plant and animal breed ers, are studying and experimenting and pushing discoverv in tin's fi(dd. Invite local experts to \ isit the class and di.scuss tiieir [)rol)lems. Often Ity comnnnuly coi')peration ])etter slock can he introduced than any one niemher could aiVord. and its rat)id increase insnres enormous profits to such midertakings. Railroad companies and tlie International I larvester C'ompanv have agricultural experts who are helping along these lines. Hunt out stories of tlie discoviM'v and introduction of new fruits, vegetables, grains, brcecls of animals, and in the s|)irit 840 CIVIC BIOLOGY of these try to find valuable variations in the neighborhood. Our native nut trees have been neglected in this matter, and the Department of Agriculture is calling for a special search of the entire continent for valuable varieties. With the whole country organized for the search and Avith breeding in control of experts, we may hope for better progress in every line of plant and animal improvement than ever was known before. Injury of germ plasm. Germinal substance is, of course, (jbliged to draw its nourishment from the body ; hence we may expect to find vigorous germs in strong, healthy bodies. Animals that become too fat are likelv to have enfeebled germs or to be totally sterile, and conditions that show no appreciable injury to the body may prove fatal to the germ plasm. This is seen in Stockard's experiments with alcohol tabulated below : Experiments with Giinea Pigs to test Influence of Alcohol ox Germ Cells Alcoholic Alcoholic males and normal females Normal males and alcoholic females Alcoholic males and alcoholic females Control Normal males and normal females Num- ber OF Abor- MAT- I TIVE INGS 24 4 14 1» Die© AT Birth 19 2 13 0 0 L Li vkd o (all runts) 2 0 17 (all vigorous) The germ cell from each parent builds half the cmbr^^o, and the twenty -four matings in Avhich the sperm alone is alcohol- ized are a proof that an alcoholized sperm cell of a guinea pig cannot do its share toward building up a normal offspring.^ 1 Stockard allowed the guinea pigs to breathe fumes of alcohol for one hour a day, six days in the week. The animals showed no outward injury, in fact they gained somewhat in weight. PKACTICAL LAWS (JF LIFE :541 The following table shows similar results obtained bv Hodge from carefully balaneed experiments with selected dogs. The males were brothers ami the females sistei*s from two unrelated litters of pedigree cocker spaniels. DtMume's observations upon iikmi iin- nddcil tm' cnmitarison. Jhxjs (Hodge) Number of whelps . Deformed .... Horn dead ... Viable Alcoholic Paih (7-7-0-3) 28 (2-8-3-0) 8 (2-2-2-8) U (4-0-0-0) 4 (17.4;;) Normal Paih (5-3-8-8-.J-0-8-7) 4r, (1-0-0-2-0-0-0-1) 4 (0-0 0-0-0-0-0-0) 0 (4-8-8-6-r)-C-.S-0) 41 (im.27,) Men (Deinme) Number of cliildren Deformed .... Idiotic Epileptic, choreic Died at birth . . Normal, viable . Tex Alcoholic Tkx Norma I F.V.MIL IK.S Fa MI LI KS ')7 01 10 (i 2 0 0 (2bk\v) 25 3 10 (17 '.) r.4 (88.. 'iM Moderate, nonintoxicating doses td' clu'mically pure alco- hol were fed to the doi>s with their meals, and Dennne's normal families were not total abstainers. In further study of the human [)roblem I>ezzola found that (»ut «d" SlUU idiots in Switzerland the majority occurred in ilie wine disti'icts, and that the larger per cent of these were born nine months after the jri-eat nati(>nal drink inir feasts. Sehweitifhofer dis- covered a similar relation between stillbirths an«l the drink ing festivals of .Vustria. To keep the germ plasm of the nation on the U[)-grade, free from any injury, taint, or tendency to degeneration, is the most worthy subject foi- lifelong stinlv by every man Caspnr N d. UX< N d. 170.") N d. 1770 The Lawful Wife (n> (N> (N> N The Xameless Feeble-Mindeil Girl Xot Married i Martin Kallikak. Sr, .1. 1S37 N Frederick Martin Kallikak. Jr. N m all busi- ness, public and private, where strengtli, endurance, and dependability are required, antl the evidence given above cre^ o ^"^"^w^ li^MM^i^i^g^ ^ 2 4 3 N ; N II I I I II Fig. 168. Recessive character of feeble-mindedness and effects of alcoholism Small black circles indicate stilll)irth.s: d, died : d. inf.. died in infancy : t. tnl)«T- cnlar: r. unknown. For other symbols see Fiij. 1(>7. After (ioddard would seem not only to give society the right but to impose 111)011 it the dutv of banishiiio: alcohol from aiiv i)ossible contact with the supreme business of evolving the race. *' You can't be strong and well unless you ///v ri;/hf." These words of Jess Willard are lite-wide in their apj)liea- tion. We are iust beo'inniiiL;- to learn tVoni the new \ ii'w- point of eugenics. Drugs like morphine and opium, cocaine and heroin, must be studied with special reference to their in- fluence upon the germ plasm. The same is tine (d' nii-otine, and it may be that we shall have to set the age at whii-li indulgence in tobacco mav safely be begun at lifty-tive years instead of at the usual sixteen or t w cntv-ctne. .\nv 844 CTVIC BIOLOGY excess in the use of coffee or tea must be viewed with suspicion, and many of our best hygienists look with appre- liension at the possible consequences to the race of our sudden, enormously increased gorging of sugar. We can onlv suggest these as possible lines of study. Eugenics and MendePs law ; bad blood and good. '' I*eo- ple say one mnst be able to read and write in order to get along in the world. Now there is ]\Iiss . She cannot read or write, yet she gets along all riglit." ^ This judgment of a feeble-minded woman by an imbecile man helps to explain the rapid increase of such defectives. Avoided by the normal, defectives generally marry defectives. 8inc(^ they are permitted to nmltiply at will and are shielded by modern charity from operation of the law of survival of the fit, this process has gone on until w^e now have nearly 3,000,000 dependents and defectives — one in thirty of our population.'