5 foes SEs = I ia it i i mit He fk it} rit HLA iit La H ts ee a i ni ai i Hea G iH Ui if i art i if ee att earth ca fait i ii eal ia ileal fee i CORNELL UNIVERSITY. THE Roswell P. Flower Library THE GIFT OF ROSWELL. P. FLOWER FOR THE USE OF THE N. Y. STATE VETERINARY COLLEGE 1897 8349-1 Cornell University Library QH 317.H94 Laboratory pr WO 3 1924 000 967 525 vet Cornell University Library The original of this book is in the Cornell University Library. There are no known copyright restrictions in the United States on the use of the text. http://www.archive.org/details/cu31924000967525 LABORATORY PROBLEMS IN CIVIC BIOLOGY BY GEORGE WILLIAM HUNTER, A.M. HEAD OF THE DEPARTMENT OF BIOLOGY, DE WIIT CLINTON IIGH SCHOOL, CITY OF NEW YORK AUTHOR OF ‘‘ ELEMENTS OF BIOLOGY,’ ‘‘ ESSENTIALS OF BIOLOGY,” ‘A OIVIC BIOLOGY,’’ ETC. AMERICAN BOOK COMPANY NEW YORK CINCINNATI CHICAGO Copyricut, 1916, BY GEORGE WILLIAM HUNTER. ALL RIGHTS RESERVED. HUNTER LABORATORY PROBLEMS. w.P. 2 | 4/94 Dedicated TO MY PUPILS WHOSE INTEREST AND ENTHUSIASM HAVE GIVEN RICH SUGGESTION FOR THE CONTENTS OF THIS BOOK I. PROBLEM CONTENTS Foreworp TO TEACHERS DIRECTIONS TO THE STUDENT FOR Kxrrpine Norges in Brotocy II. Tue Environment or PLants AND ANIMALS 1. To determine the factors of environment ox R09 bo Comparison of a natural with an artificial environment . To test my home environment 5 To learn the conditions of my city environment To determine and to illustrate by a graph the changes of ernapenaiide (one of the factors of the environment) during a given day . 6. To make a graph to show how much fluid I take into my body in a day 7. May environment influence public health? . : III. Tue Inrerrevations oF PLants anD ANIMALS . 8. A field trip ‘ 9. How to know an snNeek - ‘i ‘ 10. To learn to recognize insects that frequent fiewaning silania, 11. Td study the life history (metamorphosis) of an insect 12. To learn the structure and work of the parts of a flower 13. The cross-pollination of flowers 14. To study cross-pollination in butter and eggs 15. Special directions for the study of some fall flowers (Extra) 16. To find other pollinating agents besides insects IV. Tue Functions anp Composition or Livine Tunes 17. The uses of the parts of a plant 18. To study the needs and uses of the parts ats a living sitll, (Study of compound microscope) . 19. To determine the unit of structure in plants and sated 20. To determine some of the properties of protoplasm 21. To study structure and growth of pollen é 22. To study the reason for the growth of pollen grains in flowers 23. To discover how fruits are formed : ; 24. How and why fruits and seeds are scattered . 7 c 5 46 6 CONTENTS PROBLEM V. Puiant Growty anp Norririon. Causes oF GRowTH 25. To find the relation of the embryo to the food supply . 26. 27. 28. 29. 30. 31. 382. 33. 34. 35. 36. 37. 38. 39. 40. 41. 42, 43. 44, 45. 46. 47. 48. 49. 50. To test for starch . To test for grape sugar To test for fats and oils : To test for proteins or nitrogenous foods To test for the presence of mineral matter Seen To test for the presence of water . To test various food substances for the organic nntHentd (Home TS To show how much water is needed to make a seed germinate (Home experiment) 4 To determine the icalseeinte best fitted to cause peas to gaumtnate (Home experiment) To show that seeds need some part of the air in eniiee 2 crow To show that food is needed by the embryo in order to grow Is any part of the air necessary for combustion? (Demonstration) To test for oxygen (Demonstration) : To test for carbon To test for carbon dioxide To prove that organic substances are ‘ettticell eithin the Hadi: body To prove that growing seeds oxidize food To study the fruit of the corn plant To study the structure of a grain of corn To find the use of the endosperm of the corn grain To find whether starch or grape sugar will dissolve in water To find how the young plant makes use of the food supply. Digestion What changes take place in starchy foods in the mouth? (Demon- stration) Conditions necessary for the action of diastase What is the reason for digestion of starch in the corn grain ? VI. Tue Orcans or Nurrition 1n Puants— THE Soi, AnD ITs RELATION TO THE Roots. . To find out the structure of roots . . To determine the influence of gravity on whe dinetint of eoweh of roots . To find the effect of water on she ee of roots . To study the structure and purpose of root hairs . To discover how fluids travel through roots and stems . To find out how root hairs absorb soil water : . To determine what kind of substances will pass shrieks a saves bon ane . . To test organic material in soil . To find what kind of soil holds water Best 65 76 CONTENTS PROBLEM 60. What do plants take out of the soil ? z 61. How are root hairs able to take mineral matter eit of hi ail ee 62. What are root tubercles and what is their use ? 63. 64, 65. 66. 67. 68 69. 70. 71. 72. 73. 74. 76. 76. 77. 78. 79. 80. 81. 82. 83. 84. 85. 86. 87. 88. 89. What is crop rotation and what is its use? . What roots are useful as food ? VII. Prayt Growtu anp Nutrition—Prants Make Foop To prove that water is given off by a green plant ‘ 3 Through which surface of a leaf does transpiration take place ? To determine how the structure of a leaf fits it for the work it has to do To study the microscopic structure of a leaf To show the effect of light on green leaves To determine the relation of light to the presence of spain in a green leaf ‘ Is a part of the aira factor in scctandh mites in Tenge 2 The need of chlorophyll for starch making To consider the leaf as a manufactory . To show that a gas is given off as a waste produce when green plats make starch VIII. Prant Growrsa anp Nutrition — THE CrrcuLation AND Finat Uses oF Foop sy Puants . Groups of plants told by the structure of their stems To study the structure of a woody stem To prove that liquids rise through stems aview) To find out through which part of a woody stem food aases dein How plants with special digestive organs get their nitrogenous food IX. Ovr Forests, tHerr Uses anp THE NECESSITY FOR THEIR PROTECTION To determine how lumber is cut and how to recognize the cut in trim To determine some uses of stems To determine the value of certain woods Museum trip for study of woods To identify common trees by the use of a key XK. Tue Economic RELATION OF GREEN PLants To Man To determine the economic importance of some green plants To learn to know some green plants harmful to man XI. Puayts wirsoutT CuLoroPHyLi IN THEIR RELaTIoN TO Man To determine the relation of fungi to the destruction of certain trees To determine the conditions favorable for the growth of mold To study the structure of bread mold 94 106 106 107 110 111 112 112 8 CONTENTS PROBLEM 90. What is fermentation and what causes it ? 91. To learn to recognize yeast plants under the compound rdinseseane 92. Do yeasts grow wild? . , 93. To determine the conditions favaxatile to iia ran of yaaa 94. What are the conditions favorable for the growth of yeast in bread ? (Home work) 95. How we proceed to the study of padberti 96. How to prepare culture media 97. To demonstrate a pure culture 98. To determine where bacteria may be fond 99. To study how rapidly bacteria grow 100. What foods are preferred by bacteria ? 101. What effect has heat upon the growth of bacteria ? 102. To note the effect of moisture and dryness upon the growth of factants (Home problem) 103. To determine the effect of pustenniadition upon ike heaton quality of milk 2 104. How to care for milk battles at home z 105. To determine the bacterial content of milk 106. To determine some of the most effective preservatives 107. To determine the most effective disinfectants XII. Tue Revations or Prants to ANIMALS i 108. To study some eee relations of plants and animals in a balanced aquarium - 109. To learn what we mean by the caaicen and ihe oxygen sepelen 110. To find out the course of nitrogen in its relation to plants and animals 111. To prove a hay infusion is an unbalanced aquarium . XII. Srneve-cettep ANIMALS CONSIDERED AS ORGANISMS 112. To study a one-celled animal in order to understand better (a) its reactions to stimuli; (b) the cell as a unit of structure 113. Comparative study of various forms of single-celled animals to explain division of labor (Extra problem) XIV. Division or Lasor. Tue Various Forms or PLANTS AND ANIMALS 114. 116. 116. 117. 118. 119. How the plant kingdom is classified To compare reproduction in plants with that in entinats To study the division of labor in tissues and organs To find some of the functions common to all animals . How to know some types of animals in the animal kingdom XV. THe Economic IMporTANCE OF ANIMALS What animal foods are cheapest in any locality and why ? (Home work) . . : . . . . i CONTENTS 9 PROBLEM PAGE 120. How animals may benefit mankind . 3 ; ‘ ‘ . 148 121. To find out how birds are of economic iaportanes : & 5 . 148 122. What are the causes of decrease in the number of birds? . 4 . 149 123, To study the life history of the mosquito . : 149 124. To find the breeding places of mosquitoes in any focally anti how . destroy them ‘ : ¥ ‘ . 161 125. To determine some mattiod of destroying masquiiass : - . 161 126. To find the relation of mosquitoes to diseases of man G . . 162 127. To study the life history of the parasite causing malaria. 7 . 152 128. To study the life history of the typhoid fly : 153 129. To determine the harm done by the fly and the way it does this: fier 154 180. What is the best way to catch and destroy flies? (Home work) . 155 131. To determine harm done by insects . : ‘ : . 155 1382. To know some forms of animal life that cause disease! . . 156 XVI. Tue FisH anp Froe, an InrRopucTORY Srupy OF VERTEBRATES . : ‘ : . 159 133. To determine how a live fish is fitted for life . , ) ‘ . 159 134. To study food getting by the fish 5 3 5 . 3 : 161 135. To study the sense organs of the fish . ; P : 5 ‘ . 161 136. To study some of the internal organs of a fish . bs 161 137. To study the skeleton and central nervous system of the fish (Pstra) 162 138. How fishes are artificially propagated . 5 163 139. Trip to the aquarium (Optional, in place of Problems: 133 an 138) . 163 140. To determine some adaptations in a living frog . : . . 164 141. Adaptations of appendages for locomotion . - z - : . 165 142. Adaptations for sensation . . ‘ F ‘ ‘ ‘ ‘ . 165 143. Adaptations for food getting : ‘ z 3 : é ‘5 » 165 144. Adaptations for breathing ‘ ‘ 165 145. Museum trip to study the frog group (Hixtea pein taeed on daly to American Museum of Natural History) . é . ‘ . 166 146. To collect and study frogs’ eggs . ‘ F . 167 147. To study conditions favorable for development of fogs! eggs. - 168 148. To study the metamorphosis of the frog. : . 168 149. To work out a comparison of development of the venienraten ‘ . 169 XVII. Herepity, Variation, PLant anp ANIMAL BREEDING . 173 150. To determine if there is individual variation in any one measure- ment of the members of a given class . : 7 s : . 174 151. To show variation ina given class. é : r . 4 . 176 152. Does heredity play any part in our lives? . f 3 : 3 . 177 158. To study the fine structure of an egg cell . is a : F . 178 154. How selection is made . 4 7 r . : 5 ‘ . 178 155. A practical result of selection . ‘ . . . F * . 179 10 CONTENTS PROBLEM 156. To determine some means of selection of fruit trees from the economic standpoint ‘ 157. How hybridization is avabenpliseed in Rowers plants 158. Other methods used in plant breeding 159. To determine the working of Mendel’s Law 160. To determine some means of bettering, physically ned siepmatanies ihe human race . 161. Are good mental parts or “qualities ‘eapunts of (omarion fron parent to child ? 162. Does control of our environment ie anyelitng 6 fio wt the pitti lem of race betterment ? XVIII. Tue Human Macuiyne anp its NEEDS 163. To show that the human body is made up of cells 164. To find out some functions of the skin 165. To study the use of the muscles . a‘ 166. To study the structure and uses of the Siateton : 167. To find the relation of muscles to bones in the human os 168. To study the joints of the human body 7 169. To get a preliminary survey of the internal erates of the jin body XIX. Foops anp DietariEs 170. How to determine the nutritive value of food 171. The use of the bomb calorimeter (Optional) 172. To find the value of food as a tissue builder compared with its cout 173. To find the value of food as a source of energy compared with its price 174. To find my daily Calorie requirement ‘ 175. To find the proportion of protein, fat, and cnvanyaeats, decaea in my daily Calorie requirement 176. To obtain my daily dietary with the 100 Cslotie table of Fisher dod to make the necessary corrections in my dietary 177. To compare your day’s total Calories with the estimated vies of a person of your age doing the kind of work which you do 178. To find the relation of the value of food to its cost in the family dietary 179. To study some forms of food sdutaraiot and some means Sof detent ing adulterants , 180. To determine the effect of sledtval upon raw white abe eg: 181. To determine the amount of alcohol in some patent eee 182. To test for acetanilid and to know some patent medicines containing it 183. What are the harmful materials formed in catarrh cures and soothing sirups? . 4 F 8 ‘i f F ‘ PAGE 179 180 181 181 182 183 183 187 187 188 188 189 190 190 190 194 195 195 197 198 202 208 204 211 211 212 213 214 214 215 CONTENTS PROBLEM XX. DicEstion anp ABSORPTION . 184. To compare the digestive systein of a frog with that of man 185. Tostudy my own teeth : 186. To demonstrate the function and structure of a ain Monet 187. To find the use of digestion . 188. To determine the conditions most favor ile for gasitie iecnicn 189. To determine another effect of gastric juice 190. To note the action of pancreatic juice on starch . 191. To note the effect of pancreatic juice on oils and fats 192. To study the effect of artificial pancreatic juice on protein 193. To find one action of bile 194. To study the method and place of Sbemeititin in the een bade 195. To understand the structure of a villus 196. How may foods be absorbed by the villi ? 197. To find the pathway of absorbed foods 198. 199, 200: 201. 202. 203. 204. 205. 206. 207. 208. 209. 210. 211. 212. 218. 214. 215. 216, 217. 218. 219. 220. XXI. Tue Bioop anp 17s CircULATION To prove that blood contains nutrients To study the corpuscles of the blood : To determine the effect of oxygen and carbon dioxide. upon vie ule To study the structure of the heart To study the circulation of the blood . To determine the rate of your own heartbeat What is the effect of hard mental work on the pulse beat ? What effect has exercise on the heartbeat ? F How to stop the flow of blood in case of an accident . XXII. Respiration anp Excretion To compare the structures of the lungs of the frog and of man To determine changes that take place in air in the lungs To find the capacity of the lungs ‘ To study the mechanics of respiration To study the part the ribs play in respiration What is the function of the diaphragm? . ‘ F To find out what becomes of the oxygen in the lungs To make a study of ventilation To study air for presence of dust (Home exrevimant): To determine the best method of cleaning a room What makes a crowded, closed room uncomfortable ? To study the structure of the kidney The skin as an organ of excretion and heat utnel XXIII. Bopy Conrroy, anp Hasit ForMATION ‘ r How are we aware of the world about us ? é : é F . 11 PAGE 220 221 222 223 224 224 225 225 225 226° 226 227 227 227 228 232 232 233 234 235 236 237 237 237 238 240 241 241 242 242 243 243 244 244 245 245 246 246 247 251 251 12 CONTENTS PROBLEM PAGE 221. To determine what parts of the body are most sensitive to (a) touch, (6) heat and cold . ‘ ‘ : ‘ . 252 222. To study the anatomy of the nervous sysenh E : . 253 223. To study the structure and use of neurons . 2 ‘ : : . 254 224. What is a reflex action ? ; F : ‘ 254 225. To compare the reaction time of hearing and lauelt : 3 : . 254 226. To compare a reflex action with an act of thought . - 2 . 255 227. To study habit forming : 5 fj A : . 255 228. To study the mechanism of habit thateadiou ‘ ‘ ». » 2656 229. To consider some harmful habits s ‘ ¢ : Fi » BOT 230. How to go to work to form good habits. 257 231. To determine the relation between taste and smell with reletenee io food flavors . i 258 232. How to find out certain detects of vision in ‘the inboranany . 259 233. What are some of the effects of alcohol on the nervous system ? . 269 XXIV. Man’s ImpRoveMENT oF HIS ENVIRONMENT . 262 234. How to ventilate my bedroom (Home problem) . 263 235. To compare the duster and the dry cloth with the aslke cloth in cleaning the schoolroom - F A ; 2 . 268 236. What should I eat for luncheon ? : . i . 264 237. To make a sanitary map of my own enviomient A 265 238. To determine the bacterial content of different grades of milk . . 266 239. To determine the bacterial content of some kinds of water : 267 240. To determine some of the problems of water supply and sewage dis- posal for a city ‘ 2 ‘ . : ‘ . 268 241. Is typhoid a city or a country dinaae ? 269 242. What is the annual cost to New York city of some praventatls diseases? . é ‘ : : . 269 243. What are the chief causes of fienth ina 4 city 3 ‘ . 272 244. To study the relation of the death rate to the season . : 272 245. To find a relation between flies and mortality . ‘ . 272 246. To determine the number of school children who naciled. ereatmnett for different diseases in New York city, 1914-1915 3 A . 273 247. How to discover the presence of adenoids . ‘ ‘ ‘ 274 248. To find some ways of preventing the spread of Sissies : ‘ . 274 249. First aid in the home. A summary of what to do and how to doit . 277 FOREWORD TO TEACHERS Ir has become the fashion in modern pedagogy to teach by the so-called ‘‘ Problem Method,” that is, to attempt to make the child solve problems from the very beginning of his work in the elementary school. But it is one thing to say to the child, ‘‘ Here is your problem, solve it,’’ and quite another thing to lead him through the several thought processes necessary to the solution of the problem. A child of six may be taught to think, and think clearly, if he is guided so that he makes a generalization after comparison with what his senses tell him he knows. The mistaken notion of our educational system has been that drill and drill alone, pure memory work, is only fitted for the mental life of our young children. Nothing is further from the actual truth. The mental growth of the child is an evolutionary growth, but it is a development based more upon his reaction to the world than upon the mechanism within his body. The nervous system and its connectives develop early. Our education of the nervous system, based on the theory that the nervous system is not well developed, makes simply for the formation of concepts. Concept forming and concept enlargement are a necessary part in any scheme of education, but the method and the form of straight thinking are of even greater importance. Problems in life are not solved by knowing dates or facts, no matter how important or interesting these may be. The methods of reaching a conclusion, of weighing evidence, of making decisions upon the merits of the facts in a case, of thinking straight from evidence gained from given data, — these are the habits of mind which are worth far more to a child than the actual impact with the subject matter in a textbook. Hence pure science, the handmaiden of clear 13 14 FOREWORD TO TEACHERS thought, needs emphasis placed on method above all else. And the method of science is best found in the laboratory. Dr. H. E. Walter has well summed up the real use of laboratory work in the following words: “The laboratory method was such an emancipation from the old-time bookish slavery of pre-laboratory days that we may have been inclined to overdo it and to subject ourselves to a new slavery. It should never be forgotten that the laboratory is simply ameans to the end; that the dominant thing should be a consistent chain of ideas which the laboratory may serve to elucidate. When, however, the laboratory assumes the first place and other phases of the course are made explanatory to it, we have taken, in my mind, an attitude fundamentally wrong. The question is, not what types may be taken up in the laboratory, to be fitted into the general scheme afterwards, but what ideas are most worth while to be worked out and developed in the laboratory, if that hap- pens to be the best way of doing it, or if not, some other way to be adopted with perfect freedom. Too often our course of study of an animal or plant takes the easiest rather than the most illuminating path. What is easier, for instance, particularly with large classes of restless pupils who apparently need to be kept in a condition of uniform occupation, than to kill a supply of animals, preferably as near alike as possible, and set the pupils to work drawing the dead remains? This method is usually supplemented by a series of questions concerning the remains which are sure to keep the pupils busy a while longer, perhaps until the bell strikes, and which usually are so planned as to anticipate any ideas that might naturally crop up in the pupil’s mind during the drawing exercise. “ Such an abuse of the laboratory idea is all wrong and should be avoided. The ideal laboratory ought to be a retreat for rainy days; a substitute for out of doors; a clearing house of ideas brought in from the outside. Any course in biology which can be confined within four walls, even if these walls be of a modern, well-equipped laboratory, is in some measure a failure. Living things, to be appreciated and correctly interpreted, must be seen and studied in the open where they will be encountered through- FOREWORD TO TEACHERS 15 out life. The place where an animal or plant is found is just as important a characteristic as its shape or function. Impossible field excursions with large classes within school hours, which only bring confusion to inflexible school programs, are not necessary to accomplish this result. Properly administered, it is without doubt one of our most efficient devices for developing biological ideas, but the laboratory should be kept in its proper relation to the other means at our disposal and never be allowed to degenerate either into a place for vacuous drawing exercises or a biological morgue where dead remains are viewed.” Teaching to think is not a sinecure for the teacher. But by proper use of the laboratory material and the laboratory period, we may make a brave start toward this goal. One preconceived notion of a laboratory period is a. time in which the pupil works alone from his specimen in order to interpret something which you and I know is there but of which he is ignorant. The method of Agassiz may be fitted for the graduate university student, but it must be modified for the immature pupil of the high school. We must throw away our college and high school laboratory conception and place ourselves in the laboratory as a pupil. Be a leader in a discussion which will center around the specimens in the pupil’s hands; present, in connection with the laboratory material, some definite problems relating if possible to some phase of activity of the material in hand, something vital in the mind of the pupil. Lead the discussion (using the printed questiéns that follow, but augment them with others that will naturally arise during the discussion) toward the solution of some definite phase of the problem in hand. Allow conversation among the pupils; get as many ideas from different pupils as you can; pit the brighter ones against each other and the spirit of competition will incite the dull ones to add their mites. But guide the discussion toward a goal, — that is your function as a teacher. Do not be afraid to tell when it is time to give information and do not be afraid to say, ‘I don’t know.” Ultimately the time will come, when the discussion of facts as pupils see them has reached the place where a conclusion may safely be reached. Now is the place for the teacher, again for- 16 FOREWORD TO TEACHERS mulating the problem, to give the class — this time as individual: — opportunity to write their generalizations, or their answer tc the problem, in the form of a good English sentence or paragraph After this is done reading of conclusions by several individual: allows by comparison the fixing of the correct conclusion in the minds of all. Time is thus obtained for rectifying the tanglec ideas of those members of the class less able to cope with the problem. Incidentally, this does away to a large extent witk correcting laboratory papers, as the student, by comparison wit the final corrected conclusion, does his own correcting. This makes for more effective science teaching, as the teacher of science should be a leader, not a drudge. Sometimes a generalization is asked for, perhaps before the pupil is ready for it, for the object is to incite the worker to be something more than a blind reader of directions and a maker o! drawings. An immature conclusion — even a wrong conclusior —jin the form of a generalization, is better for the pupil thar contentment with no conclusion at all. If the child can be stim- ulated to think from the very beginning, then do not worry at first over the exactitude of his conclusion so long as he is trained in the making of judgments. It is the thought process we are after at first, the method of thinking more than the scien- tifically exact result. The latter will come gradually as the hori. zon of the pupil widens. We all know our concepts change What is an exact concept at fourteen would not stand the test at twenty-four or at forty-four. It is a true maxim that experi ence is the best teacher. Be that so, even experience does nol make thinkers of us, unless we know how to profit by her teachings The pages that follow are intended to act as a guide and a stim: ulus to the pupil so that he will be led to see beyond the printec words in the textbook. Many children do not know how to use their text. Diagrams and figures mean nothing to them. The old-fashioned thought questions found in so many textbooks o: twenty-five years ago were of great value because they crystal: lized the problem before the student and focused the attentior on the essentials within a given paragraph. The pedagogic value of questions on diagrams is great. The use of graphs is a pari FOREWORD TO TEACHERS 17 of every educated person’s equipment in life. These factors are strongly emphasized in the working out of the problems of this book. An attempt has been made by the author to be practical as well as logical, and to gain interest through the practical treatment of things that are familiar to the pupil. Whenever possible, techni- cal terms are done away with, and experiments are made as simple as possible without destroying their scientific value. In general, a few large group problems have been made that directly explain the text of the author’s Civic Biology, which this manual is intended to interpret in the laboratory. In addition to these, other secondary but closely associated problems are added with less explicit directions, so as to give opportunity for some mental activity in their solution on the part of the pupil. It is not expected that all the problems are to be attempted in a year’s course in elementary biology, but a choice should be made by the instructor of what he considers the most important for his own particular classes. The author wishes especially to thank Messrs. George T. Hastings, John W. Teitz, and Frank M. Wheat of the Department of Biology in the De Witt Clinton High School for their many helpful sug- gestions and for certain of the exercises and excellent drawings accompanying many of the experiments. All members of the department have in one way or another given ideas to the lab- oratory exercises which follow, and my sincere personal thanks are due to them as well. The author also wishes to make acknowledgment to the various sources from which the experiments and laboratory exercises of the following pages were adapted. Of especial value in this respect have been the numerous publications of the Department of Agriculture, the Bureau of Fisheries, and the various health reports of state and city Boards of Health. The Cornell Uni- versity Reading Course Pamphlets and their Nature Study Leaflets have also been of much service, especially in the work on dietetics. In the laboratory study of dietaries the 100 Calorie Portion Table of Irving Fisher, compiled from the Journal of the American Medical Association, Vol. XLVIII, No. 16, has also HUNTER LAB. PROB. —2 18 FOREWORD TO TEACHERS been useful. For the idea of the biological survey of a neighbor- hood, I wish to thank Professor Clifton F. Hodge, and his sugges- tive and inspiring Nature Study and Life. William H. Allen has kindly permitted the use of some of his excellent tables compiled in Cwwics and Health; to him I also extend hearty thanks. The arrangement of the laboratory problems, previously used by Mr. Sharpe and myself in the manual accompanying the Essentials of Biology, claims no originality except in application. The laboratory problem form was first worked out, so far as I am aware, by Arthur Stone Dewing in a manual prepared for the Knott Apparatus Company. This book adapts the problem method to young students in an urban community. The problem questions given at the end of each chapter follow the old and tried plan of summary questions given at the end of a chapter in a textbook for the purpose of bringing together the important points in the mind of the pupil. These questions are so formulated as to make the student use the material worked over in the laboratory, together with the additional information gleaned from the text, so as to reach definite and clear-cut conclusions concerning the essential points in the chapter just finished. Nearly every laboratory chapter has been prefaced with a few words to the teacher. These are important, as they serve to indi- cate the viewpoint of the writer and the philosophy underlying the various parts of the book. It is hoped that these suggestions may add clarity and help those who use this book to organize their work. LABORATORY PROBLEMS IN CIVIC BIOLOGY I. DIRECTIONS TO THE STUDENT FOR KEEPING NOTES IN BIOLOGY Ir is suggested that two notebooks be used. In one, the home notebook, all written notes, either dictation notes or those looked up from original sources, should be placed. The other, a labora- tory notebook, should be used for drawings and written work done in class as well as experiments and demonstrations performed in the laboratory. The illustrations on pages 20 and 21 will serve to indicate the appearance of a blank page after laboratory work has been done. All written work should be in ink, and great care should be exercised not only in the construction of good English sentences, but also in writing. A careless, slovenly page may spoil otherwise excellent work. Especial care should be exercised in making your drawings. A hard pencil (HHHHH) sharpened to a needlelike point should be used. Do not shade your drawings. Make each line mean something definite. We do not want artistic sketches so much as — we want accurate representations of what you see. Remember a — good workman uses good tools; therefore use a sharp pencil, a clean eraser, and an active hand and brain. Drawing without theught of what you are doing is only busy work and does you no good. Among the most important of your laboratory exercises are your experiments. An experiment should have four steps, each of which is separated from each of the others by a paragraph heading. 19 20 DIRECTIONS TO THE STUDENT The four steps are 1, the problem; 2, the method used; 3, the obser- vations made; and 4, the conclusion reached. farI5146. Cho ony om Haliby : Cen: toe queuing mg Ate.) qe oaidens dvoteades i Hh: Tube of tmewater S: Seedsim saw dust ao a Oleurovatiim: The Under the heading problem you should tell exactly what you are trying to solve ; your method should describe exactly how you went to work to set up your experiment and what you subsequently did; the observations are what you saw (as a result of what you DIRECTIONS TO THE STUDENT 21 did); and your conclusion should be reached only after weighing the evidence you have obtained in your experiment and then ap- John Brown 1° DBiclogy 123 San.” b5 , 1915 /The Stuay of the Bean Seed. © Ls Che bean seed 18 madeupof two parts, PL the embryo or has plant ana the seed ase Coat or testa, 5) a Che embs rye Consists uw c Catyledon., Embryo two cotyledons the My ccion youd the >t 1 ee Ry poesty}. FPunetions:- Ghe testa protects the embryo , the cotyledons contains the food, the plumule becSme leaves , eee eeety Aeveloys into the root ard: st In another experiment, 1 provea thot the cot Tedons contain cod b testing them for the ollowsnc- nutpients — Du ou Te Kling s tut on Aid not shor Sucar was presentin a ay bear. oO Stare he, A Save cow Sor a veny fositve = Shomine sCarch eas pres ae rotetin.. ~ Nitric an& and Ammonia showed me Rat there was proten present an abundance. Oil a grease spot ShoweA Khe Presece a ost plying it as a definite and exact result of an act of thought. An experiment, above all other things, should teach us to think straight ; for straight and definite thinking is our greatest asset in later life. 22 DIRECTIONS TO THE STUDENT PROBLEM QUESTIONS 1. Why should we write laboratory work in ink but make our drawings in pencil? 2. Why should our records be written instead of oral? 3. What are the four steps of an experiment? 4. How might an experiment be of use in everyday life? 5. Why did Huxley call science ‘‘ organized common sense ”’? II. THE ENVIRONMENT OF PLANTS AND ANIMALS Problem.— To discover some of the factors of the environment of plants and animals. (a) Environment of a plant. (6) Environment of an animal. (ec) Home environment of a Siri or boy. LaBORATORY SUGGESTIONS Laboratory demonstrations. — Factors of the environment of a living plant or animal in the vivarium. Home exercise. — The study of the factors making up my own environ- ment and how I can aid in their control. To THE TreacHEeR. — This chapter may be made one of the most vital in the course by introducing in a broad way what the environment gives to the living things which are within it, how plants and animals are limited by their environment, and how man alone of all living creatures may change and modify his environ- ment for better or for worse. This last problem is fundamental to all the work that is to follow. This introductory chapter gives the child the keynote of the problems which follow and enlists his sympathy and interest from the first, for it shows him that biology is a very human subject and one vital to the understanding of how to better his environment. It is understood that the problems as outlined are possible of many modifications, the environment of the pupils serving as the guide to the type of questions to be given. The needs of city children and the condition of their environment differ in many ways from those of country children. But the fun- damental factors of the environment are the same, and by comparison should be shown to be the same. Problem 1: To determine the factors of environment. Method and Observations. — What is a factor in arithmetic? In algebra? How might the term be used in speaking of our surroundings ? NOTE. — The environment of a living thing is that which surrounds it and from which it receives certain materials necessary for its life. What is your environment? Give examples of some different kinds of environments. (See Hunter’s Civic Biology, Chap. IT.) Explain the term “‘ factors of environment.” 23 2t ENVIRONMENT OF PLANTS AND ANIMALS Home Work. — Determine the factors of the environment of a plant; of some wild animal; of a cat or a dog (domesticated animals); of yourself. Bring to class a written statement ot your answers. Having compared these different living things in their differ- ent environments, decide what factors are common to all envi- ronments. Conclusion. — 1. What are the factors in the environment of living things? 2. Tabulate the factors as suggested below : Plant Animal Mar Factors of Environment Problem 2: Comparison of a natural with an artificial en- vironment. Method and Observations. — Determine what is added to or subtracted from your home environment to make it different from the natural environment of the country. Make two columns. In the first, place the factors of a natural environment. In the second, place the factors of the environment in a city or town. Natural Crtificial Remember that the city has various agencies which add to the air certain substances; that housing conditions are changed; that the earth is covered by pavement; and that water supplies and disposal of waste through sewers are artificial factors. Think, too, of many other ways in which the city environment is changed. PROBLEM 3 25 Put down all the artificial things that have been added to or sub- tracted from your home environment to make it different from a natural environment. Conclusion. — In what respects does a city environment differ from that of the country? Problem 3: To test my home environment. Method and Observations. — Using the house score card given below, estimate the condition of your home environment. This is an exercise for your own use and need not be shown in class unless you so destre. When in doubt consult your teacher. Hovuse Score Carp PERFECT Rooms I uo] TIL} iv | Vv | Vi | vir | Vir SCORE Light 10, gloomy 5, darkO .. . | 10 Well ventilated 15, poorly 7, badly 0 15 Repair : good 5, fair 3, poor 1, bad 0 5 Clean 10, soiled 5, dirty 2, filthyO. . . . . .| 10 One person to room 10, 2 to room 8, 3 to room As 4 or more 0: 3 10 Sinks Construction: good 5, fair2,bad1 . ....4.+.+2.+2.~:. 5 Waier-closet Construction: good 3, fair 2, poor 1, bad O . ee ee Condition: clean 3, dirty 1, filthy 0 2 4 A 3 1 compartment for 1 family 3, for 2 families 1, ‘ee more 5 ha Qfamilies 0 . 3% ww aw we ee ek ee we Se ew el US Cleanliness 1 bath tub for 1 apartment 3, for more than 1 apartment 1, no bath O . Sg Ut ra an a SS he fk AS el 8 Personal cleanliness: very clean 7, fairly clean 5, dirty 2, filthy 0 7 Washing Stationary tubs 3, removable 2, no tubs 0 ‘ 3 Cleanliness of clothing: very clean 7, fairly clean 5, dirty 2, filthy 0 7 Meals Regular 4, irregular 2, uncertainO . . a er 4 4 4 4 i) Amount and kind of food: good 4, fair 2, poor ‘1, bid 0 Cooking: very clean 4, clean 3, dirty 1, filthy 0 Refrigeration: good 4, fair 2, poor 1, none 0 26 ENVIRONMENT OF PLANTS AND ANIMALS DEFINITIONS OF TERMS USED IN House Score Carp! Rooms: Light — Light enough to read easily in every part. (In estimat- ing the light, ventilation, and repair of an apartment, divide the sum of the scores of all the rooms by the number of rooms.) Gloomy — Not light enough to read easily in every part, but enough to see one’s way about readily when doors are closed. Dark — Too dark to see one’s way about easily when doors are closed. Well Ventilated — With window on street or fair-sized yard. Poorly Ventilated — With window opening on a shallow yard or on a narrow court, open to the sky at the top, or else with 5 x 3 inside window (15 square feet) opening on a well-ventilated room in same apartment. Badly Ventilated — With no window on the street, or on a yard, or on a court open to the sky, and with no window, or a very small window, opening on an adjoining room. In Good Repair —No torn wall paper, broken plaster, broken woodwork or flooring, nor badly shrunk or warped floor boards or wainscoting, leaving large cracks. In Fair Repair — Slightly torn or loose wall paper, slightly broken plaster, warped floor boards and wainscoting. In Bad Repair — Very badly torn wall paper or broken plaster over a considerable area, or badly broken woodwork or flooring. (Rooms not exactly coinciding with any of the three classes are to be included in the one the description of which comes nearest to the condition.) Sinxs: Good — Iron, on iron supports with iron back above to prevent splashing of water on wall surface, in light location, used for one family. Water direct from city water mains or from aclean roof tank. Bad — Surrounded by wood rims with or without metal flushings, space beneath inclosed with wood risers; dark location, used by more than one family; water from dirty roof tank. Fair — Midway between above two extremes. Water-ctoser: Good— Indoor closet. In well-lighted and ventilated location, closet fixture entirely open underneath, abundant water flush. Fair — Indoor closet, poor condition—badly lighted and ventilated location, fixture inclosed with wood risers, or poor flush. Poor — Yard closet — separate water-closet in individual compartment in the yard. Bad — School sink — sewer-connected privy, having one continuous vault beneath the row of individual toilet compartments. Conclusion.—1. Is my home environment as good as it should be ? 2. How might I improve it? 1 This and the following are modified from Allen, Civics and Health, Ginn and Company. PROBLEM 4 27 Problem 4: To learn the conditions of my city environment. Method and Observations. — Use this score card in a manner similar to that of yéur last exercise. Judge each item carefully. Score Carp ror Citizens’ Use Prrrect | ALLOW Schoolhouse: Well ventilated, 20; badly, 0-10. 20 Cleaned regularly, 20; irregularly, 0-10 if 20 Feather duster prohibited, no dry sweeping, 10 . 10 Bubble fountains, 10. . F 10 Has adequate play space, 10; inadequate, 0-5 10 Has clean drinking water, 10 bo Sean 10 Has clean toilets, 10; unclean, 0-5 . 10 Outdoor recreation parks, 10; none, 0 . 10 100 Church: Well ventilated, 10; badly,0-5 . . . 10 Heat evenly distributed, 10; unevenly, 0-5 . 10 Cleaned regularly, 10; irregularly, 0-5 . 10 Without carpets, 10 . . . . . .. 10 Without plush seats, 10 . 10 50 Streets: Sewerage underground, 20; surface, 0-10 20 No pools neglected, 10 Be tae. 10 No garbage piled up, 10 2 10 Swept regularly, 20; irregularly, ( 0-10 . 20 Sprinkled and flushed, 10 : 10 Has baskets for refuse, 10 : 10 All districts equally cleaned, 20; unequally, 0- 10 20 100 Near-by Stores: Clean, 10; poorly cleaned, 0-5 10 Free from flies, 10; partly, 0-5 ra 10 Food screened, 10; partly, 0-5 10 Milk used in bottles, 10; dipped, 0 10 Grade goods high, 10; medium, 5-0 10 50 Home: Use score card already worked out . Multiply total by 2, making perfect total 200 Grand total 500 Conclusion. — Allowing 200 as bad, 250 as poor, 306 passable, 350 fair, 400 good, 450 and above excellent, estimate the condi- tions of your environment. 28 ENVIRONMENT OF PLANTS AND ANIMALS Problem 5: To determine and to illustrate by a graph the changes of temperature (one of the factors of the environment) during a given day. ° Materials. — Thermometer, clock, graph paper. Method and Observations. — Take the temperature (outside) at 7 a.m. and at each successive hour during the day until 6 P.M. On a piece of graph paper lay off a line parallel to the bottom of the page. On this line, at equal distances, place your hours, beginning at 7 and ending at 6. Then from the line made as a base, erect-perpendiculars on each of the hour marks. On these perpendiculars mark the record of the thermometer at the given hour. Begin your record at the base line, e.g., if the thermometer @ TLIO TE S yuniMd Me, 50 45 TOOT Tit 30 25 25 w 2 RELIED TET TTT Tri TILITITIITTT rr ri rr ey rrt TOIT PROBLEM 5 registers 50° at 7 A.M., make 50 your start- ing point on the line, and if the thermome- ter has risen to 56° at 8 o’clock, then count off six squares on your graph paper above the base line. Do this for each hour in the 12 for which your record has been made. Connect the marks made on the vertical lines. The result is a curve like the accompanying, showing the tempera- ture record of the day. Conclusion. — What changes take place in the temperature factor of a given day? NOTE. — Another suggested exercise is: Relation of the body to intake of water. : 29 g — a aa Tame? B8 9 1 aL Ze oe 4a 234 gs 6¢ 20 Ps) i} CHIT IU WS, D So $04 = 4s = = Pe = : ss| |B : “T30 | 30 = = 25 = Hy 50} ITT 30 6 PTT STITT ET TT Et 45 35 TTTTT TT TT TTT A 30 ENVIRONMENT OF PLANTS AND ANIMALS Problem 6: To make a Sraph to show how much fluid I take into my body in a day. Method and Observations. — Make a careful estimate of the amount of water drunk by glasses or cups and note hours when you take it. Note also milk, coffee, tea, soda, etc., taken. Make a graph to show when and how much fluid passes into the body in 24 hours. Is this graph a continuous curve? Explain. NOTE. — Ability to make and to understand graphs is something that every well- educated girl and boy should acquire. The above exercises are suggested as easy data for making two different graphs, each of which will have a different ap- pearance. Teachers are expected to give the class data from which other graphs may be constructed. Problem 7: May environment influence public health? Method and Observations. — Study the following table. Look up the location of each of the countries and cities. Find out all you can about their climate, housing conditions, location and con- dition of water supply, etc. Deata Rate per 10,000 Popuntation, PNEUMONIA AND BRONCHITIS, Five-Year Preriop 1896-1900 England and Wales . . . . .. . . 