^ By far the larger part (quite possibly, when we have studied to the real genetic root of the matter, we shall find that al- most all) of the heavy burdens imposed upon society by the idiotic, imbecile, and insane, the paupers, alcoholics, and criminals, is caused bv inherited mental and moral defect. The exhaustive studies of Goddard seem to leave no room for doubt that feeble-mindedness is a recessive, ^lendelian, unit character. Hence, according to ^lendel's law, the chil- dren of feeble-minded parents must forever e feeble- minded. Goddard finds this to V)e true. Normal-mindedness is a dominant unit character. Hence, if one parent is pure normal (duplex) and the other feeble-minded (nulliplex), the cliildren will appear normal but will all have feeble-mindedness recessive (that is, be simplex). When such people become parents, the children will be IDD -f 2DR 4- IRR. that is, three normal to outward appearance and one feeble-mmded. 1 Goddard, Feeble-mindedness : its Causes and Consequences, p. 8r>. - Kellicott. Social Direction of Human Evolution, p. 34. PKACTKAL LAWS ()]■ MIK ;^4;, Since tliesu pC()i)le arc a l»iir»k'ii ki iIil'Ium'Ivl's and lo society, no right-niindod person could risk the responsibility for bringino' them into the world : and as the i'acts come to be generally known, all such streams of bad blood will U- prevented from increasing thcii- kind and also from spread- ing out to contaminate streams of normal blood. Color of eyes and hair, night blindness, eohu- blindness, albinism, germinal deaf-nnitism, and many other human characters have been found to follow MendeFs law, but dis- covery is only beginning to break into this Held, and we merely suggest it for future individual study. Mnsi impoi-. tant studies have been made on typical streams of bad heredity. Let different mend)ers of the class volunteer to look up the following and report: "The Jukes Family," bv Dugdale : ''The Zero Family," by .Uirger ; "The Hill Folk," by Danielson and Daveniiort ; "The Nam Familv," l)V Estabrook and Davenport ; and " The Kallikak Family," by Goddard. CHAPTER XXXI KNOWING now TO KNOW HOW National Okganizatiox for Biological Instruction AND Research I do not know what I may appear to the worUl ; but to myself I seem to liave been only like a boy playing on the seashore, and diverting myself in now and then finding a smoother pebble or a prettier shell than ordinary, whilst the great ocean of truth lay all undiscovered before me. — Sir Isaac Newtox It's easy enough to do it if you only know how. It's easy enough to do everything, if you — if you only know how. — Small Boy (overheard on the street) Conclusion of the whole matter. The best '' knowing how *' tliere is in the world is none too good for the humblest child of the nation to try to live and to work by. If there were one wish that the writers of this book could have granted for the asking, it would not be that everybody should know everything, but that every child of the nation should know how to learn only the best truth there is to help him with each day's life and work. The doing may be easy and cheap ; the knowing how is very precious and may have cost years or centuries of trying, thinking, and experimenting. Still the knowing how may be easy, too, if we really know how to know how. Is it not bemg continually baffled by false, wrong, bad knowing how that makes all learning hard and work futile ? It is easy to keep well and strong if we know how, but the knowing how must be right. It would be easy to exterminate tubercle bacilli if everybody knew how, but we cannot do this as long as even a few think they know 346 l\N(»\\IN(i now K ) KNOW ||(»\\ :>47 how t(j do it will) \)]. Muck's ((iiiijidiiiKl nf pmik. alias cheap wliisky. It would he cmsn to luccd ami laisc Inn busht4 wheat, •JOii-huslicl coin. 1 <>()(►. Imslud potatoes, lOOO- pound-lnittei'-fat cows, oOO-ci^l;- liens, and so on d(.\\u tlic list, if we oidy knew liow. W'c arc i^Miuiiiir unround Ncarlv; the (k)iii«f is step hy step a test of the know Jul;. Fake sources of truth like poisoned wells. Sonictiiuc we may be organized as a people, so thai only the tiuth can he printed. Our pure food and drug laws are hcgiiuiiiiLrs in this direction, hut the millennium is still a long wav oH", and so far attempts at assum[)ti()n of human iniallihilit v have Ikmmi failures. All we can do is to a[)peal for iidormation to our best authorities. These })retend to no secrets for a pri<-«' : they always present the evidence, the proofs, tlu* experi- ments, on which their conclusions are based: and it ought to be possible to add, they nevfr say they know a thing when they do not; that is, fhr// nrrrr lir. X(» one can long remain an authority if often mistaken on this most ini[)ortant of all points, and a real authority is never afraid to say. 1 do not know." Successful farmers in ditfereiit lines, our eouni\ agricultural expert, local nurseryman and florist, local forester or tree warden, local bird man or woman ( unfortunatidv w«' seldom have any local insect students), local health oilicers and reputable [)hysicians, state and national experiment- station experts and health olhcers, any the divine light of being ali\c the best knowing how there is in the world belongs to any chikl of humanity who is hiingrv for it and wh»t knows enough to ask for it and to learn it. ( )ur country is oiganiz»'(l, throtigh its e(hi- cational forces, public press, and public libraiie^. i" nu*et this S4S (IVIC BIOLOGY right, as any child of the nation can test as often as he pleases. The o'reat lack is that we are not educated to know and to utilize the resources for knowing how that belong to us. Another great difficulty is that the world is flooded witli fake, false, selfish-motived misinformation, and we need to learn to slum all l:>ad and second-rate sources of truth as we would poisoned wells, hi proportion as one uses the best sources of information, he Avill develop the power to discrimi- nate and to detect the bad. Civic biology should, first of all, save us from fake solutions of our health problems. Xo, Mrs. Bouebrake, 1 am not going to try yonr religious fad in order to heal my sore feet ; no, jNIrs. Hardscrabble, I will not use your number rigmarole to improve my prospects ; and no, INIrs. Ukenbower, I will not wear your amulet to get rid of my rheumatism. AVhy? AVell, because I am honest. T may not be yery holy or soul- emancipated, but I pride myself on being an honest man. And T'm going to be as honest with myself as I am with, my neighbor. The fundamental ethics is the ethics of the intellect. . And that means that I will believe only upon examining the facts. My judgment shall remain absolutely automatic, and shall bend only by weight of evidence. I shall not say I believe a thing just to see if it will not help me. T shall refuse to proclaim a faith in order to help anybody else. Ladies, you touch the quick of my virtue. T will not be disloyal to my reason — no, not even to get to heaven. History is full of pious and learned men who put expediency before honesty. They did hot believe what they professed — they did not even understand it ; but they said they did, because they thought it would aid others, would not offend the weak, and would save their own souls. But I will take my chances with intellectual integrity alongside of all the earnest souls who deceived themselves and everybody else be- cause, so doing, they verily thought they were doing the will of heaven. I know, Mrs. Bonebrake, you claim that your peculiar faith, resting upon a plain denial of facts, has healed many ; so, Mrs. Hardscrabble, your cabala; and so, Mrs. Likenbower, your amulet. Why not try it? It has benefited others ; why not me ? KNUWlN KN(.)\\ lloW 349 Siniiilv because every one of your cures can U- traced as justly to tin- strange, mysterious, recuperative powers of natur*' as to your particular nostrum or form of self-hypnotism. Thousands of invalids Iiunc got well iificr Ix-ing given uj> hv phy- sicians, and got well without crossing their ling«'rs and reading your book. In fact, most people, some time in their life, have miracnlously recovered when it seemed they should have died. Hence, if you bottle Chicago river water and get enough i>eopl«' to "just try" it, you can collect innumerable testimonials. Hut doubtless if you i)ublished these you would not include in your report the eing to stay lioucst and ><••• wliat lia)>pens. \\ hell J am met l>v a proposition tlial is l>ased on fads, and not on tile ignoring of them, tliat is reasoual)le and convincing, and that i> substantiated by the known laws of evidence and sipiares with common sense, I will embrace it. Otherwise, no: and thank you all the same. Nothing doing on the esoteric, the fuzz-wii/.zy, the ecstatic t)ie self- hypnotic, the what-if-it-is-true-after-all-you-can't-tell. My intelligence may be pretty i»oor. but it's all 1 ha\f. I'm goinu to stand by it and refuse to prostitute it. no matter what the bribe. The web of destiny is comjilex. I know, and none of us knows the secret springs of life and events: Imt 1 have a notion that if a man sticks to the truth as he sees it, and declines the lure of truth as he does not see it, even if the latter promises health, wealth, and a hai»j»y ln-re- after. he Avill be likely to come out about where his Creator intend«'d.' Using a library. Tlic host iiivostnuMii any (•(•nmuinity < an make is to \m\\ catalogue, and keep np to dale a library relatiiu'- to its interests and industries: and, in anv modem sense of the \yord, that one is most efhcit'iitly rducaled who hest knows how to use sucli a lihiary. if our local and sclnud libraries are properly manaj^ed and cataloniied. it (Mi<;hl to be easy to find quickly all that is known on every su])jeet discussed in this book. If every member ol" the (lass is col- lecting bulletins up to date and doing his share to h«dp, 1 Bv Dr. Frank Crane, in the .Vssociated Newspapers. 350 CIVIC BIOLOGY the laboratory bookshelf ought to be made to answer 95 per cent of the questions that arise. Individual pupils should also be gathering libraries relating to their own problems, interests, and projects. A really practical working method in using a library is of lifelong value to everyone. How many have acquired this at the end of their school or even college courses ? This is the one thing necessary to reason- ably intelligent modern living, and if many have failed to acquire it in the course of their schooling, is it not because they have not had any real problems to solve that required such use of libraries ? Lincoln stated the case in a word when he said: ''A capacity and taste for reading gives access to whatever has already been discovered by others. It is the key, or one of the keys, to the already solved problems. And not only so : it gives a relish and facility for success- fully pursuing the unsolved ones" (p. 92). Catalogues, publication lists, and indexes. A library may be too poor to buy many books, but still be 100 per cent efficient if it keeps these indispensable helps in order and up to date. People can then find everything that has been written on any subject or by any author, and the local library can usually borrow from the state library or from that of their nearest university; or people might often buy books and donate them to their local library when they have finished with them. Every laboratory bookshelf must have for constant refer- ence the Monthly Lid of PuhUcations (which is sent free to all who apply for it) and the Experiment Station Record} The first lists every bulletin of the central Department at Washington, as it appears, and the Experiment Station Record gives a well-annotated monthly bibliography of everything relating to the practical biology of agricultural advancement for the entire country and, in fact, for the world. Another 1 For both these publications address United States Department of Agri- culture, Washington, D.C. Subscription price of the Record is |1 a year. KN()\VIX(,; HOW TO KNOW HoW :l')\ [)ubli('ation of tlic Department is the Wcfkli/ Xrn-s Lrttrr, which eontaiiis brief, timely articles and notes. Some mem- ber of the class mi^-Jit subscribe for this and kccj) it in orderly lile on the bookshelf. The (jnestion with which we starte(l i>, ijow ciin we ^el the best iid'ormation most (piickly? A concrete case will answer this question for thousands of similar problems. A botany class in a city was be<,anninj^ the study of finij^i. ami in addition to the elementary book work each nienibiT was assig^ned an interesting fungus to work up and rei)ort upon. ( )uc of thn boys, instead of the t'ungiis assigned him, asked i»erniission ti> take llic black knot. The teacher was wise and honest enough to t«'ll liiiu that siie knew nothing about it, but would be glad if he would learn all he could and give them all the benefit. He went to the library with a pack of postal cards and, going through the recent numbers of th«' Kjperimtut Stat'uni Record, took down on the cards references to all likely articles on the black knot, addressed them, and within a week he had everything that everybody knew about the black knot. The bov then went to work out doors, hunted through the woods, and collected the fungus on native wild i>lums and cherries, and he maortant stages in its growth and reproduction. He drew colored wall charts fr<»iu his pictures, supplemented by those in the books, and fimdly j)resent«'d his result.