22.70 eeotland.. fc owe SS wi le a we a oe ae we AZIRO Stockholm < « =» = = « # «= * «© # « « ¥ » « 26:70 DOr Oia og? 84! wie. Geese ‘Gee BP Vi! Vi eS) 8! Ge! ee eee or ent BAZO Berlitiie: os: yy eo Agha Ge. Me yes ae Ge oe Se S a G0 Vienna ¢ So wow Wo woe ew we ee Se Se we ww BOO Christiania. . 2. . 0. ee ee ew ew ew ew ew «21.80 BostoM «a -: 4 & a 4) wi Wow a oe -@ a we @ 4% 30:60 Chicago ae ae eg? Ge Re oat: ee ee Se SE BAO Philadelphia . . . . .. 0... ee ee O25.10 New York city .......... . . . . 386.60 Might any factors, such as climate, slums, overcrowding, etc., have an effect upon the death rate? Conclusion. — What factors may influence the death rate? REFERENCE BOOKS 31 PROBLEM QUESTIONS 1. What is meant by environment? Give examples for a plant; a canary; a cat; yourself. 2. How might a given factor of the environment, as the air, be changed in your home’? Ina factory? Ina mine? 3. How might climate affect the environment? 4. Your school is an important part of your environment. What might you do to better it? 5. What is a graph? Of what use is a graph? Explain. 6. Why should every well-educated person understand graphs? REFERENCE Booxs Hunter, Civic Biology, Chap. II. American Book Company. Hunter, Elements of Biology, Chaps. II, X. American Book Company. Hunter, Essentials of Biology, Chaps. II, XII. American Book Company. Allen, Civics and Health. Ginn and Company. Bailey, How Plants Live Together. Cornell University Nature Study Quarterly, No. 6, October, 1900. Bergen and Davis, Principles of Botany, Chaps. XXXVI, XXXVII. Ginn and Company. Caldwell and Eikenberry, Elements of General Science. Ginn and Company. Clark, An Introduction to Science. American Book Company. Coulter, Textbook of Botany, Chaps. XXI, XXII, XXIII, XXIV. D. Appleton and Company. Darwin, Different Forms of Flowers on Plants of the Same Species. D. Appleton and Company. Hessler, First Year of Science. Benj. Sanborn and Company. Hough and Sedgwick, Elements of Hygiene and Sanitation. Ginn and Company. Jordan and Kellogg, Animal Life. D. Appleton and Company. Merriam, Life Zones and Crop Zones in the United States. U.S. Department of Agriculture, Bulletin 10. Sharpe, Laboratory Manual in Biology. American Book Company. Warming, Ecology of Plants, and Introduction to the Study of Plant Communities. Frowde, Clarendon Press, London. Weed, Wild Flower Families. J. B. Lippincott Company. Il]. THE INTERRELATIONS OF PLANTS AND ANIMALS Problem. — To discover the general interrelations of Sreen plants and animals. (a) Plants as homes for insects. (6) Plants as food for insects. (ce) Insects as pollinating agents. LABORATORY SUGGESTIONS A field trip. — Object : to collect common insects and study their general characteristics ; to study the food and shelter relations of plants and insects. The pollination of flowers should also be carefully studied so as to give the pupil a general viewpoint as an introduction to the study of biology. Laboratory exercise. — Examination of simple insect, identification of parts — drawing. Examination and identification of some orders of jnsects. Laboratory demonstration. — Life history of monarch and some other butterflies or moths. Laboratory exercise. — Study of simple flower — emphasis on work of essential organs, drawing. Laboratory exercise. — Study of mutual adaptations in a given insect and a given flower, e.g., butter and eggs and bumblebee. Demonstration. of examples of insect pollination. — Field work if possible. To THe TracHeR. — In a broad way this chapter may be used to show the in- terdependence of organisms. As much of the work as possible should be made to depend upon field trips, as the interest thus gained carries over into the laboratory later. Specifically, emphasis should be placed on the accurate determination of relations existing between a given insect and flower as in cross pollination. For this purpose careful study should be made of some one flowcr in connection with some one insect that is known to act as a pollinating agent. To the city child, trips to the parks and fields are especially helpful because they set right his reaction to the term ‘‘environment.”’ For that reason especial emphasis is made in this book, a civic biology, to field trips. The young citizen should see a reason for the inclusion of vast sums in a city budget for the purchase and maintenance of parks. This trip should indirectly give him reasons which later will justify his actions as a taxpayer and a citizen. : 32 PROBLEM 8 33 Problem 8: A field trip. Materials. — For collecting purposes an insect net, cigar boxes containing sheets of cork, insect pins, and a cyanide bottle are useful. (Caution. Do not smell the cyanide ; even the fumes are deadly poison.) See Comstock’s Insect Life for good directions how to make nets, cyanide bottle, and collecting boxes. NOTE. — Read these directions carefully before beginning work. Object of trip: The object of this trip is threefold : 1. To find out some of the relations of mutual help existing between plants and animals. 2. To learn to know a few common insects, and to collect them for later study. 3. To have such an enjoyable time that you will wish to go again by yourself. a. Insects and Flowers Method and Observations. — Your trip should include fields and waste lots, covered with weeds and trees. Look for six-legged animals (insects) on plants. Do they receive any protection from such plants? Shelter? Food? Give examples under each of the above headings. Do you find any insects laying their eggs upon plants? Why do you think they do this? Follow a bee until it alights on a flower. Try to find out exactly what it gets from the flower, and how it does it. Now observe where it goes next. Do bees visit flowers of the same kind in succession ? What are your conclusions regarding the mutual relations be- tween the bee and the flower? Do both receive benefit? Write your answer on paper supplied by your instructor. Look for other flying insects that are on flowers. Extra credit is given for the working out of the relation between a butterfly and a flower. Carefully observe the goldenrod blossoms for yellow and black beetles (locust borer) about 1 inch long. Does the beetle get any good from the plant? Might it give the plant anything in return? Write a paragraph on this. Observe grasshoppers or other insects on stalks of grass. What are they doing there? Do they give any return to the plant? Write a paragraph on this relation. HUNTER LAB. PROB. —3 34 INTERRELATIONS OF PLANTS AND ANIMALS b. Collections Method and Observations. — Collect as many different sorts of insects as possible and bring them to your instructor, who will help you name your specimens. You will study these specimens in detail when you return to school, so be careful not to injure them. Problem 9: How to know an insect. Materials. — Any living or dead insect, bee, butterfly, or grass- hopper preferred. Hand lens. Method. — Carefully examine any insect. Observations. — Notice that the body is divided into three regions: the head; a middle part, the thorax; and a hind part, the abdomen. (See Figs., pp. 29, 30, Civic Biology.) These parts are further divided into joints (segments). Look at the head. Find the feelers (antenne), the large compound eyes, and certain movable mouth parts. What do you find attached to the thorax? How many pairs? Look carefully along the sides of the abdo- men for very tiny breathing holes (spiracles). All insects breathe by a system of air tubes (tracheew) opening along the sides of the body. The characters you have just found should enable you to distinguish an insect from all other animals. Conclusion.—1. Write a paragraph telling what structural char- acters an insect has. 2. Make a drawing of an insect to show all the parts that we have seen above. Label each part. Problem 10: To learn to recognize insects that frequent flowering plants. Method. — This work may best be taken on a field trip, although laboratory work from boxes containing mounted insects of differ- ent groups may well be substituted. NOTE. — Insects have been shown to be animals that have three jointed parts to the body, three pairs of jointed legs, feelers, compound eyes, and a more or less hard skeleton on the outside of the body. They may or may not have wings. They breathe through a system of air tubes called trachea. The following orders or groups of insects are likely to be found feeding or living upon flowering plants. The position and kind PROBLEM 10 35 of wings and the kind of mouth parts are the guides by which we know the orders of insects. Bees and Wasps (Hymenoptera, mem- brane wings). — The wings are gauzy and four in number. These insects have stings (look at the end of the abdomen). The mouth parts are too compli- cated for a beginner to use for identification. Butterflies and Moths (Lepidoptera, scale wings). — Char- acterized by having two pairs of large wings, covered with tiny bright-colored _ scales. Head provided with a long proboscis or suck- ing tube which is coiled up when at rest. Grasshoppers (Or- thoptera, — straight wings).— Found on most green weeds. The mouth parts are fitted for biting. Hind wings, if present, are folded up lengthwise under the outer wings when at rest. Flies (Diptera, two wings). — Usually small insects with but a single pair of gauzy wings. A short proboscis. Bugs (Hemiptera, half wings). — The wings 36 INTERRELATIONS OF PLANTS AND ANIMALS are not alone sufficient identification, as they may or may not be present. A jointed pro- boscis which points backwards is the * ge only sure means of (my eulll Nh ON PTT dds Ng knowing this group. Beetles (Coleoptera, sheath wings).— Characterized by having a strong front pair of wings called elytra, usually covering the hind wings and always meeting in a straight line down the middle of the back. Mouth parts hard, pincher-like jaws. a. Field Work Method. — Collect as many different kinds of insects as you can, making careful notes as to the locality where the insect was found, the flowers which it frequents, the kind of food it was tak- ing from the flower, and the order to which it belongs. b. Laboratory Work Observations. — From boxes containing a number of different insects pick out one from each order given above and give your reasons for placing that particular insect in the order which you have chosen for it. Conclusion. — 1. Why do certain insects always frequent certain flowers? Look at the insect, especially the mouth parts, very carefully and study the form of the flower before making your decision. 2. How would you pick out (a) a bee, (b) a butterfly, (c) a bug, (d) a grasshopper from the above insects? Problem 11: To study the life history (metamorphosis) of an insect. NOTE. — Field work may be done at a museum, or questions may be worked out from some of the excellent preparations made by the Kny-Scheerer Company or other of the biological supply houses. PROBLEM 11 37 a. Eggs Method and Observations. — In the field look on the under side of leaves for tiny ovoid structures (eggs) of moths and butterflies. The eggs of the cabbage butterfly may be found at almost any time on the under side of cabbage leaves. Conclusion. — Why are the eggs laid on the under side of certain leaves? b. Larva or Caterpillar Observations. — Note that, besides true jointed legs, the caterpillar has others called prolegs. How many true legs are there and where are they located? How many prolegs are there? Locate the spiracles or breathing holes. Remember where they are located on an adult insect. Watch the caterpillar when it feeds. What kind of mouth parts does it have? Might it do damage to plants? How? Conclusion. — 1. Is a caterpillar a worm? (Look in your bi- ology for the characteristics of worms.) 2. How might the larve of moths or butterflies be of economic importance? , c. Pupa Materials. — Cocoons of several species of moths with twigs or other parts attached should be furnished for this exercise. NOTE. — Moths spin a cocoon for themselves at this stage. Butterflies spin no cocoon but form a chrysalis. Observations. — Where do you find the cocoon or chrysalis? Of what does the cocoon seem to be composed? (The cocoon of the Cecropia is excellent for this purpose.) In a chrysalis locate by means of the body markings the head, antenne or feelers, eyes, wings, legs, and spiracles. Are all the parts of an adult present? Open a cocoon. What do you find inside? How do you explain this? Conclusion. — Making use of all the knowledge you have gained, write a brief description of the pupal stage of an insect and tell of what use this stage might be to the insect. Remember where you find these stages. 38 INTERRELATIONS OF PLANTS AND ANIMALS d. Adult or Imago Method. — Examine carefully an adult butterfly or moth. Observations. — How many body regions has it? How many legs? Wings? Antenne? How does this stage differ from the pupal stage? NOTE. — All the changes undergone by an animal from the time it leaves the egg to the time it becomes an adult are known as the stages of metamorphosis of that animal. If no great changes in form occur, then the animal is said to have an incomplete or direct metamorphosis. But if changes in form such as we have just seen occur, then the animal is said to pass through a complete or indirect metamorphosis. Conclusion. — 1. What insects that you have studied pass through a. direct metamorphosis? An indirect metamorphosis? 2. If time permits, drawings might be made to illustrate the life history (metamorphosis) of a moth or a butterfly. Problem 12: To learn the structure and work of the parts of a flower. Materials. — Any large flower, as the tulip in the spring, or eve- ning primrose or gladiolus in the fall. Method. — Carefully examine the parts of a flower. NOTE. — Flowers are built so that the parts are arranged in circles. In regular flowers the same number of parts (or multiples of these parts) will be found in each circle. Observations. How many parts in the outermost circle? These parts are called sepals. Collectively they make up the calyx. What color have the sepals? In a young flower what seems to be their use? The next circle of parts is called the petals. How many are there? What color do they have? Together they form the corolla. The little knobbed organs are called stamens; the stalk is the filament, the knob the anther. Describe what you find in the anthers. This is the pollen. Can you determine how it gets out of the anthers? Use a hand lens. In the center of the flower is the pistil.! Describe it. The 1 Tf the pistil is made up of a number of separate parts, each part is called a carpel. PROBLEM 13 39 enlarged part at the base (not always easily seen) is the ovary; the stalk is the style; the tip, which is sticky, is called the stigma. On this sticky surface pollen grains will grow. How might pollen get to the stigma? Cut a cross section through the ovary. Describe what you find inside. These little tr mish Under a (Etorvec|O* 108 Sheps [US tain conditions, which Petal we will later discuss, a part of a pollen grain will cause these ovules to grow into seeds. : Stamen Fill out a diagram like the accompany- ing in your notebook. Conclusion. — 1. What parts of the flower are essential for the production of seeds? 2. What are then the essential organs of a flower? Drawings. — 1. A flower from above. Label all parts. 2. A stamen, showing all parts. 3. A pistil, showing all parts. Sepal Pistil Problem 13: The cross-pollination of flowers. Method. — Take a trip to a locality where flowers are abundant and make a preliminary study of the relation of insects to flowers. Observations. — Notice whether the flowers are being visited by insects. To what orders do these insects belong? Do bees visit flowers of one sort in succession, or of different sorts? Make a careful study of this point by following a single bee or other insect. Work this out in the case of a butterfly. Do insects seem to prefer any one color in flowers to another color? Make careful observations on this point. Can you discover any means by which the flower might attract an insect? Remember insects can probably smell and taste as 40 INTERRELATIONS OF PLANTS AND ANIMALS well as see. Might the shape of a flower be of use to an insect? How? Conclusion. — 1. What do insects get from flowers? 2. What kinds of flowers do they frequent most? 3. What do insects give to flowers? Problem 14: To study cross-pollination in butter and eggs. NOTE. — In the fall of the year one of the best flowers for study is found in the yellow butter and eggs (Linaria vulgaris) found in vacant lots and along roadsides. Any cultivated forms of the toadflax family are useful for this purpose. Materials. — Butter and eggs or other member of the toadflax family, bumblebees in formalin, needle, hand lens. (Diagrams, p. 39, Civic Biology.) Method. — Study carefully the structure of butter and eggs for any adaptations or fitness in structure: (1) to receive insect visitors; (2). to effect self- or cross-pollination. Observations. — Note the shape of the flower. Are all its petals and sepals regular (the same size and shape)? Might the shape of the flower offer any place for an insect (as a bee) to light? Try it with a bee. What would happen when the body of the bee rested on the lower lip of the flower? Press down this lower lip and look inside the flower for the stamens and pistil. What is there peculiar about the position of the stamens? Hold the flower in a natural position. Could pollen from the stamens reach the pistil? Examine with hand lens the sides, back, legs, and head of a bumblebee. What do you find? Now push the body of the bee into an open flower. (Remember that the nectar the bee seeks is held in the spur, or pointed projection, of the flower.) Over what structures would the head and back of the bee rub? If the bee visited another flower of the same sort, what would happen? Conclusion. — 1. How is the butter and eggs fitted to receive insect visitors? 2. What kind of pollination is most common in butter and eggs? How is it brought about? 3. Explain a second method of pollination in butter and eggs. PROBLEM 15 41 4. Make a drawing (diagram) to show how a bee helps to pollinate butter and eggs. Problem 15: Special directions for the study of some fall flowers. (Extra.)} The Evening Primrose (Onagra biennis). — The habitat pre- ferred by this flower is dry fields, roadsides, or waste places. The yellow flowers are found in long, upright, densely crowded clusters. A flower cluster in which the individual flowers have no flower stalks or pedicles, with one main axis to the cluster, is called a spike. Notice that young and old flowers and fruits are all on the same cluster. Where are the youngest flowers located in the cluster? Is there any flower at the end of the main stalk? Could you deter- mine in advance the length of the flower cluster? Such a cluster is said to be indeterminate. Why? Study a single open flower. Note the calyx and corolla. Are the parts distinct? How many petals do you find? Notice that there are eight stamens and that the stigma is four-parted. Cut the ovary in cross section, and see how many locules (spaces) there are. When a flower has each circle of parts, as the sepals, petals, stamens, and pistils, made up of a certain number of divisions, or when they appear in multiples of that number, the flower is said to be symmetrical. Here we see a very striking example of sym- metry in a flower. The chief attraction to insects is the nectar, which is formed in nectar glands at the base inside the slender tubular corolla. In- formation is given to the insects of the contents by a faint, sweet odor. This flower is not visited by many day-flying insects. Can you determine the names of any that do come by day? At night the flower opens more widely and the scent becomes much 1To THE TeacHER. — If the work on flowers is taken up in the spring, field work should result in the collection of jack-in-the-pulpit, oak, willow, skunk cabbage, grasses, and also many wild flowers which show special adaptations for cross-polli- nation. In the fall butterfly weed, Salvia, turtlehead, and various composites show wonderful adaptation. Original investigation on simple problems of this kind have been found by the writer to be the best means of stimulating certain better prepared students to take an abiding interest in this work. Two or three sample investigations are given here that might be used by the student as a form in making reports on other flowers. 42 INTERRELATIONS OF PLANTS AND ANIMALS more noticeable. Moths are its chief night visitors. The long proboscis is thrust into the flower and quickly withdrawn, but usually a little pollen is carried off on the palps (projections on the sides of the head). This may be left on the next flower visited. Try to determine what other insects, if any, visit the evening primrose at night. Draw a single flower split open lengthwise to show the position of the parts, and especially any adaptations to insect pollination. Look for any special means for the prevention of self-pollination. Label all the parts. Moth Mullein (Verbascum blattaria). — The moth mullein is one of the most beautiful weeds, despite the fact that few blos- soms are found at any given time. The plant flourishes on dry, waste land, roadsides, and open fields. It was introduced into this country and has since become common here and in Canada. The flowers are found in a long, loose raceme. A raceme is like a spike, except that each flower has its own flower stalk devel- oped. Has this cluster yellow or white flowers? Into how many parts is the calyx divided? The corolla? Is the corolla perfectly regular? Notice the five stamens. Is there anything peculiar about the filaments? Are they all of the same length? In spite of the fact that the flower is called moth mullein, it is not polli- nated to any extent by moths. Bees and flies are the chief pollen bearers. Bees which alight on this flower do so for the purpose of collecting pollen. This they usually gather from the short stamens, while they cling to the longer ones.. As the bee lights on another flower, the pollen on the under side of the body is trans- ferred to the stigma of this flower. Draw the flower from above, twice natural size. Jewelweed (Impatiens biflora).— One of the most prevalent of all our brookside flowers is the jewelweed. It well deserves its name, a pendant flaming jewel of orange. This flower is very irregular in shape. Are the flowers single or in clusters? The sepals as well as the petals are colored. The former are three in number, one of which is sacklike in shape and contracted at one end into a spur. The petals are also three in number. Open the flower. Notice how short the filaments of PROBLEM 16 43 the five stamens are. Make a note of their position with relation to the pistil. Would self-pollination be possible in this flower? If it is possible to study jewelweed out of doors in its native habitat, it will be found that humming birds are the visitors which seem best adapted to cross-pollinate the flower. A care- ful series of observations by some girl or boy upon the cross- pollination of this flower might add much to our knowledge regarding it. Jewelweed has the habit of producing (usually in the fall) inconspicuous flowers which never open but which produce seeds capable of germination and growth. Such flowers are said to be cleistogamous. In England, where the plant has been introduced, it is found to produce more cleistogamous flowers than showy ones, and the showy ones do not produce seed. There are no humming birds in England, and without this means of pollination, the cleistogamous form prevails. Make a front-view drawing of the flower of jewelweed twice natural size. Problem 16: To find other pollinating agents besides insects. Materials and Method.— Study as many other flowers as possible, using Kny or other charts and books of reference to help in your work. Suggested for this are various types of orchids (described and pictured by Charles Darwin), turtlehead, Salvia, and others previously mentioned. Observations. — Look for any peculiarities of structure that seem to be for purposes of pollination. Explain. If possible, study especially the structure of the flowers of sage, pea or bean, and butterfly weed. Find out how pol- Agents 9 lination is accom- PETnation Exaraples plished in the corn Insects plant; in the pines and grasses. Read- ing as well as field water work will help here. Are stamens and pis- wand Other Agent s 44 INTERRELATIONS OF PLANTS AND ANIMALS tils ever separated by being on different plants? Give examples. Explain. Conclusion. — Using a form like that on page 43, tabulate the various ways in which pollination is brought about. PROBLEM QUESTIONS 1. What relation might insects and plants have to each other? Is this relation always a useful one? . How could you tell an insect from other animals? . How could you tell a bee, butterfly, bug, grasshopper, beetle? . What is meant by metamorphosis? . Of what use might metamorphosis be to an insect?’ . Which is the most beneficial stage of the metamorphosis of a fioth or a butterfly? The most harmful stage? Why? 7. Of what use to a flower are its sepals, petals, stamens, pistil? 8. What parts could a flower do without? Why? 9. What do insects get from flowers? What do they do with what they get? 10. Is pollination intended by an insect? 11. What do we mean by an adaptation? Tllustrate from a flower. 12. What do we mean by a mutual adaptation? Illustrate from a flower and an insect. 13. What adaptations are found in flowers to prevent self- pollination? Give examples. 14. What agents other than insécts might transfer pollen? 15. Compare with your own environment the environment which you have found animals and plants to have in the park. How are the two environments alike and how do they differ? 16. What constitutes an artificial environment? A natural environment ? : 17. What are some uses to you of a city park? Do not look in your book for an answer. Oo Pr Ww DY REFERENCE Books Hunter, Civic Biology, Chap. III. American Book Company. Hunter, Elements of Biology, Chap. IV. American Book Company. Hunter, Essentials of Biology, Chap. 1V. American Book Company. Andrews, Botany All the Year Round, pp. 222-236. American Book Company. . REFERENCE BOOKS 45 Atkinson, First Studies of Plant Life, Chaps. XXV-XXVI. Ginn and Company. Bailey, Crossing of Egg Plants, Bulletin 26, Cornell Experiment Station. Bailey, Effect of Pollination upon Tomatoes, Bulletin 28, Cornell Experiment Sta- tion. Bailey, Philosophy of Crossing Plants, Considered in Reference to their Improvement under Cultivation. Report of Massachusetts State Board of Agriculture, 1891. Bailey, New Ideals in the Improvement of Plants. Country Life in America, July, 1903. Bailey, Plant Breeding. The Macmillan Company. Bergen and Caldwell, Practical Botany, Chap. VIII. Ginn and Company. Campbell, Lectures on the Evolution of Plants. The Macmillan Company. Coulter, Plant Life and Plant Uses, pp. 301-322. American Book Company. Coulter, Plant Studies, Chap. VII. D. Appleton and Company. Coulter, Barnes, and Cowles, A Textbook of Botany, Part II. American Book Company. ~ ; Crosby, School Exercises in Plant Production, Farmers’ Bulletin 408, U. S. Depart- ment of Agriculture. Crosby and Howe, School Lessons on Corn, Farmers’ Bulletin 409, U. S. Depart- ment of Agriculture. Dana, How to Know the Wild Flowers. Scribner’s Sons. Dana, Plants and Their Children, pp. 187-255. American Book Company. Darwin, Insectivorous Plants. D. Appleton and Company. Darwin, Different Forms of Flowers on Plants of the Same Species. D. Appleton and Company. Darwin, Fertilization in the Vegetable Kingdom, Chaps. I and II. D. Appleton and Company, Darwin, Orchids Fertilized by Insects. D. Appleton and Company. Darwin, Cross and Self Fertilization in the Vegetable Kingdom. D. Appleton and Company. De Vries, Plant Breeding. Paul, Kegan, Trench, Triibner and Company, London. East, The Réle of Selection in Plant Breeding. Popular Science Monthly, August, 1910. Ely, Color Arrangement of Flowers. Scribner’s Magazine, March, 1910. Gibson, My Studio Neighbors, p. 227. Harper and Brothers. Henderson, Functions of an Environment. Science, April 10, 1914. Howe, How to Test Seed Corn in School. Circular 96, U. 8. Department of Agri- culture. Iles, Teaching Farmers’ Children on the Ground. World’s Work, May, 1903. Lubbock, British Wild Flowers. The Macmillan Company. Lubbock, Flowers, Fruits, and Leaves, Part I. The Macmillan Company. Lyle, Plant Breeding in a Dutch Garden. Everybody’s Magazine, June, 1902. Miller, The Fertilization of Flowers. The Macmillan Company. Needham, General Biology, pp. 1-50. The Comstock Publishing Company. Newell, A Reader in Botany, Part II, pp. 1-96. Ginn and Company. Osterhout, Experiments with Plants, Chap. VI. The Macmillan Company. Parsons, Children’s Gardens for Pleasure, Health, and Education. Sturgis and Walton. Sharpe, A Laboratory Manual in Biology. American Book Company. Stack, Wild Flowers Every Child Should Know. Doubleday, Page and Company. IV. THE FUNCTIONS AND COMPOSITION OF LIVING THINGS Problems. — To discover the functions of living matter. (a) Inaliving plant. (0) Ina living animal. LABORATORY SUGGESTIONS Laboratory study of a living plant. — Any whole plant may be used; a weed is preferable. Laboratory demonstration or home study. — The functions of a living animal. Demonstration. — The growth of pollen tubes. Laboratory exercise. — The growth of the mature ovary into the fruit, e.g., bean or pea pod. To THE TracHEer. — The object of this chapter is first to giye the child a pre- liminary or pre-view of the larger problem outlined in the six following chapters, t.e., plant growth and nutrition. Then the concept of the cell as a unit of structure should be worked out and the very important notion of fertilization in its relation to the development of the plant. Problems 17, 18, 19, and 20 might well follow Chapter IT, if the teacher desires, and the problems on fertilization introduced after that of the structure of the flower. Experience has shown the sequence here followed, however, to work out well. Any simple plant or animal tissue can be used to demonstrate the cell. Epider- mal cells may be stripped from the body of the frog or obtained by scraping the inside of one’s mouth. The thin skin from an onion stained with tincture of iodine shows well, as do thin cross sections of a young stem, as the bean or pea. One of the best places to study a tissue and the cells of which it is composed is in the leaf of a green water plant, Hlodea. In this plant the cells are large, and not only their out- line, but the movement of the living matter within the cells, may easily be seen, and the parts described in the next problem can be demonstrated. Problem 17: The wses of the parts of a plant. Materials. — Growing plants, seedlings, and red ink. NOTE. — A growing plant has roots, stems, leaves, flowers, and fruits. Method and Observations. — Locate each part in the specimen before you. If you water a growing plant that is badly wilted, 46 PROBLEM 18 47 what happens? What would one use of the roots be? What holds a plant in the ground? In seedlings the roots of which have been placed in red ink note carefully the appearance of root, stem, and leaves. Note that the red fluid extends into the leaves. How did it get there? What is one use of the stem to the plant? Examine a piece of sugar cane, a stem. Taste it. What does it contain? What might another use of stems be? Examine leaves which are in a sunny window. How are they placed with reference to the light? Later we will find that green leaves make food for the plant when in the sunlight. We have seen flowers, and found that in time they form fruits. Fruits in turn hold the seeds which give rise all Use toPlant| Use to Man to new plants. Conclusion. —1. | Root Write a short compo- sition on the uses of | Stem all of its parts to a Leaves green plant. 2. Fillin a table like Blower the accompanying. Problem 18: To study the needs and uses of the parts of a living animal. Method. — Study your pet cat or dog. Make a list of all the things that your pet requires in order to live. Classify the intake of the pet under the headings, Food, Water, Air, etc. What parts of the body have to do with taking in food? Water? Air? When a structure has a work to do, we call that work its function. What other functions has your pet besides those already mentioned? (Your teacher will help you here.) Conclusion. — What are the needs and what are the functions of a living animal? How do you think they compare with those of a plant? STUDY OF COMPOUND MICROSCOPE 1. NOTE. — The microscope, an instrument for making smdil objects appear larger, comprises two parts: the stand (A, B, C) and the lenses (F, G). 48 FUNCTIONS OF LIVING THINGS 2. NOTE. — The stand consists of the following parts: base (A), pillar (B), stage (M), arm (C), tube (D), diaphragm (S), mirror (O), revolving nose piece (E), the coarse (K) and the fine (L) adjustment. aol Of what material is the stand made? What are the advantages of using such material? 3. NOTE. — The stand rests upon a broad base or foot. What is the shape of the base? Why should the base be broad and heavy? PROBLEM 19 49 4, NOTE. — The jointed, vertical pillar gives attachment to the arm, support- ing the main tube of the instrument. What are the advantages of having the pillar jointed? 5. NOTE. — Extending forward from the pillar below the arm is the stage, on which is placed the object to be examined. Describe the location of the perforation in the stage. What is its use? What is the use of the revolving wheel, or diaphragm, pivoted to the stage? 6. NOTE. — Below the stage is a movable bar (P), carrying the mirrors or reflectors. In how many different directions can you move the mirrors? What is the advantage of having them movable? What kind of surface do the mirrors respec- tively show? What is the use of the mirrors? 7. NOTE.—A hollow cylinder containing two lenses fits into the upper end of the tube. It is called the eyepiece or ocular (G). Why is the name eyepiece applied? 8. NOTE. — Small brass mounts, each containing several lenses, are attached to the tube at its lower end; they are the object lenses or objectives (F, F). Why is the name objective given to these lenses? How many objectives are there in your microscope? 9. NOTE. — The low power (a slightly magnifying objective) has a short and broad mount. The high-power objective has a long and narrow mount. What fractional numbers do you find on the mount of the high and the low power objectives, respectively ? 10. NOTE. — The objectives are attached to a revolving device, the nose piece. What are the advantages of a revolving nose piece? 11. NOTE. — To obtain a clear image of the object under examination, we must be able to vary the distance between the lenses and the object; that is, to focus the instrument. The microscope is brought into focus by slightly turning either of the large wheels placed at the top of the arm near the tube. Why are these wheels called the coarse adjustment? (Turn one of them gently !) What movement results? 12. NOTE.— The milled head of the fine adjustment is found at the top of the pillar. Carefully turn the fine adjustment back and forth. (No more than half a turn in either direction!) Why is this adjustment called ‘‘fine’’? Problem 19: To determine the wnit of structure in plants and animats. Materials. — Onion skin, sc.apings from mouth, compound microscope, slides, methy] blue. Method. — Scrape some cells from the inside lining of the cheek with a sterilized knife. Mount in water. Stain with methyl blue. Onion skin may be used and stained with methyl blue or iodine. NOTE. — A cell is a small living structure made up of living matter (protoplasm) containing a portion which in part readily absorbs stain. This structure is called the nucleus. A cell is usually bounded by a cell wall or cell membrane. HUNTER LAB. PROB. —4 50 FUNCTIONS OF LIVING THINGS Observations. — What is the shape of a single cell? Are all cells examined the same size? Shape? Can you lo- cate the nucleus (a deeply stained body), cytoplasm (pro- toplasm outside the nucleus), and cell wall? Any other structures? Are the cells separate or united with one another? Diacram SHOWING CELLS. N, nucleus; P, protoplasm; W, walls. NOTE. — Cells of the same sort joined together in a plant or an animal form tissues. Tissues are grouped in both plants and animals to form organs, struc- tures which have some certain work to do, as a leaf, a root, a hand, an eye, etc. Conclusion. — 1. In the onion do the cells form tissues? Give reason for your answer. 2. What are tissues? Of what are tissues composed ? 3. What are organs? Give examples from your own body. 4. Define a cell from what you have seen under the microscope. 5. (Optional.) Draw a few of the cells stained with methyl blue or iodine, showing cell walls, nuclei, and protoplasm. Problem 20: To determine some of the properties of proto- plasm. Materials. — Stamen hairs of spiderwort (Tradescantia), leaves of Elodea, or the root hairs of radish or grain seedlings are useful. As Elodea is easily grown in aquaria, it is recommended for this exercise. Observations. — Examine a bit of mounted leaf of Elodea. What is its general appearance under the low power? Can you locate individual cells in the mass? Note the green bodies in the cells (chlorophyll bodies). Can you find the cell walls? The liv- ing matter (protoplasm) ? Look closely along the edge of the cells for any movement of living matter within the cell. Does the protoplasm move in any particular direction? PROBLEM 22 51 Heat the slide very slightly. What is the result? Cool the slide and note the effect on cell movement. Conclusion. — 1. In what part of plants may protoplasm be found? 2. Write a paragraph, describing the appearance, movement, and composition of protoplasm in Elodea. What are its reactions (look up this word in the dictionary) to heat and cold? Problem 21: To stwdy structure and growth of pollen. Materials. — Pollen of snapdragon, sweet pea, nasturtium, or tulip; sugar solution (3 per cent, 10 per cent, and 15 per cent), bell jar, sponge, a compound microscope, hand lens. Method. — Dust some pollen of snapdragon on a glass slide. Examine it with a hand lens. Make a 10 per cent solution of cane sugar and dust some ripe pollen in a drop of the solution placed on a glass slide. Place this slide under a small bell jar with a moist sponge and examine after 24 hours with the low power of the compound microscope. Try sweet pea or nasturtium pollen in ‘a 15 per cent sugar solution, or tulip with a 3 per cent sugar solution. Observations. — Look for a tubelike structure, the pollen tube, growing out of the pollen grains. Describe and sketch one. Conclusion. — 1. What made the pollen tube grow? 2. Under what other condition have you heard of the growth of pollen? Problem 22: To study the reason for the Srowth of pollen Srains tn flowers. Method and Observations. — Study the following diagram, the figures, pages 53 and 54, in your Civic Biology, and charts for further explanation. Within the pollen tube is a cell known as the sperm cell. Note that the cell in the end of the pollen tube is about to unite with the egg. Observe the pathway taken by the pollen tube. How does the sperm cell from the pollen grain get into the ovary? Study the longitudinal section of the ovary. Note a number of ovoid bodies (ovules) in the ovary. How could a pollen tube reach an ovule? 52 FUNCTIONS OF LIVING THINGS NOTE. — If a sperm cell reaches a large cell (called an egg) located in the ovule, the sperm and the egg unite to form asingle cell. The egg cell is then said to be fertilized. This process is known as fertilization. After fertilization the egg will grow into a tiny structure known as an embryo. The ovule then is known as a seed. The embryo within the seed will, under favorable conditions; develop into a young plant. Conclusion. — 1. What is fertilization and how does it take place ? 2. What results from fertilization of the egg of a flower? 3. Why are the stamens and pistils called essential organs? 4. Why is the process of fertilization nec- essary ? 4, spillens seein Bak Problem 23: To discover how fruits are time it falls upon formed. stigma; 3, starting to grow; 4, with a a. The Bean pollen tube; s, sparaieell aualete: Materials. — Pea or bean flowers, bean pods. Diagram, page 55, Civic Biology. Method and Observations. — Examine an unopened pod. Compare it with the pistil of an old flower. Find the ovary or seed case, the style, and the stigma. Open the pod. Notice the little seeds. How are they attached to the pod? Why are not all the seeds the same size? (Look up the diagram on fertilization.) Conclusion. — 1. What part of the flower forms the bean fruit? 2. What is one use of a fruit to the plant? Drawing. — Draw an opened pod showing the seeds. Label all the parts. b. The Apple Materials. — Apple blossoms in various stages, or chart. Apples. Diagram, page 56, Civic Biology. Observations.—In an apple blossom how are the sepals placed with reference to the ovary, above or below it? Note the position and appearance of the receptacle, or base, of the flower. Observe several young apples in different stages of develop- PROBLEM 24 53 ment. What parts of the flower appear to grow into the fruit? Cut cross and longitudinal sections of an apple. Find seed cases of the ovary. How many are there? What do you find in them? Conclusion.— 1. From what does the fleshy part of the apple develop? The part that holds the seeds? 2. Give reasons for your answer in a well written paragraph. Problem 24: How and why fruits and seeds are scattered. Materials. — Fruits of burdock, jimson weed, clotbur, thistle, beggar’s tick, maple, linden, dandelion, crane’s-bill, raspberry, acorn, peach, chestnut, pines, and witch-hazel in boxes or glass bottles. Method. — Collect as many as possible of the above-mentioned fruits and seeds yourself, taking notes on where they were found. Any overgrown city lot will yield some of the above, a trip to a park or to the country in the fall will give you many more. The rest may be obtained from your instructor. After bringing your mate- rial to class, place it in boxes provided for that purpose. Observations. — Classify your fruits and seeds in the following table, giving means of scattering: Wind | Burrs and Carried] Stickers other i ird Explosive] Birds | Man |Water Pteans Conclusion. — 1. Write a paragraph telling the devices you have found in the seed or fruit to help it be scattered. Also tell all the ways in which seeds or fruits may be scattered. 2. Give as good a reason as you are able, why it is desirable for plants to scatter their seeds and fruits at some distance from the parent plants. PROBLEM QUESTIONS 1. What are the needs of living things? 2. What are the functions of living things? 