^ on the life history, distribution, and treatment of the Idack knot in a carefully i)repared lecture which oct iipird an entire ]>cri(»d of the class. One of his classmates hui»i>ene(l to be a reportii- mi a local daily, and she presented the subject to tlie public in a well-w riltea article «»f about two colunnis, and there followed such a cleaning up of black kn()\\L\(i MOW To KN<»\\ ll(i\\ :\;y.l American Associatiox foj; iiik Advanc k.min i nr Scikx< k. Dr. L. O. Howard, I'tTmaiifut sccretarv, Wasliingtun, D.C, was f«mnfl«Ml in 18-17 aiul lias 11,000 iueinl)er.s. Tlif l)iological sections an* F. Zoology; (i, Botany: K, IMiysioloiny and Kxperiinciital Mi-diciiu': and M, Agriculture. Sister ornani/.ations are the liritish aixl Freneli associations for the advanoeiuent of xieiicf. Tlir dllicial (»ri;an i> Sriencc, j)ul»lished \vef] was first organized in l>»io (reorganized in 188:5) and is the parent from whicdi many of the m(»re sj)ecial scientific societies have split off. It has 400 mend»ers. C'KNTRAL AsS<>( lAlIOX OF SCIENCK AX1> .M A I II I.M A IK S 'JKACHKns (and many similar societies of science teachers). The oHi<-ial organ for all is School Science and Maf/iematics. Amkricax Xature Study Society, fonnded in I'.tos; i.ificial organ. Xalure-Sindii Rerieir, Ithaca, X.Y. Amkricax PiHLic IIkai III Associatiox. The otiicial organ. American Journal of PitUic Jha/i/i, siioidd he in every biological lihrary. National Association' foi: the Sifdy axd Pi:eventiox of TrnERCi'LOSis, founded in 1904, has altoiit •J.'tOd nieml>ers and pnl«- lishes accounts of annual meetings. Society of Amei;ican 1>A( i Fiiroi.odis i s, founded in iMi'.t, limited to 7.") members. AmERICAX Asso( I V I loX OF 1* A IIlnl.0."», now has about 4000 members, with branch sorirties in tiearlv e\erv a list of learned societies, with dates of founding, number of nieiuhei's, addresses of some of the officers, and names of journals publisluMl, with their places of publication. Local libraries may .supply more exteiuh-d lisi.s. 354 CIVIC BIOLOGY state. The official organ is Bird Lore, edited l)y Frank M. Chapman and pnblished at Ilarrisburg, Pa. American Ornithologists' Union, founded in 1883, has 1126 members, publishes the Auk, the official journal of American ornithology, and also prints and keeps up to date the A. O. U. Check-List, giving the authoritative names, popular and scientific, of all l>irds of the United States. American Association of Economic Entomologists, founded in 1889, has about 5(10 members; official organ. Journal of Economic Ento- mology, Concord, N.H. A complete set of this journal ought to be accessible in every city and town library. American Entomological Society, founded in 1859, has 110 mem- bers and is devoted to purely systematic entomology. American Phytopathological Society. American Pomological Society, founded in 1819, has about 500 members and publishes biennial reports and special catalogues of fruits. American Society of Landscape Architects. American Genetic Association (continuation of the American Breeders Association), founded in 1908, has about 1200 members and jmblishes the Journal of Heredity, a monthly publication devoted to plant, breeding, animal breeding, and eugenics. Washington, D.C. We have given dates of founding and number of mem- bers in order to emphasize the fact that organization for kno^^- ing how to do tilings is only just beginning, and that as yet very few are actively concerned with these vital problems. CIIAPTKK XXXII PKOGHKSS IN DISCOVERY Aiiytliint,' which sheds lii^ht on the nature of life and of man himself, his orj^anic constitution and ecjuipment, the laws and pussihilities of his mind and body, his place and fate in and relation to the rest of the universe, will appear innneasurably more important than the fate (tf individual men or nations, — because those thin^j^s have a fundamental si<;nilicance f(jr the whole human race everywhere and for all time, and likewise have the deep- est sort of personal significance for everyone who is reflective enou<,di tcj be conscious of the questions presented by his own beinu. The great battles of man have not been fought on (irecian plains or Spanish mains or over Eurt)pean hill and dab', but within the skulls of the great investigators, up and down the brain valleys and ridges of the great thinkers and the immortal i)oets. It is the great captains of thought and feeling that have led forth the bright-shining forces of the human mind and soul in the only wars that have results of permanent and universal impor- tance,— wars in which thoughts, ideas, facts, conceptions are deployed and maneuvered in phalanxes and battalions to the greater issues of our human fate. Measured against such Himalayas of the human mind and soul as Darwin and Marx and Newton, Napoleon and Bismarck and Alexander are not even among the foothills of human significance. The publication of "The Origin of Species" was a more vital event in human history tlian the battle of Waterloo. — CotuTNKv Li:mon, Pearson s Ma niak(^ tlie discovery. Tfave yon told anyone about tht'iii or i>ul)lislu'(l your diseoveries so that 855 356 CIVIC BIOLOGY others may be helped or benehted by thein ? How do you know that someone else has not discovered the same thuig before you ? Has your father or mother, or some other member of your family, discovered anything of value to the community ? Do you know of anyone in your town or city wlio has discovered anything? If so, can you lind the story in print or can you go to the person and get the story at first hand ? Do we know of anyone in the United States or Canada, South America, Europe, Asia, Australia, or Africa, who has made notable biological discoveries ? Who is he, and what is the story of his A\'ork ? ^ Kinds of discoveries. Discoveries may be big or little ; they may be easv. made at a olance, or even stumbled on l)v accident, though in this case one must be intelligent enough to know what he has found, and be able to think what his discovery may mean to the world (" Accidents never happen among the Hottentots," it is said) ; or thev may require years of application, complicated apparatus, and costly laboratories. A little girl of eight, by working from daylight till dark, discovers that a bob white will eat 1286 rose slugs in a day, and that when fed abundantly on insects, she will lay eggs. These are valuable little discoveries and have doubtless influenced efforts to protect the bob- white. A young woman devotes three years to studying the foods of the bobwhite, and publishes what is probably the most complete statement of the food of any bird. This will exert still more influ- ence for bird protection and must hasten the day M'hen we shall have enough bobwhites to reduce weed seeds and insect jiests, and it may suggest to others similar studies of other birds.- 1 As early as practii-able. when tlie course is well begun and interest aroused, bring up these questions and make them the main subject of a lesson period ; or appoint a date and ask the class to prepare brief written statements in answer to the questions, and have them read and discussed-. Invite some local discoverer to visit the class and tell of his aims, methods, and discoveries. 2 Margaret Morse Nice, " Eood <»f the Bobwliite." Journal of Economic Entomologi/. Juno. IDIO, p. 295 ff. In IslO Mrs. Isal)ella (Jibbs discovcn-fl the Isaltelhi grajx-, ami this discovery is said to have turned attention f llit- world. Mr. Hull works a few years, and the Conc(nvl grape. ;iiid with it a ut-w iudiisti'v. is added to Anicrican horticulture. Mended works eight years in his garden, and dhscovers his law of heredity, tlenncr and Darwin each work twenty years, and the ideas of vaccination and the origin of species are placed at the service of mankind for all time. Importance. ' ( )iu' single idea may liave more value iban all llu^ labor ( < >\ i:i: \ :>.V.i g'miiis, Iruils, and mils have lived and dird mit Ix'cause IK) one saw tlic difference clearly enon^li lo i)c able to tiiink what they niii;hl mean to the world; and thousands more will <'"o the same road' until \\»' learn to see and think eivieally. Our present-day discoverers. A nnmher of munes ret'en-e(l to in the text under various to[)ies may be nse(l lor refer- ence. Our best authorities, as indicate(l in the ])recedini^ chapter, are often discoverers in their respective tields. They have probably won their positions by some creditable research work. Instead of tryiuii- to <'ive a list of tliese it is better to gather the names as they appear as authors of our best books on birds, insects, forestry, agriculture, bacteria, health problems, and so on, or as tht^v come to us from month to month in the bioloo-ical jourmils or scientific bnl- letiiis. AVe should be thankful to our discoverers for what they write, realizing that their work re(piires patient api)li- cation and crveiit sacrifice of time: and while we follow their investigations in the libraries and journals, we should l)e very careful about encroaching upon their precious time by l)ersonal letters. Perhai)s the most discouraging feature of our present situation is the overwhelming ot our dis- coverer with inquiries by i)eople ^\ho are too indolent to go to their libraries and read what he has written. l*'or any special field we may have one or one hnndretl discoverers for our one hundred million people. Figure out aboui how nuich time it would take to answer a million letters. Biological discoverers. Prom the folhtwing brie! list, or from anv historv of science or of medicine, let t'acli member of the class choose some one discoverer, with whom he will become intimately ac(iuainte0 Eustachio : anatomist 1588 Caisalpinus: classified plants by flowers 1 500 .Janssen, .T. and Z. : discovered compound microscope l40 Eudbeck: discovered the lym- phatics l(i50 Swammerdam : first great stu- dent of iu.sects in relation to plants and medicine 1061 Malpighi: discovered the capil- laries in the lungs ; founded modern embryology by a study of the incubation of the chick (1672) 1667 Leeuwenhoek : first to see bac- teria 1 Historical books to which the class should have access for this work are Locy, Biology and its Makers, New York, 1908 ; Baas, Outlines of the History of Medicine (translated by Handerson), Xew York, 1889 ; Mial, History of Biology, New York and London, 1911. PKOGKE.s.s IN. D1SCUVE1{V :i<;i 10G8 Redi : disproved sponuineous generation of insects by the discovery of eggs and 1704 larvai ; -wrote " Esperiejize intorno alia Generazionc degl' Insetti "' I(>70 Mayow : studied animal res- 171>('» piration 17'.»'i 1<>71 Hooke : worked out iMJcm- scoi)ical structure of plants 1800 1680 Borelli: proved that all the movements of animals arc caused by nniscles pulling IHO] on bone levers; wrote " Dc Motu Animaliuni " 1082 Grew : studied structni-c of plants 1(393 Kay : classified plants 1801 1727 Hales: investigated respiration of plants 1743 Haller : father of modern physiology 1744 Reaumur: studied insfcts 1804 1 741> Buffon : wrote a natural his- tory 1H07 1 7o3 Linnaeus: classilicd plants 17(31 Kolreuter : studit'(l livbridi/.a- tion of plants 1811 17r) 1 Bonnet: evolutionist ; groupe 1771 Priestley: discovered oxygen and studied the breathing of plants 1775 iSpallanzani : disproved si«)n- taneous generation of bac- 1830 teria and molds and demon- 183.') strated presence of living 1838 germs in the air 1789 Galvani : discovered animal 1838 electricity 1700 Goethe: worked out a scheme "I ilie metamorphohih oi the parts of i)lants Darwin, Jhasnuis: grandfather of Charles Darwin ; wrote "Zoonomia," a long |K)eni outlining evolution of life Jenner: discovered vaccinati<»n Sprengel : studied fertilization of jilants Cuvier : stiulied lomparatiNc anatomy ; wrote " Le K^^ne animal," 1817 Lamarck: invented a scheme for the evolution of animals (by conscious effort and in- heritance of acquired char- acteiN ; not jiroved) Treviranus: introduced the name "biology"' as dis- tinguished from "botany," '' zoology," " physiology," "anatomy," etc. Humboldt : stu 864 CIVIC BIOLOUV Apanteles, enemies of, 140 Aphids, 51, U2, 152, 156 Apoplexy, 232 Apparatus, 11 Appendicitis, 234 Apple, 94, 165 Apple Day, 299 Apple of Peru, 75 Apple tree, blight