54 FUNCTIONS OF LIVING THINGS Why is reproduction such an important function? What is the difference between pollination and fertilization? What are the parts of a cell? The functions of a cell? What are the characteristics of living matter? What are the properties of living matter? What part of a flower becomes the fruit? Why is it important for plants to scatter their fruits? SOHO AO? RES REFERENCE Books Hunter, Civic Biology, Chap. IV. American Book Company. Hunter, Elements of Biology, Chap. III. American Book Company. Hunter, Essentials of Biology, Chap. III. American Book Company. Andrews, Botany All the Year Round, pp. 222-236. American Book Company. Atkinson, First Studies of Plant Life, Chaps. XXV-XXVI. Ginn and Company. Bailey, Lessons with Plants, Part III, pp. 131-150. The Macmillan Company. Bailey, Plant Breeding. The Macmillan Company. Campbell, Lectures on the Evolution of Plants. The Macmillan Company. Coulter, Plant Studies, Chap. VII. D. Appleton and Company. Coulter, Barnes, and Cowles, A Tertbook of Botany, Part II. American Book Company. Curtis, Nature and Development of Plants. Henry Holt and Company. Dana, Plants and Their Children, pp. 187-255. American Book Company. Darwin, Different Forms of Flowers on Plants of the Same Species. D. Appleton and Company. : Darwin, Fertilization in the Vegetable Kingdom, Chaps. I and II. D. Appleton and Company. Darwin, Orchids Fertilized by Insects. D. Appleton and Company. Ganong, The Living Plant, Chap. XI. Henry Holt and Company. Gray, Structural Botany. American Book Company. Jost, Lectures on Plant Physiology. Tr. by R. J. H. Gibson. Frowde, London. Lubbock, Flowers, Fruit, and Leaves, Part 1. The Macmillan Company. Lubbock, British Wild Flowers. The Macmillan Company. Miller, The Fertilization of Flowers. The Macmillan Company. Newell, A Reader in Botany, pp. 1-96. Ginn and Company. Sharpe, A Laboratory Manual in Biology. American Book Company. V. PLANT GROWTH AND NUTRITION. CAUSES OF GROWTH Problem. — What cawses a young plant to grow? (a) The relation of the young plant to its food supply. (6) The outside conditions necessary for Sermination. (ec) What the young plant does with its food supply. (d) How a plant or animat is able to use its food supply. (e) How a plant or animal prepares food to use in various parts of the body. LaBoraTory SUGGESTIONS Laboratory exercise. — Examination of bean in pod. Examination and identification of parts of bean seed. Laboratory demonstration. — Tests for the nutrients: starch, fats or oils, protein. Laboratory demonstration. — Proof that such foods exist in bean. Home work. — Test of various common foods for nutrients. Tabulate results. Extra home work by selected pupils. — Factors necessary for germination of bean. Demonstration of experiments to class. Demonstration. — Oxidation of candle in closed jar. Test with lime- water for products of oxidation. Demonstration. — Proof that materials are oxidized within the human body. Demonstration. — Oxidation takes place in growing seeds. Test for oxidation products. Oxygen necessary for germination. Laboratory exercise. — Examination of corn on cob, the corn grain, longitudinal sections of corn grain stained with iodine to show that em- bryo is distinct from food supply. Demonstration. — Test for grape sugar. Demonstration. — Grape sugar present in growing corn grain. Demonstration. — The action of diastase on starch. Conditions neces- sary for action of diastase. To THe TEeacHErR. — One of the most essential reasons for placing biology early in the school curriculum is due to the fact that as an experimental science it makes for straight thinking. If any one chapter in this book lends itself to logical devel- opment, it is the chapter that follows. All laboratory work here outlined builds, 55 56 PLANT GROWTH AND NUTRITION step by step, the general concepts of the necessity for food, for digestion of food, and for the oxidation of food for the release of energy. The food tests are inci- dentally shown, as they should be, in connection with the main problem of food in its relation to the young plant. All tests as tests are subordinated to the main problems as outlined above. Thus the pupil gets his incidental information about certain factors of the environment of the young plant by means of association. Throughout this entire chapter a conscious effort should be made by the teacher to correlate the processes which go on in the young developing plant with the same fundamental processes which go on in the human body. Thus experimental proof lays a foundation for the work in human physiology later. Problem 25: To find the relation of the embryo to the food supply. Materials. — Dry pods containing beans, soaked beans. Method and Observations. — Open the pods and pull a bean from its attachment. Note the scar where the bean was attached. This is called the hilum. Look for a tiny hole, the micropyle, at one end of the hilum. It was through this hole that the sperm cell reached the egg cell (micropyle means ‘little gate’’). Peel off the outer coat (testa) of a soaked bean. What use might it have? Note that the bean separates into two parts, called the cotyledons. Take off one cotyledon very carefully, and find two tiny folded leaves, the plumules, and a rodlike part, the hypocotyl. How does the hypocotyl point with reference to the hilum edge of the bean? All the parts within the seed coat are collectively known as the embryo. Conclusion. — 1. How is the embryo protected? 2. Can you find a use to the young plant of the hypocotyl? The plumule? The cotyledon? 3. Compare the bean seed with some growing beans (seedlings) a week or two old. How can you answer the questions above? 4. Notice in the older beans the cotyledons seem to be smaller than in the beans that have not sprouted. To account for this let us learn how to test for certain food substances or nutrients, then after making these tests, apply the same tests to the bean cotyledon and draw some valid conclusions as to the use of the cotyledon. PROBLEM 27 57 TEsts ror OrGANIC NUTRIENTS Problem 26: To test for starch. Materials. — Cornstarch, iodine solution,! and test tube. Method and Observations. — Add a small bit of starch to a test tube containing a little cold water. Add a few drops of iodine solution. Note the result. Make a little starch paste by heating with water; cool, add iodine as before. Do you get the same result ? NOTE. — The presence of starch and no other known substance is shown by a change to a deep blue color on addition of iodine. Now mash up a little of the bean cotyledon and add iodine. Is there any starch in the. bean? Work out in experiment form. Conclusion. — How would you detect the presence of starch in a substance? Problem 27: To test for rape sugar, a. Test with Fehling’s Solution Materials. — Glucose, Fehling’s solution,? test tubes, Bunsen burner. Method. — Place in a test tube a little glucose and water, add an equal amount of Fehling’s solution. Heat to the boil- ing point. Observations. — What color changes take place? NOTE. — If the color of the mixture becomes brick red upon heating, then grape sugar is present. Conclusion. — Is grape sugar present in the substance tested? 1Todine solution may be made by adding a few crystals of iodine to enough 95 per cent alcohol to dissolve it well. Or to 1 gram of iodine crystals, add ? gram of potassium iodide, and dilute to a dark brown color in 35 per cent alcohol. 2 Fehling’s solution may be made as follows: Add 35 g. of copper sulphate to 500 c.c. of water. Solution No. 1. To 160 g. caustic soda (sodium hydroxide), and 173 g. Rochelle salt, add 500 c.c. of water. Solution No. 2. For use mix equal parts of solutions 1 and 2. This may also be obtained of druggists, in tablet shape. 58 PLANT GROWTH AND NUTRITION b. Test with Benedict’s Solution Materials. — The same as above, but substitute for Fehling’s solution Benedict’s second solution.’ Method. — Place the material to be tested in a test tube with an equal amount of Benedict’s solution. Heat to boiling. Con- tinue boiling for two minutes. Observations. — Are there any changes in color? NOTE. — If grape sugar is present, a precipitate will be formed having a red, yel- low, or green color, depending upon the amount of sugar present. Conclusion. — 1. Is grape sugar present in the material tested? 2. Test apples, grapes, bananas, pears, or any other fruit to see whether grape sugar is present. 3. Make a table showing the amount of grape sugar present in various foods. Problem 28: To test for fats and oils. Materials. — Nuts or animal fat, white paper. Method. — Rub the nut or material to be tested on a piece of paper, and hold to the light, or put material to be tested on a piece of white paper in an oven for a few minutes. Observations. — What happens to the paper? Conclusion. — How would you know the presence of oil in a substance ? NOTE. — Ether and benzine extract oils from substances, and on evaporation leave the oil on the container. Test beans in this manner and write out in problem form for extra credit. Problem 29: To test for proteins or nitrogenous foods. Materials. — Raw and hard-boiled white of egg, hair, nitric acid, ammonia, test tubes. 1 Benedict’s second solution. — Copper sulphate i 17.3 g. Sodium citrate : 173.0 g. Sodium carbonate (anhydrous) 100.0 g. Make up to 1 liter with distilled water. With the aid of heat dissolve the sodium salts in about 600 c.c. of water. Pour through filter paper into a glass graduate and make up to 850 c.c. with distilled water. Dissolve the copper sulphate in about 100 c.c. of water, and make up to 150 c.c. with distilled water. Pour the carbonate citrate solution into a large beaker and add the copper sulphate solution slowly with constant stirring. After Hawke’s Biochemistry. PROBLEM 30 59 Method. — Place material to be tested in a test tube, with a little strong nitric acid, and heat gently. Note any color that appears. Rinse with water to wash off acid. Add a little am- monia and note any change in color. Observations. — What change in color takes place when the material is heated with nitric acid? NOTE. — If «a lemon-yellow color appears after the addition of nitric acid fol- lowed by a deep orange color on addition of ammonia, there is protein present. Home Experiments. Method 1.— Put some white of egg in a saucepan and heat it. Observations. — What happens as the white of egg is heated? NOTE. — Any substance thickening and becoming white in color is said to coagulate, and this indicates the presence of an albumen (a protein). Method 2. — Burn a hair, a feather, or a piece of meat. Observations. — Note the peculiar odor of burning hair or feather. This shows the presence of a protein. Conclusion. — 1. What are three ways of knowing the presence of proteins in a given substance? 2. By means of the nitric acid and ammonia test, find out whether there is protein present in the cotyledons of beans. Write up in experimental form. Tests ror InNorcanic NuTRIENTS Problem 30: To test for the presence of mineral matter. (Optional. ) Materials. — Meat, tin plate, and flame. Method. — Heat a piece of meat in a tin plate over a very hot fire. Observations. — Does all the meat disappear? Describe what is left. NOTE. — The remainder is a tasteless or slightly salty mass of mineral matter. Conclusion. — How can you determine whether a substance contains mineral matter? Home Work. — Test beans to see whether there is any mineral matter present, remembering that when heated ‘to a sufficient tem- 60 PLANT GROWTH AND NUTRITION perature, all organic material disappears; the remainder is ash or mineral matter. Problem 31: To test for the presence of water. Materials. — Meat, oven, balance. Method. — Weigh a piece of meat. Place it in a warm oven until it is thoroughly dry, then reweigh it. Observations. — What percentage of its original weight does the meat lose? Conclusion. —1. What is the cause of most of the loss in weight ? 2. As a result of your experiments, write a short statement as to what organic and inorganic nutrients are present in the bean. 3. What happens to the nutrients when the young plant grows? Give reasons for your answers. Problem 32: To test various food sub- mut riajeentios = >a 1 stances for the or- || te re (55 3 8 ganic nutrients. Food e =. & S$ a pe (Home Work.) Tested a : 3 A |S es : : 7 (48 1 1S Materials. — Pupils Potato may be supplied with testing chemicals to Bread take home or this exer- cise may well be a lab- Beans oratory exercise. Method and Obser- Egg vations. — Test with chemicals, as above, Peanut asmany different foods as possible, said foods QOpple to include meats, ce- reals, nuts, vegetables, Butter fruits. Make a table Nest Used like the accompanying. : After testing a food for Nee. i a given nutrient place one of the three fol- PROBLEM 33 61 lowing words in the proper column on a line with the food tested: none, little, much. Several pupils may work together and give their results to the class so as to make the record cover as many foods as possible. Conclusion. — 1. Name five common foods rich in protein; in starch; in grape sugar; in oil; in water. 2. Verify your results by comparing with food charts on pages 278-279 of your Civic Biology. A Stupy OF THE CONDITIONS NEEDED TO AWAKEN THE EMBRYO IN THE SEED Problem 33: To show how much water is needed to make a seed Serminate. (Home Experiment.) Materials. — Soaked peas, sawdust, cups. Method. — Pupils performing this or any other experiments must remember that the success of an experiment depends upon the accuracy with which it is performed and the exclusion of all factors from the experiment except the one which you are trying to prove. For example, in the following experiment on the effect of different amounts of moisture, all the other factors — tempera- ture, light, food, ete.—must be the same in each of the three cups; the only variable factor being moisture. Place an equal amount of moist sawdust in the bottom of each of three cups. Put ten soaked peas in each. Keep the seeds in one cup very wet, those in the second slightly moistened, and those in the third dry. Keep the cups covered in a moderately warm place. Examine them daily for seven days. Observations. — Tabulate results as follows: Number of Peas Sprouteda Day Dry Moist Wet First Day Second Day etc.,to Seven Days 62 PLANT GROWTH AND NUTRITION Conclusion. — What amount of water seems best for germina~- tion? Give your reasons. Problem 34: To determine the temperature best fitted to cause peas to Serminate, (Home Experiment.) Materials. — Soaked peas, sawdust, boxes. Method. — Plant twenty soaked peas in each of three boxes filled with moist sawdust. Put one box where the temperature is about 90° F., another where the temperature is about 70° F., and the third where the temperature is about 40° F. Give all the same conditions of air, light, and moisture. Observe them for ten days. Observations. — Tabulate the daily observations as follows: Temperature » * ~ Ast | 2na| 3a | 4th] Sth] 6th | Vth | Bth| 9th [10th 90 degrees " 70 degrees 40 degrees Conclusion. — What temperature seems best for germinating seeds? Reasons. Problem 35: To show that seeds need some part of the air in order to Srow. Materials. — Wide-mouth bottles, sand, soaked peas, corks, paraffin. Method and Observations. — Fill five flasks with varying amounts of wet sand so that one bottle contains very little air and others are one quarter, half, and three quarters full of air. Put an equal number of soaked peas into each bottle. Cork, and paraffin each cork so as to allow no air to enter. Place where all will have the same conditions of heat and light. Note daily growth on a table like the following. Conclusion. — In which bottles do the peas grow best? Why? PROBLEM 37 63 Number of Peas Sprouted Ist Day| and. ee Ath Sth. 6th Fth . 8th . 9th . loth Problem 36: To show that food is needed. by the embryo in order to $row. Materials. — Growing pea and bean seedlings. Method. — We have already found that beans contain a supply of food for the young plant. Test peas to see if food is also pres- ent in the cotyledons. After the peas and beans have begun to germinate remove the cotyledons and place them under favor- able conditions for continued growth. What happens? Allow bean seedlings to grow to a height of an inch, then remove both cotyledons from some, one cotyledon from others, and leave others with both cotyledons for controls. Which grow most rapidly? Conclusion. — What do you conclude from these results? Problem 37 ; Is any part of the air necessary for combustion ? (Demonstration. ) NOTE. — We have seen that seeds use up food in order to grow and that seeds grow only in the presence of air. We must now study the air in order to find what there is in it that enables seeds to use food and release the energy necessary for growth. 64 PLANT GROWTH AND NUTRITION Materials. — Bit of phosphorus, dish, float, bell jar. Method. — Place a bit of phosphorus on cork and float it in a pan of water. Ignite the phosphorus and quickly invert a bell jar over it. Observations. — What happens to the phosphorus? What happens to the water in the pan? NOTE. — Air is composed principally of two elements, nitrogen (about 79 per cent) and oxygen (about 20 per cent). When the phosphorus burns, it unites with one of the elements and forms a substance which dissolves in water. (See p. 20, Civic Biology.) Conclusion. — Judged by the amount of air which is dis- placed by water, which of the two gases of the air was used up? Problem 38: To test for oxygen. (Demonstration. ) NOTE. — Certain tests may be made by which the presence of some of the gases which compose the air may be isolated and studied. Pure oxygen, a colorless and odorless gas, is known by its ability to support combustion. Materials. — Oxone, potassium chlorate, black oxide of man- ganese, Bunsen flame, test tube with cork and delivery tube, wide-mouth bottle, large dish. Method. — Heat a little potassium chlorate in a test tube with about the same amount of black oxide of manganese. Chemical action takes place which results in the evolution of oxygen. This may be collected by a delivery tube or used in the test tube. Instead of this method, a patented substance known as oxone may be used. A small piece of oxone placed in water will liberate enough oxygen for several tests. The gas may be collected with the aid of a delivery tube by displacing water from test tubes or bottles. Observations. — In a test tube containing oxygen plunge the glowing end of a match. What happens to the glowing miatch? What difference is there between the burning of ae match in air and in oxygen? Place a piece of red-hot iron wire in oxygen; a ie of heated magnesium wire. What happens in each case? NOTE. — When oxygen combines with any substance, the process is called oxidation. The substance with which the oxygen unites is said to be oxidized, and heat is released as a result of the process. PROBLEM 40 65 When an iron nail is placed in a damp place, it rusts. This is also an oxidation, the iron of the nail uniting with the oxygen of the air. Conclusion. — 1. Explain exactly what happens when a glow- ing match is placed in pure oxygen. 2. Is it correct to say that oxygen burns up? : 3. What is always released as a result of oxidation? 4. Explain the difference between rapid oxidation (combustion) and slow oxidation. Problem 39: To test for carbon. Materials. — Meat, bread, starch, etc., glass plate, candle. Fig- ure page 65, Civic Biology. NOTE.— All organic substances contain the chemical element carbon. This may be proved by burning a substance. If it becomes charred or blackened, it contains carbon. Method and Observations. — Test meat, bread, dried peas, and starch for carbon. Hold a clean piece of glass over the flame of a candle. What forms on the glass? Where does it come from? Conclusion. — Make a table showing substances tested, noting whether or not they contain carbon. Problem 40: To test for carbon dioxide. NOTE. — We have seen that substances that burn unite with the oxygen of the air when they are oxidized. Let us next see what happens to the air when carbon unites with oxygen. Materials. — Candle, limewater,! wide-mouth bottle. Method. — Burn a candle (which has been proved to contain carbon) in a wide-mouth bottle, then add a little limewater and shake the bottle. Observations. — What change takes place in the limewater? NOTE. — A gas called carben dioxide causes limewater to become milky. Conclusion. — 1. How is carbon dioxide formed? 2. What is the test for the presence of carbon dioxide? 3. Explain this formula, C + 20 = CO.. 1 Limewater is made ty adding a piece of quicklime the size of your fist to about 2 quarts of water. Filter before using. HUNTER LAB. PROB. —5 66 PLANT GROWTH AND NUTRITION Problem 41: To prove that organic substances are oxidized within the human body. Materials. — Wide-mouth bottle, glass tube, limewater. Method and Observations. — Force the breath through a tube into limewater. What happens? Conclusion. — 1. What is one substance that comes from the lungs? 2. How and where must this substance have been formed? 3. If oxidation takes place in the human body, and heat or energy is released as a result of this oxidation, then something must be oxidized within the human body when it does work. Your answer will be helped by reference to the next problem. 4. Burn several different substances as starch, sugar, bread, cake, nuts, and meat in closed jars. Test contents of jars with lime- water. What do you conclude was present in these substances? How do you know? What other substance is given off when these materials burn? Touch the jars. What does this suggest with reference to energy released? Problem 42: To prove that Srowing seeds oxidize food. Materials. — Two Erlenmeyer flasks, rubber stopper, soaked peas, blotting paper. Co Method 1.— Put soaked blotting paper in mM each of two flasks and place an equal number of peas in each flask. Cork one flask only. Observations. — Watch for evidences of growth ineach flask. Note carefully just what happened to the peas in the closed flask ; in the open flask. Conclusion. — Remembering what you have learned in your previous experiments, how would you account for what you see? Method 2.— Now test the air in the closed flask with limewater. (Or a bottle containing limewater may be placed in the jar at the be- ginning of the experiment. See accompanying figure.) THEe INcCLOSED BOTTLE CONTAINS LIMEWATER. Observations. — What happens? PROBLEM 45 67 Conclusion. — 1. How do you account for the presence of carbon dioxide in the closed flask? 2. Why did the seeds in the open flask grow? 3. From what source did the seeds get their energy to grow in the open flask ? General Conclusion. — Write up a brief statement, using proof to show that energy is locked up in food and that it can be released and used only by oxidation. Problem 43: To study the fruit of the corn plant. Materials. — Ripe corn on the cob. Method. — Compare the ripe corn on the cob with the picture on page 67 of your Civic Biology and with specimens shown by the teacher. Observations. — What differences are there between the young and the old specimens? Conclusion. — Is the ear of corn a single fruit or a bunch of fruits? Give reasons for your answer. Problem 44: To study the structure of a Srain of corn. Materials. — Entire soaked corn grains and some cut lengthwise at right angles to the flat surface. Figure page 66, Civic Biology. Method and Observations. — In an entire corn grain find a light-colored area on one side. Th‘s marks the position of the embryo. In a grain cut lengthwise at right angles to the flat side find the embryo. Describe its shape, position, and relative size compared with the rest of the corn grain. NOTE. — The area outside of the embryo is known as the endosperm. Place iodine on the surface of the cut corn grain. Describe what happens. ‘Test for protein. Conclusion. — 1. What nutrients are present in the corn? 2. Where are they found? Problem 45: To find the use of the endosperm of the corn Ssrain. Materials. — Sprouted corn grains, scalpel, and sawdust. 68 PLANT GROWTH AND NUTRITION Method. — In some corn grains that have sprouted remove the endosperm. Place them side by side in moist sawdust with some normal sprouted grains. Give each lot of seedlings the same con- ditions of water, light, and air. Observations. — Watch them carefully for a period of at least two weeks. What differences do you observe in the rates of growth in the two lots of seedlings? Conclusion. — What is the use of the endosperm to the corn? Problem 46: To find whether starch or Srape sugar will dis- solve in water. Materials. — Test tubes, starch, grape sugar. Method. — Shake up a little starch with water. Let it stand for a few minutes. Shake up an equal amount of dry grape sugar in water. Let it stand for the same length of time as the starch. Observations. — How do the two compare in appearance? NOTE. — A substance is said to be soluble when it dissolves or entirely disappears from view in water or some other liquid. Conclusion. — Is starch or grape sugar soluble in water? Problem 47: To find how the young plant makes use of the food supply. Digestion. Method and Observations. — Wash some dry, unsprouted corn grains and test them for grape sugar. Then cut some corn grains that have just begun to germinate lengthwise through the embryo and test for grape sugar. Look for changes in color between the embryo and endosperm. NOTE. — Under certain conditions when starch is changed to grape sugar it is said to have been digested. In the corn plant this is accomplished by a digestive ferment, or enzyme, called diastase. What differences between the unsprouted and sprouted corn do you find? Conclusion. — 1. What happens to the starch when corn sprouts? 2. What causes this change? 3. Of what use would this change in the form of the food supply be to the young plant? PROBLEM 50 69 4. Why is it necessary that plants digest starchy and other foods? Problem 48: What changes take place in starchy foods in the mouth? (Demonstration.) Materials. — Cracker, Fehling’s solution, Bunsen burner, test tube. Method and Observations. — Chew an unsweetened cracker slowly. Note any change in taste. Test some of the unchewed cracker with Fehling’s solution. Result? Place a little of the chewed cracker and saliva in a test tube, add Fehling’s solution, and heat. What happens? Conclusion. — What happens to starchy foods in the mouth? Of what use might this be to man? Problem 49: Conditions necessary for the action of diastase. Materials. — Test tubes, diastase, starch paste, ice, Fehling’s solution, Bunsen flame, test-tube rack. Method. — Place a little diastase in three test tubes containing starch paste. Label them 1, 2, and 3. Place 1 in the icebox on the ice; boil the contents of 2 and then place it with 3 in the test- tube rack in the laboratory. Observations. — After 24 hours test the contents of each of the three tubes for sugar. Has digestion taken place in all tubes? NOTE. — Diastase has thus been shown to act only under certain conditions. Water must be present and a certain temperature. Its action may be prevented by extreme heat. In these respects it acts as if it were like a living substance. Conclusion. — What conditiors are most favorable to digestion by the diastase? NOTE. — Pure diastase must be used for this experiment. Most diastase prepa- rations contain grape sugar. Problem 50: What is the reason for digestion of starch in the corn grain? Materials. — Funnels, filter paper, starch, sugar, beaker. Method. — Take two funnels, place filter papers within each. In one funnel place a mixture of starch and water, in a second a 70 PLANT GROWTH AND NUTRITION solution of grape sugar and water. Collect in a beaker the filtrates (the substances that pass through the filter paper). Observations. — Do the contents of both funnels pass through the filter papers? Test the contents of the vessels into which the contents of the first and second filter have passed, the first with iodine, the second with Fehling’s solution. What happens? Conclusion. — 1. If the corn seedling absorbs or takes in food, what forms must it be in? How do you know? 2. What is the purpose of digestion in plants? PROBLEM QUESTIONS 1. What results from the fertilization of a flower? 2. What are the uses of the various parts of a plant embryo? 3. How is an embryo protected? (Think of a corn or bean embryo.) 4. What are nutrients? 5. How could you detect starch, protein, grape sugar, or oil in any substance? 6. Why would it be necessary to mash up or boil a. substance which you wished to test for starch? 7. How could you detect the presence of mineral matter in a bean ? 8. How could you test for the presence of water in a substance? 9. Name five substances containing starch; fat; protein. 10. What conditions are necessary to make an embryo grow? 11. Why is air necessary? Explain just what air does. 12. Could a plant do work without oxygen? Explain. 13. What happens as a result of oxidation of wood or coal? 14. What happens when oxidation takes place in the body? 15. How could you prove that plants and animals use oxygen for the same purpose? 16. What is an ear of corn? A grain of corn? Explain with reference to diagrams in your Civic Biology, pages 67, 69. 17. How and where is food stored in a corn grain? 18. A corn grain grows. How can it get its food so as to make use of it? REFERENCE BOOKS 71 19. Will starch pass through a filter paper? Will sugar? How can you explain this? REFPRENCE Booxs Hunter, Civic Biology, Chap. V. American Book Company. Hunter, Elements of Biology, Chap. VI. American Book Company. Hunter, Essentials of Biology, Chap. VI. American Book Company. Corbett, The Propagation of Plants. Farmers’ Bulletin No. 157, U. S. Depart- ment of Agriculture. Ganong, The Living Plant. Henry Holt and Company. Kerner (translated by Oliver), Natural History of Plants. Henry Holt and Com- pany, 4 vols. Vol. II, Part 2. Lubbock, Flowers, Fruits, and Leaves. The Macmillan Company. MacDougal, Experimental Plant Physiology. Longmans, Green and Company. Sargent, Corn Plants. Houghton Mifflin Company. Schimper, Plant Geography on a Physiological Basis. Frowde, London. Soraurer, A Popular Treatise on the Physiology of Plants. Longmans, Green and Company. VI. THE ORGANS OF NUTRITION IN PLANTS — THE SOIL AND ITS RELATION TO THE ROOTS Problem.— What a plant takes from the soil and how it Sets it. (a) What determines the direction of Srowth of roots? (6) How is the root built? (ec) How does a root absorb water? (d) What is in the soil that a root might take out? (e) Why is nitrogen necessary, and how is it obtained ? LaBoraTory SUGGESTIONS Demonstration. — Roots of bean or pea. Demonstration or home experiment. — Response of root to gravity and to water. What part of root is most responsive? Laboratory work. — Root hairs, radish or corn, position on root, gross structure only. Drawing. Demonstration. — Root hair under compound microscope. Demonstration. —- Apparatus illustrating osmosis. Demonstration or a home experiment.— Organic matter present in soil. Demonstration. — Root tubercles of legume. Demonstration. — Nutrients present in some roots. To tHe TrEacHeEeRr. — The principle of osmosis, one of the most difficult concepts the child has to grasp, is the keynote of the work of this chapter. The practical side is seen in the reference to crop rotation, nitrogen-fixing bacteria, and the like. Every educated person should be informed on the principles underlying the work of the bacteria of decay and the nitrogen-fixing bacteria in soils. The root as an organ of absorption should be demonstrated fully, with individual laboratory work on root hairs as structural organs, so that the child may realize the extreme delicacy of these absorbing organs. ’ Problem 51: To find out the structure of roots. Materials. — Bean, pea, or corn seedlings grown in sawdust. Method and Observations. —In the roots of a bean seedling notice the main root. From what part of the embryo did this come? Branches of this main, or primary root, are called sec- 72 PROBLEM 53 73 ondary roots. Notice the direction taken by the main root; by the secondary roots; by the rootlets. Conclusion. — Remembering that a tall stem is sent into the air: 1. What is one reason for the wide spreading of roots? 2. What might be one other use of roots to a plant? Problem 52: To determine the influence of gravity on the direction of Srowth of roots. Materials. — Radish or mustard seeds, pocket garden. Dia- gram page 72, Civic Biology. Method. — Grow radish or mustard seeds in a pocket garden placed on edge until the roots are a half inch long; then turn it on another edge and examine again after 24 hours. Repeat after another 24 hours. Observations. — Which part of the root grows down each time the garden is turned? NOTE. — The force which pulls objects toward the center of the earth is known as gravity. Conclusion. — 1. What causes roots to turn downward? 2. What part of a root is most influenced by this force? Problem 53: To find the effect of water on the growth of roots. Materials. — Radish or mustard seeds, sponge. Method. — Plant soaked mustard or radish seeds on the outer side of a moist sponge. Suspend the sponge under a bell jar in moderate temperature. Observations. — What happens to the roots? Conclusion. — 1. What effect does water have on the direc- tion of growth of roots? 2. Which influence is more powerful, moisture or gravity? 1A pocket garden may be made as follows: Get a couple of 4 * 5 negative plates, clean them, and cut five pieces of blotting paper about } inch smaller than the glasses. Lay the blotters on one of the plates, and cut four }-inch strips of wood so as just to fit on the glass outside the blotters. Moisten the blotters, place some well-soaked seeds of mustard, barley, or radish on them, cover the seeds with the other glass, and bind the glasses together with bicycle tape. 74 SOIL AND ITS RELATION TO ROOTS Problem 54: To study the structure and purpose of root hairs. Materials. — Radish or mustard seeds, blotting paper, Syracuse watch glasses, thin glass plates, glass slide, cover slip, microscope. Diagrams pages 74, 75, Civic Biology. Method. — Grow radish or mustard seeds on blue blotting paper in Syracuse watch glasses, covering each watch glass with a thin glass plate. Observations. — Describe the structures you see growing from the roots. These are called root hairs. Where are they the longest? Where the most abundant? Place a radish or mustard seedling on a glass slide. Mount in a drop of water and cover with a cover slip. Examine with the low power of a microscope. What can you say of the thick- ness of their walls? Of how many cells does a root hair seem to consist ? If the root were covered with these thin-walled, delicate struc- tures, what effect would they have upon the absorbing surface of the root? Conclusion. — 1. Tell what you believe to be the purpose (function) of root hairs. Give good reasons. 2. Why should the wall of a root hair be thin? Drawing. — A seedling showing position of root hairs. Problem 55: To discover how fluids travel through roots and stems. Materials. — Carrot or parsnip, iodine, red ink, scalpel, micro- scope. Method. — Cut a cross section through a fleshy root (carrot or parsnip) and dip in iodine. Also place sprouting parsnips in red ink for two or three days, then cut cross and longitudinal sections. Observations. —In a stained cross section note the cortex (outer part) less deeply stained than the wood (the inner part). To THe TracHEer.— Excellent demonstration material may be obtained by placing celery stemsin red ink. Asparagus also shows well. Several different types of stems might be shown to bring out differences in dicotyledonous and monocoty- ledonous stem structure. Our next experiment will show us how the fluid gets from the outside to the inside of the root. PROBLEM 56 75 Find little cores of wood extending out through the cortex into the rootlets. This so-called central cylinder is made up of bundles of tubelike cells. The cells collectively form the fibrovascular bundles. In the picture of the cross section (see page 74, Civic Biology) find (1) the vortex, (2) the central cylinder, and (3) the root hairs. How many cells are in a root hair? From what part of the root do the root hairs grow? Place some bean or corn seedlings in red ink. Allow them to remain in the sun for a few hours and then examine the stem and leaves carefully. What has happened? Cut a cross section of one of the above stems. Which part of the root and stem shows the pres- ence of red ink? Examine free-hand sections under the microscope. Conclusion. — By what path do fluids pass up the root and stem? Problem 56: To find out how root hairs absorb soil water. Materials.— Egg or glass test tube (large), celloidin, sealing wax, glass tubing, thistle tube. Method. — To make an artificial root hair we may take either an egg, or a celloidin cell, which is made by pouring a little thin celloidin into a clean test tube, revolving the tube rapidly, and then carefully removing the film of celloidin which has been formed within the tube. With care a nearly uniform artificial membrane will have been formed within the tube. This, when removed, may be filled with glucose solution, or any dense material that will dissolve in water. Tie the upper end of | aan APPARATUS TO SHOW Osmosis. it tightly over the wide end of a thistle tube and insert the bag in a dish of water. If an egg is to be used, break the shell at one end and remove 76 SOIL AND ITS RELATION TO ROOTS part of it so carefully as not to tear the membrane directly under the shell, then break the other end, insert a glass tube in it, and cement the tube in place with sealing wax. Then place the egg with the exposed membrane in water. Observations. — Are there any changes in the level of the liquid in the tube? NOTE. — The process by which two fluids or gases, separated by a membrane, pass through the membrane and mingle is called osmosis. The greater flow is usu- ally from the less dense toward the denser medium. Test the water in the jar (if you used glucose in your artificial cell) to see if glucose passed through the membrane. Conclusion. — 1. Explain, using one of the above experiments as a basis, how osmosis takes place. 2. How do root hairs take in soil water? 3. What might help force liquids up the stem of the plant? Problem 57: To determine what kind of substances will pass through a membrane. Materials. — Glass jar, two thistle tubes, membrane or parch- ment paper, starch, grape sugar, iodine, Fehling’s solution, test tubes. Method. — Fill two thistle tubes, one with glucose and water, the other with starch and water ; tie membranes tightly over each. Wash carefully to remove all starch or sugar from outside of tubes. Then place each in a jar half filled with water. After 24 hours, test contents of the jars, one for starch and the other for grape sugar. (See lower figure, page 100, Civic Biology.) Observations. — Notice if any change has taken place inside the thistle tubes. What changes take place after testing the contents of the jar? Conclusion. — 1. Does starch or sugar pass through a mem- brane by osmosis? 2. Can you make a generalization to cover soluble and insolu- ble substances? NOTE. — Osmosis or exchange of gases will also take place through a membrane. If carbon dioxide and oxygen gases were separated by a membrane, they would tend to pass through the membrane and mingle with each other. PROBLEM 59 77 Problem 58: To test organic material in soil. Materials. — Samples of different kinds of soils, balance and weights, Bunsen burner, pieces of tin. Method. — Obtain a small quantity of vegetable mold, rich gar- den soil, and soil from a sandy road. Allow each lot to remain for several days in a dry place so as to remove surplus water. Then take eight ounces of vegetable mold from a forest, eight ounces of rich soil from a garden, and the same amount from a sandy road. Weigh carefully, place each on a piece of tin or sheet iron, and heat red-hot for at least 20 minutes. Now reweigh each sample. Observations. — Tabulate results as follows: Vegetable | pichSoil | Barren Original Weight Weight after burning Loss in Weight Conclusion. — 1. How do you account for the losses in weight ? 2. Might there be a loss of more than one substance to account for this? Problem 59: To find what kind of soil holds water best. Materials. —Gravel, sand, clay, loam, leaf mold, wide-mouth bottles, balance and weights, one-hole rubber stoppers, glass tubing. Method. — Weigh out an equal amount of gravel, sand, clay, rich loam, leaf mold, and one quarter as much by weight of dry leaves. Prepare six bottles, cut out the bottoms, placing the various materials in the bottles as shown in the lower figure, page 78, Civic Biology. Into each bottle now pour slowly one pint of water. Measure the amount of water that drips through each bottle. 78 SOIL AND ITS RELATION TO ROOTS Observations. — Tabulate the exact amount of water left in the soil in each case. unt i of Water Gravel) Sand | Clay Banks. ree a|Leaves Addea ec aught Left in Soils Conclusion. — 1. Of what use is the forest covering of leaf mold? 2. Which kinds of soils would be most favorable for crops and why? Problem 60: What do plants take out of the soil? Materials. — Glass jars, distilled water, nutrient solution, corn seedlings. Method. — Partly fill five jars, the first with distilled water, the second with nutrient solution! without potassium nitrate, a third with nutrient solution without calcium phosphate, the fourth with nutrient solution without ferric chloride, and a fifth with nutrient solution. Place in the jars corn seedlings with their roots in the liquids. Keep them under observation for two or more weeks. 1A nutrient solution known as Sach’s solution may be made as follows: Potassium Nitrate OL a. aes OP ity hae Ah SS. See ae ei 1.00 gram Sodium Chloride 3 “ . Bo Rhy SB 0.50 gram Calcium Sulphate B. Ge raps Aan way Se: Tats etn ae SO Bir 0.50 gram Magnesium Sulphate >) Yr ke a 78 i 2 & wo 0.50 gram Calcium Phosphate iar ee ee ae ‘ 0.50 gram Ferric Chloride . . % ‘ ‘ . 0.005 gram Distilled Water . Ge Oe ee Se RE ee . . 1000.00 grams Add the ferric chloride at the time the solution is to be used, by adding a drop or so to the solution in the bottle used for the seedlings. PROBLEM 62 79 Observations. — In which does the most vigorous growth take place? Conclusion. — 1. What materials do plants take in with water? 2. What is the source of these materials? Problem 61: How are root hairs able to take mineral matter out of the soil? Materials. — Vigorous bean or corn seedling, test tubes on base, phenolphthalein solution. Method. — To a solution of phenolphthalein add drop by drop a little strong nitric acid. Notice what happens. Place in another tube containing a phenolphthalein solution (which should be almost neutral) a growing seedling. Leave overnight and then observe. Compare with a control tube con- taining phenolphthalein. Observations. — Compare the color in the control tube with the color in the tube containing the seedling. Compare the tube to which acid was added with that containing the seedling. Conclusion. — 1. What substance is given off by roots? 2. What effect might this have upon certain minerals in the soil? (Try the effect on a bit of limestone.) Problem 62: What are root twbhercles and what is their use? Materials. — Clover or bean plants. Diagram page 81, Civic Biology. Method. — Remove and wash carefully the roots of a clover or bean plant. Place in a test tube with a base for laboratory study. Observations. — Do you find little lumps or tubercles on the roots? Locate exactly. NOTE. — Root tubercles are small knoblike structures which develop on the roots of leguminous plants (clover, alfalfa, peas, beans, cowpeas, etc.). In these tubercles develop millions of little plants called nitrifying bacteria. These plants alone of all others are able to take nitrogen from the air and to combine it with certain mineral substances in the soil to form nitrates. In this form it is taken up by plants. 80 SOIL AND ITS RELATION TO ROOTS Conclusion. — 1. By what means do plants get a fresh supply of nitrogen? 2. Why do peas and beans contain so much protein food? Problem 63: What is crop rotation and what is its use? NOTE. — A regular order of crops in which some nitrogen-fixing crops are fol- lowed by plants which take nitrogen from the soil is known as crop rotation. Method. — Suppose on four farms crops are planted each year as follows: lst YEAR 2p YpHaR 8p YEAR 4TH YEAR 5TH YEAR 6TH YEAR ‘ Beans 1. Clover Wheat Tobacco Clover Wheat and Peas Wheat 2. Corn Rye or Grass Clover Wheat Oats 3. Corn Oats Wheat Grass Potatoes Corn Clover Clover Clover 4. Clover Corn Corn and and and Grass Grass Grass Conclusion. — 1. Which of the above crops are nitrogen pro- ducing? Nitrogen taking? 2. Which of the four farms gets the most out of the soil? Why? 3. Explain what is meant by crop rotation. Why is it of great importance? Problem 64: What roots are useful as food? Method. — Test as many different roots as possible for the presence of nutrients. Make a list of some roots used by man as food and some used by animals other than man. Conclusion. — 1. What roots are most useful to man as food? 2. What roots are used by animals other than man ? PROBLEM QUESTIONS 81 PROBLEM QUESTIONS 1. Why is the root called the mouth of a plant? 2. From where would water come that roots take in? 3. How could water pass from the root hairs into the woody center of a root? 4. What has osmosis to do with plant nutrition ? 5. What has osmosis to do with our own nutrition ? 6. How do you know gravity affects roots? 7. Why might forests have an effect upon the climate of a given part of the country? 8. Why is it important not to cut down trees near the sources of our rivers? 9. What do roots have to do with the holding and distribu- tion of water? 10. Why do peas and beans contain a large amount of nitroge- nous food? 11. Very much larger yields are had from crops in some parts of the world than in others. How do you account for this? 12. Why do some farmers plant beans or cowpeas in their corn fields between the hills of corn? Is the custom good or bad? Explain. 13. What plants store food in their roots? 14. How do foods become stored in roots? 15. For what reason should a city boy or girl study about roots? 16. Why do farmers plant seeds a short distance below the sur- face of the ground? 17. Why do farmers cultivate (break up) the soil? 18. What is the reason for placing dead leaves or other dead organic matter on the surface of the ground early in the winter? 19. What is weathering? How does it affect rocks? 20. Find the factors that influence the making of soil. 21. Why should plants not be crowded together in the soil? 22. What kinds of soil retard evaporation? Why? 23. Why do we hear so much nowadays of going back to the soil? What does this term mean? HUNTER LAB. PROB. —6 82 SOIL AND ITS RELATION TO ROOTS REFERENCE Books Hunter, Civic Biology, Chap. VI. American Book Company. Hunter, Elements of Biology, Chap. VII. American Book Company. Hunter, Essentials of Biology, Chap. VII. American Book Company. Andrews, Botany All the Year Round, Chap. II. American Book Company. Atkinson, First Studies of Plant Life, Chaps. IX, XI, XII. Ginn and Company. Bailey, Principles of Agriculture, Chaps. V, VI. The Macmillan Company. Bailey, The Rotation of Crops. Cosmopolitan Magazine, April, 1905. Baldwin, The Human Side of Farming. The Outlook, Aug. 27, 1910. Briggs and others, The Centrifugal Method of Soil Analysis. Bulletin No. 24, Bureau of Soils, U. 8. Department of Agriculture, 1904. Burkett, The Vital Facts of Agriculture. Country Life in America, January, 1905. Burkett, What Crops to Grow and How to Put the Land in Condition. Country Life in America. January, 1905. Clinton, Soil, What it Does. Cornell University Nature Study Quarterly, No. 2, October, 1909. Clute, Agronomy. Ginn and Company. Coulter, Plant Life and Plant Uses, Chaps. III, IV. American Book Company. Coulter, Barnes, and Cowles, A Textbook of Botany, Part II. American Book Company. Detmer-Moor, Practical Plant Physiology. The Macmillan Company. Duggar, Plant Physiology. The Macmillan Company. Fairchild, The New Hope of Farmers. World’s Work, July, 1906. Field, Scientific Agriculture. Report of the Rhode Island Board of Agriculture, 1896. Fippin, The Soil, Its Use and Abuse. Cornell Reading Course Bulletin, Oct. 15, 1911. Goff and Mayne, First Principles of Agriculture. American Book Company. Goodale, Physiological Botany. American Book Company. Gray, Structural Botany, pp. 27-39, 56-64. American Book Company. Green, Vegetable Physiology, Chaps. V, VI. J. and A. Churchill. Hall, The Soil as a Battle Ground. Harpers’ Magazine, October, 1910. Hilgard, Soils, their Formation. The Macmillan Company. Hunt, The Importance of Nitrogen in the Growth of Plants. Cornell University Experiment Station Bulletin, No. 247, June, 1907. Huntington, Beans and Peas for Fertilizer. Long Island Agronomist, No. 8, Nov. 3, 1909. Jenkins, Keeping up Fertility. Garden Magazine — Farming, June, 1910. Kerner-Oliver, Natural History of Plants. Henry Holt and Company. MacDougal, Plant Physiology. Longmans, Green and Company. Martin, The Work of the Brook. Cornell University Nature Study Quarterly, No. 5, June, 1900. Massey, Practical Farming. A.C. McClurg and Company. Moore, The Physiology of Man and Other Animals. Henry Holt and Company. Moore, Sowl Inoculation. Century Magazine, October, 1904. Murray, Soils and Manures. D. Van Nostrand and Company. Pfeffer, The Physiology of Plants. Clarendon Press. Seton, Gophers as Soil Formers. Century Magazine, June, 1904. REFERENCE BOOKS 83 Stevens, Introduction to Botany, pp. 31-44. D.C. Heath and Company. Tarr, A Handful of Soil. Cornell University Nature Study Quarterly, No. 2, Octo- ber, 1899. Tarr, A Summer Shower. Cornell University Bulletin No. 1, June, 1899. Warren, Elements of Agriculture. The Macmillan Company. Wilkinson, Practical Agriculture. American Book Company. VII. PLANT GROWTH AND NUTRITION — PLANTS MAKE FOOD Problem.— Where, when, and how Sreen plants make food. (a) How and why is moisture given off from leaves? (6) What is the reaction of leaves to light? (ec) What is made in green leaves in the sunlight? (a) What by-products are Siven off in the above process? (e) Other functions of leaves. LABORATORY SUGGESTIONS Demonstration. — Water given off by plant in sunlight. Loss of weight due to transpiration measured. Laboratory exercise. — (a) Gross structure of a leaf. (b) Study of stoma and lower epidermis under microscope. (c) Study of cross section to show cells and air spaces. Demonstration. — Reaction of leaves to light. Demonstration. — Light necessary to starch making. Demonstration. — Air necessary to starch making. Demonstration. — Oxygen a by-product of starch making. To THE TEAcHER. — In this chapter experimental work may be made to carry almost the entire plan of the chapter. That plants make food out of raw food materials may be demonstrated by a series of logical experiments which leave no doubt as to the steps taken or the factors involved in this wonderful process. That the whole world depends upon the process of photosynthesis is well known. A concevt of what the process is and what it does for mankind should be known by every ‘pil when he has finished the exercises which follow. Laboratory problems having ‘vid adherence to the logical sequence of events which culminate in food making aid food storage in the leaf, will result in increased power on the part of the pupil and a beginning of appreciation of what a developed problem really means. To the critic who would object to so much time given to the processes involved in photosynthesis we would say: starch making and food making may be tied up in a vital manner to the interest of the city child by drawing atten- tion to the economic importance of cereal and other staples furnished man by plants, and by making clear the tremendous importance of green plants in the réle of food makers on the earth. (See Chapter XI, Civic Biology.) 8&4 PROBLEM 67 85 Problem 65: To prove that water is given off by a green plant. Materials. — Bell jar, a growing single-stemmed green plant as a geranium, rubber tissue, balance. Method 1.— Cover with rubber tissue a flower pot in which a vigorous rubber plant or geranium is growing, so that only stem and leaves are exposed. Water the plant prior to covering with the rubber tissue. Then weigh the plant. Record weight. Then reweigh the plant after two or three hours. Observations. — What difference in weight do you observe? Method 2.— Water the plant, tie up with rubber tissue as be- fore, and place under a bell jar. Observations. — What collects on the inner surface of the jar? Conclusion. — 1. To what is the loss of weight due? 2. How and when does the water get out of the plant? NOTE. — The giving off of water in the form of vapor through the leaves is called transpiration. Problem 66: Through which surface of a leaf does transpir- ation take place? Materials. — Two rubber-plant leaves, vaseline, scales. Method. — Cover the upper surface of one leaf and the lower surface of the other with vaseline. Vaseline both leaf stalks at the end where the leaves were broken off. Balance the leaves exactly on the scales and place in a sunny place. Observations. — What happens? Conclusion. — Through which surface of a leaf does transpira- tion take place? How do you know? Problem 67: To determine how the structure of a leaf fits it for the work it has to do. Materials. — Entire leaf. Method and Observations. — Examine a leaf of maple or oak. Notice that it consists of two parts: astem, the petiole, and a broad expanded part, the blade. Note, also, that the petiole leads into a number of branching veins which support the blade. Estimate the amount of green leaf surface in a plant in the room by multiply- ing the surface area of one leaf by the number of leaves on the plant. 86 PLANTS MAKE FOOD Conclusion. — 1. What seems to be one purpose of the veins? 2. Remembering that the veins contain fibrovascular bundles, the tubes which conduct fluids through the plant, determine another function. 3. How is the leaf fitted to receive light? Explain. Problem 68: To study the microscopic structure of a leaf. Materials. — Leaf of geranium, glycerine, compound microscope, glass slides, cover glasses, needles. Diagram, page 86, Civic Biology. Method. — Remove with a needle a tiny portion of the under surface of a leaf such as the geranium, or Tradescantia, mount in water or glycerine, and examine with the low power of a compound microscope. Observations. — Note numerous small structures (stomata) scattered between the irregular cells of the epidermis. NOTE.— Each stoma is bounded by two bean-shaped cells, guard cells. By slight changes of shape these control the size of the openings into the leaf. Study a cross section of a leaf cut through a stoma, or a good chart showing a cross section through a stoma and a vein. Into what do the stomata open? The outer layer of cells, the epidermis, has little chlorophyll. What function might these cells have? (Look at the walls.) Beneath the epidermis find a layer of long cylindrical cells, palisade cells. Do these contain chlorophyll bodies? Below this layer note a layer of loosely joined cells, the spongy parenchyma. Do these cells contain as much chlorophyll as the palisade cells? How are they placed with reference to the stomata? Look at the vein. Where would water pass through it? Conclusion. — Knowing what you do about the use of a green leaf to the plant, determine one use of the stomata. Drawings. —1. Cross section under microscope. Label all parts. 2. Part of lower epidermis showing a stoma. ‘ Problem 69: To show the effect of light on Sreen leaves. Materials. — Oxalis or nasturtium plants. Method. — Place oxalis or nasturtium plants near a window. PROBLEM 71 87 Observations. — After several days notice the position of the blades of the leaves. Notice also the leaf stalks. Conclusion. — What is the effect of light on leaves and stems? NOTE. — Evidently sunlight has something to do with the life of a green plant; for a plant growing in complete darkness is yellow or bleached (for example, sprout- ing potatoes kept in darkness). Let us see if we can find out by experiment just what is the relation between light and green leaves. Problem 70: To determine the relation of light to the pres- ence of starch in a Sreen leaf. Materials. — Green plant, black alpaca, alcohol, iodine. Method. — Place any small green plant in a dark room for 24 hours. Then cover parts of several different leaves with strips of black alpaca. Expose to direct sunlight for an hour or more. Pick off the leaves partly covered with the black cloth, take off the cloth, and place the leaves in hot methyl alcohol. Next wash the leaves and place them in a solution of iodine. Observations. — What happens to the leaves after placing them in the alcohol? What happens to the leaves placed in iodine solution? Conclusion. — 1. Why do we place the plant in the dark at the beginning of this experiment? 2. What effect does sunlight have upon green leaves? How do you know? 3. What effect does absence of light have? NOTE. — Evidently a green leaf under certain conditions (light is one) manufac- tures starch. Let us find out another. Problem 71: Is apart of the air a factor in starch making in leaves? Materials. — Green potted plant, vaseline, iodine, alcohol. Method. — Treat the plant as in the last problem. After removing the plant from the dark room, vaseline both sides of two or three leaves. Place the plant in the direct sunlight for an hour or two, then pick off the vaselined leaves and some others, marking them so that you may know them. Place in hot methyl alcohol. After the chlorophyll is removed, test both vaselined and un- vaselined leaves for starch. 88 PLANTS MAKE FOOD Observations. — Do both lots of leaves show the presence of starch? Conclusion. — What is another factor necessary for the manu- facture of starch in green leaves? Problem 72: The need of chlorophyll for starch making. Materials. — Coleus or other plant with variegated leaves, iodine, methy] alcohol. Method. — Place the plant in full sunlight for an hour or two. Test these several leaves with iodine after removing chlorophyll with methyl alcohol. Observations. — Do all the leaves show the presence of starch? Do all parts of the variegated leaves show starch? Conclusion. — Is chlorophyll necessary for starch making? Problem 73: To consider the leaf as a manufactory. NOTE. — Starch is made of the elements carbon, oxygen, and hydrogen. We have seen that the roots of a plant take up soil water and we have found holes in the leaves through which gases of the air might enter. Water (H:O) would account for the hydrogen and oxygen, and carbon dioxide (CO:) will furnish the carbon and oxygen. Let us compare the leaf with a mill for making starch. The sun furnishes the energy to run the mill and the chlorophyll grains are the millstones. Carbon dioxide and soil water are the raw products put into the mill. Observations. — Study figures on pages 92, 93, Civic Biology. 1. What is the source of the water used in the leaf? 2. Where does the carbon dioxide come from? Trace it back to its manufacture. 3. What does the sun have to do with the work of a leaf? Conclusion. — Write a paragraph telling how starch is made in a leaf. Use the terms machinery, raw materials, manufac- tured products. Problem 74: To show that a gas is Siven off as a waste product when green plants make starch. Materials. — Elodea, glass jar, funnel, test tube. Method and Observations. — Place some Elodea under a funnel in fresh water. Then invert a test tube filled with water over the funnel. See that the tube of the funnel is completely filled with PROBLEM QUESTIONS 89 water. Place the jar in the sunlight for a day or two and collect any escaping gas in the test tube. (See figure on page 95, Civic Biology.) If carbon dioxide is occasionally passed from a gener- ator through the water in the jar, the evolution of the gas is increased. Place a glowing splinter in the gas. What happens? What does this indicate? Set up the apparatus again and let it stand overnight. Has any gas been formed? NOTE. — The process of starch formation in green leaves in sunlight is called photosynthesis (photo— light, and synthesis — a building up). Chemically, water (HO) and carbon dioxide (COz) are built up by the energy of the sun into a sub- stance which ultimately becomes starch (CsHiw0;). During this process oxygen gas is given off as a by-product. Conclusion. — 1. If work is done by the plant, then how does it use oxygen? 2. What gas would a green plant give off at night? Explain. 3. What gas would be given off in the sunlight? PROBLEM QUESTIONS 1. What substances are given off by green leaves? 2. Trace the pathway of water in a dicotyledonous plant from the time it enters to the time it leaves the plant. 3. What does a plant do with the water it takesin? The gases of the air that enter the leaves? The mineral matter that passes in through the roots? 4. If dead plants are burned in the fall, does as much raw food material get back in the soil as if the dead bodies were plowed under? 5. Why are green plants said to be constructive while animals are said to be destructive? 6. Compare a leaf toafactory. Where does the energy to run the plant come from? 7. Why should the leaves of plants in our homes be frequently dusted and washed? 8. Why do the leaves of lettuce or cabbage when “headed ” turn white? 9. What are some adaptations in leaves to receive light? 10. Find some ways in which leaves are protected. 90 PLANTS MAKE FOOD 11. Fill out, with the help of your teacher, a table like the following as a summary of the functions of leaves : . ‘ Cenditionsunder : Taken in | Given out} which process | Finished takes place | Product Respiration Transpiration Photosynthesis| Protem making REFERENCE Books Hunter, Civic Biology, Chap. VII. American Book Company. Hunter, Elements of Biology, Chap. IX. American Book Company. Hunter, Essentials of Biology, Chap. IX. American Book Company. Bartlett, Values from City Garbage. Engineering Magazine, May, 1914. Coulter, Barnes, and Cowles, A Textbook of Botany, Vol. II. American Book Company. Dana, Plants and Their Children, pp. 135-185. American Book Company. Goodale, Physiological Botany, pp. 337-353 and 409-424. American Book Com- pany. Lubbock, Flowers, Fruits, and Leaves, last part. The Macmillan Company. MacDougal, Practical Textbook of Plant Physiology. Longmans, Green and Company. Ward, The Oak. D. Appleton and Company. a VIII. PLANT GROWTH AND NUTRITION — THE CIR- CULATION AND FINAL USES OF FOOD BY PLANTS Problem.— How green plants store and use the food they make. (a) What are the organs of circulation? (6) How and where does food circulate? (ce) How does the plant assimilate its food ? LaBoRATORY SUGGESTIONS Laboratory exercise. — The structure (cross section) of a woody stem. Demonstration. — To show that food passes downward in the bark. Demonstration. — To show the condition of food passing through the stem. Demonstration. — Plants with special digestive organs. To THE TEAcHER. — The work following is simply intended to develop the con- cept that the stem is an organ of circulation; that it puts the upper part of the plant, the food-making organs, in connection with the lower part of the plant, the organs which absorb raw materials for food making and which act as a storage for manufactured food. Problem 75: Groups of plants told by the structure of their stems. NOTE. — Plants which produce flowers are divided into two great groups depend- ing on whether they have one or two cotyledons in the seed, 7.e., monocotyledons and dicotyledons. A bean is an example of the latter, a corn plant of the former. Certain marked differences in the leaves or stems also appear, the dicotyledon usually has veins forming a network while those of the monocotyledon usually run parallel to each other. A third difference is seen in the stem. In the dicotyledon growth takes place from just under the bark and we have annual rings of growth which tell us approximately the age of the stem. Ina monocotyledon (for example a cornstalk) the main bulk of the stalk is made up of pith, while scattered through the pith are numerous stringy, tough structures. These are fibrovascular bundles. The outside of the corn stem is formed of large numbers of these bundles, which, closely packed together, form an outer rind. Thus the woody material gives mechanical support to an otherwise spongy stem. 91 92 CIRCULATION AND USES OF FOOD BY PLANTS Observations.— Compare stems of a dicotyledon (apple) and a monocotyledon (corn) ; also, leaves of dicotyledons, oak, elm, or chestnut with those of monocotyledons, lily, grass, or corn. Conclusion. — 1. Make table comparing differences of (1) stems, (2) leaves, (8) seeds. Note the difference in position in the stem of pith and bundles. (Use lens.) 2. Where is the woody part ina dicoty- ledon? Where in a monocotyledon? Problem 76: To study the structure of a woody stem. Materials. — Small cross sections of apple, Stem horse chestnut, or any c, cotyledon; e, endosperm; h, hypocotyl; p, plu- other woody stem. mule; fb, fibrovascular bundles. Page 98, Civic Biol- ogy. Observations. — In a cross section of apple or any other woody twig note: 1. The central soft part, the pith. 2. The wood. 3. The bark. Can you find radiating lines, medullary rays, in the wood? How many layers of bark do you see? NOTE. — Between the wood and the bark is a rapidly growing layer called the cambium. PROBLEM 77 93 Conclusion. — 1. Judged from the texture, what might be the use to the plant of the outer layer of the bark? 2. Judged from the color, what might be the use of the middle layer? NOTE. — The inner layer of bark is known as the bast. It consists of tubelike cells which carry food from the leaves toward the roots. 3. What are all the uses of the bark? Drawing. — Make a cross section of a woody stem, labeling all the parts. Home Work. — Take two potatoes of equal weight. Peel one, leave the other unpeeled. Place the peeled potato (with peelings) on one pan of a balance, the unpeeled potato on the other. Allow these to remain on the balance for several days. What changes do you note? Remembering that the potato is an underground stem, determine another function of the bark. (See page 99, Civic Biology.) Problem 77: To prove that liquids rise through stems. (Review. ) Materials. — Growing pea or bean seedling, red ink. Method. — Place the roots of a growing plant in a weak solution of eosin or red ink. Leave a few hours in a sunny place. Observations. — Notice the stems and leaves of the young plants, particularly the veins in the leaves. Copy the accom- panying figures in your note- book and color them to show where fluids rise. Conclusion. — Through what part of the stem and leaves uo liquids rise? 94 CIRCULATION AND USES OF FOOD BY PLANTS Problem 78: To find out throwgh which part of a woody stem food passes down. Materials. — Growing willow twigs, nutrient solution, or water. Upper figure page 100, Civic Biology. N. B.— This experiment should be started at least three weeks before it is to be used. Method. — Allow willow twigs to grow in water until they have formed roots, then girdle them by removing a strip of bark about half an inch wide and about an inch above the cut end of the twig. Replace the twigs in water. Observations. — After several days notice what has happened both above and below the girdled area. Conclusion. — 1. Through which part of the stem does food get to the roots? How do you know? 2. Write a paragraph telling how water rises and food materials pass through a woody stem, giving reasons from this and other experiments. Drawing. — Illustrate your experiment with drawings before and after girdling. The teacher should at this point recall the experiment to show the condition of the food in the stem or root when it passes up or down through the fibrovascular bundles. Problem 79: How plants with special digestive organs get their nitrogenous food. Materials. — Specimens of pitcher plant, sundew, Venus’s-fly- trap, and charts to illustrate. Figures page 102, Civic Biology. Observations. — Look carefully within the pitcherlike leaves of the pitcher plant. What do you find? With the aid of the chart work out exactly how the sundew and Venus’s-flytrap catch insects. Conclusion. — What do the above plants do with the dead insects? PROBLEM QUESTIONS 1. Of what use to a plant is each part of a woody stem? 2. In what condition must food be to pass through a stem? How do you know? REFERENCE BOOKS 95 3. In what condition must food be in order to be stored in the cells of a plant? Explain. 4, Mention some stems in which food is stored. From where must this food have come? 5. What is the cambium layer and what is its use to a plant? 6. Look up a reference textbook to find out how water and food pass up and down a monocotyledonous stem. 7. Read a textbook to find out how a dicotyledonous stem grows. How a monocotyledonous stem grows. REFERENCE Booxs Hunter, Civic Biology, Chap. VIII. American Book Company. Hunter, Elements of Biology, Chap. VIII. American Book Company. Hunter, Essentials of Biology, Chap. VIII. American Book Company. Andrews, A Practical Course in Botany, pp. 112-127. American Book Company. Apgar, Trees of the Northern United States, Chaps. II, V, VI. American Book Company. Atkinson, First Studies of Plant Life, Chaps. IV, V, VI, VIII, XXI. Ginn and Company. Coulter, Plant Life and Plant Uses, Chap. V. American Book Company. Coulter, Barnes, and Cowles, A Textbook of Botany, Vol. I. American Book Com- pany. Dana, Plants and Their Children, pp. 99-129. American Book Company. Duggar, Plant Physiology. The Macmillan Company. Ganong, The Teaching Botanist. The Macmillan Company. Goebel, Organography of Plants, Part V. Clarendon Press. Goodale, Physiological Botany. American Book Company. Gray, Structural Botany, Chap. V. American Book Company. Hodge, Nature Study and Life, Chaps. IX, X, XI. Ginn and Company. Kerner-Oliver, Natural History of Plants. Henry Holt and Company. MacDougal, The Nature and Work of Plants. The Macmillan Company. Mayne and Hatch, High School Agriculture. American Book Company. Strasburger, Noll, Schenck, and Schimper, A Textbook of Botany. The Macmillan Company. Ward, The Oak. D. Appleton and Company. Yearbook, U. S. Department of Agriculture, 1894, 1895, 1898-1910. IX. OUR FORESTS, THEIR USES AND THE NECES- SITY FOR THEIR PROTECTION Problem.— Man’s relations to forests. (a) What is the value of forests to man? (6) What can man do to prevent forest destruction? LABORATORY SUGGESTIONS Demonstration of some uses of wood. — Optional exercise on structure of wood. Method of cutting determined by examination. Home work on study of furniture, trim, etc. Visit to Museum to study some economic uses of wood. Visit to Museum or field trip to learn some common trees. To Tue TreacueEr. — The practical value of work on forestry is unquestioned. Every pupil of high school age should have not only some knowledge of our forests and their uses, but also a little first-hand experience in recognition of some common trees: their habitat and their use. The methods-of cutting lumber and trim also gives a practical side which is of interest to pupils. Problem 80: To determine how lumber is cut and how to recognize the cut in trim. Materials. — Diagrams, school furniture, Hough’s sections of woods. Method. — Examine the sections shown you. Compare with lower figure, page 111, Civic Biology. NOTE. — Most lumber is cut tangentially. Hence the yearly rings take a more or less irregular course. The grain of wood is caused by the fibers not taking straight lines in their course in the tree trunk. In many cases the fibers of the wood take a spiral course up the trunk, or they may wave outward to form little projections. Boards cut out of such a piece of wood will show the effect seen in many of the school desks, where the annual rings appear to form small elliptical markings. Study the top of your desk, the wainscoting, the floor, and any other wood at hand to determine the kind of cutting. Study 96 PROBLEM 82 97 the figures and compare with the specimens of wood just noted. Can you observe any differences in color of the wood ? Conclusion. — 1. What is the common method of cutting wood for trim? Why? 2. Does most dried wood show any difference between heart and sap wood? What is this difference ? Problem 81: To determine some uses of stems. Method. — See Chap. X, page 133, Hunter’s Essentials of Biology, or Chap. IX, page 105, Hunter’s Civic Biology. After reading carefully fill in the following table : Substance From what plant? | From what locality? Cork Food Fuel Hemp Latex for Rubber Linen Lumber Quinine Resin sugar Yannin turpentine Wood Pulp Conclusion. — Write a paragraph summing up the uses of stems to man. Problem 82: To determine the value of certain woods. Method. — Find out as many woods as you can that are of value because of properties listed in the following table and record in proper column. See Chap. X, Hunter’s Essentials of Biology, or Chap. IX, Hunter’s Civic Biology. After reading your text, or taking a trip to a commercial museum, fill out the table on page 98. HUNTER LAB. PROB. —7 A 98 OUR FORESTS : Durahbility Beaut Paper Making ae Strength Softness of Grain Conclusion.— 1. Which woods are useful for skeletons of houses? 2. Which are useful for trim? 3. Which are useful for paper making? 4. In general, which are more used, soft or hard woods? Problem 83: Museum trip for study of woods. Materials. — Collection of commercial woods, or trip to a museum.! Method and Observations. — Examine specimens of the most important commercial woods. Note such woods as: white pine spruce sugar maple white oak black cherry tulip poplar basswood hemlock fir black oak chestnut hickory walnut cherry white birch Describe any six of the above, telling : (a) The region where the trees grow. (b) The shape of the leaves. (c) The color of heart and sap woods. (d) Comparative weight of the wood. (e) Rapid or slow growth. (f) Economic value. Examine a specimen of a section of any big tree, such as a California big tree. Notice the so-called annual rings in the wood. About how old was this tree when it was cut? 1 A study such as here outlined may be made at any well-equipped city museum. Work of this nature may also be done in school by means of loan collections. PROBLEM 84 99 If you go to school in New York city use this diagram for your KatebouL. 3 Walnut “Sima Conclusion. — If a trip is taken, write out carefully a report of the observations made. Cottonwood Willow Oak Chestnut Beech Birches ider Ironwood Problem 84: To = identify common gece” Juniper trees by the use of a key. Materials. — Vari- ous specimens of wood with leaves on twigs; pictures of trees, flow- ers, and fruits; ruler. Method and Obser- vations. — Using the material and the Key on the following pages under the supervision of your teacher, make Giant Sequeiq careful observations a Spruce Hemlock of leaves given you. A Diacram or rae Haut conrarninG THE JESSUP Note and measure CoLLEcTION OF Woops, AMERICAN MusfeUM OF “ NaturaAu History, New York. size of leaf, structure, shape, etc. Refer to the Key which follows. Determine whether the specimen which you have belongs under A or B. If it belongs under A, for example, then place it under I or II. Having done this, determine whether it is a, b, or c, then 1, 2, or 8, etc., until you finally determine the specimen of leaf, and by it, the name of the kind of tree to which it belongs. Conclusion. — What are the names of the various trees from which you have made observations? 100 OUR FORESTS KEY TO SOME OF THE COMMON TREES OF THE NORTHEASTERN UNITED STATES The following Key was prepared by George T. Hastings of the Department of Biology of the DeWitt Clinton High School. This Key does not include the common cultivated fruit trees, or any but the commonest of cultivated shade or ornamental trees. A. Leaves, needle-shaped, or very small, scalelike. Evergreen trees, except No. 9. ; Conifers or Soft Woods I. Leaves needle-shaped. a. Leaves over 13 inches long, in bundles of 2, 3, or 5. 1. Leaves 5 in a cluster. 1. White Pine. 2. Leaves 3 in a cluster. 2. Pitch Pine. 3. Leaves 2 in a cluster. *Leaves 13 to 3 inches long. 3. Scotch Pine. **Leaves 3 to 5 inches long. 4. Austrian Pine. b. Leaves about 1 inch long, many in a cluster on tiny knoblike branches. 5. Larch or Tamarack. c. Leaves less than 13 inches long, singly on the twigs. 1. Leaves flattened, growing horizontally on the twigs. *About 4 inch long. 6. Hemlock. ** 3 to 1 inch long. 7. Balsam. 2. Leaves 4 angled, growing on all sides of the twigs. *Leaves dark green, cones 4 inches or more long. 8. Norway Spruce. **Leaves bluish green, cones 14 to 2 inches long. 9. White Spruce. II. Leaves scalelike, very small. a. Leaves rounded, overlapping, flattened on the twigs, which appear as if ironed out flat. Fruit a cone about 3 inch long. 10. White Cedar or Arbor Vite. b. Leaves sharp-pointed, on all sides of the rounded or square twigs. Fruit a small blue berry. 11. Red Cedar or Juniper. B. Leaves not needle-shaped or scalelike. Broad-leaved or Hardwood Trees I. Leaves in pairs, opposite on the branches. a. Leaves simple, palmately veined, notched or lobed. 1. The depressions between the 3 to 5 lobes narrow, acute. twigs red. KEY TO SOME OF THE COMMON TREES 101 *Leaves notched less than halfway to the midrib. 12. Red Maple. **Leaves divided more than halfway. 13. Silver Maple. 2. The depressions between the lobes broad and rounded, twigs brown or greenish. *Twigs slender. 14. Sugar Maple. **T wigs stout, petioles when broken exude acrid milky sap, which coagulates. 15. Norway Maple. b. Leaves simple, entire, pinnately veined. 16. Flowering Dogwood. c. Leaves compound. 1. Palmately compound. 17. Horse-chestnut. 2. Pinnately compound. *Leaflets 3 to 5, coarsely dentate. 18. Box Elder. **Leaflets 5 to 9, finely serrate, each with a short stalk. 19. White Ash. ***Teaflets 7 to 11, finely serrate, without stalks. 20. Black Ash. II. Leaves large, entire, growing 3 at a joint on the twigs. 21. Catalpa. ‘III. Leaves alternate on the twigs, one at a joint. a. Leaves simple. (For b see page 103.) 1. Leaves palmately veined. *Leaves star-shaped, with 5 to 7 sharp lobes. 22. Sweet Gum. **Leaves broadly oval, toothed or irregularly lobed. 23. Sycamore. 2. Leaves pinnately veined. *Not deeply cut or lobed. tLeaves narrow, lanceolate. ‘Twigs slender, not greatly drooping, leaves smooth and green both sides. 24. Fragile or Crack Willow. ‘Twigs slender, not greatly drooping, leaves with small hairs and pale on both sides. 25. White Willow. ++ “Twigs very slender, drooping, leaves smooth. 26. Weeping Willow. ttLeaves broader, oval or ovate. ‘Leaves dentate, smooth. 27. Beech. * ‘Leaves serrate. ’Bark on twigs and branches smooth, shining, black, bitter to the taste. 28. Black Cherry. 102 OUR FORESTS ” Bark not as in’. :Leaves usually 4 inches or more long. !Large sharp teeth on edges. 29. Chestnut. !!Large rounded teeth on edges. 30. Chestnut or Rock Oak. ::Leaves less than 4 inches long. !Leaves smooth, in more than 2 rows on the stem, bark peeling in thin sheets. xz. Twigs brown, bark with wintergreen flavor, bark dark brown or black. 31. Black Birch. y. Twigs gray or yellowish, trunk silvery or grayish. 32. Yellow Birch. z. Twigs brownish, bark chalky white. 33. White Birch. !\Leaves rough, in 2 rows on the twigs. xz. Leaves very rough above, buds and twigs hairy, grayish, mucilaginous when chewed. 34. Slippery Elm. y. Leaves slightly rough above, buds and twigs smooth or nearly so, brown or reddish, not mucilaginous. 35. American Elm. tttLeaves as broad as long, or broader. ‘Leaves sharp-pointed. ’Petioles (leafstalks) flattened at right angles to the blade. :Tree tall, slender, branches all ascending. 36. Lombardy Poplar. ::Tree broader, leaves green. 37. Carolina Poplar. :::Tree broader, leaves white below. 38. White Poplar. ”Petioles rounded. 39. Basswood. *-Leaves rounded at tip often with a lobe on one or both sides. 40. Sassafras. -++Leaves square, or notched at tip and sides. 41. Tulip Tree or Tulip Poplar. **Leaves deeply cut or lobed. {Lobes rounded. 42. White Oak. ttLobes sharp-pointed. PROBLEM QUESTIONS 103 ‘Lobes cut less than halfway to midrib, smooth, acorn large (1 inch long) with shallow cup. 43. Red Oak. Lobes cut more than halfway, acorns small (3 inch or less), cup covering at least 4 of acorn. *Leaves smooth both sides, scales of cup pressed down at tip. 44. Scarlet Oak. "Leaves hairy below, at least in the angles of the veins, scales of cup spreading at tip. 45. Black or Yellow-barked Oak. b. Leaves compound. 1. Trunks or branches thorny, leaflets rounded at the tip. *Thorns large, often 3 parted. 46. Honey Locust. **Thorns small, in pairs at the base of leaves, or sides of leaf scars. 47. Common Locust. 2. No thorns, leaflets pointed at tip. *Twig very stout, 4 inch or more in diameter. Leaflets 11 or more. {tT wigs smooth. 48. Ailanthus. ttT wigs very hairy. 49. Staghorn Sumach. **T wigs more slender, not over 3 inch thick at tip. {Leaflets 11 or more. ‘Twigs smooth, nut round. 50. Black Walnut. --Twigs downy, nut oval. 51. Butternut. ttLeaflets 9 or less. ‘Bark of tree furrowed, not in long flat plates. 52. Pignut. - ‘Bark of tree in long flat plates loose at lower end. 53. Shagbark Hickory. PROBLEM QUESTIONS What are the direct uses of stems to man? What are the direct uses of stems to plants? How are forests of value to man? Name three enemies of the forests. Name three ways of conserving our forests. How do the forests of New York indirectly influence the commercial importance of New York city? 7. What special tree products give factories employment in your home city? 8. Of what value are trees in a city park? 9. Look in your Civic Biology and find ten ways in which trees are of value in a city. POE ROO RO 104 OUR FORESTS REFERENCE Booxs Hunter, Civic Biology, Chap. 1X. American Book Company. Hunter, Elements of Biology, Chap. VIII. American Book Company. Hunter, Essentials of Biology, Chap. X. American Book Company. Andrews, Botany All the Year Round, Chaps. VI, VII. American Book Company, Apgar, Ornamental Shrubs. American Book Company. Apgar, Trees of the Northern United States, Chaps. II, V, VI. American Book Company. Atkinson, First Studies of Plant Life, Chaps. IV, V, VI, VIII, XXI. Ginn and Company. Bailey, Trees in Winter, How they Look. Teachers’ Leaflets, Nature Study, No. 12, Cornell University, January, 1899. Bergen and Caldwell, Practical Botany, Chap. XXII. Ginn and Company. Blakeslee and Jarvis, Trees in Winter. The Macmillan Company. Burba, Tree Surgery. Pearson’s Magazine, April,'1910. Burroughs, The True Test of Nature Literature. Country Life in America, May, 1904. Camphor Tree. Botanical Circular 12, U. 8S. Department of Agriculture. Coal as a Commercial Factor. Metropolitan Magazine, March, 1909. Coles-Finch, Water, Its Origin and Use. D. Van Nostrand and Company. Commercial Tree Studies. U.S. Department of Agriculture, Forestry Service, Bulletins 13, 22, 31, 33, 37, 38, 53, 58, and 64. Coulter, Plant Life and Plant Uses, Chap. V. American Book Company. Coulter, Barnes, and Cowles, A Textbook of Botany, Part I and Vol. II. American Book Company. Dana, Plants and Their Children, pp. 99-129. American Book Company. Duggar, Plant Physiology. The Macmillan Company. Fernow, A Brief History of Forestry in Europe. University of Toronto. Fernow, Care of Trees in Street, Lawn, and Park. Henry Holt and Company. Fernow, History of Forestry. Forestry Quarterly, Cambridge, Mass., 1910. Forest Fires in the Adirondacks. Forestry Circular 26, U. 8. Department of Agri- culture. Forestry in Public Schools. Forestry Circular 130, U. S. Department of Agriculture. Ganong, The Teaching Botanist. The Macmillan Company. Goebel, Organography of Plants, Part V. Clarendon Press. Goff and Mayne, First Principles of Agriculture. American Book Company. Goodale, Physiological Botany. American Book Company. Graves, The Advance of Forestry in the United States. Review of Reviews, April, 1910. Gray, Structural Botany, Chap. V. American Book Company. Hemp Industry in the United States. Yearbook, 1901, U. S. Department of Agri- culture. : : Hodge, Nature Study and Life, Chaps. IX, X, XI. Ginn and Company. Hough, Handbook of the Trees of the Northern States and Canada. Hough, Lowville. Hough, The Slaughter of the Trees. Everybody’s Magazine, May, 1908. Jackson, Forestry in Nature Study. Farmers’ Bulletin 468, U. S. Department of Agriculture. Keeler, Our Northern Shrubs and How to Identify Them. Charles Scribner’s Sons. REFERENCE BOOKS 105 Kellogg, Lumber and Its Uses. Radford Architectural Company. Kerner-Oliver, Natural History of Plants. Henry Holt and Company. MacDougal, The Nature and Work of Plants. The Macmillan Company. Maple Sugar and Syrup. Farmers’ Bulletin 252, U. 8. Department of Agriculture. Mayne and Hatch, High School Agriculture. American Book Company. Moon and Brown, Elements of Forestry. J. Wylie and Sons. Murrill, Shade Trees. Bulletin 205, Cornell University Agricultural Experiment Station. Newell, The Reclamation of the West, p. 827. Annual Report Smithsonian Insti- tution, 1904. Osterhout, Experiments with Plants, Chap. V. The Macmillan Company. Pinchot, The Forest Service. U.S. Department of Agriculture, Circular 36, 1906. Pinchot, Primer of Forestry. Farmers’ Bulletin 173, U. 8. Department of Agri- culture. Rogers, The Tree Book. Doubleday, Page and Company. Rogers, Trees Every Child Should Know. Doubleday, Page and Company. Roosevelt and others, Forests and Timber Supply. Forestry Circular 25, U. 8. Department of Agriculture. Roosevelt and others, Forest Preservation and National Prosperity. Forestry Cir- cular 25, U. S. Department of Agriculture. Stevens, Fungi Which Cause Plant Disease. The Macmillan Company. Strasburger, Noll, Schenck, and Schimper, A Textbook of Botany. The Macmillan Company. Taylor, Street Trees, Care and Preservation. Cornell University, Agricultural Bulletin 256, June, 1908. Treadwell, A Primer of Conservatism. Circular 157, Forest Service, U. 8. Depart- ment of Agriculture. Waning Hardwood Supply of the Appalachian Forests. Forestry Circular 116, U. 8. Department of Agriculture. Ward, The Oak. D. Appleton and Company. Ward, Timber and Some of its Diseases. The Macmillan Company. Weed, Our Trees and How to Know Them. J.B. Lippincott Company. Whipple and Wilson, The Part Played by the Forests in Everyday Life. Suburban Life, April, 1908. Winkerwerder, Forestry in the Public Schools. Circular 130, Forest Service, U. S. Department of Agriculture, 1907. Wood Distillation. Forestry Circular 114, U. 8. Department of Agriculture. Wyman, Leaves and Acorns of our Common Oaks. Teachers’ Leaflet, Nature Study, No. 8, Cornell University, September, 1897. Yearbook, U. 8. Department of Agriculture, Division of Forestry, Bulletins 7, 10, 13, 16, 17, 18, 20, 26, 27. Yearbook, U. 8. Department of Agriculture, 1894, 1895, 1898-1910. X. THE ECONOMIC RELATION OF GREEN PLANTS TO MAN Problems.— How Sreen plants are useful to man. (a) As food. (6) For clothing. (e) Other wses. How green plants are harmful to man. Suecestep Laporatory Work If a commercial museum is available, a trip should be planned to work over the topics in this chapter. The school collection may well include most of the examples mentioned, both of useful and harmful plants. A study of weeds and poisonous plants should be taken up in actual laboratory work, by collection and identification, or by demon- stration. To THE TEACHER. — This chapter, which is intended to sum up the preceding chapters from the practical aspect, may be made largely in the nature of reading and reports. It is wise when teaching a course in biology (or any other subject) to vary the work as much as possible, both to maintain interest and to prevent stagnation of thought on the part of the pupil. Problem 85: To determine the economic importance of some green plants. Materials. — Toothaker’s Commercial Raw Materials is an invaluable reference book for this exercise. This might well be planned for a field and museum trip to some commercial museum, or the school museum may be used. Also visit the public or pri- vate markets in your locality and list all the food plants or their products used for food. Method. — Fill out a table like the following. Conclusion. — In what ways are green plants useful to man? 106 PROBLEM 86 107 Fruits Native |Cultivatea] USes to! Method of| Notes of Mean | Preparing] Interest Garden Fruits Beans Cucumbers Peas Pumpkins etc. Orchard Fruits Apples Apricots Cherries Peaches Pears Plurs Quinces etc. Grains Barley Corn Oats Rice Rye wheat etc. Miscellaneous Bananas Cocoa Coconut Coffee Cotton Pepper etc. Problem 86: To learn to know some green plants harmful to man. Materials. — Copies of Chestnut’s Thirty Poisonous Plants of the U. S., Farmers’ Bulletin 86, and Dewey’s Two Hundred Weeds, How to Know Them and How to Kill Them, Farmers’ Bulletin 17. A few of the common plants which are weeds in your locality. (Poison ivy can be studied if placed in air-tight jars.) Method and Observations. — Using Farmers’ Bulletin 86, iden- tify and give the characters by which you would know the follow- ing: pokeweed, corn cockle, black cherry, loco weed (very harmful in the West), snow-on-the-mountain, poison ivy, poison oak, poison sumac, water hemlock, poison hemlock, poison weed, black nightshade. Using Farmers’ Bulletin 17, identify and classify ten of the most common weeds of eastern United States. Conclusion. —1. Write a paragraph on some one poisonous plant and the best means of eradicating it from your vicinity. 