of, 212, 213, 216 ; enemies of, 155, 156 Aquaria, 10, 315; cement for, 15; making of, 12-15; management of, 299-303 Aquatic duck foods, 307 ^rachnids, problems of spiders, mites, and ticks, 163-168 Arbor Day, 299 Arbor vitse, 59, 165 Army worm, 156, 317 Arsenate of soda, 71 Arsenic, poison for rats, 180 Artesian wells, 219 Asepsis, 248 Asiatic poppy, 73 Asparagus beetle, 156 Asters, 86 Atlantic salmon, 309 Atlantic squid, 284 Australian duck-bill, 169 Bacteria, 176, 214; blight or wilt from, 215 ; control of bacterial diseases, 231-251 ; culture of, 224-230 ; distribution and forms of, 218 ; fungous and bacterial diseases of plants, 207-217; gen- eral discussion and treatment of, 186-191, 218-251 ; kinds of, 218, 220, 221, 234, 236, 242; labora- tory methods and experiments, 224-230; parasitic, 187; pictures of, 236; reproduction of, 220, 221; saprophytic, 221; size of, 218; symbiotic, 187, 221 ; venomous forms of, 234; work of, 221 Bacterins, 248 Badger, 171 Bald cypress, 59 Bald eagle, 45 Balsam, 59 Baltimore oriole, 48 Banana, food for mosquitoes, 131 Bank swallows, 49 Banostine Belle de Kol, 103 Barium carbonate, 179 Bark disease, 247 Barn swallows, 49 Barnacles, 287 Basket willow, 307 Basses, 309 Basswood, 59, 82 Bats, 129, 169 Bean blight, 215 Bear corn, 76 Bears, 155, 169 Beaver, 171, 172, 261 Bedbug, 154, 236 Beech, 59 Bees, 152, 153, 158; honeybee, 157 Beetles, 20, 21, 153-156, 317, 318 Belladonna, 73 Belted kingfisher, 46 Benzine, 165 Bindweed, 71 Biological library, 16, 17; using of, 349-351 Biology, instruction and research in, 346 Birch, 59, 83, 84 Bird Day, 299 Bird fountain, 29 Birds, 22-53, 313, 317 ; adaptation of, to environment, 37 ; attracting, 28, 31, 33; conservation of, 53; destruction of insects, 23, 24, 25 ; divisions of, 32 ; economic value INDEX :iO.") of, 24 ; food of, 24, 25, 30, 34, 42 ; food chart, 33 ; methods of bird study and special problems, 35- 53 ; migration, 20, 30, 31 ; niunbcr needed, 28 ; orders of, 22, 37-53 ; outdoor laboratory ^vork, 2531 : plan of course, 23 ; topics for study, 31,32; topography of, 37; Nvintcr feeding of, 31 ; work suggested, 31 Bison, 169, 171 Bitter rot, 210, 212, 213 Bittersweet, 7f> Bivalves, 274 Black basses, 30'.» IJlack carpet beetle, 154 I'.lack cherry, 59, 75 Black deatli, 175, 177, 238 Black flies, 113 Black gum, 50 Black knot, 207 Black mustard, 70 Black nightshade, 76 Black rot of cabbage, 212 Black snakes, 326 Black walnut, 50, 60. 82, 88 ; i-irtun-s of, 61, 66 Black-and-white warbler, 50 Blackberry, 04 Black-billed cuckoo, 46 Blackbirds, 34, 48 Blackleg, 248 Blight, on bean, 215; tire blight, 212 : on pear and apple, 212. 218; on potato, 210, 215 Blister, or oil, beetle, 15r. Blood, good and bad, 344 Blood-sucking conenose, 164 Blowfly, 154, 318 Blowing adder, 32(5 Blowing viper, 327 Blue crabs, 287. 202 Blue jay, 48 Blueback salmon. 809 Bluebird, 4'.», 51 Bluebottle, 112, 154 Bluegill, 290, 306, 307, 8t)'.' Blue-tailed lizard, :^25 Bobolink, 48 Bobwhite, 34, 11. »-'. 5:;. MVJ Body lou.se, 154 Boils, 233, 234, 286, 248 Bollworm, 156 Bordeaux mixture, 209, 217 Borer beetle, 155 Botflies, 113, 157 Bovine malaria. 257 Bovine tuberculosis. 1 jo. 228 Box tortoise, 324, 825 Bright's disease, 232 Broad-leaf laurel, 75 Bronchitis, 234, 235 Bronzed grackle, 48 Brook trout, 309 Br< >oks*s law, 291, 292, 308 ; applied to food and game fi.shes, 308 ; apj^lied to the lobster problem, 28(5, 291, 292 Brown creeper, 51 Brown rot, 207, 2lo. 211 Brown thrasher, 51 Brown-tail moth. 20. 156. 160-162 Bubonic plague, 2. 107. 175-177. 215. 234, 248 Bugbane, 76 Bull thistle, 71 Bullfrogs. 318, 815, 81«;. 817. 819 Burdock, 71, 72 Burrowing roots! ocks. 71 Butter i-laiii. 278 Butterflies. liVJ; rabbage, 21. 18«5-140 Butterimt, 59 Cabbage, 94, 98; black rot of, 212 Cabbage butterfly, 21, 186-140; con- trol. 138-140; disi.ers;\I. 137; fe- cundity, 186; life history. 186 187: natural i-neniies. 1."J<1 366 CIVIC BIOLOGY Cabbage caterpillar, 25 Cabbage looper, 156 Cabbage and radish maggot, 156 Cabbage worm, 156 Caddis flies, 153 Calcium, 98, 99, 100 Calcium chloride, 249 Calico bush, 75 Calico mosquito, 127 California poison sumac, 75 Camel, 261 ; itch mite of, 166 Campaign, anti-fly, 119, 120; anti- mosquito, 134, 135 Camphor tree, 73 Canada goose, 39 Canada thistle, 71 Cancer, 232, 234 Canker, 215 Cankerworm, 50, 51, 155 Cannas, 86 Caper spurge, 76 Carabid beetle, 317 Carbolic acid, 71, 249 Carbon, 98 Carbon bisulphide, used in destroy- ing rats, 181 Carbonic acid, 187, 191, 194, 195 Cardinal flower, 67, 154, 306, 307 Carpenter ant, directions for study of, 146, 147 Carpet beetle, 154 Carrot, 105 Casein, 189 Case-making moth, 154 Cases, insect-rearing, 10 Cashes, 75 Cat, 165, 182, 256, 263, 267 ; relation of, to diphtheria, 245, 246 Catbird, 51 Caterpillar, 45 Catfish, 306, 307, 309 Cattle, 171 Cattle tick, 167 Cedar, 83 Cedar wax wing, 50 Cephalopods, 274, 284 Cerebral hemorrhage, 232 Cerebrospinal meningitis, 248. See also Meningitis Cestodes, 260, 262 Chameleon, 325 Chara, 307 Cheese, Camembert, 189; Limburger, 189 ; Roquefort, 189 ; Stilton, 189 Cheese or ham skippers, 154 Cherry bird, 50 Cherry louse, 156 Chestnut, 59, 60, 82, 83 Chestnut-bark disease, 215 Chewink, 49 Chickadee, 50, 51 Chickens sick with limber neck, 122 Chicks killed by rats, 174 Chickweed, 70, 71 Chiggers, 165 Children's bane, 75 Chimney swift, 47 Chinchbug, 42, 156 Chinese pernicious scale, 156 Chinook salmon, 309 Chipping sparrow, 47, 49 Chlorine, 98, 114 Cholera, 107, 235, 236, 245, 248; fowl, 110, 233 ; hog, 110, 248 Cholera infantum, 20, 107 Cicadas, 153 Cinchona, 73 Citronella, 128 Civic biology, definition of, 1 ; plan of course, 3-9 Civic fly campaign, 119, 120 Civic forestry, 55-66 Clam, 274 ; butter, 278 ; gaper, 278 ;' giant, 278 ; hard, 273 ; life history of, 278, 279 ; little-neck, 277; razor, 273 ; soft, 273 ; surf, 273 INDKX 3«;t riiff swallows, 40 Clothes iiKttlis, lo-l Clover mite, 1()0 Cluster fly, 154 Clydesdales, 338 Coal oil, 71 Coast newt, 320 Cobra, 327 Cocaine, 343 Cockles, coiulis of, 273 Cockroaches, l.")3, 154. Sec also Koaches Cod, 30! > Codlingnioth,21, 155; typeforstudyj; Coffee, 344 Cold, 233, 234, 240, 250. 251 Cold storage, 2()0 Coleoptera, 153 Collecting nets, 12 Colorado blue spruce, 83 Colorado potato beetle, 15(5 Connnon stramonium, 75 Conchs, 273, 274 Concord grapevine, 339 Condiments, 71 Conifers, 51) Consumption, 234 Contact infection, 240 Coontail, or horn wort, 307 Cooper's hawk, 45 Copepods, 287, 288, 280 Copperas, 114 Copperhead, 322, 327 Coral snake, 328 Corn, 03, 94, 95 Corn cockle, 75 Corn snake, 320 Corn-ear and tomato worm. 15(; Corn-root ajihis, 15(5 Corrosive sublimate, 240 Cotton, 93; pests t)f, l.'.r, Cotton worm. 15(5 Cottoinnoutli. ;;27 Cotton wootl. 59, 1(55 Cottony cusliion scale, 20, 15'i Cottony iiiai)h' seal*'. 15«5 Couch grass, 71, 72 Cow, 102, 1(J3, 1(55, 2(W Cowl)aii«', 75 Cowbini, 47, 48 Cow pox, 258 Cowslip, 30(5, 307 Crab, 287,292-294 ( lab apple, H2 Crappics, 30(5, .300 Crawlish, 287, 293, 294. :]()*'>, ;;((7. 317, 318 Crested flycatcher, 47 ('rickets, 153 Crimson Hamblcr rose, 97 Crocodiles, 321. 323 Crocus, 197 Crops, standards an Forest flre.s, cause.s of, r»l. «;4 ; ilam- age from, 55, 02, 04; laws regulating. 00; relation of, Ui tree-planting, o.'> Forest preserves, 171 Forestry, annual growth of trees, 55 ; consumption of wood, 55 ; eflfect.s of adetiuate planting, 57, 58 ; natural enemies of trees 15<5; .study of local problem.s of, 58 ; study of trees and civic viewpoint. 54-00 Formalin, a.s germicide, 249 ; u.se of, to prevent potato bliifht, 210 Formicary. 145 Ft)ul brood. 288 Fowl cholera. 110,238 Fowl tuberculosis. 110 Fox sparrow. 49 Foxglove, 78 Foxtail, 70 Fresh-water mu.s.sel. 278. 279. 2S1 Fringed gentian, 07 Frog, 39, 800, 818, 814. 815. 817. .118. 820; i)ossibilities of culture, 81 H Fruit tly, 154 Fungi, 78. '.»7. 18tl-191 ; bactorisi. general treatnient of. 218-251; fungou.s and bacterial diseases of plant.s, 207 217; molds and mil- dew.s, 197-199; mu.slirooms. jmm- sonousand edible. 200- 2rw5 • x . ,t'. 25 Household insects. 1'.}. 155 Hydrotren, 1»8 Hydro])hobia, 250 Hymenoptera. 153. 15(*» Hypochlorites. 240. 251 Hy])oclilorons acid. 2 1'.' Human tlea, 154 Human mite, UHi Human tapeworm, 2>»0 Hummini; l)ird. (i, 40 Humminy-binl moth. i.')5 Ichneumon tly. 18<» Imported currant fly. 21 Indian corn, 05 Indian pipe. 188 Indian poke. ~i\ Indian-meal moth. 155 Indii^o l)untini:. 4t» Infantile paralysis. 20. 122, 230, 250 Infection, llo. 122. 24«; Inflannnation, 284, 280 Inflanunatory fever. 248 Influenza. 285 Insect-catchintr bottle, 181 Insecticides, 152 In.sectivorous biril>. 44 Insects. 44. 51. 1)7. 1 TC. -j.-.d. j:a, 818. 815: attackinj: animals. 157; lH»ne- flcial, 157; cases for mounting. 1 1 ; cla.s.sifl('ation of. l')<». I'.I. 152: (Iamai,'e and lo.s.s from. 10.20,24; fecundity of. 18; hou.sehold, 154. 155; injurious to vejretation. 155, 15(>, 157; literatun* on, 140; nets for catchiiii:, 11. 12; orders of, 15:^; parts of, 152; size of, 18; work of, 18: Work of controllini:. 20 heland, famine in. 208 Iri.s. 8() Iron. 71. OS. '.»'.> Iron Wood. 50 Itch mites. IC.C. ItchwetMJ. 7ti Ivy. 75. 7'> Ivy wo(»d, 7."» .lack pin«', 50 Jamestown lilv. 75 372 CIVIC BIOLOGY Jamestown weed, 75 Japanese maple, 83 Japanese quince, 89 Japanese snowball, 89 Jays, 48 Jimson weed, 72, 75 Jukes family, 345 Junco, 49 June beetles, 153, 150 Kallikak family, diagram outlinin,': history of, 342 Kalmia, 75 Kangaroo, 261 Kerosene, remedy for dog tick, 168 King cobra, 328 Kingbird, 47 Kingfisher, 46 Kinglets, 51 Kissing bug, 154 Laboratory, outfit of, 10 Laboratory work, outdoor, 25 Lacewings, 153 Lady beetle, 153; Chinese, 20-21 Lady's-slipper, 67 Lamb's-quarters, 69, 70 Lamellibranchs, 279 Lancaster elm, 78, 79, 80 Land, relative value of, 100, 101 Land salamander, 315 Land snail, 283 Landscape gardening, 77-90 Larch, 83 Larder beetles. 155 Lark, 34, 48 Larkspur, 70 Late blight, or rot, 216 Laurel, 75 Lawn, 71 Lead acetate, antidote f(jr poison of ivy, oak, and sumac, 74 Leaf spot. 212 Leaf-eating sawHies, 157 Least flycatcher, 47 Leghorn, white, 104 Legumes, 188, 222 Lemna, 307 Leopard frog, 315, 316, 319 Leprosy, 107, 234, 251 Lettuce, 94 Library, using of, 349 Lice, 153, 154 Life, practical law^s of, 330-345 Lilies, 86 Lily, 94 Limber neck, chickens sick with, 122 Lime, 99, 100, 102, 223 Lincoln, 92, 95 Linden, 82 Little black ant, 155 Little house fly, 112 Liver fluke, 261 Lizard, 321, 323, 325 Loblolly pine, 59 Lobster, 286-294 ; propagation, 289 Lockjaw, 234, 248 Loco weed. 73, 74 Locust, 59, 82 Loggerhead turtle, 324 Long-leaf pine, 59 Loons, 38 Louse, 154, 156 Lupus, 234 Li/copeydacecu, 203 Lynxes. 169 Magnesium, 98, 99 Magpie, 48 Maidenhair fern, 67 Malaria, 20, 123, 124, 125, 134, 236, 252, 254 ; bovine, 257 ; prevention of, 133, 257 Malarial mosquito, 154 Malarial parasites, 256, 257 Mallard duck, 39, 306 INDKX MamniiUs. 84. 107, 17(); Auiorii'iin Maiiimal l'rul)lenis, 1(V.)-172 : orders of. with pictures of liabi- tats, 170 Man, 17<) MaiiiraiR'se. 1>8 Maiuirc. barnyard, 70 ; disposal ot. 115 ; relation of. to tlics. ] 14. li:, -Maples, ;V.l, 88 Mari.t,^old, 8(> Mark weed, 7o Marsh hawk. 45 Mars! I wren, 51 Martin, 41», 171 Massasauoas, 827 Mayweed. 70 Meadow lark, 48 Meal worm, 155 Measles, 36, '215. 282. 288. 280, 280. 247, 250 Medicinal plant.s, 71 Mendel's law, 380, 387. 844. 845; diagram iilustratinu. 885, 888 : history of, 880 Meningitis, 107, 234. .Scr nl.so Cere- brospinal meningitis Meningococcus, 234 Mercuric acid, cure for i)otato seal). 210 Mercuric chloriib-. 240 Mercury, 75 Miasms, 287 Mice, 30, 34, 44. 174. 1h-j. l,s8. 184. 185, 245, 2f;7 Mildew. See Molds Milk, pasteurizing of. 244 Milkweed, 00. 71 Minks, 1(50 Mission grape, 85 Mites, 103-108, 280; clover mite. '65; harvest mite, 103, 105; itch • lite, 106; poultry mite. 167; red '.aite, 129; .sheep-.scab mite. 1(50 Mocca.sins, 327, 328 Mocking bird, 50, 51 .Molds anerimentswilh. lit* Mi>\{- i»h»nt, 70 Moles, 80. 1(55. 171 Mollusca, cbissilicatii.il <>i. l'7I .Moliu.sks, 271-2H4 Mongolian, or iiiifr-necke(». 111. 11.;. IP... 123-135. 153, 154. 101. 1H2, 23»i. 24(>. 2.'».3. 257. 332 ; bree. 250, 251 Poison ash. 75 Poison eldei-, 75 Poison hendoek. 72, 75 Poison ivy. 74. 75 Poison laurel, 75 Poison oak, 74, 75 l*oison root, 75 Poison snakeweed, 75 / Poison sumac, 74. 75 Poisonous i)lants, damage from, 73; list of, 75, 70 Poisonous snakes, 110, 327-329 Pokeroot. 70 Pokeweed. 75 Poliomyelitis. 122 Ponds, as balanced aijuaiia. 304 ; possiltle i)roduction from. 307 I'ol)lar. 105 Porpoises. 109 Potash, 102. 223 Potassium, 90, 9H. 99. ]n0. 101 Potato, 93, 97; blight or sc:ib of, 210. 215 Potato beetles, 42, 153 Poultry. 