108 RELATION OF GREEN PLANTS TO MAN 2. Make a table modeled after the following. In it place any ten plants in which you are interested. Fill out completely. E stimatea | What harm ~wreed s Habitat sce they do Dandelion Canada Thistle Cocklebur Milkweed oxeye Daisy Pigweed Purslane Ra gwreed wila Carrot wald Lettuce etc. PROBLEM QUESTIONS 1. What effect ought plant products in a given locality to have on the prices of animal products having the same food value? Is this true, in your opinion? Get your teacher to help you inter- pret this question. 2. Name ten food plants grown in your locality. 3. Name ten food plants that must be imported for our use. 4. Using the school or other museum, make a report on three different fiber plants, giving their habitat, method of manufacture from raw materials, and their ultimate uses by man. 5. Name five plants used for medicine. 6. Discuss the value of some one plant just mentioned as a specific remedy against some particular disease. 7. Show three ways in which weeds may do harm to man. REFERENCE Books Hunter, Civic Biology, Chap. X. American Book Company. Hunter, Elements of Biology, Chap. V. American Book Company. Hunter, Essentials of Biology, Chap. V. American Book Company. Bailey, Cyclopedia of American Agriculture. The Macmillan Company. Bailey, The Evolution of our Native Fruits. The Macmillan Company. REFERENCE BOOKS 109 Bergen and Caldwell, Practical Botany. Ginn and Company. Bergen and Davis, Principles of Botany. Ginn and Company. Coulter, Plant Life and Plant Uses. American Book Company. Coulter, Barnes, and Cowles, A Textbook of Botany. American Book Company. Dunn, Remedies for the Beef Famine. Literary Digest, p. 773, April 4, 1914. Gannett, Garrison, and Houston, Commercial Geography, Chap. IX. American Book Company. Georgia, A Manual of Weeds. The Macmillan Company. Huntington, Poisonous Vagrant Weeds. House and Garden, September, 1909. Kramer, Applied and Economic Botany. B. G. Smith. Needham, Natural History of the Farm. Comstock Publishing Company. Sargent, Plants and Their Uses. Henry Holt and Company. Sharpe, A Laboratory Manual in Biology. American Book Company. Toothaker, Commercial Raw Materials. Ginn and Company. U. S. Dept. of Agriculture, Farmers’ Bulletin 86, Thirty Poisonous Plants of the United States, V. K. Chestnut. Bulletin 17, Two Hundred Weeds, How to Know Them and How to Kill Them, L. H. Dewey. Bulletin 295, Potatoes and Other Root Crops as Food. Bulletin 132, Nuts and Their Use as Food. XI. PLANTS WITHOUT CHLOROPHYLL IN THEIR RELATION TO MAN Problems. —(a) How molds and other saprophytic fungi do harm to man. (6) What yeasts do for mankind. (ce) A study of bacteria with reference to (1) Conditions favorable and unfavorable to growth. (2) Their relations to mankind. (3) Some methods of fighting harmful bacteria and dis- eases caused by them. LABORATORY SUGGESTIONS Field work. — Presence of bracket fungi and chestnut canker. Home experiment. — Conditions favorable to growth of mold. Laboratory demonstration. — Growth of mold, structure, drawing. Home experiment or laboratory demonstration. — Conditions unfavor- able for growth of molds. Demonstration. — Process of fermentation. Microscopic demonstration. — Growing yeast cells. Drawing. Home experiment. — Conditions favorable for growth of yeast. Home experiment. — Conditions favorable for growth of yeast in bread. Demonstration and experiment. — Where bacteria may be found. Demonstration. — Methods of growth of bacteria, pure cultures, and colonies shown. Demonstration. — Foods preferred by bacteria. Demonstration. — Conditions favorable for growth of bacteria. Demonstration. — Conditions unfavorable for growth of bacteria. Demonstration by charts, diagrams, etc. — The relation of bacteria to disease in a large city. To THE TracHEeR. — In these days when the application of biology to human welfare is so often made the chief aim of a course in biology, it is refreshing to know that there are teachers left who believe in logic and in the building of a super- structure before proceeding to work upon the top of the building. In point of interest and of instructive value, the exercises which follow are vital; as experi- ments, however, they are not always absolutely to be relied upon. The extreme delicacy with which some of the factors work, the fact that we are dealing with microérganisms which cannot be handled except in bulk, the fact that most school laboratories have neither equipment nor means to obtain some of the necessary matcrials, make absolutely accurate experiments sometimes out of the question. 110 PROBLEM 87 111 The method of science can, however, be used and all reasonable care and accu- racy be given in the performance of any experiments which follow. The informational content is certainly of the widest possible importance. An entire course could well be devoted to the numerous experimental questions which present themselves. It is unwise, however, to give more than a month to six weeks’ time to the chapter because of the need for balance in the course. Materials for the study of bacteria (nutrient agar or gelatine) may be obtained from any good chemist, from manufacturing chemists, and from the local board of health. Directions for making culture media follow in this chapter, but the work need not be given up because of lack of proper apparatus or laboratory facil- ities. Problem 87: To determine the relation of fungi to the de- struction of certain trees. NOTE. — Suggestions for field trip to work out loss of trees by the attack of shelf fungus and chestnut canker. A field trip to a park or grove near home may show the great destruction of timber by these means. a. Shelf Fungus Observations. — Count the number of perfect trees in a given area. Compare it with the number of trees attacked by the shelf fungus. Does the fungus appear to be transmitted from one tree to another near at hand? In how many instances can you discover the point where the fungus first attacked the tree? Do healthy trees seem to be attacked? Conclusion. — Under what conditions will shelf fungus attack a tree? b. Chestnut Canker NOTE. — Chestnut canker is spread by tiny reproductive bodies called spores. These, if they obtain a foothold on a sound tree, soon grow to form plants which feed upon the tree, ultimately causing its death. Observations. — Ina given area are all the chestnut trees dead or dying? How might tiny spores get from one tree to another? What appears to be the first sign of the disease in a tree? Pull off the bark of an infected tree and note the silvery threads running in every direction. These form the body of the canker called the mycelium, which reaches out after food. What part of the tree would it be likely to attack and why? NOTE. — A plant or animal which lives at the expense of another living plant or animal is called a parasite. Is the canker a parasite ? 112 PLANTS WITHOUT CHLOROPHYLL Conclusion. — 1. What will a parasite eventually do to the host on which it lives? 2. Why is chestnut canker an enemy to man? 3. Why is it so difficult to combat? Problem 88: To determine the conditions favorable for the Srowth of mold. Materials. — Four wide-mouth jars or bottles, bread. Method. — Place a piece of bread in each of the four wide-mouth bottles or jars, add a little water, and expose all four to the air of the living room or kitchen for half an hour. Then cover all the jars and plunge one into boiling water for a few moments; place this and a second jar side by side in a moderately warm room. Place the third jar in the ice box and the fourth in a hot and dry place. Observations. — 1. Notice day by day any changes that occur in the contents of the jars. 2. In which jar does growth appear first? 3. Do all jars have a like growth of mold at the end of a given period of time? Conclusion. — 1. How does the mold get on the bread? 2. Where does it come from? 3. Why did we add water to the jars? 4. What conditions must you have for the growth of mold? 5. Conversely, how would you keep molds from getting a foot- hold on foods? Problem 89: To study the structure of bread mold. Materials. — Bread mold. Figure page 133, Civic Biology. NOTE. — Directions for Growth of Mold.— Bread mold may be conveniently grown for laboratory use in small shallow dishes (Syracuse watch glasses, Petri dishes, or butter chips). If bread is exposed to the air for a few minutes and then left in the covered dishes for a day or two, with a bit of wet sponge or blotting paper in the dish to keep the air moist, a good supply of mold may be obtained in a convenient dish for observational purposes. Observations. — Examine the tangled mass of threads which cover the bread. This is called the mycelium, each thread being called a hypha. How do the hyphe appear to be attached to the bread? PROBLEM 90 113 NOTE. — Some of these threads reach down into the bread and act as roots, di- gesting and absorbing nourishment. These are called rhizoids. Many of the hyphe are prolonged into tiny upright threads, bearing at the top alittle ball. This is called the sporangium. With the low power of the microscope the structure of a sporangium may be made out. The dark-colored ones are full of ripe spores, which may be seen by lightly tapping the cover slip over the slide. How do the spores get out of the sporan- gium? Try to find some young sporangia and note the differences in size and color between them and the older ones. Conclusion. — 1. How does bread mold get its food? 2. How do you know that it cannot manufacture its own food? Explain. 3. Have you seen any other kinds of molds on foods? If so, on what foods? 4. What effect do molds have on food? 5. What are the spores on bread mold for? 6. What effect do their size and numbers have on the spread of the mold? Drawings. — Draw a series of sporangia as seen under the low power. Problem 90: What is fermentation and what cawses it? Materials. — Fermentation tube, yeast, molasses, test tube, Erlenmeyer flask, limewater, absorbent cotton, cork, and delivery tube. Method. — Carefully fill a fermentation tube with a mixture of molasses, water, and a little piece of compressed yeast cake. Plug the open end with absorbent cotton. Put in a warm place over night. Partly fill an Erlenmeyer flask with a mixture of molasses, water, and compressed yeast cake. Close the flask with a stopper fitted with a delivery tube which leads into a test tube filled with limewater. Observations. — What has happened to the filled end of the fermentation tube? How do you account for this? Smell the contents of the flask after a day or two. What is this odor? What has happened to the limewater? HUNTER LAB. PROB. — 8 114 PLANTS WITHOUT CHLOROPHYLL Conclusion. — 1. What happens when fermentation takes place? 2. What gas is formed? Explain fully. 3. What substance is present in the ask? How do you know? Inner |] Tube where alcohol|} and water vapor condensed. , Water Mixture of [~~ ~ Jacket Yeast %a Glucose+ Alcohol APPARATUS TO PROVE THAT ALCOHOL MAY BE DISTILLED FROM FERMENTING Y3BastT. NOTE. — If we were to distill off the contents of the Erlenmeyer flask, we could prove the presence of alcohol. Fermentation is the process which breaks up sugar (CvxH2On) into carbon dioxide (COz) and alcohol (C2H;OH). Problem 91: To learn to recognize yeast plants under the conupound microscope. Materials. — Compound microscope, nutrient solution con- taining growing yeast plants from a compressed yeast cake (com- posed of food and yeast plants), iodine. Lower figure, page 136, Cwic Biology. Method. — Place a drop of solution on a slide and add iodine. Observations. — Note the dark blue bodies. What are they? (Remember the iodine test.) The smaller ovoid bodies are the yeast cells. What color are they? Shape? Do you find any budding (one growing out from another cell)? Note the clear areas (vacuoles) within the cells. Conclusion. — 1. Write a paragraph descriptive of yeast cells and their method of reproduction. 2. Draw a few cells showing budding. Add a starch grain for comparison. Draw both to scale. PROBLEM 93 115 Problem 92: Do yeasts $row wild ? Materials. — Molasses or nutrient solution, Petri dish, fer- mentation tube. Method. — Place a Petri dish, or other flat dish, with nu- trient solution in it for a day in any locality exposed to ordinary drafts of air. Then pour its contents into a fermentation tube and plug with absorbent cotton. Observations. — Note any change in the contents of the closed end of the tube. Conclusion. — 1. Is there any yeast present? If so, where did it come from? NOTE. — Spores (reproductive bodies) of yeast are found in the air, and yeasts grow on grape, apple, pear, and other fruit skins. 2. What causes wine to ferment, cider to become hard (ferment), etc. ? Problem 93: To determine the conditions favorable to the Srowth of yeast. Materials. — Fruit jars, yeast cake, molasses. Method. — Label three pint fruit jars A, B, and C. Add one fourth of a compressed yeast cake to two cups of water containing two tablespoonfuls of molasses or sugar. Stir the mixture well and divide it into three equal parts and pour them into the jars. Place covers on the jars. Put jar A in the ice box on the ice and jar B over the kitchen stove or near a radiator; boil jar C by im- mersing it in a dish of boiling water, and place it next to B. After forty-eight hours, look to see if any bubbles have made their appearance in any of the Jars. Observations. — Which jars, if any, show bubbles on the surface? After bubbles have begun to appear at the surface, the fluid in jar B will be found to have a sour taste and will smell unpleasantly. The gas which rises to the surface, if collected and tested, will be found to be carbon dioxide. Conclusion. — 1. What conditions are favorable for the growth of yeast? 2. How do you know that yeast has grown? 116 PLANTS WITHOUT CHLOROPHYLL Problem 94: What are the conditions favorable for the Srowth of yeast in bread? (Home work.) Materials. — Flour, water, sugar, salt, yeast cake, pans. Method. — Make a dough by mixing flour, sugar, salt, and water in proportions to make a thick paste. Knead with a little yeast which has previously been mixed with water. Now place one lot of dough in the ice box, one at the temperature of the room, and one in a warm place (over 90° F.). Later bake each lot and use in the laboratory. Observations. — Which of the three lots has raised the most? Which, after baking, has the best appearance? The best taste? What makes the holes in the bread? Conclusion. — 1. What caused the bread to rise? 2. Under what conditions does this best take place? Experiments with yeast may be continued almost indefinitely. For excellent suggestions, see Conn’s Bacteria, Yeasts, and > Molds in the Home, pp. 274-278. if ~ i) | STERILIZING Problem 95: How we pro- CHAMBER. ra ceed to the study of bacteria. SHELF 3 Materials. — Dry sterilizer, Bs steam sterilizer, Petri dishes, fermentation tubes, pipettes, and compound microscope. Several pieces of apparatus are useful though not indispen- sable in the study of bacteria. All of this apparatus should be shown to the pupils and its use explained. Older pupils should be encouraged to assist in pre- Heat applied under the sterilizer turns paring the culture media and the water into steam, which circulates .- hk 5 cedilina tl through the holes in the shelves, es- 12 the subsequent sterilization capes between ‘he door and the inner of the material. Sterilizers may jacket, and returns as water after con- be 4 ‘ovised ‘ densing between the inner and outer e improvise ; y using two jackets of the sterilizer. pans, one of which fits closely PROBLEM 96 117 over the other. Any sheet-iron or tin box that will stand heating red-hot may be used as a dry sterilizer. Methods. — Study the construction of the steam and dry sterilizers. NOTE. — Sterilization means the raising of the temperature to such a degree of heat as will kill all germs. Conclusion. — How is the sterilizer fitted to do its work? Problem 96: How to prepare culture media. Method. — Beef bouillon which has been cleared and filtered may be used for growing bacteria. Nutrient agar-agar! is the best medium in which to grow bacteria. It may be prepared from the following materials: 1000 c.c. water, 10 g. salt, 10 g. peptone, 10 g. Liebig’s beef extract, a little cooking soda, and 10 g. agar-agar. If agar-agar cannot be obtained, use 100 g. of the best French gelatin. Dissolve the beef extract in the 1000 c.c. water. Cut the agar into pieces and add with the salt and peptone. The mixture must then be heated to cause the agar to dissolve, care being taken that it does not burn. Enough cooking soda is added to cause red litmus paper dipped in the mixture to turn blue, 7.e., the liquid should be faintly alkaline. Filtering hot agar should be carried on within the steam sterilizer. A glass funnel should be put in the mouth of an Erlenmeyer flask and one or two layers of absorbent cotton placed within the funnel. If the agar, flask, and funnel are kept hot within the sterilizer, the liquid will readily pass through the cotton. After filtering, the mouth of the flask should be closed with a plug of absorbent cotton. Then boil in the cooker for half an hour. If the agar mixture is not clear, it should be filtered through cotton a second time. If care has been taken, the nutrient solution is now ready for use, and may be set aside as a stock solution. If it is desired to make a nutrient solution for molds, omit the cooking soda and add a few drops of dilute hydrochloric acid ; because molds grow best in a slightly acid medium, while bacteria thrive in a slightly alkaline medium. \ 1 Agar-agar is a preparation from seaweed which gives an excellent vegetable gelatin (a protein food). 118 PLANTS WITHOUT CHLOROPHYLL To prepare the nutrient agar-agar for use, it may be poured while hot into Petri dishes which have been previously sterilized with dry heat for several hours and then kept in a dry place free from dust. It is well to sterilize the plates once or twice after they are coated, using a steam sterilizer. Test tubes partially filled with the nutrient jelly are also useful. Immediately after pouring the hot jelly into the test tubes they should be plugged with absorbent cotton and then placed in the steam sterilizer. Problem 97: To demonstrate a pure culture. Materials. — Culture media in Petri dishes, one dish containing colonies of bacteria; sterile needle. Method. — The instructor transfers some of a colony of bacteria on the point of a sterile needle to the sterile surface of a new Petri dish which has in it nutrient jelly. Watch the growth of the colony on subsequent days. 3 Observations. — How long before colonies appear on the sur- face? Are these colonies all alike in appearance? Conclusion. — Have you obtained a pure culture? If so, how did you do this? To tHe TEACHER. — In this and all the problems that follow, the teacher should be ready to start the experiments at least three or four days before they are to be used in class laboratory for demonstration. Pupils should be led to notice the conditions at the beginning of an experiment which may be several days be- fore any notes or drawings are expected from their observations. Interest will be held by discussing beforehand the nature of the problem and by making sure that the pupil knows the aim of the experiment. Far too much work in our labora- tories is blind, unreasoning, busy work following directions that lead nowhere. At the beginning of these experiments in bacteriology, the instructor should make sure by demonstration that the pupil knows what to work for on a plate and in a tube. The making of a pure culture should be shown, not so much because it will be a pure culture as to impress at the start the need for extreme care in making all of these experiments. Pupils at the outset should be taught to recognize bacteria by (a) odor, e.g., decay ; (b) change in appearance of nutrient media, e.g., cloudiness of bouillon; and (c) appearance of colonies. Microscopic demonstration is inter- esting but unnecessary with young students. A scale drawing on the board or on the chart means much more to the average pupil. Problem 98: To determine where bacteria may be found. Materials. — A number of covered Petri dishes containing sterile agar. . PROBLEM 99 119 Method. — Expose a number of these Petri dishes containing nutrient for the same length of time in as many of the following conditions, and as many others, as possible: (a) to the air of the schoolroom. (b) in the halls of the school while pupils are passing. (c) in the halls of the school when pupils are not moving. (d) at the level of a dirty and much-used city street. (e) at the level of a well-swept and little-used city street. (f) in a city park. (g) in a factory building. (h) to dirt from hands placed in dish. (z) to contact with the interior of the mouth. (j) to contact with decayed vegetable or meat. (k) to contact with dirty coin or bill. Petri Dish} eee eae ote es ae ee (1) to contact with Exposed |pay|DayDayDay|Day|Day|Day | Day] r three hair Air o ine = on ene 0 eel coomd from pupil’s head. a Ib Bus» Halls Observations. — of School After three. to five |e of stor days note the condi- |, Busy City tions of the various crest plate cultures. Each [* Fte- day count the num- ber of spots (colonies) of bacteria and molds growing on the cul- ture medium. Make a table like the above to show your results. Conclusion. — 1. Where are bacteria found in greatest num- bers? 2. What are the factors in your environment by means of which bacteria might get to your body? Problem 99: To study how rapidly bacteria Srow. Method. — Imagine that you have inhaled a germ causing cold or consumption (bacillus tuberculosis) while riding on the subway train or street car at 8.30 a.m. You are in such poor physical condition that the bacterium can grow and multiply. Scientists who have studied germs (bacteriologists) tell us that the bacterium 120 PLANTS WITHOUT CHLOROPHYLL causing consumption divides every half hour. Make the following table complete for 24 hours, using numbers only. §.30 AM: a hbacterium taken in _ 1 9.00 ~ the . divides _ — 2 9.30 “" the bacteria civide ofan — — — — - 4 10.00 “ «and _— —— ———~.8 10.30 “ “16 11.00 " = 32 11.30 " 64 12.00 ™- - 128 12.30 PM: = 256 ete... Conclusion. —1. How many bacteria would there be in your lungs at 8.30 a.m. the following morning? 2. Why do we not catch some disease each day? We breathe, eat, and drink countless dangerous bacteria every day. (See page 154, Civic Biology.) Problem 100: What foods are preferred by bacteria? Materials. — Raw meat, cooked meat, white of egg, beans, Indian meal flour, cake, sugar, butter, test tubes, absorbent cotton. Method. — Moisten all of the above food substances, place in test tubes with a little water. Expose all to the air for half an hour. (This can be done during a class period.) Plug with absorb- ent cotton and allow to stand for several days. Observations. — Note the appearance and odor of the various substances after five days. Conclusion. — 1. In which substances was there rapid growth of bacteria? 2. Can you make any generalization with reference to the class of nutrients most favorable for the growth of bacteria? Problem 101: What effect has heat upon the gsrowth of bacteria? Materials. — Test tubes, bouillon. Method. — Number four tubes containing bouillon. Place PROBLEM 103 121 number 1 in the ice box, number 2 in a dark box at a moderate tem- perature, number 3 in a box at a hot temperature (100° F. or over), and boil number 4 for 15 minutes and then place with number 2. Observations. — In which tube does the greatest amount of growth take place? (Note the odor as well as color of bouillon.) In which tube did the least growth take place? Conclusion. — What is the effect of intense heat upon bacteria? From this experiment we derive the very important method of fighting bacteria by means of sterilization. From experiments already performed give a definition of sterilization. Problem 102: To note the effect of moisture and dryness upon the growth of bacteria. (Home problem. ) Materials. — Beans, test tubes. Method. — Take two beans. Remove the skin and crush one. Soak the second bean overnight and then crush it. Place in test tubes, the first dry, the second with water. Leave both in a warm place for two or three days. Then smell each tube. Conclusion. — 1. In which is decay taking place? 2. In which tube are bacteria at work? How do you know? NOTE. — Heat and dryness are thus shown to be unfavorable to the growth of bacteria. From experiments dry sterilization, if continued long enough and if the heat is sufficiently high, seems the more effective. Some foods are spoiled by too great heat. Milk, in particular, is changed by boiling so as to be quite a different food. Hence a method of killing germs known as pasteurization is of importance. Problem 103: To determine the effect of pasteurization upon the keeping quality of milk. Materials. — Milk, two sterilized covered jars, thermometer, double boiler, or pasteurizing apparatus. Method. — Place half of the milk in a sterilized jar, cover, and leave in a warm place for 24 to 48 hours. Place the remainder of the milk in the other jar, cover, and put it in the double boiler or pasteurizing apparatus. Bring the hot water surrounding the jar from 160° to 180° F. for about 30 122 PLANTS WITHOUT CHLOROPHYLL minutes. This is known as pasteurization. Afterwards treat exactly as you did the first jar of milk. Observations. — What is the odor of milk in each jar after 24 and 48 hours? What is the taste of the milk in each jar after 24 and 48 hours? Conclusion. — 1. What are found in milk that cause it to sour? How do you know? 2. What is the use of pasteurization ? Problem 104: How to care for milk bottles at home. Materials. — Recently used milk bottles. : Method. — Place a recently used milk bottle in a warm place for 24 hours. Note the odor. Rinse out a second milk bottle with cold water, a third with boiling water. Set aside and note odor after 24 hours, as before. Observations. — Describe the odor. Note any differences in odor in the three bottles. Conclusion. — How should milk bottles be treated to prevent rapid souring of milk ? Problem 105: To determine the bacterial content of milk. Materials. — Sterile Petri dishes containing agar culture media, a sample of milk. Method. — Milk should be collected by pupils from some near-by source as, for example, the lunchroom of the school. To 1 c.c. of this milk add 19 c.c. of distilled water in a sterile pipette. Shake well and then flood the surface of a sterile Petri dish with the mix- ture. Pour off all excess fluid. Then cover quickly and place the dish in a moderately warm place. Observations. — Notice that after 24 hours (or even less if the temperature is warm) colonies of bacteria appear on the surface of the culture. media. Note the number of colonies of bacteria present on the second, fourth, and sixth days after preparing the experiment. Conclusion. — 1. What can you say of the number of bacteria in this milk ? 2. What do bacteria do to the milk? (Smell the Petri dish.) PROBLEM 106 123 NOTE. — A similar experiment should be tried with water from various sources. Bottled drinking water, rain water, artesian well water, tap water, and water collected from surface pools are suggested for possible experiments. Problem 106: To determine some of the most effective pre- servatives. Materials. — Test tubes containing beef bouillon and various preservatives, salt, sugar, vinegar, formalin, boracic acid, alcohol. Method. — Expose the tubes to the air unplugged. Number the tubes and label them. To No. 1 add nothing. No. 2 add } spoonful of salt. No. 3 add 1 spoonful of sugar. No. 4 add a saturated sugar solution. No. 5 add 1 spoonful of vinegar. No. 6 add a few drops boracic acid (saturated solution). No. 7 add 4 spoonful boracic acid. No. 8 add 5 drops formalin. No. 9 add 1 spoonful alcohol. Observations. — Note the appearance, odor, and color of each tube at the end of three days, five days, one week, and two weeks. Tabulate your results . ie s as shown in accom- Pu | Zu |Z 51S, §] 28) oe | 2S] 0] 35 nee Appearance] 29] FQ | Poi ees| Fs | £2 | Ss| Se | Bs panying chart. ont, [ES | a0) be lee2 BS 15 2] AE] 5 EES Conclusion. — 1. oF 2S Pe) 30 linn) «oa [8B ne id What are the most ef- {At fn4 fective preservatives ? ae 2. Which of the |, es above are permitted [Ary.a bylaw? (See Hunter’s | ;wWher Civic Biology, p. 148.) [At Ena 3. On which solu- | 2veks tions did mold grow? 4. Which preservatives prevented bacteria but not molds? 5. Which preservatives prevented the growth of both bacteria and molds? 124 PLANTS WITHOUT CHLOROPHYLL Problem 107: To determine the most effective disinfectants. Materials. — Use tubes of bouillon containing different strength solutions of formalin, lysol, iodine, carbolic acid, and bichloride of mercury. Method. — Expose all tubes unplugged to air, having previously inoculated each tube with germs from a Petri dish culture. Num- ber and label tubes. To tube 1 add 1 drop formalin. 2 add 5 drops formalin. 3 add 1 drop lysol. 4 add 3 drops lysol. 5 add 1 drop iodine. 6 add 5 drops iodine. 7 add 4 drops carbolic acid. 8 add 10 drops carbolic acid. 9 add 1 drop bichloride mercury solution. 10 add 5 drops bichloride mercury solution. Observations. — Tabulate daily for a week or more the results for the contents of each tube on a table as shown below. Conclusion. — 1. Which of the above is the best disinfectant? Why do you answer ec] | al & Appearance if né| a lBol ee] te] 8 a3] 8] 22| a8 you do? (Remem- Odor ot [Pel ee] Paleo aa| ke] ee] ee) ki fe) ber that according to the Ena of [A E/AE | A RIA DIA 3/83 | A) Oe [Ag las a ae] og [amore |or| ts] aolsloe] definition an antisep- 3 days tic may retard the growth of bacteria but will not of neces- 1lweek sity kill them; a ger- micide destroys all bacteria if used prop- erly; while a disinfect- ant is a solution used to kill disease germs, usually in the excreta of sick people.) 2. Using the data from the last two problems, classify the materials used, as antiseptics, germicides, or disinfectants. Give reason for each. 5 days 2 weeks REFERENCE BOOKS PROBLEM QUESTIONS 1. Fill out the accompanying comparative table: 2. Where may mold spores be found? What must they have in order to grow? 3. On what part of foods do molds grow? 4. How would you prevent mold spores from getting into food? 5. Is food that has become moldy fit to eat? Explain. 6. Why are we able to eat moldy jelly after removing the mold? 7. How may molds be harmful to man? Useful to man? 8. Howmay yeastsbeusefultoman? 125 Mop YEAST Bacrersa) Drawing Size Conditions Favorable ForGrowth Conditions avm ful Growth Use toMan Harm toMan 9. Where are yeasts found? Give proofs. 10. What products are formed when bread rises? ' What be- comes of these products? 11. It is said that yeast plants are at once the friends of man and yet make him their slaves. Explain what this means. 12. Why do we place foods in the ice box? 13. Why are some meats and fish salted? 14. Why are some meats and fish smoked? 15. Why is corn, wheat, or other grain stored in a dry place? 16. Why do canned goods keep? 17. Why are preserves sometimes not fit to eat? 18. Why do we place eggs in salt, liquid glass, or coat them with paraffin in order to keep them? 19. How would you prevent milk from souring? 20. What would you do to prevent the possible spread of dis- ‘ease germs in your home if you had a case of typhoid fever there? Tuberculosis? Grippe? REFERENCE Booxs Hunter, Civic Biology, Chap. XI, American Book Company. Hunter, Elements of Biology, Chap. XI. American Book Company. 126 PLANTS WITHOUT CHLOROPHYLL Hunter, Essentials of Biology, Chap. XI. American Book Company. Atkinson, Mushrooms, Edible, Poisonous, etc. Henry Holt and Company. Bacteria and the Nitrogen Problem. Reprint Yearbook, U. 8. Department of Agriculture, 1902. Bergen and Caldwell, Practical Botany, Chap. XI. Ginn and Company. Bigelow, Introduction to Biology. The Macmillan Company. Bolduan, Bactericlogy and Your Health, Serums and Vaccines. ‘Scientific American, June 14, 1913. . Bowker, Bacterial Fertilizers. Scientific American, February 14, 1914. Conn, Agricultural Bacteriology. P. Blakiston’s Son and Company. Conn, Bacteria, Yeasts, and Molds in the Home. Ginn and Company. Conn, Story of Germ Life. D. Appleton and Company. Coulter, Barnes, and Cowles, A Teztbook of Botany, Vol. I. American Book Com- pany. Davison, The Human Body and Health. American Book Company. De Bary, Comparative Morphology and Biology of the Fungi, Mycetozoa, and Bacteria. Oxford University Press. Duggar, Fungous Diseases of Plants. Ginn and Company. Elliott, Botany of To-day, Chap. IV. Seeley and Company, London. Frankland, Bacteria in Daily Life. Longmans, Green and Company. Goodhue, Battle of the Microbes. Cosmopolitan, February, 1913. Hendrick, Exploring the Infinitely Little. World's Work, May, 1914. Hendrick, Life of a Microbe. Literary Digest, April 11, 1914. Hendrick, Longevity of Microbes. Scientific American, January 3, 1914. Hitchens, Sanitary Bacteriology. Science, September 19, 1913. Hough and Sedgwick, The Human Mechanism. Ginn and Company. Kelly, Walter Reed and Yellow Fever. Doubleday, Page and Company. Lipman, Bacteria in Relation to Country Life. The Macmillan Company. Lyon and Byzzell, Some Conditions Favoring Nitrification in Soils. Science, Novem- ber 26, 1909. Marshall, Microbiology for Agricultural and Domestic Science Students. P. Blakis- ton’s Son and Company. McBride, The North American Slime Molds. The Macmillan Company. Muir and Ritchie, Manual of Bacteriology. The Macmillan Company. Newman, The Bacteria. G. P. Putnam’s Sons. Overton, General Hygiene. American Book Company. Prudden, Dust and its Dangers. G. P. Putnam’s Sons. Prudden, The Story of the Bacterta. G. P. Putnam's Sons. Ramsay, Making the Microbe Work. Hearst Magazine, July, 1913. Ritchie, Primer of Sanitation. World Book Company. Rowe, Raising Germs for Profit. Pearson's Magazine, April, 1910. Sedgwick, Principles of Sanitary Science and Public Health. The Macmillan Com- pany. Stevens, Fungi Which Cause Plant Disease. Science, July 31, 1914. Thompson, Our Invisible Allies. Everybody’s, September, 1913. Thompson, Pathologic Bacteriology. Science, September 26, 1913. Winslow, Characterization and Classification of Bacterial Types. Science, January 16, 1914. Winslow, Evolution of Diseases.. Literary Digest, May 16, 1914. XII. THE RELATIONS OF PLANTS TO ANIMALS Problems.— To determine the Seneral biological relations ex- isting between plants and animats. (a) As shown in a balanced aquarium. (6) As shown in hay infusion. SuGGESTIONS FoR LABORATORY Work Demonstration of life in a ‘“‘balanced” and “unbalanced” aquarium. — Determination of factors causing balance. Demonstration of hay infusion. — Examination to show forms of ani- mal and plant life. Tabular comparison between balanced aquarium and hay infusion. To THE TEACHER. — The gap between plants and animals is not a wide one. The bridging of the gap is undertaken by means of the exercises which follow. First the pupil is led to see the interdependence of organisms on the earth; then the dependence of one kind of organism upon another; and then he is brought face to face with the fact that there are two kinds of organisms, one constructive, the other destructive. These, he learns, may both live in a small aquarium jar and they may both be single cells. Problem 108: To study some biological relations of plants and animals in a balanced aquarium. Materials. — A balanced aquarium containing living green plants, fish, tadpoles, snails, and other forms of animal life. Observations. — Watch the animals within the aquarium to see if any are feeding. Note what they eat, also that the fish are continually opening their mouths as if biting. What might the fish be taking from the water (not food)? In an aquarium placed in the sunlight, what gas is given off from the green plants? How might this gas be useful to animals? Does this explain the action of the fish mentioned above? What gas is given off by animals that plants would use under certain conditions? Are these conditions present? Fish and other ani- 127 128 THE RELATIONS OF PLANTS TO ANIMALS mals give off nitrogenous wastes. How might these be used by the plants in the aquarium? Conclusion.— 1. What might the plants within the aquarium furnish the animals? What might the animals furnish the plants? 2. Remembering that the sun furnishes energy, tell what makes the balance within the Balancea Aquarium aquarium. How Contents Income from Outgo to could you destroy : this balance? eines 3. Fill out the ac- Plants companying balance sheet. Problem 109: To learn what we mean by the carbon and the oxygen cycles. Method. — Carefully study the following figures. y CHLOROPHYL T STARCH, LSu — re T PROTEIN a. Carbon Cycle Observations. — In the plant world where does the carbon come from? Trace it to the animals. In what form do they take it in? In what forms do they release it? How does carbon get back to the plants? b. Oxygen Cycle Observations. — Begin with animals. What happens to oxygen within their bodies? In what form does it leave the animal body? PROBLEM 111 129 How does it get to the plant? Does the plant use oxygen as the animal does? Conclusion. — 1. How are plants able to store up energy? Where does it come from? What becomes of it? 2. Explain the carbon cycle. 3. Explain the oxygen cycle. Problem 110: To find out the course of nitrogen in its rela- tion to plants and animals. Method. — Begin at the point of the diagram marked “ Free N,” following the direction of the arrows. Observations. — What «eid ete © ae | Life do we mean by “ free Ured nitrogen’? Where is it found? How do green plants get the free nitro- gen? In what form does the nitrogen get into the animal body? In what > 56 form does the nitrogen (2aftatoq<— Nitric Bacteria leave the bodies of ani- " mals? What causes this material and the dead bodies of animals to become usable by plants? Does any nitrogen get back into the atmosphere again? If so, how and when? Look this up in any good book of reference. Conclusion. — 1. Fill out a summarizing table like the accom- panying. Proteids Plant Life Nitrous Bacteria, Plants |icome, of | Outge, of, | 2. In your notebook explain in a well-writ- Green . ten paragraph what is ree meant by the nitrogen cycle. Problem 111: To prove a hay infusion is an unbalanced aquarium. Materials. — Hay, glass jar, microscope, glass slides, cover glasses, and pipette. HUNTER LAB. PROB. —9 130 THE RELATIONS OF PLANTS TO ANIMALS Method. — Make a hay infusion by placing a wisp of hay in a jar of warm water. Let it stand a few days. Observations. — What has happened to the hay? Any change in color? Appearance? Odor? What do you know has hap- pened to materials within the hay infusion? With a bulb pipette take a drop of water from the edge of the jar near the surface of the water. Place it on a glass slide. Examine with the low power of the compound microscope. The tiny structures moving about are one-celled animals. Grass for hay is often cut near pools that dry up at haying time. These pools contain millions of one-celled animals (Protozoa) which, as the pond dries up, proceed to form a heavy wall about each tiny body. In this form (like spores of mold) they may be blown about in dust and still retain their vitality. Conclusion. — 1. What does the presence of decay in the hay infusion indicate? 2. How do the Protozoa get in the infusion? 3. On what might the Protozoa feed? 4. Why is the hay infusion unbalanced? 5. How long might life exist in it? PROBLEM QUESTIONS 1. Why is an aquarium called balanced ? 2. What factors are necessary for the balance? 3. What are the food relations existing between plants and animals in an aquarium? 4. Compare life on the earth to a balanced aquarium. 5. What kinds of bacteria are necessary to life on the earth? Why? 6. What substances are formed through the influence of the bacteria of decay? 7. What is meant by the carbon cycle? 8. What do you understand by the oxygen cycle? 9. Explain the nitrogen cycle in an aquarium; on the earth. 10. What are the indispensable bacteria? Why? 11. In what stage must the one-celled animals have been when they were attached to the hay? Why? REFERENCE BOOKS 131 REFERENCE Booxs Hunter, Civic Biology, Chap. XII. American Book Company. Hunter, Elements of Biology, Chap. XII. American Book Company. Hunter, Essentials of Biology, Chap. XIV. American Book Company. Abbott, Elementary Principles of General Biology. The Macmillan Company. Arnold, The Sea Beach at Ebb Tide. Century Company. Bateman and Bennett, The Book of Aquaria: Part I, Fresh-water Aquaria; Part II, Marine Aquaria. Charles Scribner’s Sons. Bateman, The Vivarium. Charles Scribner’s Sons. Calkins, Biology. Henry Holt and Company. Eggeling and Ehrenberg, The Fresh-water Aquarium and its Inhabitants. Henry Holt and Company. ; Furneaux, Life in Ponds and Streams. Longmans, Green and Company. Hall, The Soil as a Battle Ground. Harper's Magazine, October, 1910. Jones, The Aquarian Naturalist. Van Voorst, London. Kellogg, Elementary Zoélogy. Henry Holt and Company. Mayer, Seashore Life. The New York Aquarium Nature Series, 1905. Murbach, Fresh-water Aquaria. Journal Applied Microscopy, September, 1900: also American Naturalist, March, 1900. Nevins, The Balanced Aquarium. Pearson’s Magazine, October, 1907. Parker, Biology. The Macmillan Company. Rogers, The Salt-water Aquarium. Country Life in America, July, 1904. Rogers, Life in an Aquarium. Teachers’ Nature Study Leaflets, No. 11, Cornell University, April, 1898. Samuel, The Amateur Aquarist. Baker and Company. Sedgwick and Wilson, Biology. Henry Holt and Company. The Care of Balanced Aquaria. New York Zodlogical Society Bulletin for April, 1903. Whedon, The Fresh-water Aquarium. Country Life in America, January, 1905. XIII. SINGLE-CELLED ANIMALS CONSIDERED AS ORGANISMS Problems. — To determine: (a) How a@ one-celled animal is influenced by its environ- ment. (6) How a single cell performs its function. (e) The structure of a single-celled animal. LasBoratory SUGGESTIONS Laboratory study. — Study of paramcecium under compound micro- scope in its relation to food, oxygen, ete. Determination of method of movement, turning, avoiding obstructions, sensitiveness to stimuli. Draw- ings to illustrate above points. Laboratory demonstrations. — Living paramcecium to show structure of cell. Demonstration with carmine to show food vacuoles and action of cilia. Use of charts and stained specimens to show other points of eell structure. Laboratory demonstration of fission. To THE TEacHuER. — With the introduction given by the previous chapter, it is easy to demonstrate some of the reactions of a single-celled animal, and compare them with those of a single-celled plant. The structure of a cell and its various functions as an organism make this chapter of great interest to all pupils, espe- cially as the wonders of the world of the microscope are placed at their disposal. Problem 112: Yo study a one-celled animal in oruer to understand better (a) its reactions to stimuli; (6) the cell as a unit of structure. Materials. — Hay infusion, pipette, glass slides, cover glasses, and compound microscope, Kny or Leukart charts. Method. — Remove, by means of a pipette, a few drops of the whitish scum on the top of the hay infusion. This scum contains great numbers of paramecia (a one-celled animal). Mount on a slide with a little spirogyra or other green alga. After allowing slide to stand for a few moments, examine under the low power. 