103. 104 Poultry mite, 107 Pout, 300 Praiiie chicken. 53 Prawns, 28 7 l»roteans. 313 I'roteiii. 1S7. 189 I'roto/.oa. 255, 250 376 CIVIC BIOLOGY Fuerperai fever, 234 Puffballs, 189, 191, 203, 206 Pulmonary tuberculosis, 249 Turple beech, 83 Purple cornliower, 73 Purple tincli, 49 Purple martin, 49 Purslane, 69, 70 Quack grass, 72 Kabbit, 169, 261 Kabid dogs, 110 Kabies, 248, 256 Kagweed, 70 Kailroad worm, 156 Rainbow trout, 309 Raspberry, 94 Rat snake, 326 Rats, 30, 34, 44, 245, 267, 332; damage from, 2, L74, 175, 176; extermination of, 3, 177-184; fecundity of, 2, 173; poisoning of, 179, 180, 181 ; problem of, 173-185; trapping of, 177, 178, 179, 182, 184, 185 Rattlebox, 76 Rattlesnake, 253, 322, 327, 328 Red ant, 155 Red buckeye, 75 Red cedar, 59 Red gum, 59 Red mite, 129 Red pepper, 73 Red pine, 59 Red spider, 163, 164 Red-backed salamander, 316 Red-eyed vireo, 50 Red-headed woodpecker, 46 Red-humped apple-tree caterpillar, 156 Red-legged locust, 156 Red-shouldered hawk, 44, 45 Redstart, 50 Red-tailed hawk, 45 Red-winged blackbird, 48 Reptiles, 321-329 ; products of, 321, 323 Rheumatism, 233, 234, 236 Rhinitis, 234, 235 Rhizopus, 198 Rhododendron, 76 Roaches, 245. See also Cockroaches Robin, 51 Rock bass, 306 Rock pine, 59 Rocky Mountain spotted-fever tick. 167 Rodents, 326 Root gall, 212 Root knot, 265 Root rot, 211, 212 Root tubercles, 188 Eosa nigosa, 89, 97 Rose, 86, 94, 97 Rose chafer, 156 Rose slug, 157 Rose-breasted grosbeak, 49 Round-headed apple-tree borer, 155 Roundworms, 264, 265, 266 Ruby-crowned kinglet, 51 Ruby-throated humming birtl, 47 Ruffed grouse, 41, 42, 52, 53 Rum cherry, 75 Rust, 186, 207, 210, 212 Sable, 171 Saccharomycetes, 191 Salamanders, 313, 316, 319, 320, 325 ; enemies of mosquitoes, 131 Salmon, 309, 310, 311 San Jose scale, 20, 69, 152, 156, 158, 332 ; fecundity of, 18 Sand flies, 113 Saprolegnia, 305 Saprophytic bacteria, 221 TXDKX :3TT Sapsncker, 40 Siiwtiit's, 1');^ Sayorni.s plin-bi', 47 Scab, on apple, 212 ; on in.tatn. 2l(i Scale insects, 158, 1")() Scallops, 273, 274, 277 Scarlet fever, 177. 2;{2, 288. 28('», 281), 243, 24o, 24(), 247, 2.')1. 2:)(; Scarlet tanager, 25, 40 Schick reaction, 251 Scientific organizations, journals of, 352, 353, 354 Scorpion, 1G3, 1<»4 Screech owl, 45 • Screens, cost of. 20 Screw-worm fly. 118, 157 Scrub pine, 50 Scurvy scale, 15(5 Sea nuissels, 271, 272, 278. 275; pic- ture of beds of, 270 Seed, 188 Selection and survival of the fittest, 330 Seneca snakeroot. 78 Septictemia, 284 Serum, 248 ; antitoxic sera for snake poisons (antivenins). 820 : Floxner's antimeningitis. 111; w- sistance of. 240 Sliad, 20(i, 800. 810, 811 Shagbark hickory, 82 Sharp-shinned hawk. 45 Sheep, 257, 2(58; itch iiiitc of, IOC; liver fluke in, 20)1 Sheep botfly, 1 57 Sheep laurel, 75 Sheep-scab mite, 108, lOiO Shepherd's-purse, 70, 71 Shetland ponies, 333 Shore bird, 40 Short-leaf pine, 50 Shrikes, 30, 84. 50 Shrubs. 84. 8(5 Silicon, 08 Silver fox. 172 Sirens, 818. 814 Si.struru.H, 827 Skink. 325 Skunk, 1(50. 25(5 Sleejting sickness. 28«; Shig, currant. 157: pear, 157; nnw, 157 Slugs, 282, 283. 815; eaten by »x)X tortoise, 325 Small laurel, 75 Smallpox. 107. 211. l';;8. 1'80. :;;;;, 247, 251, 25(5 ; control of. by vacci- nation, 258. 250 Smart weed. 70 Smuts. 18(5, 2(»7, 2ln: ..n c,,rn. 218. 21(5 : on oats, 212 Snails. 274. 288 Snake venom, treatment of, 320 Snake.s, 40, 821. 828: numlxT of species of. 82(5; ]Miis4>nous, 110, 327-328 Snakeweed. 75 Snapping terrajiin. 824 Sneeze weed. 7(5 Snowball, 07 Sno\v-on-t he-mountain, 70 Society for the rn.tt it ion ..f N'.ntive riants, (57 Sodium. 08 Sodium chloride. 240 SiMliuni hyi»ochlorite. 240 Soft, or long-necked, clam, 270. 278 Soft-shelled terrai)in, 325 Soil, elTt'cts idemic of. 241 : p-hiti f tlirty hands to, 25«) Typhoid fly, 107, 112; life liistor>- of, 113. Sec tiiso House fly Typhoid Mary, 242 Typhus fever, 23«}. 25'enom(tus snakes. 324 \'ermin. 245 \'inegar e«'ls, 2<>5 \'ines. 87 ; relation of. tt> landsfa]H' gardening. 87. 88, 80 \iosca"s ]>igeon. 43 ^'iper. 327 Vire<.s. 48. 50 \'irginia scrub pine. 50 Vivaria. 10, 131 Walking sticks, 15:J Walnut. Set Hlack walnut Wapata. 307 Warblers, 48. 60 380 CIVIC BIOLOGY Warbling vireo, 50 Wasps, 153 Water beetles, larvai of, 131 Water bugs, 153 Water cress, 306, 307 Water hemlock, 73, 75 AVater lilies, 306, 307 Water snakes, 326 Waterfowl, 38, 39, 40, 45, 324 Wax wings, 50 Weasels, 169 Weeds, 67-76; adaptability of, 70; classes of, 70, 71 ; damage from, 68 ; destruction and control of, 34, 69, 71 ; medicinal, 71, 72 Weeping willow, 84 Weevils, 155, 156, 317 Western little-neck clam, 278 AVestern prairie chicken. 42 Whale, 169 Wheat, 93, 94, 95, 97 Whippoorwill, 47, 129 Whistling swan, 39 White ants, 153, 155 White ash, 82 White cedar, 59 White diarrhea of chicks, 233 White elm, 59 White hellebore, 76 White man's plant, 75 White pine, 59,' 84 ; type for study, 4. 5, 6 White-breasted nuthatch, 51 Whitefish, 309 White-marked tussock moth, 156 White-throated sparrow, 49 Whooping cough, 232, 234, 247 Wicky, 75 Widal reaction, 251 Wild boar, 263 Wild carrot, 71 Wild cat, 169 Wild celery, 307 Wild cherry, 75 Wild duck, 53, 325 Wild onion, 71 Wild rice, 307 Wild rose, 86 Wild sago, 307 AVild trout, 305 AAlld turkey, 42, 53 AA^illow^ 59, 307 AAHson snipe, 40 AA^ilson's thrush, 51 Wilt disease, 212 ; bacterial blight, 215 ; stem blight, 216 AVindow flytrap, 108, 109 VA^ode-whistle, 75 AA^olf, 169, 256 ; itch mite of, 166 AA^olfsbane, 76 Wolf's-milk, 76 AA' olverine, 169 AA^ood duck, 39, 40, 306, 307 AA^ood frog, 315, 316, 319 Wood laurel, 75 AA^ood pewee, food of, 24, 47 AVood thrush, 51 AVood ticks, 1(55, 168 AA^oodcock, 40 AA'oodpecker, 7, 46 AA^oolly apple louse, 156 AA^'oolly loco weed, 76 AA'orms, 51, 315 AA'ormseed. (iO AA^rens. 50 Yeara. 75 Yeast, 186, 189-197 ; a cause of dis- ease, 197 ; description of, 191, 192 ; distribution of, 192 ; pure aulture of, 195 ; uses of, 194 Yellow fever, 20, 123, 124, 126, 134, 233, 236, 240, 253, 254, 256, 258 Yellow perch, 309 ; topography of, 298 Yellow pine, 59 1M)KX 381 Yellow i)()i)lar, 51) Yi-llow-tliroan-il vin*<.. ;,<) Vt'llow \v;irl)lt'r, 50 Yellow woolly bear, 155 Zno fjuiiily, .'i45 Yellow-billed cuckoo, 4<» Zinnias, Hit Yellow-fever mosquito, 124. 1l'5 Zoological parks, 171 «««","?^. «^sU"c-w» <^ North Carolina State University Libraries S02776829 Q