132 PROBLEM 112 133 a. Reaction to Stimuli Observations. — Do the moving structures appear to have any definite shapes? Do they move with any definite end forward? Do they collect in any locality? Ifso, what influences them to do this? Heat a needle and introduce at one side of the cover glass. Any movement on the part of the paramcecia? Notice some of the animals grouped around masses of food. Why do you suppose the parameecia are there? Notice other paramcecia with refer- ence to the position of air bubbles or to threads of spirogyra. How do they lie with reference to the air bubble? What might the animal get from the air bubble if it is to do work? How would a cell covered with a membrane take anything from an air bubble? What might it give in exchange? NOTE. — All things that influence a plant or animal to react are called stimuli. Conclusion. — 1. Write a paragraph explaining how a para- mececium reacts to the stimuli in its environment. 2. Make drawings to illustrate your conclusions. b. Movement Observations. — Look at the chart or at the prepared material for tiny projections from the body walls of the paramcecium. These structures, which are flexible threads of living matter, are called cilia. Conclusion. — How might locomotion be accomplished by means of cilia? Explain with the aid of a diagram. c. Internal Structure Observations. — To study the internal structure of parameecia use living animals which have been fed on green microscopic plants or on carmine grains. Examine with high power and also use charts. The small round spaces filled with green plant mate- rial or with red carmine grains are food vacuoles. Look for a groove on one side of the cell; this leads into a funnel-like opening, the gullet (g). (See page 134.) Explain how food might be taken in by a parameecium. How might it circulate within the body? 134. SINGLE-CELLED ANIMALS AS ORGANISMS Remember that the paramcecium is a semi-fluid body, covered with a membrane. Other structures found within the cell are (1) contractile vacuoles (cv), usually one at each end of the cell; these serve to excrete liquid waste; (2) water vacuoles, clear spaces; (3) the nucleus (n), con- sisting of a double structure, the micro- and the macro-nucleus which can be seen only in a stained specimen. (Demonstra- tion.) Conclusion. — 1. What struc- tures are found in a one-celled animal ? 2. What uses have these struc- tures? 3. Draw a paramcecium show- ing all structures. d. Reproduction Observations. — Sometimes paramcecia may be found divid- ing crosswise by fission. In this process each of the two new cells o> formed contains half the original ACOoLoNIAL TYPE nucleus and half of the rest of the cell body. Draw such a specimen if you find one. In another method of reproduction, parts of the nuclei of two adjoining cells become exchanged, so that the first cell has part of the nucleus of the second cell and the second cell has part of the nucleus of the first cell. This is known as conjuga- tion. Conclusion. — 1. How do parameecia reproduce? 2. What is the difference between fission and conjugation ? (a) REFERENCE BOOKS 135 Problem 113: Comparative study of various forms of single- celled animals to explain division of labor. (Extra Problem.) Materials. — Figures on opposite page showing amceba, paramce- cium, vorticella, and a colonial form, such as charchesium or z06- thamnium. Observations. — Examine the figure of an amceba. Are there any special structures for locomotion? The entire cell body changes shape as the animal moves. Has the animal any definite mouth? QGullet? Look at the figures. How is food taken into the body? Look for food vacuoles, contractile vacuoles, nucleus. Compare an amceba with a paramcecium. In which cell is the work performed by more separate parts of the cell? NOTE. — The performance of different kinds of .work by different structures in a plant or animal is called division of labor. Compare the amceba and parameecium with vorticella. Note the stalk; it is contractile. Is the entire body covered with cilia? Are the cilia used for the same purpose as in paramcecium? Is there a definite food opening? How does food get into this opening? (Demonstration of a vorticella in a weak carmine mix- ture will show this point.) Look at the colonial form. How does it differ from vorticella? How does it move? How is food obtained? Is there greater or less division of labor than in a single cell? Conclusion. — What is division of labor? Explain from com- parison with at least three one-celled animals. PROBLEM QUESTIONS ce ” 1. Explain the term “ reaction to stimuli” with reference to paramcecium. 2. What parts of a cell are found in parameecium? 3. How does paramecium move? Feed? Breathe? Re- produce? 4. How is division of labor illustrated among the Protozoa? REFERENCE Books Hunter, Civic Biology, Chap. XIII. American Book Company. Hunter, Elements of Biology, Chap. XII. American Book Company. 136 SINGLE-CELLED ANIMALS AS ORGANISMS Hunter, Essentials of Biology, Chap. XV. American Book Company. Calkins, Protozoélogy. Lea and Febiger. Calkins, The Protozoa. The Macmillan Company. Davison, Human Body and Health, Advanced, Chap. XXIII. American Book Company. Guyer, Animal Micrology. University of Chicago Press. Jennings, Study of the Lower Organisms. Carnegie Institution Report. Jordan, Kellogg, and Heath, Animal Studies. D. Appleton and Company. Macfadyen, The Cell as the Unit of Life. P. Blakiston’s Son and Company. Parker, Lessons in Elementary Biology. The Macmillan Company. Ritchie, Primer of Sanitation, Chap. XXVI. World Book Company. Shannon, The Microscopic Animals of the Sea. Harper’s Magazine, June, 1910. Sharpe, Laboratory Manual in Biology, pp. 140-143. American Book Company. Wilson, The Cell in Development and Inheritance. The Macmillan Company. XIV. DIVISION OF LABOR. THE VARIOUS FORMS OF PLANTS AND ANIMALS Problems.— The development and forms of plants. The development of a simple animal. What is division of labor? In what does it result? How to know the chief characters of some great animal Sroups. LasBoratory SUGGESTIONS A visit to a botanical garden or laboratory demonstration. — Some of the forms of plant life. Review of essential facts in development of bean or corn embryo. Demonstration. — Charts or models showing the development of a many- celled animal from egg through gastrula stage. Demonstration. — Types which illustrate increasing complexity of body form and division of labor. Museum trip. — To afford pupil a means of identification of examples of principal phyla. This should be preceded by objective demonstration work in school laboratory. To THe TEeacuer. — The object of this chapter is to give the pupil a bird’s-eye view of the plant and animal kingdoms. This is not done for the sake of accurate classification, but simply to impress him with the wonderful diversity and com- plexity of form and structure in the living world about him. Also these exercises should bring home the idea that division of labor and complexity of structure in plants and animals go hand in hand. The exercise in determining the place of animals and plants in the evolutionary scale should be largely an exercise in deter- mining the amount of division of labor shown in a given group. It is needless to say that the work can best be done by means of type collections in a museum or in the laboratory. The outline (Problem 118) in the hands of the pupils aids in the identification of the various phyla. Comparison of type forms under these phyla gives the pupil an excellent opportunity for study of relation of forms. Problem 114: How the plant kingdom is classified. Materials. — Specimens of alge, fungi, mosses, ferns, and flowering plants. NOTE. — All animal and plant life shows greater or less division of labor, the more complex forms showing greater division of labor. We classify as higher the plants or animals showing greater division of labor. 137 138 DIVISION OF LABOR a. Alge Method and Observations. — Examine some pond scum with a hand lens. What kind of body has the plant? Has it any root, stem, and leaves? Look at specimens under the microscope and on the chart to determine the methods of reproduction. Conclusion. —1. Would such a plant as this have much division of labor? Many different organs? 2. How does such a plant reproduce? b. Fungi Method and Observations. — You have already studied a yeast and a mold as examples of fungi. Study in addition a shelf fungus. Remember that the shelf-like part is the reproductive portion (much like the sporangium and stalk of black mold). Study a piece of decayed wood containing mycelium of bracket fungus. What is its general appearance? Compare with mycelium of mold. Conclusion. — Is division of labor greater in the alge studied or in the fungi studied? Explain fully. y c. Mosses Method and Observations. — Notice that the body of the moss shows rootlike structures, rhizoids; an upright stem; and _ leaf- like structures. Notice that some bear stalks with a little capsule on the top. The stalk and capsule bear asexual spores and are known as the asexual generation. The moss plants produce egg and sperm cells in different organs, giving the title of sexual generation to this part of the plant. Conclusion. — Does the separating of the plant into two phases, a sexual and an asexual phase, result in greater or less division of labor? Explain. d. Ferns Method and Observations. — The fern plant has roots, an underground stem, and large leaves called fronds. On the backs of some of the fronds are found asexual spore-producing bodies, sporangia. The sexual part of the fern (see chart) is a very tiny body called a prothallus. PROBLEM 115 139 Conclusion. — Compare the ferns with other plants in com- plexity of structure. e. Flowering Plants Method and Observations. — In the flowering plants the sexual generation is reduced to a very small part of the flower, the stamens and pistil. What structures found therein make this the sexual generation? All the rest of a plant — root, stem, leaves —is the asexual generation. Conclusion. — 1. Compare the various structures of a flowering plant with those of the fern, moss, fungus, and alga. 2. Show that division of labor is greatest in the flowering plant. f. Physiological Development Refer back to your work on the function of the flower. At the time of fertilization, how many cells make up the young plant? What happens to it as it grows into an embryo? Is an embryo a more complex structure than an egg? Why? In the above forms is the development of this young plant in any way similar? (See charts or text figures.) General Conclusion. — 1. What group of plants studied has the most complex structure? The greatest division of labor? 2. Is there any connection between the position of a plant in the plant kingdom and its complexity of structure? Explain. Problem 115: To compare reproduction in plants with that in animals. Materials. — Charts and models illustrating processes of fertilization and development in plants and animals. Method. — Compare, by means of charts, fertilization in several types of plants with that in some simple animal. Use models illustrating early development of amphioxus, fish, and frog. Observations. — How does fertilization take place in a flower- ing plant? In a fern? In a moss? In a very simple plant? By what means does the sperm cell get to the egg cell in each of the above cases? Is there any outside agency that helps in this? 140 DIVISION OF LABOR NOTE. — In animals, as in plants, two cells, the sperm and the egg, unite to form a fertilized egg. This cell will, under favorable conditions, develop into a new animal. In animals, which is the larger, sperm or egg cell? Which is the movable cell? Suppose an animal, as a fish, laid its eggs in the water, how might fertilization’ take place? NOTE. — The embryo of a plant (e.g., the bean seed) grows as the result of the division of the original fertilized egg into first two, then four, then eight, etc., cells. An animal embryo develops in a similar manner. Arrange models in order to show development from a single cell (the fertilized egg) to a hollow ball of cells, called the blastula stage. (See figures above.) Note what happens next in develop- ment. The cup-like structure is called a gastrula. How is the gastrula stage formed? NOTE. — Most animals, including man, pass through the stages shown above. Suppose that all the cells had cilia in the blastula stage. How would locomotion take place? Suppose the hollow of the gastrula is used as afood tube. Is there then any division of labor? _ Conclusion. — 1. In what respects is fertilization similar in plants and in animals? 2. What stages of development are alike in all animals? Problem 116: To study the division of labor in tissues and organs. Materials. — Charts and slides showing different kinds of tissues, microscope. Method and Observations. — We have already found that cells having the same structure and performing the same work form tissues. Examples in our bodies are muscle tissue, nerve tissue, connective tissue, etc. Does a blastula have more than one tissue? A gastrula? Give reasons for your answers. Examine figure, page 179, Civic Biology, or slides showing different PROBLEM 118 141 kinds of cells, such as muscle, nerve, and bone. Why do we have different tissues in a plant or in an animal? NOTE. — The hand is an organ, a structure made up of different tissues, all of which work together for the performance of certain work. Name some organ found in an animal; in a plant. Name some tissues that make up your hand; your foot; youreye. (Use your Cwvic Biology, pages 266-271, for this purpose.) Conclusion. — 1. Why are cells of different shapes and sizes? 2. Of what purpose are tissues in our body? 3. Why are organs composed of tissues? Use the term division of labor in writing your answer. Problem 117: To find some of the functions common to all animals. Method. — Review the needs of a single-celled animal. What must a single-celled animal do in order to live? NOTE. — Remember that food must be obtained, digested, and oxidized to re- lease energy (in a many-celled animal this food must be circulated about the ani- mal). Some of it must be made into living matter, and wastes must be excreted from the body. What organs has a single-celled animal that perform each of these functions? Compare the needs of a paramcecium with our needs. Compare the functions of a paramcoecium with our func- tions. Compare, in each, the organs which perform these func- tions so far as you know them. Get assistance from your text- book (Civic Biology, pages 180, 181). Conclusion. — How does a single-celled animal compare with a very complex animal in the number of functions and in the organs it has for performing these functions? Problem 118: How to know some types of animals in the animal kingdom. Materials. — Dried or formalin specimens of sponge, sea anemone, starfish, segmented worms, crustaceans, insects, mollusks, and vertebrates (fish, frog, turtle, bird, and mammal).: 142 DIVISION OF LABOR Groups or ANIMALS NOTE. — Animals may be arranged in an evolutionary series beginning with simple forms and ending with very complex forms, such as man. Division of labor in a steadily increasing degree is seen as we go from the simple to the higher forms. We shall try to arrange the forms given in an evolutionary series, beginning with the *simplest forms and working up to the most complex. a. Protozoa First would come one-celled animals, Protozoa. Name three Protozoa which you have studied. b. Porifera Sponges, Porifera (containing pores). Examples: bath sponge, Grantia. Simple fixed forms. Note a specimen of the bath sponge. Has it a skeleton? What is the internal structure of a sponge? (See figure on page 180, Civic Biology.) c. Celenterates Celenterates (Caelom = body cavity, enteron = food tube). Examples: Hydra, sea anemone, jellyfish. There is a single cavity in the body with one opening. (See figure on page 179, Civic Biology.) The animals in this group are provided with sting- ing cells. d. Segmented Worms Examples: sandworm, earthworm. Long jointed or segmented animals with or without jointed legs. Nervous system on the under side of the body. (Pages 183, 184, Civic Biology ) e. Echinoderms Examples: starfish, sea urchin. These animals have spines in the skin, body organs more complicated. (Pages 184, 185, Civic Biology.) f. Arthropods Having jointed body, jointed appendages, and outside skeleton. Nervous system on under side‘of the body. There are two great groups of these animals: s PROBLEM QUESTIONS 143 (a) Crustacea. Limy skeleton, segmented, body divided into two regions, more than three pairs of walking appendages, breathe through gills. Examples: crayfish, crab, lobster. (b) Insecta. Having a horny skeleton (chitin), only three pairs of walking legs, breathe through trachee. Examples: bee, ant, grasshopper. Two smaller groups of Arthropods are also found: the Arachnids, spiders, having four pairs of legs, and the Myriapods, ‘ thousand leggers,”’ which have many pairs of simi- lar jointed legs. (Page 185, Civic Biology.) g. Mollusks Examples: clam, snail, oyster. Have a soft, unjointed body, usually covered with a hard limy shell of one or two pieces (valves). This shell is formed by a covering called the mantle. These ani- mals breathe through gills. (Page 185, Civic Biology.) h. Vertebrates Examples: fish, frog, turtle, bird, dog. Having an internal limy skeleton composed of pieces of bone jointed together. Also an external skeleton which may be scales, bone, feathers, nails, or hair. Breathe by gills or lungs. Central nervous system on back or dorsal side of body protected by a chain of bones called the vertebral column. (Pages 185-192, Civic Biology.) Method and Observations. — Using the above directions pick out of the material given you one specimen of each group and arrange the specimens selected in a series showing evolutionary order. Conclusion. — 1. What do you mean by evolutionary order? 2. Has division of labor anything to do with your placing these specimens as you have? PROBLEM QUESTIONS 1. Why do we speak of the plant or animal kingdom ? 2. What results from fertilization in both plants and animals? 3. How are egg cells protected in birds? In a flower? Why should they be protected ? 144 DIVISION OF LABOR 4. How does nature make up for lack of protection of the eggs of fishes? (See Civic Biology, pages 238-239.) 5. What is division of labor? 6. What is a blastula? A gastrula? An embryo? Give examples. 7. What is a tissue? An organ? 8. What are the functions necessary for all animals? 9. How are these functions performed in a single-celled animal? Ina many-celled animal? 10. What do we mean by evolutionary order? ReFERENCE Books Hunter, Civic Biology, Chap. XIV. American Book Company. Hunter, Elements of Biology, Chap. XVI. American Book Company. Hunter, Essentials of Biology, Chap. XVI. American Book Company. Adams, Guide to Study of Animal Ecology. The Macmillan Company. Comstock, Manual for Study of Insects. Comstock Publishing Company. Comstock, The Spider Book. Doubleday, Page and Company. Davenport, Introduction to Zoélogy. The Macmillan Company. Fabre, Life of the Fly. Dodd, Mead and Company. Fabre, Life of the Spider. Hodder and Stoughton. Fabre, Social Life in the Insect World. T. Fisher Unwin. Flower, The Horse. D. Appleton and Company. French, The Butterflies of the Eastern United States. J.B. Lippincott Company. Hahn, Hibernation of Animals. Popular Science Monthly, February, 1914. Harmer and Shipley, The Cambridge Natural History. Vol. V. The Macmillan Company. Herrick, Household Insects and Methods of Control. Cornell Reading Courses. Holland, The Butterfly Bock. Doubleday, Page and Company. Holland, The Moth Book. Doubleday, Page and Company. Hornaday, Our Vanishing Wild Life. New York Zodlogical Society. Hornaday, American Natural History. Charles Scribner’s Sons. Hough and Sedgwick, The Human Mechanism. Ginn and Company. Howard, The Insect Book. Doubleday, Page and Company. Kellogg, Elementary Zoélogy. Henry Holt and Company. Kingsley, The Comparative Anatomy of the Vertebrates. P. Blakiston’s Son and Company. Linville and Kelly, Textbook in General Zoélogy. Ginn and Company. Maeterlink, Life of the Bee. Dodd, Mead and Company. Miall, Aquatic Insects. The Macmillan Company. Miller, Butterfly and Moth Book. Charles Scribner’s Sons. Miner, Animals of the Wharf Piles. American Museum of Natural History. Miner, Sea Worm Group. American Museum of Natural History. Needham, Elementary Lessons in Zoélogy. American Book Company. REFERENCE BOOKS 145 Parker and Haswell, Manual of Zoélogy. The Macmillan Company. Porters, Wild Beasts. Charles Scribner’s Sons. Pycraft, Domestication of Animals. Scientific American, January 10, 1914. Schaler, Domesticated Animals, Their Relations to Man and to His Advancement in Civilization. Charles Scribner’s Sons. Scudder, Guide to the Common Butterflies. Henry Holt and Company. Seton, Wild Animals I Have Known. Charles Scribner’s Sons. Shipley, Honeybee. Edinburgh Review, January, 1914. Stone and Cram, American Animals. Doubleday, Page and Company. Wright, Four-footed Americans. The Macmillan Company. HUNTER LAB. PROB. — 10 XV. THE ECONOMIC IMPORTANCE OF ANIMALS Problems. — I. To determine the wses of animals. (a) Indirectly as food. (6) Directly as food. (ce) As domesticated animals. (d) For clothing. (e) Other direct economic uses. (f) Destruction of harmful plants and animals. IT. To determine the harm done by animals. (a) Animals destructive to those used for food. (0) Animals harmful to crops and gardens. (e) Animals harmful to fruit and forest trees. (d) Animals destructive to stored food or clothing. (e) Animals indirectly or directly responsible for disease. To THe TEAcHER. — Inasmuch as this work is planned for the winter months the laboratory side must be largely museum and reference work. It is to be ex- pected that the teacher will wish to refer to much of this work at the time work is done on a given group. But it is pedagogically desirable that the work as planned should be varied. Interest is thus held. Outlines prepared by the teacher to be filled in by the student are desirable because they lead the pupil to individual selec- tion of what seems to him as important material. Opportunity should be given for laboratory exercises based on original sources. The pupils should be made to use reports of the U. 8. Department of Agriculture, the Biological Survey, various state reports, and others. Special home laboratory reports may be well made at this time, for example: determination at a local fish market of the fish that are cheap and fresh at a given time. Have the students give reasons for this. Study conditions in the meat market in a similar manner. Other local food conditions may also be studied first hand. This chapter is intended to be a practical résumé of the use and harm done by animals. Some of the work is intended as a change from pure laboratory work to that of reference reading. But some extremely important work outlined in this chapter should be taken when the season will allow, in the laboratory, in the field, orathome. Practical work on the relation of mosquitoes and flies to disease should be part of every educated person’s knowledge, for ability to deal with these pests may mean health as well as comfort in the home locality. 146 PROBLEM 119 147 Problem 119: What animal foods are cheapest in any locality and why? (Home work.) Method and Observations. — a. Visit your local fish and meat markets. If in New York, read the publications of the Mayor’s Food Supply Committee. Make tables of the fish and meats that i is : nN Amimalit |oopitat| cuter | cost Name of Fish||Habitat |Priceper| Remarks of Meat | Comes foom| 2&bitet port Exten| per 1b| Remarks] lb. are relatively cheap and those that are expensive. Go to the li- brary and look up in an encyclopedia or Jordan and Evermann’s American Food and Game Fishes the habitat of each fish you have priced. In Hornaday’s American Natural History or an ency- clopedia look up the habitat of the animals which supply the meats you have priced. Read Kipling’s Captains Courageous to see how certain fish are _ obtained. i ia, b. Using the figure, locate the various cuts of meat priced at the market. You will find that the cut of meat (part of animal used) determines the price, and this price is further determined by the de- mand of people buying and the supply in the market. Conclusion. —1. Does the habitat of the animal have any- thing to do with its price in the market? 2. What other factors might influence the price of fish? Ask your teacher to help you in this. 3. What factors might determine the price of meat? 4, What factors largely determine the price of cuts of meat? 148 THE ECONOMIC IMPORTANCE OF ANIMALS Problem 120: How animals may benefit mankind. Materials. —Hunter’s Civic Biology, pages 197-231, Toothaker’s Commercial Raw Materials, Government and State Department re- Use of Habitat! proaucts Preparation of Products Other Facts ports of various kinds. A visit to a commercial museum. Method. — Using your sources of in- formation, make out in tabular form a report giving (1) habitat, (2) use, (3) prep- aration of product, (4) other interesting facts with reference to the following animals: walrus, honeybee, ichneumon fly, silk- worm, ladybug, tach- ina fly, gall insects, blister beetles, lac in- sect, cochineal, bum- blebee, carrion beetle, toad, house wren, cuckoo, bank swallow, bluebird, woodpecker, brown thrush, gull, vulture, owl, black snake, milk snake, green snake. Conclusion. — In what ways are the above animals useful to man? Problem 121: To find out how birds are of economic tm- portance. Materials. — Pam- phlets of the Depart- cow, sheep, horse, pig, whale, Insects Grains Fruits Weed Seed Rodents Fishes Miscel. Bobolink Blackbird Catbir a Coopers Hawk Crow Cucko oO Dove En gli sh Sparrow Gull Kingbird Kingfisher Ow], Horned Phoebe Quail Robin Sapsuck er Starling Swallow Thrush Wren PROBLEM i23 149 ment of Agriculture (see list of Reference Books) and Civic Biology, pages 209-211. Method and Observations. — Fill out the preceding table on the food of some birds, using references suggested above. Conclusion. — Which of the birds are of usetoman? Of harm? Which may be of both harm and use? Explain your answers. Problem 122: What are the causes of decrease in the number of birds? Method and Observations. Fact Birds | How | Remedies A aetens ffected Affected Proposea — Using your own experience and the information obtained from Hornaday’s Our Van- ishing Wild Life, complete a laveher/rGane Clearing of Forests Cultivation of Land table like the accompanying. fa vecincrs Conclusion. — In a care- | Fesyisn”’ fully written paragraph sug- [use as Fooa gest some methods of prevent- —[Cats.weasels, ing the decrease of our helpful a birds. Sparrows, Jays.ete Problem 123: To study the life history of the mosquito. NOTE. — There are four distinct stages in the development of the mosquito: egg, larva, pupa, and adult. These will be taken up and studied in order. a. The Egg Method. — The eggs of mosquitoes are laid on the surface of still salt or fresh water pools from April to October. By placing a can of water in a lot, we can Zs often obtain the small rafts C2 of eggs of the common mos- ~e, quito, the culex, and less often the single floating eggs of the malarial mosquito, the anopheles. Any standing water, especially in barrels, old cans, neglected drains, catch basins, and swamps, may make a near-by neighborhood almost uninhabitable. The yellow- fever mosquito, stegomyia, is not found in the North but is found in the warmer parts of the United States. 150 THE ECONOMIC IMPORTANCE OF ANIMALS b. The Larva (Wiggler) Materials. — The eggs will hatch if kept in a warm place, « wigglers can be scooped from a pond or pool of water. The may be kept in a screened battery jar half full of water. Observations. — What is the shape of the larvae? How c they move throug the water? Wat« the larve while at tl surface. Which er is up? (Note tl breathing tube th reaches through tl] surface of the water.) What is the position of the larvee whi at the surface? If they lie horizontal to the surface, they a the larve of the anopheles, the malarial mosquito; if at an acu angle, the larve are those of culez, the harmless mosquito. c. The Pupa Method and Observations. — Place a number of wigglers in screened battery jar. Allow them to cast off their skins ar become pup. How does this stage differ from the larval stage? Notice the empty shells of the pupe floating on the surface of the water. How did the adult mosquitoes get out? Do the pupe come to the surface of the water? If so, why Compare the position of the pupe at rest with the figures. the mosquito a culex or an anopheles ? d. The Adult Observations. — In a hatched adult observe the number ar kind of wings. In which insect group do mosquitoes belons Notice the antenne or feelers. (The males have more bust PROBLEM 125 151 feelers. Males do not bite.) What is the resting position of the adult? Compare with the figures on page 218, Civic Biology, and decide what kind of mosquito it is. Conclusion. — Write in a concise paragraph a short life history of the mosquito, either culex or anopheles. Problem 124: To find the breeding places of mosquitoes in any locality and how to destroy them. Field Trip. — Plot a map of your district showing all the water that might contain mosquito larve. Remember that tin cans in rubbish heaps, flat tin roofs or gutters, anything that can hold water for two weeks at a time may breed mosquitoes. Look care- fully for larve or pups. On the map note with a cross where you have found them. If such localities are found, go to the householder and explain what you have found. Conclusion. — If mosquitoes can fly several hundred yards from their breeding places, is my home safe from mosquitoes ? Problem 125: To determine some methods of destroying mosquitoes. Materials. — Mosquito larve and pups, battery jar, kerosene oil, goldfish. 152 THE ECONOMIC IMPORTANCE OF ANIMALS Method 1. — Put a few mosquito larve and pup in a small battery jar. Pour in a few drops of kerosene oil. Observations. — What happens to the oil and the water? What becomes of the larve and pupe? Remembering that all eggs are laid on the surface of the water, what would happen to the eggs when laid? Method 2.— Place some small goldfish or sticklebacks in a Jar containing larve and pupe. Observations. — What happens? Conclusion. — Now go over the map you have made. Which of the above means would you use to exterminate mosquitoes in your locality? Problem 126: To find the relation of mosquitoes to diseases of man. NOTE. — Malaria and yellow fever, diseases caused by tiny protozoans, are transmitted to man through the bite of mosquitoes. This is proved because men have escaped malaria in malaria-infected districts by taking precautions to have their bodies at all times protected from the bite of the mosquito. This was done by screening, by remaining indoors at times when the mosquitoes were out, and by wearing, when exposed, head nets and gloves. In 1890 two London doctors allowed themselves to be bitten by anopheles mos- quitoes which had previously bitten people who had malaria. In a little over two weeks both came down with malaria. . Observations. — What causes malaria? What have swamps and stagnant water to do with malaria? Why did the people who were screened not get malaria? Why did the London doctors get malaria? Conclusion. — What has the anopheles mosquito to do with malaria? Problem 127: To study the life history of the parasite caws- ing malaria. Material. — Charts, or illustration in Hunter’s Civic Biology, page 217. Observations. — Note the lower part of the diagram which represents the blood tube of a man. What changes take place in the parasite within the corpuscles? What two kinds of organisms ultimately are formed? PROBLEM 128 153 Notice that the malarial parasite passes part of its life history in the body of the mosquito, and part in the human body. The lower part of the figure repre- sents a blood vessel in man. The parasites live part of their lives in the blood corpuscles. Then they multiply and break out of-the corpuscles. (See right side of figure.) Using this figure and information from your Civic Biology, work out the complete life history of the malarial parasite. What happens if these organisms are taken into the mosquito’s body ? NOTE. — Only when both forms of cells are taken into the body of the mosquito are the parasites able to continue their development there. Conclusion. — How might malaria be transmitted? Problem 128: To study the life history of the typhoid fly. Materials. — Raw meat, glass dishes. Method. — Expose pieces of raw beef where flies will light on them. After a few hours cover in glass dishes or small battery jars with screen covers. Observations. — Watch the meat. In pieces on which eggs were laid by the flies describe the stages of development as they appear. Do the larve grow any? They are called maggots. How do the 154 THE ECONOMIC IMPORTANCE OF ANIMALS pup differ from the larve? Watch to see the adults emerge from the pupal case. How long does a complete life history take? Conclusion. — How many generations of flies might develop during a hot summer? Problem 129: To determine the harm done by the fly and the way it does this harm. Material. — Sterile Petri dish containing culture medium. Method. — Allow a fly to walk over the surface of a sterile Petri dish with culture medium within it. Cover the dish. After three or four days examine the surface of the culture medium. Observations. — What do you see? NOTE. — Flies breed in manure, filth of all kinds, and human excrement as well. Study a diagram showing the relation of typhoid fever to open toilets and flies in Jacksonville, Fla. (page 224, Civic Biology). Why were there fewer cases when the toilets were screened? Study the diagram below. What relation exists between diarrheal diseases and flies? Explain. Examine the foot of a fly under the compound microscope or study upper figure, page 223, Civic Biology. What adaptations for carrying germs do you find? JAN. | FEB | MCH.} APR.| MAY | JUNE | JULY | AUG. | SEPT. | OCT. Nov. 500} 2000 725) rar a mI L400 / ag] ag ss =i RS4 Lf bag \ NY 82 Bo E— a — 268 xe i Se ches 2 255, pee # i NX oN ; a pe fee eT ar ; 150 [ss 28.0 rl [ x e 100} | aN [50 eal iu \ 22 \ < > : oll so 2 5 “To of 0 6, ®t a a Inrant Morrauity CURVE. a, prevalence of flies; b, diarrheal under five years; c, deaths under one year; d, mean temperature. PROBLEM 131 . 155 Conclusion. — 1. What diseases may be carried by flies? 2. Where do they get the germs of these diseases? 3. How do they carry these diseases? Problem 130: What is the best way to catch and destroy flies? (Home Work.) Materials. — Flytrap, tin plate, carbolic acid, and insect powder. Method and Observations. — Make a flytrap according to the plan shown ; bait it with stale fish or other food. Leave it for one day, then plunge it into boiling water and count the number of flies which you caught. Heat a tin plate containing strong car- bolic acid so that. the fumes will fill a room (e.g., the kitchen) con- taining a number of flies. What results? How does it compare with your trap? Burn a few ounces of insect powder in a pan in the same room on another day. Compare your results with those above. Conclusion. — 1. Which is the best method of those given for destroying flies in your home? 2. Knowing when and where flies breed, when would be the best time to “swat the fly’? How would this method com- pare with other ways of extermination studied? AN EASILY MADE FLYTRAP. Problem 131: To determine harm done by insects. Materials. — Trips to museum, reference to texts, and various bulletins of the Department of Agriculture. Observations. — Make out in the form of the following table a report on the harm done by insects: 156 THE ECONOMIC IMPORTANCE OF ANIMALS 1. To gardens.— Report on cutworm, corn worm, potato beetle, squash bug. 2. To crops. — Boll weevil, chinch bug, plant lice, Hessian fly. 3. To fruit and forest trees. — Codling moth, gypsy moth, tussock moth, hickory isht} borer, maple borer Name | Harm dene| Stage when | How7igh , , it does harm | the pest scale insect. 4. To stored food. —Weevils, roach, ant. 5. To clothes, etc. —Clothes moth, roach. 6. A& disease carriers. — Flies, mosquitoes, fleas, bedbugs. Report, using the above sources of information, on specific ways of combating one pest from each of the above groups. Conclusion. — What specific harm is done by the above-named insects and how would you go to work to prevent this harm? Problem 132: To know some forms of animal life that cawse disease. Materials. — Use your Civic Biology, Chap. XV, or any other source of infor- mation. Name of Disease Disease How to fight Howto fight Giesmotions = Disease |Causedby|Carried by| Cause Carrier oats ag Bubonic Plague Fill inthe accOMpany- — eckewerm ing chart, giving Infor \ieleAger mation with refer- [Tepresy ence to disease-caus- Malaria ing animals,especially | Rabies hookworm, trichina, [SirieSide= s and tapeworm. es is Tapeworm Conclusion. — 1. hat x 1 Texas Fever Ww at animals cause | Trickinesis disease and what dis- | Typhoia eases do they cause? YellowFever 2. How would you attempt to cure any three of these diseases? 3. How would youattempt to prevent any three of these diseases ? REFERENCE BOOKS 157 PROBLEM QUESTIONS 1. How long does it take for one generation of flies to develop? 2. During what part of the year are flies most abundant? Why? 3. During the Spanish-American War flies were more deadly than Spanish bullets. Explain. 4. What diseases may be carried by flies? 5. What relation has the garbage pail to the typhoid fly? Ex- plain. 6. Why should food exposed for public sale be kept covered? 7. Why should food on the table be screened? 8. What dangers come from open spittoons and what do flies have to do with this danger? 9. Why should garbage pails be frequently sprinkled with slaked lime or kerosene? 10. Why the cry in the early spring — “ Swat the fly ”’? 11. What harm do mosquitoes do? How do they do this harm ? 12. What are the natural enemies of the mosquito? 13. How would you go to work to rid your neighborhood of mosquitoes ? 14. How would you tell harmful from harmless mosquitoes? REFERENCE Books Hunter, Civic Biology, Chap. XV. American Book Company. Hunter, Elements of Biology, Chap. XIX. American Book Company. Hunter, Essentials of Biology, Chap. XVII. American Book Company. Bigelow, Visiting a Fish Hatchery. Guide to Nature, December, 1908. Britton, Mosquito Plague of Connecticut Coast Region. Connecticut Agricultural Experiment Station. Burroughs, Squirrels and Other Fur Bearers. Houghton, Mifflin Company. Carter, The Vampire of the South. McClure’'s Magazine, October, 1909. Chappell, The House Fly — Man Killer. Pearson's Magazine, June, 1910. Daugherty, Economic Zoélogy. W. B. Saunders. Davenport, Introduction to Zoélogy, pp. 151-158. The Macmillan Company. Doane, Insects and Disease. Henry Holt and Company. Dotey, The Mosquito. N. Y. State Journal of Medicine, 1908. Felt, Insects Injurious to Forest Trees. New York State Reports, 1898. Field, Sea Afussels as Food. Bureau of Fisheries Document, 1910. Forbes, The Lakeasa Microcosm. Bulletin, Peoria (Ill.) Science Association, 1887. Frost and Voorhees, The House Fly Nuisance. Country Life in America, May, 1908. 158 THE ECONOMIC IMPORTANCE OF ANIMALS Hatch, The Indictment of the House Fly. Suburban Life, March, 1910. Haynes, Mad Dog. Country Life, July, 1914. Herrick, Textbook in General Zoélogy, Chap. VIII. American Book Company. Hodge, Nature Study and Life, Chap. XVI. Ginn and Company. Howard, The House Fly, Disease Carrier. F. A. Stokes Company. Howard, The Typhoid Fly. Bulletin 78, Bureau of Entomology, U. S. Department of Agriculture. Howard and Marlatt, Principal Household Insects of the United States. Bulletin 4, U.S. Bureau of Entomology, 1902. Huber, Insects and Disease. New York State Journal of Medicine, November, 1908. Insects — pamphlets, Bureau of Entomology, 158; Farmers’ Bulletin, 155. Jordan, Fishes. Henry Holt and Company. Jordan and Kellogg, Animal Life, Chaps. X-XI. D. Appleton and Company. Kellogg, Shellfish Industries. Henry Holt and Company. Kellogg, Elementary Zoédlogy, pp. 297-298. Henry Holt and Company. Kellogg and Doane, Economic Zoélogy and Entomology. Henry Holt and Company. Kinyoun, Uncinariasis in Florida. Report of American Health Association, 1907. Langworthy and Hunt, Economical Use of Meats in the Home. Bulletin 391, U.S. Department of Agriculture, 1910. McGuire, The Hookworm and the South. Pearson's Magazine, September, 1909. Medical Influence of the Negro in Connection with Anemia in the White. Bulletin North Carolina Board of Health, June, 1908. Osborn, Economic Zoélogy, Chaps. IV-V. The Macmillan Company. Ransom, Trichinosis: a Danger in the Use of Raw Pork for Food. Circular 198, U.S. Department of Agriculture, 1907. Seymour, War on Agricultural Pests. World’s Work, May, 1914. Smith, The French Sardine Industry. Bulletin U. 8. Fish Commission, 1901. Smith, Uncinariasis (Hookworm) in Texas. American Journal of Medical Science, 1903. Soil Pollution and the Hookworm in the South. Alabama Board of Health. Spangler, The Decrease of Food Fishes in American Waters, and Some of the Causes. Bulletin U. 8. Fish Commission, 1893. Stevenson, Preservation of the Fisheries on the High Seas. Popular Science Monthly, April, 1910. The Coming War on the Hookworm. Current Literature, December, 1909. Thompson, The Study of Animal Life, Chap. IV-V. Charles Scribner’s Sons. Webster, The Value of Insect Parasitism to the American Farmer. Yearbook U.S. Department of Agriculture, 1907. Wieland, Conservation of the Marine Vertebrates. Popular Science Monthly, May, 1908. XVI. THE FISH AND FROG, AN INTRODUCTORY STUDY OF VERTEBRATES Problems. — To determine how a fish and a frog are fitted for the life they lead. To determine some methods of development in vertebrate animals. (a) Fishes. (6) Frogs. (ce) Other animals. LaBoratory SUGGESTIONS Laboratory exercise. — Study of a living fish — adaptations for protec- tion, locomotion, food getting, ete. Laboratory demonstration. — The development of the fish or frog egg. Visit to the aquarium. — Study of adaptations, economic uses of fishes, artificial propagation of fishes. To THe TracusErR. — This chapter is intended to introduce the student to the life history, structure, and adaptations found in a vertebrate, the fish or frog. If time permits, both forms may be used, but the writer has found that for use in the early spring (which would be the logical time for this exercise if the course was be- gun in the fall) the frog is a more useful form because of its superficial similarity to the structure of man and because of the ease with which developmental material may be obtained. The fish, however, as a living specimen for laboratory use is excellent, espe- cially for the study of adaptations. The concept of a structural adaptation is ex- tremely difficult for a pupil beginning, and considerable drili should be given in an attempt to fasten the concept. Field or aquarium trips may be made to form an important part of this work, thus adding interest through varied work. Problem 183: To determine how a live fish is fitted for life. Materials. — Small battery jar with small living fish such as goldfish, bream, or minnows. a. Locomotion Observations. — Note adaptations for locomotion. How is the body of the fish fitted for life in the water? Mention three dif- 159 160 THE FISH AND FROG ferent adaptations. Watch the fish carefully and locate its organs for movement. How many single fins are there? How many paired fins? NOTE. — Fins on the upper side of the body are called dorsal fins, the tail fin is called the caudal fin, and the single fin on the lower side is the anal fin. The front paired fins are called the pectoral fins, while those just below and behind are called the pelvic fins. Try to discover the use in movement of each of the above- named fins. Conclusion. — 1. How does a fish move? Watch the fish swimming and try to decide what fins are used in moving forward, in turning, in moving backwards. Note whether the body is used in locomotion. 2. Tell just how any particular fin is adapted or fitted to do its work. (Remember you must show how a structure is especially designed to do a particular work.) 3. How is the body fitted for life in the water? b. Protection Method. — Examine carefully a preserved specimen. Observations. — What structures do you find on the surface of the body? How are these structures placed with reference to each other? Feel the body of the fish. What adaptation for protection exists here? Note the color both above and below. Remembering that many of the enemies of the fish are below him and some above, explain how the animal receives protection from its color. Conclusion. — What are the principal adaptations for protec- tion in the fish? c. Breathing Method. — Look at the fish carefully and observe the move- ments of the mouth. Observations. — What is the relation of the movement of the mouth to that of the operculum, the flap which covers the gills? Note position and color of the gills. What gives them this color? Introduce a few grains of carmine in the water in front of the mouth of thefish. Trace the course of thecarmine. Where does it PROBLEM 136 . 161 come out? What gas is in the water? How might the fish use this gas? How might this gas come in contact with the gills? Conclusion. — Tell just how a fish breathes, writing a paragraph in explanation and illustrating with a diagram. Problem 134: To study food getting by the fish. Material. — Live fish. Method. — Watch the fish to see if it will eat. Remember what you know about catching fish. Observations. — Do fish see or are they made aware of the presence of food by other means? Do fish have teeth? Do they chew their food? Give uses of teeth. How does the fish’s means of obtaining food compare with ours? Conclusion. — Write a paragraph telling how a fish gets its food. Problem 135: To study the sense organs of the fish. Material. — Specimens of fish. Method. — Study the external sense organs of the fish. What are they? Observations. — What shape are the eyes? Does a fish move its eyes? Describe any movement. A fish is very nearsighted owing to the shape of the eye. Find two nostril holes. These lead to little pits in which are located the nerves of smell. Does a fish breathe through its nose? Find a distinct line running down the side of the fish. This is called the lateral line and contains organs of sense. The ears of the fish are out of sight in the head and are largely used for balancing. Conclusion. — Write a paragraph telling how the fish is fitted with sense organs. Compare its vision, sense of smell, and power of hearing with your own in respect to keenness. Drawing. — Make a side view of a fish. Label all the struc- tures we have discussed. Problem 136: To study some of the internal organs of a fish. Material. — Preserved specimens with under body wall cut away. HUNTER LAB. PROB. —11 162. THE FISH AND FROG Observations. — Push a blowpipe down the gullet, into the baglike stomach. Then follow the folded intestine until it reaches the anus or vent, where the solid waste leaves the body. Find, partly covering the stomach, a large lobed gland, the liver. Just above the stomach you will find the ovary or spermary, depending on the sex of fish (female or male). Still more dorsal, find a glisten- ing, thin-walled sac, filled with gases, the air bladder. Close to the backbone will be found the dark red kidney. Make a drawing to show all of these organs in natural position. The heart is found just in front of the stomach. Study it carefully, comparing it with the figure on page 235, Civic Biology. Make out its connec- tion with the gills, the red structure on each side of the fish’s head. What use has the heart? The gills? Why should blood be sent to the gills? Study a chart of the circulation of a fish to see where blood comes from as it goes to the heart and where it goes to after leaving the gills. The complete round of the blood from the heart back to the heart makes up the circulation of blood in the fish. Conclusion. — 1. What are the various systems within the body cavity of the fish? 2. What do you understand by the circulatory system ? Problem 137: To study the skeleton and central nervous system of the fish. (Extra.) Material. — Use prepared skeleton or chart. Observations. — Notice the column of bones extending from the head into the tail of the fish. This is called the vertebral column, or backbone. Of what advantage to the fish is a series of bones over one bone? NOTE. — The central nervous system, consisting of the brain and spinal cord, lies inside this chain of bones. To this central system nerves pass in from the out- side of the body, bringing sensations, while other nerves pass outward to muscles, causing movement. Conclusion. — 1. What are the uses of the skeleton to the fish? 2. Why is it made of many bones? 3. Arethereany otherbonesinthe fish? Whereare they located ? 4. How is the nervous system protected? PROBLEM 139 163 Problem 138: How fishes are artificially propagated. Method. — The operations of stripping can be demonstrated in the classroom at certain times of the year, or if the school is in the neighborhood of state or government fish hatcheries,! visit them. Make careful notes on the artificial methods of raising fishes. Observe especially the equipment of the hatchery tenks, caretaking of fish, etc. (See page 240, Civic Biology.) Observations. — Note the strepping of the females for roe (eggs) and the males for milt (sperms). Collect and examine roe and milt under the compound microscope. Which cells are larger, roe or milt? Which are the more active? Why? Why are the eggs squeezed into a bucket with fresh water and the milt immediately poured over them? Why are the eggs then placed in receptacles which have water running through them? NOTE. — Fresh-water fishes usually lay their eggs on the bottom of brooks or rivers, sometimes in nests prepared for this purpose. After the eggs are laid the male sprays them with milt. In what respects does artificial fertilization resemble this process? Conclusion. — 1. Write a paragraph on the process of artificial fertilization in fishes. f 2. Which would be a surer method of fertilization, artificial or natural? Explain. 3. Of what value is artificial propagation of fishes? Problem 139: Trip to the aquarium. (Optional, in place of Problems 133 and 138.) Method and Observations.— Select a lively fish. Is the fish protected by form or color? If so, explain how. Show exactly what each fin does for the fish in the process of loco- motion. Can a fish see? Hear? Smell? Give reasons based on your observations. Explain exactly how a fish gets its oxygen in breathing. Make a diagram in your notebook to illustrate 1In place of hatcheries, study figures of the process, for salmon or trout. See a Manual of Fish Culture, Department of U. 8. Fish Commission for 1898, Plates 16, 28, 34, 53, especially for salmon and trout. ‘ 164 THE FISH AND FROG this. Extra credit will be given for any additional observations to show how the fish is fitted (adapted) to its surroundings. Make three columns on your paper. Select ten fishes of eco- nomic importance. Place in the first column the name of each fish, in the second its habitat (where found), in the third its use to man. Name of Fish Habitat Use to Man Write a paragraph telling how these different fishes actively protect themselves and two ways in which fishes are protected. (By being like their surroundings is an example of the latter.) Give the name of the fish, and its habitat in each case. Visit a hatchery and make careful notes telling, (1) The method of fertilization of the egg. (2) The kinds of eggs that are hatching. (3) The apparatus used in hatching different fish. (Make dia- grams to illustrate.) (4) Methods of caring for young fish after they are hatched. (5) Any other observations on the process and its general use to man. Conclusion.— Write up your trip in an interesting manner. Illustrate it if possible, and hand it in to your instructor not later than two days after the trip. Problem 140: To determine some adaptations in a living frog. Materials. — Live frogs, battery jars, charts. Observations. — How does the shape of the frog fit it for life in the water? Note the color and markings. Feel the skin. In what respect is it an adaptation? Conclusion. — Remembering where a frog lives, write a para- graph telling how the frog is fitted to its surroundings. PROBLEM 144 165 » Problem 141: Adaptations of appendages for locomotion. Observations. — Locate the appendages. How many do you find? What differences do you find between the fore and hind legs? What purposes do the hind legs serve? The fore legs? Conclusion. — 1. Show exactly how the legs of the frog are fitted for locomotion. 2. Of what kind of locomotion is the frog capable? Problem 142: Adaptations for sensation. Observations. — Touch the frog gently (if possible without its seeing you). How does it respond? How is the eye fitted for its work (position, movement, etc.)? How is the eye protected? Touch it. Back of the eye find the eardrum. Describe it in size and position. Conclusion. — What are the uses of each of the sense organs? Give experimental proof if possible. Problem 143: Adaptations for food getting. Method and Observations. — Open the mouth of a freshly killed frog and move the tongue. Compare with figure on page 242, Civic Biology. Feel both jaws to find whether the frog has teeth. Feel the roof of the mouth. Conclusion. — Write a paragraph telling how the frog uses its tongue and teeth in catching its prey. Problem 144: Adaptations for breathing. Method. — Watch carefully the throat and sides of a frog that has its head out of water. Note the pulsations of the throat. Count the number of movements per minute. Note that every so often another more noticeable movement occurs. What happens to the nostril holes when this movement takes place? Does this latter movement, when the nostril holes are closed, make the mouth cavity larger or smaller? Examine a dissected specimen, or chart showing glottis, trachea, bronchial tube, and lungs. Insert a blowpipe in the glottis and inflate the lungs. Are they elastic? 166 THE FISH AND FROG a Conclusion. — 1. Where must the air go when the frog makes a swallowing movement with the nostril flaps closed? 2. Write a paragraph comparing the breathing of the frog and of yourself. Drawing. — Draw a side view of the living frog, natural posi- tion. Label all parts mentioned in the previous study. Problem 145: Museum trip to study the frog Sroup. (Extra Problem based on trip to American Museum of Natural History.) The following suggestions might be modified for a field trip where such a trip is possible. Method. — Begin work at one of the two groups on which ques- tions follow. Read the labels in front of each group and learn all you can about what the group contains before you begin to answer the questions. Then answer the following questions, making the answers tell a connected story in your notebook. Ask questions of your teacher only when you cannot find the answer to a question yourself. a. The Toad Group What time of year does it seem to be? How do you know? What flowers are most abundant at this time in this locality? (Ask help from your teacher if you do not know them.) What animals are found living in the water? On the land or in the trees? Both on land and in the water? What are the latter animals called? (Amphi = both.) Look for specimens of the tree frog (hyla diversicolor). Describe three different changes in color in these frogs. In what ways are these changes adaptations? Explain. Describe where and when toads lay their eggs. Compare the egg masses of the toad with those of the frog. How are the eggs protected? What differences can you find between toad and frog tadpoles? (Examine preserved specimens.) Enumerate all the enemies of a toad seen in this group and tell how the toad is fitted (adapted) to escape from each of these enemies. Mention three structural adaptations found in a toad or frog PROBLEM 146 167 which fit it for the life it leads. Explain exactly how each struc- ture you have described is an adaptation. b., The Bullfrog Group Show three ways not mentioned in the last question in which the bullfrog is fitted or adapted to its‘environment. At what time of year do frogs deposit their eggs? How does it compare with that of the toad? (See the toad group.) How do you account for the presence of the large tadpoles found swimming about? What might be some of the enemies of the bullfrog? How might it escape from its enemies? Explain exactly how a frog catches an insect. Compare the habitat of the bullfrog with other amphib- ians found in the groups in this alcove. How is it similar and how does it differ? Problem 146: To collect and study frogs’ eggs. Materials. — Trip to shallow fresh-water pond. Battery jars or aquarium. Method. — Look for eggs in shallow fresh-water ponds late in March or early in April. Collect some eggs and place them in a shallow aquarium with some alge in a sunny place. Observations. — Notice that the eggs look like little black dots in a mass of jelly. Is their color uniform? The collected eggs have probably been fertilized. They were laid in the water by the female ; the males fertilizing them by plac- ing sperm cells on them, as soon as the eggs were laid. After laying, the thin albuminous coating with which they are covered swelled up and they stuck together. Examine some of the eggs under a magnifying glass. Some of them have probably begun to segment (divide into many cells). Which side of the egg, the black or white side, seems to be broken into smaller cells? NOTE. — The white side is filled with yolk, or food. Conclusion. — Write a paragraph telling where frogs lay eggs, how the eggs are fertilized, and how they are protected after fertilization. 168 THE FISH AND FROG Problem 147: To study conditions favorable for development of frogs’ eg Ss. Materials. — Live frogs’ eggs, glass dishes. a. Temperature Method. — Place some eggs in shallow dishes. Place one lot in a moderately warm room, another in a cold room, and a third in an ice box. Observations. — Watch and record results daily for.two weeks. Conclusion. — What is the relation between temperature and the development of frogs’ eggs? b. Oxygen Method. — Place a large number of eggs in a dish containing one quart of water. Place a few eggs from the same egg mass in another dish containing a like amount of water. Place both dishes where they receive the same conditions of light and heat. Observations. — Make and record operations daily for two weeks. Conclusion. — 1. Which lot receives the more oxygen per egg? Explain. 2. Does oxygen affect the development of frogs’ eggs? Problem 148: To study the metamorphosis of the frog. Materials. — Wax models of development of frog, living or preserved specimens of various stages, charts, and young and old stages of tadpoles in shallow dishes. Method and Observations. — Using the wax models, try to find the chief differences in the development of this egg as compared with the egg without any yolk. Can you find any gastrula stage here? Look at the model cut in section to answer this point. (See also page 245, Civic Biology.) Trace the changes from the time the egg segments to the time it becomes a free-swimming tadpole. Where are the gills located at first? What kind of mouth parts does the tadpole seem to have? Notice the sucker and the horny jaws. How would the early stage of the tadpole breathe? What sort of PROBLEM QUESTIONS 169 food must it of necessity eat? Using the models, charts, and living specimens, now compare the later stages of the tadpole with those of its earliest life. Are external gills always present? If not, what becomes of them? Examine the internal gills in the older tad- poles. Also try to find out why some tadpoles seem to come to the surface of the water, swallow a bubble of air, and then go under the water again. NOTE. — There is a stage in the life of the tadpole when it uses both gills and lungs in breathing. At what stage of the metamorphosis does the tadpole breathe by internal gills? By both lungs and gills? Which grow first, the front or hind legs? What becomes of the tail? Are there any changes in the appearance of the mouth in an older tadpole? Are there teeth in the mouth of a tadpole? A frog? Conclusion. — What changes take place during the life of the tadpole and how do these changes fit it for the life which it has to lead? Problem 149: To work out a comparison of development of the vertebrates. Method. — Fill out a table like the accom- panying. Number Conclusion. — In of Fees which of the above |¢/Segs. animal groups do the Gee eggs have the best | of Eggs likelihood of reaching [Probability development into |¥®ges adults? Explain your answer. Fish | Frog | Bird | Mammal PROBLEM QUESTIONS 1. What do we mean by adaptation to environment? Illus- trate with certain organs in a fish; in a frog. 2. Might color be an adaptation? Give examples. 3. Might habits of life he adaptations or the results of adapta- tions? Explain. 170 THE FISH AND FROG 4. Compare breathing in the fish, in the frog, and in your own body. What especial adaptation do you note? 5. Why do some fishes lay more eggs than others? 6. What have life habits of fishes to do with their possible extermination through overfishing? 7. What is artificial propagation of fishes? 8. Some kinds of fish eggs are provided with a minute drop of oil in each egg. Of what use might this be in the development of the egg? 9. Why are many more sperm cells manufactured than egg cells ina cod? Explain with reference to the egg-laying habits of the fish. 10. Name ten food fishes that are cheap in your locality; ten that are expensive. Why are they either cheap or expensive? 11. What are the amphibia and why are they so called? 12. How is a frog fitted to live in water? On land? 13. Do fishes and frogs lay their eggs at any especial time of year? Give examples. 14. How does the development of a frog differ from that of a fish? 15. Explain the term metamorphosis. 16. What are the chief enemies of the frog? How is it pro- tected from these enemics? 17. How may frogs and toads be useful to man? 18. How are the eggs protected and from what enemies? 19. Of what use is the yolk of an egg in development? REFERENCE Books Hunter, Civic Biology, Chap. XVI. American Book Company. Hunter, Elements of Biology, Chaps. XXII, XXIII. American Book Company. Hunter, Essentials of Biology, Chap. XXII. American Book Company. FISH Bulletins of the U. S. Commission of Fish and Fisheries. (Write to the Com- mission.) Butler, The Codfish — its Place in American History. Transactions Wisconsin Academy of Science, Vol. IX, p. 261, 1898. Green and Roosevelt, Fish Hatching and Catching. Rochester, N. Y. Johnstone, Conditions of Life in the Sea. G. P. Putnam’s Sons. Jordan, Fishes. Henry Holt and Company. REFERENCE BOOKS 171 Jordan and Evermann, American Food and Game Fishes. Doubleday, Page and Company. Lydell, Habits and Culture of Black Bass. Bulletin U. 8. Fish Commission, 1902; Report Indiana Fish Commission, 190+. Mather, Modern Fish Culture in Fresh and Salt Water. Forest and Stream Pub- lishing Company. Pahlow, The Wonders of the Deep. Cosmopolitan Magazine, July, 1908. Reed, The Study of Fishes. Cornell University Nature Study Quarterly, No. 8, January, 1901. Reighard, Breeding Habits and Development of Black Bass. University of Michi- gan, 1907. Report of Fish Commission, 1900. Townsend, Cultivation of Fishes. New York Zodlogical Society. FROGS Dickerson, The Frog Book. Doubleday, Page and Company. Ecker, The Anatomy cf the Frog. The Macmillan Company. Frogs, Pigmies and Giants by Feeding. Literary Digest, January 3, 1914. Holmes, Biology of the Frog. The Macmillan Company. Morgan, Development of Frogs’ Eggs. The Macmillan Company. The Usefulness of the Toad. Farmers’ Bulletin 196, U. S. Department of Agri- culture. ' Workman, The Toad as a Garden Benefactor. House and Garden Magazine, March, 1910. BIRDS Apgar, Birds of the United States. American Book Company. Baynes, New Method of Bird Study. Literary Digest, January 17, 1914. Beal, Some Common Birds in their Relation to Agriculture. Farmers’ Bulletin 54, U.S. Department of Agriculture, 1898. Beal and McAtee, Food of Some Well-known Birds. Farmers’ Bulletin 506, 1912. Beebe, The Bird. Henry Holt and Company. Beebe, Domestication of Wild Birds, Nation, April 9, 1914. Blanchan, Bird Neighbors. Doubleday, Page and Company. Bryant, Number of Insects Destroyed by Western Meadow Larks. Science, December 20, 1912. Burroughs, Birds and Bees. Houghton Mifflin Company. Chapman, Handbook of the Birds of Eastern North America. D. Appleton and Company. Clarkin, Who Killed Cock Robin? Everybody's Magazine, January, 1910. Dearborn, How to Destroy English Sparrows. Farmers’ Bulletin 383, U. 5. Depart- ment of Agriculture, 1910. Dugmore, Bird Homes. Doubleday, Page and Company. Fisher, The Economic Value of Predacious Birds and Mammals. Yearbook, De- partment of Agriculture, 1908. Forbush, Game Birds, Wild Fowl, and Shore Birds. Massachusetts Board of Agri- culture. Forbush, Useful Birds, their Protection. Massachusetts Board of Agriculture. Hammond, My Friend the Partridge. Forest and Stream Publishing Company. 172 THE FISH AND FROG Henshaw, Does it Pay the Farmer to Protect Birds? Yearbook, Department of Agriculture, 1907. ‘Job, Triumphs of Bird Protection. Harper's Magazine, July, 1909. Job, How to Study Birds. Outing Publishing Company. Job, The Sport of Bird Study. Outing Publishing Company. Kimsey, Why the Birds are Decreasing. Bird Lore, July, 1914. Miller, The Bird, Our Brother. Houghton Mifflin Company. Miller, Little Brothers of the Air. Houghton Mifflin Company. Pearson, Economic Value of Birds. Craftsman, January, 1913. Walter, Wild Birds in City Parks. Mumford. Ward, Making Bird Houses. Country Life, February, 1914. Weed and Dearborn, Birds in their Relation to Man. J. B. Lippincott Company. Wright and Coues, Crtizen Bird. The Macmillan Company. XVII. HEREDITY, VARIATION, PLANT AND ANIMAL ‘ BREEDING Problems. — To determine what makes the offspring of ani- mats or plants tend to be like their parents. To determine what makes the offspring of animals and plants differ from their parents. To learn about some methods of plant and animal breeding. (a) By selection. (6) By hybridizing. (ce) By other methods. To learn about some methods of improving the human race. (a) By ewgenics. (6) By euthenics. SuacrEstions For Lasoratory Work Laboratory exercise. — On variation and heredity among members of a class in the schoolroom. Laboratory exercise. — On construction of curve of variation in meas- urements from given plants or animals. Laboratory demonstration. — Stained egg cells (ascaris) to show chro- mosomes. Laboratory demonstrations. — To illustrate the part played in plant or animal breeding by (a) selection. (b) hybridizing. (c) budding and grafting. Laboratory demonstration. — From charts to illustrate how human characteristics may be inherited. To THe TEAcuER. — The contents of this chapter will probably prove of more interest and, if seriously taken up by teacher and pupils, of more lasting value than any other part of the course. The immense significance of variation and heredity and the application of these factors in eugenics certainly make a theme of vital interest. The direct teaching of sex hygiene in the public secondary school is not recommended, both because of lack of preparation on the part of teachers, because of the intimacy of contact required between teacher and pupil, making work with 173 174 HEREDITY AND VARIATION large groups impracticable, and because the proper place for such direct teaching isin the home. It is, however, the function of biology to teach the primary facts known about reproduction and heredity as applied in plant and animal breeding. On these facts the child of to-day will build for the experiences of to-morrow. Problem 150: To determine if there is individual variation in any one measurement of the members of a given class. Materials. — String, ruler. Sft 1 1G 5s Grd. 140 bs 14 15 16 18 19 Method. — With the string carefully measure the circumfer- ence of your right wrist. Observations. — Verify your figures by having your neighbor take the measurement for you. Do the same thing for him... The PROBLEM 150 175 instructor will give you an individual number. Hand in your results with your number to one pupil of the class who will tabulate the figures on the board. Make a graph showing the individual variation in circumference of the wrist in the members of your class. Conclusion. — Is there variation in this measurement among the members of your class? 20 21 22 23 24 25 NOTE. — Exercises on variation are numerous and may be worked out from charts, from collected material showing variations, or from work done by pupils in the field. In every case where possible, a graph should be made to illustrate the normal and the variation from the normal. The exercise that follows will show the method to be used. 176 HEREDITY AND VARIATION Problem 151: To show variation in a Siven class. Materials. — Figures on pages 174, 175. Later the measure- ments of the individual boys or girls of a class. a. Variation in Height Method and Observations. — Using the figures on pages 174, 175 have the members of the class place on graph paper a dot for each boy seen in the eee PO saunas tein z6 dl 2232425 Plate, taking them in ES fF] numerical order. a | f Connect the points 2h f TCE made. Notice the or it \ i t SGN /H irregularity of the line a3} Rae PAY formed. et " | 1 Now rearrange the au via boys so that the tall- ao =e ict est is at one end of 4.8] 1 the line and the short- 470 46 | ; est at the other end, 149158 561723 7 16 12 184 2 23 1911 22 2624 20113 . . Boys rearranged ----- with those of various heights graded in be- tween. Place dots on graph paper as in previous exercise. What difference do you notice in the line made? The accompanying graph shows the variation in height of the boys. But these boys differ slightly in mentality, considerably in height, considerably in weight. Is there any relation between the height and weight in a given group of boys? NOTE. — In the following figure the line zy represents the normal curve of weight and height relation obtained by weighing and measuring thousands of boys. b. To Form a Curve Showing the Relation of Weight to Height in a Given Class Method. — Notice that a boy of 4 feet 5 inches should weigh 65 pounds, while a boy 5 feet 11 inches should weigh 170 pounds. Knowing your own height, note what your weight should be. PROBLEM 152 177 But we find that most of us differ slightly from the normal and in the class represented the first boy is 5 feet 10 inches tall and weighs 140 pounds, while the boy number 10 is but 5 feet 5 inches in height and also weighs 140 PETeTeeetrrerttrrr rier pounds. Seite Sra ee Arrange your graph —s-s \ paper as shown at £8 LY the right, with the ib | greater weights to the = 54 L}—-*T ’ t } left of the page and 33 marl the less at the right. eis ! The heights are to be 4 } given vertically at the °33 1 left side of the paper. a Now pick out the i 7 members of the class and arrange them according to their weights and heights, placing a dot on the graph paper at the intersection of a given weight and height (as in the case of the boy who weighs 165 pounds and who is only 5 feet 4 inches in height). After you have finished connect all the dots. Observations. — Does the line formed follow the normal curve shown in the chart (line zy) or does it vary? How do you ac- count for this? NOTE. — This curve you have made is called the curve of correlation between weight and height. We might also correlate age and weight, or age and height. Conclusion. — Using the above method, make a curve of cor- relation showing the correlation between weight and height in your own class. Problem 152: Does heredity play any part in our lives? Materials. — Statistics gathered by class demonstrations. Method. — Let each member of the class try to bring photo- graphs of his parents and if possible of their parents. Write down a list of all the physical traits or likenesses you can find in your own family. Bring in written or verbal reports given by your HUNTER LAB. PROB. — 12 178 HEREDITY AND VARIATION parents or, if possible, your grandparents, telling of any mental or physical characteristics they may find repeated in you from an earlier generation. Observations. — Make notes on as many striking cases of in- heritance as you can. Compare with your own case. Conclusion. — 1. Are we in any ways like our ancestors? 2. Are mental as well as physical characteristics inherited? 3. Do these characteristics seem to be the same as those in your ancestors? 4. What do we mean by heredity? Problem 153: To study the fine structure of an eg$ cell. Materials. — Egg cells, — preferably from ascaris (a worm), — stained with iron hematoxylin to show nucleus and chromosomes ; cells showing fertilization stages; charts; books. Observations. — Look at the stained cells each lying within a more deeply stained capsule or covering. What structure do you find within it? (Compare figure on page 252, Civic Btology.) Look for the chromosomes within the nucleus. How many can you find? NOTE. — The chromosomes in the cells of the body are always definite in number for every species of animal and vary from two in ascaris to over 150 in Crustaceans. In man there are sixteen. The chromosomes are believed to carry the hereditary qualities from one generation to the next. Examine stained specimens that show fertilization and study carefully the figure on page 252, Civic Biology. NOTE. — Before fertilization takes place, the number of chromosomes in each sperm and egg cell is reduced one half. Each cell, so far as the chromosomes are concerned, is now a half cell. Conclusion. — 1. What happens when fertilization takes place? Study the figure. 2. If new characters are brought to the new animal or plant by means of the chromosomes, then what part would fertilization play in heredity? In variation? Problem 154: How selection is made. Materials. — Corn on ear, photographs or description of differ- ent corn plants. PROBLEM 156 179 Observations. — Compare several ears of corn and select the ear which has most even rows, largest kernels, etc. Suppose this ear came from a plant which had but few ears. Would you select for planting, ears from this plant or ears which were not quite so perfect from a plant with more ears? Conclusion. — In selecting seed for planting, what are some of the factors to be kept in mind? Problem 155: A practical result of selection. NOTE. —In a government test of corn to increase the yield, ears were chosen from plants that gave a high yield and the seed planted in rows. Next year seed from these rows was planted in rows alternating with seed from equally good-look- ing ears from the same kind of corn grown in the field. Note the results with eight pairs of ears. Pounps oF CORN YIELDED BY THE SEED OF ONB Ear FIELD EARS EARS FROM HIGH-YIELDING PARENTS 170 Ibs. 177.5 lbs. 139.5 ‘* 180‘ io Cl 199 =“ 173 = 197 +‘ 154 “ 172 =‘ 133“ 176 156.5 ‘* 194.“ 153“ 200.5 ‘ Observations. — What per cent of increase was there from the selected corn? If the seed from the field-grown corn yielded 42 bushels per acre, what would have been the gain per acre by planting seed from the selected corn? Conclusion. — State results both in bushels and in dollars, corn being worth 75 cents per bushel. Problem 156: To determine some means of selection of fruit trees from the economic standpoint. Method and Observations. — Given an area 1000 feet long and 500 wide, which might be planted as follows: (1) Trees 20 feet apart, bear after five years, average five hun- dred apples per tree, continue bearing twenty-five years. Apples wholesale $1 per hundred. (2) Trees 22 feet apart, bear after seven years, average six 180 HEREDITY AND VARIATION hundred apples, sell $1.75 per hundred, continue bearing thirty years. (3) Trees 25 feet apart, bear after six years, produce four hun- dred and fifty apples per tree, continue bearing forty years, price $2.25 per hundred. (4) Trees 18 feet apart, bear after five years, average three hundred and fifty apples per tree, bear for twenty years, average price $3 per hundred. (5) Trees 30 feet apart, bear after six years, average six hun- dred and fifty apples per tree, continue bearing twenty-five years, average price $2 per hundred. (6) Trees 24 feet apart, bear after six years, average five hun- dred apples, bearing thirty years, average price $3.25 per hundred. (7) Trees 20 feet apart, bear after four years, average two hun- dred and fifty apples per tree, continue bearing thirty years, price per hundred $3.75. Conclusion. — Which of the above would you choose to grow in the area? Give your reasons. Problem 157: How hybridization is accomplished in flower- ing plants. Materials. — Plants in flower, manila bags, camel’s-hair brush. Method. — Tie a manila bag over a growing apple or pear bud (or any other large available flower) that is about to open. Remove from another flower of the same family, but another species, all parts except the pistil, be- fore the flower opens. Cut at line marked W on figure. Tie a bag over it also. When the flower in the first bag opens, transfer some of the pollen to the stigma of the flower without stamens. This may be done by means of asmall camel’s-hair brush. Cover the surface of the stigma with pollen. Label the stigma thus pollinated, stating the date, and all data concerning source of pollen, etc. Observations. — Why do we cover the PROBLEM 159 181 flowers in this experiment? Why such care in the transfer of pollen? What ought to happen after the transfer of the pollen? Conclusion. — 1. Remembering that the egg cell from one flower has united with the sperm cell of another flower, if the operation has been successful, what characters ought the new plant to have? Explain.. 2. What is the use of hybridization? Problem 158: Other methods used in plant breeding. Materials. — Examples of budding, grafting, layers, and slips. Charts and texts. Observations. — Notice carefully what has been done in making a tongue graft, acleft graft. Study the steps in budding (page 256, Civic Biology). Consult any good book on agriculture to see how layering and slipping are done. Conclusion. — 1. How might these processes enable man (a) to form new kinds of plants? (b) to reproduce useful plants (see page 255, Civic Biology)? 2. What kind of reproduc- tion is this called, sexual or asexual? Explain your answer in a well-written paragraph. Problem 159 : To determine the working of Mendel’s Lay. Materials.— Text illustra- tions, charts, material illustrating Mendel’s Law. Observations. — Study the il- lustrations very carefully. No- Dracram To IntustraTe MENDEL’s Law. : h : Waite Dominant, Biack RECESSIVE, tice that there are three possi- Cuanacren. bilities of offspring : those having A fist weneradion’ Bs eeapadl gence: dominant, recessive, and mixed _ tion; C, third generation. 182 HEREDITY AND VARIATION characters. What will happen if animals or plants having pure dominant characters are bred together? Pure recessive char- acters? Mixed characters? (See chart.) What would be the proportion of dominants, recessives, and mixed offspring in the next generation if breeding continued as in A? Conclusion. — Why is Mendel’s Law of great value to plant and animal breeders? Explain. Problem 160: To determine some means of bettering, physi- cally and mentally, the human race. Materials. — Charts adapted from Davenport, Goddard, etc. showing heredity of feeble-mindedness, alcoholism, epilepsy, etc. Method. — Careful study of the charts to answer the questions. Observations. — If one of the parties in a marriage is feeble- minded, are any of the children likely to be feeble-minded? If both parties in the marriage are feeble-minded, what is the likelihood of the children being feeble-minded ? Z . 6oun6n 66066 ualiedm A CHART TO SHOW THE ere es OF ee THE SQUARES REPRESENT MALES; THE CIRCLES, FEMALES. A, alcoholic; F, feeble-minded; N, normal; d.inf., died in infancy. Does alcohol have any effect on the production of feeble-minded children? Look at the left-hand side of the chart shown above. Does feeble-mindedness there seem to be a dominant or recessive character? Explain. Note to TracHer. — Other problems of a similar nature may be taken up and discussed with seriousness and exceptional interest even in mixed classes. The child is at the receptive age and is emotionally open to the serious lessons here wWvolved. PROBLEM 162 183 Conclusion. — Should feeble-minded persons be allowed to marry? Problem 161: Are good mental parts or qualities capable of transmission from parent to child? Materials. — Charts, reference books, ete. Observations. — Study the chart to see if artistic ability may be inherited? Think of any case in your family of inheritance of some mental trait, such as musical ability. Conclusion. — Are mental traits handed down? Problem 162: Does control of our environment have anything to do with the problem of race betterment? Method. — A study of your own environment. Observations. — Remembering that certain factors of the en- vironment react upon the health and vitality of the people living within that environment and remembering also that certain germ diseases may enter the body through body openings or even through scratches or cuts, then (1) How might dirty streets, stores, and houses affect health in a neighborhood? (2) How might the milk or water supply affect the health in a given neighborhood? (3) What effect might improper or insufficient food have upon persons within a given locality? (4) How might any of these factors affect the health of mothers with newly born children? (5) Might such factors as mentioned above affect these babies? If so, how? (6) Knowing what we do about disease germs, should we use public drinking cups? Explain. (7) How might public roller towels be dangerous? (8) What other factors of the environment might work against a healthy race? Explain. Conclusion. — 1. What factors of the environment have to do with the betterment of the race? 2. How could you improve your own environment ? 184 HEREDITY AND VARIATION PROBLEM QUESTIONS What do we mean by variation? Heredity? Show how these factors work in plant or animal breeding. What is hybridization? Who is Luther Burbank and what has he done? Why should farmers select seeds with great care? What part of egg and of sperm cells has to do with heredity? Who was Mendel, and what is his law? What did De Vries do in the problem of heredity? What is meant by eugenics? What is meant by euthenics? 11. How might alcohol play a part in the problem of heredity ? (See Civic Biology, pages 289-294, 361-372.) 12. What have clean thoughts to do with a clean body? I — fo SO" 00 ORG er Ge) OES REFERENCE Books Hunter, Civic Biology, Chap. XVII. American Book Company. Hunter, Elements of Biology, pp. 80, 81. American Book Company. Hunter, Essentials of Biology, pp. 81, 83. American Book Company. Allen, Civics and Health. Ginn and Company. Bailey, Plant Breeding. The Macmillan Company. Bailey, Survival of the Unlike. The Macmillan Company. Barr, Mental Defectives. P. Blakiston’s Son and Company. Bergen and Caldwell, Practical Botany, Chap. XXIII. Ginn and Company. Bigelow, Sex Instruction as a Phase of Social Education. American Medical Asso- -ciation, Chicago. Blatchford, Not Guilty. Albert and Charles Boni. Blood Will Tell. Independent, July 27, 1914. Bulletins and educational pamphlets 1 to 6. Society of Sanitary and Moral Pro- phylaxis. Campbell, Plant Life and Evolution. Henry Holt and Company. Castle, Heredity. D. Appleton and Company. Circulars 1-4. Chicago Society of Social Hygiene. Conklin, Heredity and Environment. Princeton University Press. Coulter, Castle, East, Tower, and Davenport, Heredity and Eugenics. University of Chicago Press. Darwin, On the Origin of Species by Natural Selection. D. Appleton and Company. Davenport, Domesticated Animals and Plants. Ginn and Company. Davenport, Heredity in Relation to Eugenics. Henry Holt and Company. Davenport, Principles of Breeding. Ginn and Company. Dawson, Right of the Child to be Well Born. Funk and Wagnalls Company. De Vries, Plant Breeding. Open Court Publishing Company. Duggall, The Jukes. G. P. Putnam's Sons. REFERENCE BOOKS 185 Elliott, Botany of To-day, Chap. XXV. Seeley and Company, London. Ellis, Problem of Race Regeneration, Chap. I. Moffat, Yard and Company. Foerster, Marriage and the Race. Advanced. F. A. Stokes Company. Forbush, The Coming Generation. D. Appleton and Company. Goddard, The Kallikak Family. The Macmillan Company. Goddard, Feeble-mindedness. The Macmillan Company. Hall, Adolescence and Psychology. Advanced. D. Appleton and Company. Hall, John’s Vacations; Chums; The Doctor’s Daughter; Life Problems. American Medical Association, Chicago. Harwood, New Creation in Plant Life. The Macmillan Company. Haynes, Dog Breeding. Outing, March, 1914. Hegner, The Germ Cell Cycle in Animals. The Macmillan Company. Holmes, The Evolution of Animal Intelligence. Henry Holt and Company. Jewett, The Next Generation. Ginn and Company. Johnson, Sexuality in Plants. Science, February 27, 1914. Jordan, The Heredity of Richard Roe.’ American Unitarian Association. Jordan and Kellog, Scientific Aspect of Luther Burbank’s Work. Robertson. Kellicott, The Social Direction of Human Evolution. D. Appleton and Com- pany. Kellogg, Darwinism To-day. Henry Holt and Company. Lucas, Animals of the Past. Doubleday, Page and Company. Morgan, The Development of the Frog's Egg. The Macmillan Company. Morley, The Spark of Life. Revell and Company. Morley, Song of Life. McClurg and Company. Mottram, Controlled Natural Selection. Longmans, Green and Company. Plant Breeding, Articles as follows: Webber and Bessey, Yearbook, Department of Agriculture, for 1899. Hays, Yearbook, Department of Agriculture, for 1901. Bailey, World’s Work, 1902, p. 1209. Wickson, Sunset Magazine, December, 1901, April, 1902, February, 1903. Harwood, Scribner's, May, 1904. Garner, Cosmopolitan, July, 1904. Plumb, Types and Breeds of Farm Animals. Ginn and Company. Punnett, Mendelism. The Macmillan Company. Pycraft, Courtship of Animals. Henry Holt and Company. Reik, Safeguarding the Special Senses. F. A. Davis Company. Report of Committee on Matter and Methods of Sex Education. Advanced. American Federation of Sex Hygiene, N. Y. Richards, Euthenics, the Science of Controllable Environment. Whitcomb and Bar- rows. Roosevelt, Twisted Hugenics. Outlook, January 3, 1914. Saleeby, Parenthood and Race Culture, Moffat, Yard and Company. Smith, The Three Gifts of Life. Dodd, Mead and Company. Thompson, Heredity. John Murray, London. Torelle, Plant and Animal Children. How they Grow. D.C. Heath and Com- pany. Wallace, The Geographical Distribution of Animals. Harper and Brothers. Walter, Genetics. The Macmillan Company. Warbasse, Medical Sociology. Advanced. D. Appleton and Company. Wasmann, The Problem of Evolution. Paul, Kegan, Trench, Triibner and Company, London. 186 HEREDITY AND VARIATION Whethan, The Family and the Nation. Longmans, Green and Company. Wile, Sex Education. Advanced. Duffield and Company. Williams, Every Woman her own Burbank. Good Housekeeping, April, 1914. Williams, With Burbank on the Lawns. Gopd Housekeeping, September, 1914. Winship, Jukes-Edwards — A Study in Education and Heredity. R. L. Myers and Company. XVII. THE HUMAN MACHINE AND ITS NEEDS Problem.— To obtain a Seneral understanding of the parts and uses of the bodily machine. Lasoratory SUGGESTIONS Demonstration. — Review to show that the human body is a complex of cells. Laboratory demonstration by means of (a) human skeleton and (bd) manikin to show the position and gross structure of the chief organs of man. To THe TeacuerR. — As in certain of the previous chapters, the student here takes a preliminary view of the general problem that lasts for the rest of his course in biology, 7.e., that of adaptation to function in the human body. A general sur- vey gives an initial interest in problems which are solved later ; it defines the future problems and marks the beginning of some new concepts. Certain structures of the body, as, for example, bones and muscles, are now treated and dismissed, not because of their non-importance, but because of the time demanded by the more practical questions relating to dietaries and bodily nutrition. Problem 163: To show that the human body is made up of cells. Materials. — Scalpel, methyl blue, glass slides, cover glasses, microscope. Method. — Scrape mucous lining from the mouth, mount on a glass slide, and stain with a drop of dilute methyl blue. Cover with cover glass and examine under microscope. Observations. — The large irregular bodies with dark blue bodies within them are flat cells (epitheliwm) from the lining of the mouth. What are these dark blue structures within the cell? (The small dots or rods stained deep blue are bacteria.) Cells from other parts of the body, gland, muscle, nerve, etc., should be demonstrated under the compound microscope. Conclusion. — What are the units of building material in the body? 187 188 THE. HUMAN MACHINE Problem 164: To find out some functions of the skin. Materials. — Hand lens, ether or alcohol, large glass jar, two thermometers, model or chart of skin. Method and Observations. — Find out whether all parts of the skin are equally sensitive, by touching with the sharp point of a pencil. Cool a large glass jar, and hold the hand and wrist in the jar for a few moments, closing the opening of the jar with a cloth or a towel. What collects on the inner surface of the jar? What happens when you take violent exercise? Weigh yourself before and after a period of hard work in the gymnasium. Is there any loss in weight? How do you account for it? Place a few drops of ether or alcohol on the back of the hand and note the evaporation of the liquid. What sensation do you feel while the evaporation takes place? Study the model or figure, page 342, Civic Biology. Locate the two layers by means of your textbook. Find and describe the sweat glands, oil glands, and sense organs. Draw a diagrammatic sketch of the model and label all parts. Write a state- ment giving the function of each part. Conclusion. — 1. Is the skin an organ of sensation? 2. What passes off through the skin? 3. What result to your bodily comfort does this last function have? Problem 165: To study the use of the muscles. Material. — Frogs preserved in formalin. Method. — Remove the skin from the hind leg of a frog. +f agar aete Observations. — Note the “flesh’’ forming Lurr Lec or ran the muscle of the leg. (The wide part or belly of Froe. a muscle is attached to the bone by a tough _ biceps; g,gastroc- tendon.) Move the leg by pulling the foot up oe” and down. What effect does this have on the semi-membra- nosus; tr, triceps. muscle? To what are the muscles attached? om PROBLEM 166 189 At how many points are they attached? Explain how move- ment of the leg results from contraction (shortening) of certain of the muscles. What must occur when some of the muscles éon- tract? (Look at the position of the muscle on the opposite side of the leg.) Note the shape of your upper arm. To what is the rounded surface due? Conclusion. — 1. Why do muscles cause movement? Explain fully. 2. What use, other than movement, have muscles? Problem 166: To study the structure and uses of the skeleton. Materials. — Prepared human skeleton, manikin. Observations. — Note that the skeleton is divided into two groups of bones : a main framework of the body, the azial skeleton ; and a framework for the appendages, the appendicular skeleton. In life the bones are attached to each other by tough ligaments. Why are the bones jointed? Notice the bones of the head, skull, and face. Knowing that the skull covers part of the delicate nervous system, the brain, what would you say its use was? Note that the backbone, made up of numerous pieces of bone, has a hole running through it. This hole contains in life the spinal cord. Attached to the vertebre of the backbone are the ribs. Com- pare the position on the manikin.. What is one use of the ribs? Feel your own ribs; bend forward, and take a full breath. What is another function of your ribs? (Remember, to obtain move- ment, muscles must be attached to bones. Why?) Notice that the arm is attached to the main skeleton by means of two bones, the collar bone and the shoulder blade. These bones form the pectoral girdle. The leg is in the same way at- tached to a group of strong bones called the pelvic girdle. Notice various bones, such as the long arm bone (humerus), shoulder blade, pelvic bones, the spines on the ribs, for roughness To rae TracHEer.— A demonstration should be shown at this point to illus- trate the structure of striated and plain muscle tissue. Detailed laboratory work on this material is not desirable. 190 THE HUMAN MACHINE where muscles might be attached. In each case seek a place for attachment for the other end of the muscle. Conclusion. — 1. Write a statement giving'three general uses of the human skeleton. Take a special bone or bones to illustrate each use. 2. Compare the skeleton with the figure on page 268, Civic Biology. Make a drawing to identify the principal bones. Problem 167: To find the relation of muscles to bones in the human body. Method. — Using the diagrams in your Civic Biology, page 269, work out the different classes of levers. Observations. —In the human body which class of lever is represented when we raise a weight in the hand? What kind of lever do we use when we rise on the toes? What kind of lever do we use when we nod the head? Conclusion. — 1. Prove that three classes of levers are present in the human body. 2. Find another example of each kind of lever in the human body. Problem 168: To study the joints of the human body. Materials. — Human skeleton. Method. — Study the following joints in the human skeleton: arm at shoulder, knee, head on neck bones, bones of spinal column. Move them in each case. Observations. — Is the joint hinge-like, ball and socket, gliding, or rotary? Conclusion. — 1. How many different kinds of joints can you find in a skeleton? 2. What are their specific uses? Problem 169: To Set a preliminary survey of the internal structure of the human body. Materials. — Manikin and charts showing organs of the human body. Observations. — If we compare the human body to a machine, then the bones and muscles are the framework. Within the body, PROBLEM 169 191 partially protected by the ribs, is a cavity, the body cavity, divided into two unequal parts by a wall of muscles, the diaphragm. The body cavity contains the working parts of the machine: a. The organs of digestion, gullet, stomach, small intestine, large intestine, the liver and pancreas (two digestive glands), and the spleen (a gland connected to the digestive organs). 6. The organs of respiration, the lungs and tubes which connect them with the outside of the body. c. The organs of circu- lation, the heart and blood vessels. d. The organs of excretion, the kidneys. e. Most im- portant of all is the nervous system. This con- sists of the brain and spinal cord with the nerves growing out from them, and several different sense organs, which are at the outside of the body and send nerves inward to connect with the central nervous system. Your instructor will demonstrate these to you. We will spend most of the remainder of our course in learning more about the use of these various organs in the human machine. Conclusion. — 1. What are the chief organs of the human body cavity? 2. Which of these are in the body cavity and which extend into other parts of the body? 3. Which are chiefly outside the body cavity but send branches in? (Get help from your instructor or your textbook, page 271, Civic Biology.) 4. Why are sense organs in the skin? sages to other parts of the body? PROBLEM QUESTIONS THE ORGANS WITHIN THE Human Bopy. READ FROM ABOVE DOWN: t, tongue; D, larynx; @, gullet; 7, lung; H, heart; st, ster- num; s.c, spinal cord ;d, diaphragm ; L, liver; S, stom- ach; k, kidney; p, pancreas; 7%, small intestine; J, large intestine ; u, vermi- form appendix; B, bladder; R, rectum. How do they send mes- 1. What is the unit of structure in the human body? 2. Why do the cells in different parts of the body differ in shape and size? 192 THE HUMAN MACHINE 3. Of what use is the skin to man? 4. Would the skin serve the same purposes in the frog as in man? 5. Name the functions of muscles. 6. How do muscles work? Explain fully. 7. Explain the difference between a voluntary and an involun- tary muscle. 8. What effect would working of the muscles have upon heat within the body? Explain. 9. What effect might muscular work have upon the skin? 10. Why are the muscles arranged in pairs? 11. Name three uses of the skeleton. 12. What attaches muscles to bones? 13. What is a lever? Give examples. 14. Show how some one part of the body might illustrate the action of three classes of levers. 15. Of what use are the joints? 16. Explain the difference between a break and a sprain. 17. What is the body cavity? 18. Which sets of organs are found entirely in the body cavity? 19. Which organs are found partially in the body cavity? 20. Why might the nervous system be called the “ director of the body ”? REFERENCE Booxs Hunter, Civic Biology, Chap. XVIII. American Book Company. Hunter, Elements of Biology, Chaps. XX XI, XXXII. American Book Company. Hunter, Essentials of Biology, Chap. XXIII. American Book Company. Davison, Hyman Body and Health (Advanced), Chap. XVII. American Book Company. Goldmark, Fatigue and Efficiency. Charities Publication Committee. Gulick, The Gulick Hygiene Series. Ginn and Company. Gulick, Physical Education by Muscular Exercise. P. Blakiston’s Son and Com- pany. Hall, Elementary Anatomy. American Book Company. Halliburton, Kirkes Handbook of Physiology. P. Blakiston’s Son and Company. Hammarsten, Textbook of Physiological Chemistry. J. Wylie and Son. Hawk, ‘Practical Physiological Chemistry. P. Blakiston’s Son and Company. Hough and Sedgewick, The Human Mechanism, Chap. II. Ginn and Company. Howell, Physiology. W. B. Saunders. Hutchinson, Exercise and Health. Outing Publishing Company. REFERENCE BOOKS 193 Hutchinson, Athletics and the Heart. Outing Magazine, July, 1910. Hutchinson, Errors in Exercise. Outing Magazine, April, 1910. Overton, General Hygiene. American Book Company. Pusey, Care of the Skin and Hair. D. Appleton and Company. Ritchie, Human Physiology, Chaps. III-V. World Book Company. Schafer, Textbook of Physiology. The Macmillan Company. Sharpe, Laboratory Manual in Biology, pp. 218-225. American Book Company. Stewart, Manual of Physiology. W. B. Saunders. Stiles, Nutritional Physiology. W. B. Saunders. Verworn, General Physiology. The Macmillan Company. HUNTER LAB. PROB. — 13 XIX. FOODS AND DIETARIES Problems. — A study of foods to determine : (a) Their nutritive value. (b) The relation of work, environment, age, sex, and digest- ibility of foods to diet. (ce) Their relative cheapness. (d) The daily Calorie requirement. (e) Food adulteration. (f) The relation of alcohol to the human system. LABORATORY SUGGESTIONS Laboratory exercise. — Composition of common foods. The series of food charts supplied by the United States Department of Agriculture makes an excellent basis for a laboratory exercise to determine common foods rich in (a) water, (b) starch, (c) sugar, (d) fats or oils, (e) protein, (f) salts, (g) refuse. Demonstration. — Method of using bomb calorimeter. Laboratory and home exercise. — To determine the best individual bal- anced dietary (using standard of Atwater, Chittenden, or Voit) as deter- mined by the use of the 100-Calorie portion. Demonstration. — Tests for some common adulterants. Demonstration. — Effect of alcohol on protein, e.g., white of egg. Demonstration. — Alcohol in some patent medicines. Demonstration. — Patent medicines containing acetanilid. Determi- nation of acetanilid. To THe TracuEr. — The practical work in this chapter, although outlined to take not more than two to three weeks, has such possibilities of interest and im- portance that more time may well be spent in its consideration. The working out of an individual or family dietary with an estimate of the cost is an exercise that appeals strongly to the average pupil. Food economy and the balance of a ration are needed topics in every household to-day. The practical correlation of work in biology with that of home economics is found here. It might well be worth while to expand this side of the course with girls so that several weeks be devoted to the practical side of dietetics. Much of 194 PROBLEM 171 195 the laboratory work can be transferred to the laboratory of home economics or to the home. Problem 170: How to determine the nutritive value of food. Materials. — Set of government charts on food values. Tables on pages 276, 278, 279, Civic Biology. NOTE. — Food has two possible values: it may be oxidized to release energy or it may help build tissue. The burning value of foods may be measured by heat units called Calories (a Calorie is the amount of heat needed to raise the tempera- ture of a kilogram of water through one degree centigrade). Remember food is composed of nutrients, water, and refuse. Therefore not all food taken into the body is made use of. Observations. — In the chart on page 276, Civic Biology, deter- mine the actual percentage of nutrients in beef, potatoes, oysters, and corn meal. Do all foods have equal nutritive value? From the government charts make a table in which you will place : (a) Ten foods rich in protein (15 per cent or more). (b) Ten foods rich in carbohydrates (50 per cent). (c) Ten foods rich. in fat (50 per cent or more). (d) Ten foods having a high fuel value (1500 Calories or more per pound). (e) Ten food substances that are over 50 per cent water. How would water affect the cost of food, providing you had to pay for the water? (f) Five foods rich in mineral salts. Conclusion. — In your opinion which of the foods shown are the best tissue-building foods? The best energy-producing foods? Explain. Remember that living matter is made up of carbon, oxygen, hydrogen, nitrogen, sulphur, and a minute amount of mineral salts. Problem 171: The use of the bomb calorimeter. (Optional) The bomb calorimeter may be demonstrated by the instructor and its mechan- ism explained. Boys should be urged to try to experiment at home with homemade apparatus. An interesting series of home experiments on the burning value of different food substances worked out first hand will do much toward getting indi- vidual interest in the topic. Girls should approach this entire subject from the side of household economics. Much work can be done in household economics that will be scientifically explained in the biological laboratory, the two subjects giving and taking much from common ground. 196 FOODS AND DIETARIES The experiments of Atwater with the respiration calorimeter should be explained and pictures of the apparatus shown so that the pupils may be impressed with the delicacy and magnitude of the experiments. This respiration calorimeter is de- scribed by Professor Atwater as follows: “Its main feature is a copper-walled chamber 7 feet long, 4 feet wide, and 6 feet 4inches high. This is fitted with devices for maintaining and measuring a ventilat- ing current of air, for sampling and analyzing this air, for removing and measuring the heat given off within the chamber, and for passing food and other articles in and out. Itis furnished with a folding bed, chair, and table, with scales and appliances for muscular work, and has telephone connection with the outside. Here the sub- ject stays for a period of from three to twelve days, during which time careful analyses and measurements are made of all material which enters the body in the food, and of that which leaves it in the breath and excreta. Record is also kept of the energy given off from the body as heat and muscular work. The difference between the material taken into and that given off from the body is called the bal- ance of matter, and shows whether the body is gaining or losing material. The difference between the energy of the food taken and that of the excreta and the energy given off by the body as heat and muscular work is the balance of energy, and if correctly measured, should equal the energy of the body material gained or lost. With such apparatus it is possible to learn what effect different conditions of nourishment will have on the human body. In one experiment, for instance, the subject might be kept quite at rest, and in the next do a certain amount of muscular or mental work with the same diet as before, then by comparing the results of the two, the use which the body makes of its food under the different conditions could be determined; or the diet may be slightly changed in the one experiment, and the effect of this on the balance of matter or energy observed. Such methods and apparatus are very costly in time and money, but the results are proportionately more valuable than those from simpler experiments.” The experiments of Chittenden should also be explained. (See Chittenden’s Nutrition of Man.) ATWATER’S CALORIMETER (See diagram on page 197.) Atwater’s respiration calorimeter, an apparatus for determining the income and outgo of energy, and respiratory products of the human body, under varying con- ditions, consists of an air-tight copper chamber, insulated from the surrounding air by a zinc casing and three wooden ones, with dead-air spaces between. It is provided with a door and w window for the introduction and removal of food. Closely attached to the outside of the copper wall are 304 thermoelectric couples (A) which, electrically, report the temperature of the calorimeter chamber to the observer’s table (B). The temperature of the chamber is maintained as nearly constant as possible by a current of cold water, pumped by the electric pump (C) through the cooling tank (D) to (EF), where its temperature is taken just before it enters the large-surface, winged pipes around the chamber. When the water emerges at (F), its temperature is taken again and its volume and flow measured at the water meter (@) before it returns to the pump. From these data, knowing the rise in temperature and the amount of water so raised, the amount of heat developed within the calorimeter may be computed. The flow of water may be regulated so as to carry off any amount of heat developed. PROBLEM 172 197 In order to assure accurate work on the respiratory products, the system of ventilation is also a closed one. The vitiated air is drawn out by the pipe (A), and then through a double row of vessels of sulphuric acid (J, I, I, I) to remove water vapor, and vessels of soda lime (J, J, J, J) to remove COz, to the electric pump (K). From here it is returned through pipe (L) to (M), where any deficiency in oxygen is noted and remedied from a tank of that gas before it is pumped through the regulating pans (N, N) into the chamber. Method. — Using the diagram and explanation, try to explain to your own and your teacher’s satisfaction the working of the Atwater calorimeter. Conclusion. — What is the practical value of the apparatus? Problem 172: To find the value of food as a tissue builder compared with its cost. Method. — Use the tables on pages 198-201; make sure you understand the various column headings. NOTE. — Foods may be considered cheap if they furnish more than .12 of a pound of protein (the tissue builder) for 10 cents at present prices ; medium priced 198 FOODS AND DIETARIES if they furnish from .06 to .12 pound of protein for ten cents; expensive if they furnish less than .06 pound of protein for ten cents. Conclusion. — 1. Pick out ten cheap, ten medium, ten expensive tissue-building foods. 2. In which of the following groups are the cheapest protein foods found: meats, cereals, vegetables, fish, shellfish, dairy prod- ucts, fruits? Note also the most expensive. Problem 173: To find the value of food as a source of energy compared with its price. Method. — Use the following tables as suggested above, NOTE. — Cheap foods give more than 1500 units of energy for 10 cents at pres- ent prices; medium priced give between 750 and 1500 units of energy for 10 cents at present prices ; expensive give less than 750 units of energy for 10 cents at present prices. Conclusion. —1. Find ten cheap fuel- or energy-giving foods, ten medium priced, and ten expensive ones. 2. Can you find ten foods that are cheap both as energy pro- ducers and as tissue builders? NOTE. — An interesting exercise on economic buying of foods for a family or for individual consumption may be worked out from this table, which has been revised by inserting present-day prices. This is of especial value in connection with work in home economics. CompaRaATIVE NUTRITIVE VALUES AND Prices oF Foop Marertats } TEN CENTS WILL PurcHasE PRICE PER EF d in oe Protein Garba. in lbs. ENERGY Calories Beef Porterhouse steak Se. fee PL) A) 32 .050 325 Sirloin steak . ee : 28 058 370 Round steak (top round), ye ee 28 .O79 370 Chuck steak .. &. Gudea 2 22 .070 420 Flank steak . . fe te See 22 .077 510 1 Revised by John W. Teitz of the Department of Biology, De Witt Clinton High School. PROBLEM 173 199 CompParATIVE Nutritive VALUES AND Prices or Foop Marreriats— Continued Tren CENTS WILL PURCHASE PRIcE PER ee. Protein ene in lbs. ENERGY Calories Beef — Continued Porterhouse roast . . . . .. . 30 -054 350 Ribroast: 0 Gos GS ee eS 25 .056 470 Bottom round . a teat tal es teh 20 .082 300 Plate (corned beef) fe des $8 rah Se 10 138 1290 Shank (soup beef) . . . . . . 12 107 455 Veal Gutletisns Ga- Ge Se Oe CaP AP aS 30 .069 170 Loin and rib ot fe ter wa He Ope te) ty 26 .065 270 TSO Ge kay, Ge 2th en Se le, ey (on /Ghe 25 .063 215 Breast .. Pe ee ee eee 22 .098 290 Neck (stew weal eo, 8 - . 20 .080 255 Knuckle or shank (veal broth) a “ae 15 138 395 Mutton and Lamb Om?) ae eR aR eS Se A 30 .046 490 GOR oe a Seo tae see oe Ser PER ike, ine eas 23 -065 390 Shoulder . . ft cats fe. . iz, Us? Was I 20 .060 370 Neck (stew lamb) SD, Aue sity Ge. ee 16 183 1480 Pork Ham; fresh 3 & & Sw ee es 23 .067 670 Ham,smoked ....... 23 -062 730 Shoulder, fresh . . . . .... 18 .067 820 Shoulder, smoked . . . gitar 18 .078 760 Ribs and loins . ........ 24 .056 635 Fat salt pork. . . .....~. 16 .012 2295 BaGOM scaler a ae Gk Se 22 .042 1265 Poultry Turkey e-. al a) Gel Gs Op ae eo a SP B82 .052 340 Ghieken 2 6 se & ow we a a 24 .058 325 Sea Foods Bluefish: a4 oS) Se Se A a ee ed 14 .072 150 Cod; fresh ie xe we ea eye 15 112 224 Cod, salted . . 2. 2. 1. ee 16 119 200 Halibut, fresh . . 2... 20 072 240 Halibut, smoked ... . : 25 .078 380 Mackerel, fresh. . . .... . 12 .096 305 Mackerel, salt . . . . she oh 15 .109 688 Salmon, canned. . . .... . 25 .088 370 200 FOODS AND DIETARIES ComparaTIVE NUTRITIVE VALUES AND Prices or Foop MarTreriaLs — Continued Tren CENTS WILL PURCHASE PRIcE PER I POpAD Protein Cee in lbs. ENERGY Calories Sea Foods — Continued : Clamsin shells . . ..... 40 .025 79 per peck Lobsters, canned . ...... 45 .041 135 Oysters, solids ee ae ee ee 18 .030 130 Dairy Products Butter... Byte aes muir ero 32 .003 1135 Gheesors: ee “ae es ae ws eS 21 .096 940 HSCS EC 2 ee Ges ES BAS 23 .058 280 Milk, whole . . ......~. 4.5 .072 720 Milk, skimmed . . ...... 3 .102 565 Milk, condensed . . ~~... . 12 .073 1260 Cream: 4 ee [ap ec aera a Re 15 -034 1220 Vegetables Beans, green. . . 4 .102 925 Beans, baked (canned) 15 .045 400 Beans, dried . 2 7 -320 2580 Beets 2 .052 840 Cabbage 3 -047 415 Caulifiower 3 .036 465 Celery .- 7 .032 250 Corn, green 3 .040 600 Corn, canned. . . . ..... 15 .028 455 Onions . : 4 033 515 Parsnips 2 .052 1200 Peas, split . 7 351 2515 Potatoes : 2 -090 1555 Potatoes, sweet . 3.5 .035 1085 Pumpkins . 4 .013 150 Squash 4 .018 265 Tomatoes, gunned a 6 .020 175 Turnips 1.5 -060 835 Cereal Products Barley . 7 121 2355 Buckwheat 6 .069 2770 Corn meal. 4 .230 4138 Hominy : 5 .166 3300 Oatmeal (in pkgs. Die 9 185 2050 PROBLEM 173 201 Comparative Nurritive VaLurs anp Prices or Foop Marrerrats— Continued Tren CENTS WILL PurcHASE PRIcE PER -; Ce Protein oe in Ibs. ENERGY Calories Cereal Products — Contin” e1 Oatmeal (in as 6 .278 3085 Rice . 9 .089 1815 Flour, graham 4 333 4170 Flour, rye . 4 170 4075 Flour, entire wheat 5 .275 3350 Flour, wheat . 4 .285 4170 Bread, white . 6 154 2025 Crackers, soda 8 134 2380 Miscellaneous Cornstarch . . . . . oe 8 — 1850 Molasses . . . .... 6 — 2580 Oliveoil . 2... 70 — 605 Sugar’ 2. 4 Gob a ee Re a 5 —_ 3756 Tapioca 0 gw ak we a 9 _ 1855 Dard, 2. an ae i htt S% 16 — 2435 Sausage . fw a SO : 22 .060 965 Fruits Apples. . .... a 2 .021 700 Apples, dried . s% ae : 18 .010 750 Apricots, dried . . . ...... 10 .047 1290 Bananas ‘ : aac ae 8 -096 375 Berries . : er bie asa Sy & 6 .007 290 Cherries . ... , iy: ore 6 .015 575 Cranberries “8 a ee te @ 5 -008 430 Dates. nc. a8: 2g: |e oe tes Dal Sg x. oe 12 .016 915 BG Siang Se, A aS ar A Se a SS et 4 20 .022 745 Grapes. % » & «© 6 6 # «4 4 025 840 Muskmelons. . ....... 7 .005 640 Oranges: ok a ae wk 6 014 390 Peaches . .. . ee ee 5 .020 510 Peaches, canned. . . . .... 10 .008 255 IPOATS ~~: Se ae Be ve War Side. Se ae R 4 .015 735 Pineapple. . . ..... - 10 -004 200 Prunes. . . ae ee R 12.5 .014 950 Raisias 2 4 32 % % # 8 wow 15 .015 1045 Watermelons. . . ...... 4 -004 150 202 FOODS AND DIETARIES Problem 174: To find my daily Calorie requirement. Method. — Use the following tables carefully. TABLE 1 Dairy Catorize NrEEps For a child under 2 years . . 2 oe ew ee ee) e)~© -900 Calories For a child from 2 to 5 years . Pe ee 1200 Calories For a child from 6 to 9 years bs: Gh oi . . . 1500 Calories For a child from 10 to 12 years : . 1800 Calories For girl from 13 to 14 years (woman, light work, also) . 2100 Calories For boy from 12 to 14, girl from 15 to 16 (man, seden- tary). . 2400 Calories For boy from 15 to 16 years (man, light muscular work) 2700 Calories For man (moderately active muscular work) ‘ 3000 Calories For farmer (busy season). . . . . . . . . 3200 to 4000 Calories For ditchers, excavators, ete. . . . . . . 4000 to 5000 Calories For lumbermen, ete. . . . . . .. 5000 and more Calories NOTE. — According to Professor Chittenden, a person doing moderate work should not eat more than < of an ounce of protein for each pound of his body weight and enough fuel foods added to bring the total up to between 2500 and 3000 Calories. This is a good general rule to follow. Still another check on your daily needs when doing light work may be obtained by multiplying your body weight by 16.1 Calories. The result will be approximately your daily Calorie requirement. But the body needs more energy when it works hard. The hourly Calorie requirement is shown in the following table. TABLE 2 Hovurzy Ovuteo 1n Heat anp ENERGY FROM THE HumAN Bopy as DETER- MINED IN THE RESPIRATION CALORIMETER BY THE UNITED STATES DEPARTMENT OF AGRICULTURE AVERAGE (154 LB.) CaLoriEs Resting (asleep) OA cl atta Conclusion. — Which part of the body seemed most sensitive to touch? b. Heat and Cold Materials. — Large wire nail, pen, ink, and ruler. Method and Observations. — With a ruler and a pen, draw a square inch on the under side of your wrist. Heat a wire nail so PROBLEM 222 253 it feels very warm. Now lightly touch all parts of the skin within the square area. Do all parts feel the heat, or only the sense of slight pressure of the nail? Mark with a little cross all spots that are sensitive to heat. Now cool off the nail by placing it onice. Wipe it dry and apply while still cold in the same way to the area marked off on the wrist. Do you feel the sensation of cold in all spots? Mark as before, this time using a dot. NOTE. — Certain sense cells of the body are sensitive to heat, others to cold. Conclusion. — 1. Do these sense cells occupy the same area? 2. Do all parts of the skin feel heat and cold? Problem 222: To study the anatomy of the nervous system. Materials. — Frogs preserved in formalin, with body cavity opened and viscera removed, scissors, scalpels, forceps, hand lens, charts showing nervous system of man, model of brain of man. Method. — In a frog from which the organs of the body cavity have been removed, note white glistening cords (nerves) which seem to come from under the backbone. Follow the course of some of the larger nerves. Where do they lead? Now turn the frog over and with sharp scissors and a scalpel remove very care- fully the bony covering (the skull) from the whitish body (the brain). Observations. — How many parts do there appear to be in the brain? Notice the white elongated hemisphere of the fore brain or cerebrum. The two anterior projections of the cerebrum are called olfactory lobes. Where do these lobes seem to lead? What do you think, from the name, their use is? Just back of the cerebrum, find two large lobes, known as optic lobes, which have to do with sight. Look at the chart. Are the eyes connected with the optic lobes? Back of the optic lobe we find the cerebellum and medulla, the latter running directly into the spinal cord, from which rise the spinal nerves you have noted before. Compare, part by part, the brain of the frog with the model of the brain of man. 254 BODY CONTROL AND HABIT FORMATION Conclusion. — 1. In what respect is the frog’s nervous system like that of man? How does it differ? 2. Write a description comparing the nervous system of the frog with your own, using charts and models as a guide. Problem 223: To study the structure and use of neurons. Method. — Study the figure on page 351, Civic Biology. The cell pictured is known as a neuron or a unit of the nervous system. The brain and spinal cord contain many millions of them. One end of a neuron may be in the brain and the other end far away in the spinal cord; or one end may be near the surface of the body and the other end in the spinal cord or brain. Observations. — How do these cells compare in length with other cells of the body? NOTE. — If a neuron has for its function the sending of messages from within outwards (to muscles), itis a motor nerve. If it receives stimuli from without, it is @ SENsory nerve. Conclusion. — What structures in the nervous system carry the impulses from the surface to the brain? From the brain to the muscles or other parts of the body? Problem 224: What is a reflex action? Method and Observations. —If somebody, without warning, pretends to strike you in the face, what happens? Through what parts of the nervous system would you become aware of what was happening? With your eyes closed touch a hot surface. What happens? Did you think about withdrawing your hand? Conclusion. — 1. Actions of the sort just described are called refleces. Explain as well as you can, using the figure, the path- way of a reflex action. 2. Does this pathway reach the cerebrum or thinking part of the brain? Problem 225: To compare the reaction time of hearing and touch. Method and Observations. — Let the class form a large circle and then start a whispered word at one end of the circle. Let the PROBLEM 227 255 teacher note the number of seconds for the word to get back to the starting point. By dividing this time by the total number of participants the average reaction time for hearing of the class can be obtained. Now let members of the class just touch finger tips. In the same manner as in the previous experiment, let the instructor start a signal (a short pressure of the fingers). Get the average reaction time as in the previous experiment. Conclusion. — Which gives a quicker reaction, hearing or touch? Problem 226: To compare a reflex action with an act of thought. Method. — Using the figures note the pathway with relays of cells between the eye when you see a book, and the rest of the nerves in- volved when you de- termine to pick it up and do so. Observations. — Make a diagram showing the path- way. Compare this pathway with the one taken when you touch your hand against a hot stove in the dark. Conclusion. — What is the chief difference in the nervous path- way between a reflex and an act of thought? se Organ (Skin) An Invotunrary Act. Problem 227: To study habit forming. NOTE. — A little chick just hatched in an incubator picks at food. It has no mother to teach it. Such an act is called instinctive. It is an act accomplished without reasoning. When a new-born baby sucks, its act is also instinctive. Upon such instincts life depends. Observations. — When a baby is just learning to walk, the first step would probably be brought about by its reaching or stretch- 1 256 BODY CONTROL AND HABIT FORMATION ing for something it wanted. This would in a way be an instinc- tive act. Can you explain how? When you first learned to write, did you think about making the letters of the words you wrote? Do you now? How do you account for the ease with which you now write? What is the chief difference between the instinctive act of the baby learning to walk and the act of writing? Do we think about writing now? Did we think about it when we began to learn? An act consciously repeated many times eventually becomes a habit. Might a habit be formed through the unconscious repeti- tion of an act? Conclusion. — 1. What is an instinct? 2. What is a habit? How might it be formed? 3. What is the difference between instinct and habit ? Problem 228: To study the mechanism of habit formation. NOTE.— The formation of a habit involves the simplifying of a complicated process. In an act of thought, ¢.g., picking up a toothbrush from the washstand (see diagram) the eye sees the brush and relays the message through some sight cells to a nerve center in the back of the brain (O.C.). From there the message is again relayed to (AM.C.), where the impulse is originated to pick the brush up. This results in a message being sent by another relay of several sets of cells down the spinal cord to the muscles of the arm where the fibers from this neuron end in the muscles. Now if the act becomes habitual, as it does when we brush our teeth each morning, the stimulus caused by the sight of the brush causes a short circuit of the impulse which goes to O.C. and then directly down the spinal cord. Conclusion. —1. If M.C. is the THE COURSE TAKEN BY THE Acr or THoucst. thought center, then what does habit O.C., nerve center; M.C., forming do? unguebe penter: 2. Would it be better to make a problem of brushing your teeth each morning or to do it auto- matically (by habit) ? 3. Just how is a habit formed in the nervous center? 4. Of what advantage are habits? PROBLEM 230 257 Problem 229: To consider some harmful habits. a. Tobacco Method. — Allow the smoke from half a dozen cigarettes to pass through the water of a small jar containing a goldfish, or add a small piece of tobacco to the water. Observations. — What is the result? Conclusion. — Might tobacco have any similar effect on other living things, as man? b. Alcohol Method and Observations. — Using the figures given in your Civic Biology, on pages 363, 369, 370, 371, explain why life insur- ance companies consider moderate drinkers an extra risk. Conclusion. — What effect does the drink habit have upon man? Problem 230: How to go to work to form good habits. Method and Observations. — Study the following statement : “The hell to be endured hereafter, of which theology tells, is no worse than the hell we make for ourselves in this world by ha- bitually fashioning our characters in the wrong way. Could the young but realize how soon they will become mere bundles of habits, they would give more heed to their conduct while in the plastic state. Weare spinning our own fates, good or evil, and never to be undone. Every smallest stroke of virtue or of vice leaves its never-so-little scar. The drunken Rip Van Winkle, in Jefferson’s play, excuses himself for every fresh dereliction by saying, ‘I won’t count this time.’ Well! he may not count it; but it is being counted none the less. Down among his nerve cells and fibers the molecules are counting it, registering and storing it up to be used against him when the next temptation comes. Nothing we ever do is, in strict scientific literalness, wiped out. Of course this has its good side as well as its bad one. As we become permanent drunkards by so many separate drinks, so we become saints in the moral, and authorities in the practical and scientific spheres, by so many separate acts and hours of work. Let no youth have any anxiety about the wpshot of his education whatever the line of it may be. If HUNTER LAB. PROB. —17 258 BODY CONTROL AND HABIT FORMATION he keeps faithfully busy each hour of the working day, he may safely leave the final result to itself. He can with perfect certainty count on waking up some fine morning, to find himself one of the competent ones of his generation, in whatever pursuit he may have singled out.” — Jamgs, Psychology. Man is thus shown to be a bundle of appetites. Conclusion. — 1. What are the best ways of forming good habits and continuing to observe them? Write a short composition on this important subject. 2. How should one’s judgment and appetite relate to each other? Problem 231: To determine the relation between taste and smell with reference to food flavors. Materials. — Vegetables, spices, flavors. Method. — Close the eyes and hold nose tightly with one hand; with the other place on the tongue pieces of peeled apple, peeled raw potato, peeled raw turnip, and onion. Have the pieces exactly the same taste? Have some one record the results. Are you aware of the different flavors? Are you with the nos- trils open? Experiment with a number of other substances, as sugar, vinegar, va- Recognized | Recognized | nilla, mustard, salt, by Taste by Smell : : Apple : spices, etc., holding Onion nose and closing eyes. Potato Rub the tongue dry. Turnip Place a little sugar on Salt it. In what condition Sugar must materials be in Mustard order to be tasted? Vanilla Observations. — In Vinegar tabular form note those substances which are learned by taste only and those which are recognized by taste and smell. Conclusion. — What is the relation of taste and smell in dis- tinguishing flavors? PROBLEM 233 259 Problem 232: How to find out certain defects of vision tn the laboratory. Materials.—Schnellen’s test cards, spectacles with diopter lenses, clock dial chart. ; a. Test for Farsightedness Method. — Using the Schnellen’s test cards, locate the finest line that can be read at a distance of 20 feet. Test each eye separately, covering the eye not in use with a piece of cardboard. Then place a pair of spectacles with a 50 plus diopter lens before the eyes. If as fine or a finer line can now be read, then far- sightedness is present and an oculist should be consulted, espe- cially if headaches or other symptoms of eye defects are present. Farsightedness is one of the most frequent causes of eyestrain and is hard to detect because the eyesight seems so good. b. Test for Nearsightedness Method. — Use the above-mentioned charts. Determine the finest type you can read at a distance of 20 feet. If it is larger than the 20/20 line, then your vision is defective and you should probably consult an oculist, especially if you have any symptoms of eyestrain. c. Test for Astigmatism Method. — Use the clock dial disk at 20 feet. If some lines are blacker than others, then astigmatism is present. If headaches or other symptoms are present, then you should consult an oculist and have glasses fitted to correct this trouble. Next examine a chart or model of the human eye and deter- mine what defects must occur within your eye to cause the defects in vision you have found. (Your teacher will explain the terms “ nearsightedness, farsightedness, and astigmatism.’’) Conclusion. — Have I any eye defects? If so, what are they, and how must I go about to correct them? Problem 233: What are some of the effects of alcohol on the nervous system ? Method. — Using the figures on pages 363, 365, 366, 369, 370, 371, 372, Civic Biology, make a graph to show the effect of alcohol upon 260 BODY CONTROL AND HABIT FORMATION memory, mental work, ability to do physical work, efficiency, acci- dents. Conclusion. —1. What effect does alcohol have upon the nervous system ? 2. Write a short composition on this subject. PROBLEM QUESTIONS 1. Do you suppose the neurons of a child just learning to walk find it easy to send out exactly the right orders to the muscles? Explain your answer. 2. Do you consciously think about making steps when you now walk? Why not? (Consult chart.) 3. In learning to do anything in concert, how does the first re- hearsal compare with the last? 4. What is a necessary factor in forming a habit? Remember that pathways become worn along certain lines so that the neurons in those pathways take up the work instinctively. 5. Explain this story: ‘A practical joker saw a discharged veteran carrying his dinner home and suddenly called out, ‘ Atten- tion’; whereupon the veteran instantly brought his hands down, dropping his dinner in the gutter.” 6. What is the advantage of forming good habits in life? 7. Does habit forming throw work off part of the nervous sys- tem? Explain fully. 8. How are habits formed? 9. Write a paragraph on the increased effectiveness and power acquired through good habits. 10. Is it easy to break a habit? Explain your answer. 11. Why is a grammar school idler quite likely to continue to be an idler in high school, and a high school idler a college idler? 12. Why are the railroads requiring their employees to abstain from liquor? REFERENCE Booxs Hunter, Civic Biology, Chap. XXIII. American Book Company. Hunter, Elements of Biology, Chap. XXXV. American Book Company. Hunter, Essentials of Biology, Chap. XXVIII. American Book Company. Angell, Psychology. Henry Holt and Company. REFERENCE BOOKS 261 Berol, System of Memory Training. Funk and Wagnalls Company. Brewer, Rural Hygiene. J.B. Lippincott Company. Brown, Good Health and Long Life. Published by author Dr. W. Brown, Chicago. Clouston, Hygiene of the Mind. Unsoundness of Mind. E. P. Dutton and Com- pany. Cook, Health through Rational Living. D.C. Cook Publishing Company. Dotey, Prevention of Nervous Diseases. D. Appleton and Company. Du Bois, Self Control and How to Control It. Funk and Wagnalls Company. Eyestrain from Movie Habit. Literary Digest, May 30, 1914. Forel, Hygiene of Nerves. G. P. Putnam’s Sons. Gordon, Modern Mother. Fenno and Company. Gulick, Mind and Work. Doubleday, Page and Company. Gulick, Control of Mind and Body. Ginn and Company. Gulick, The Will to be Cheerful. World’s Work, July, 1908. Hartman, First Book of Health. World Book Company. Hope and Browne, A Manual of School Hygiene. G. P. Putnam’s Sons. Hough and Sedgwick, The Human Mechanism. Ginn and Company. Human Being without Cerebral Hemispheres. Scientific American, December 13, 1913. Hutchinson, Civilization and Health. Houghton Mifflin Company. James, Psychology, Chap. X. Henry Holt and Company. Johnston, What Science Has Done for the Child. The Designer, March, 1910. Little Danger of Brain Strain. Literary Digest, April 11, 1914. McCabe, Evolution of Mind. A. and C. Black, London. McComb, Alcoholism, Its Causation and Its Arrest. Everybody's Magazine, April, 1909. McComb, Nervousness, A National Menace. Everybody's Magazine, February, 1910. , Nervousness. Review of Reviews, January, 1914. Overton, General Hygiene. American Book Company. Partridge, The Nervous Life. Sturgis and Walton. Paton, Nervous and Chemical Regulators of Metabolism. The Macmillan Company. Ritchie, Human Physiology. World Book Company. Roddy, Hygiene. J. A. Roddy, Philadelphia. Rowe, Habit Formation and the Science of Teaching. Longmans, Green and Com- pany. Saleeby, Worry, the Disease of the Age. F.A. Stokes Company. Stiles, Nervous System and its Conservation. W. B. Saunders. Supplement to the Brain. Literary Digest, March 14, 1914. Walton, Why Worry? J.B. Lippincott Company. Ward, Problem of Instinct. Independent, August 24, 1914. Worry, Its Cause and Cure. Harper's Bazar, January, 1910. XXIV. MAN’S IMPROVEMENT OF HIS ENVIRON- MENT Problems.— How may we improve our home conditions of living? How may we help improve our conditions at school? How does the city care for the improvement of our environ- ment? (a) In inspection of buildings, etc. (6) In inspection of food supplies. (c) In inspection of milk. (ad) In care of water supplies. (e) In disposal of wastes. (f) In care of public health. LABORATORY SUGGESTIONS Home exercise. — How to ventilate my bedroom. Demonstration. — Effect of use of duster and damp cloth upon bac- teria in schoolroom. Home exercise. — Luncheon dietaries. Home exercise. — Sanitary map of my own block. Demonstration. — The bacterial content of milk of various grades and from different sources. Demonstration. — Bacterial content of distilled water, rain water, tap water, dilute sewage. Laboratory exercise. — Study of board of health tables to plot curves of mortality from certain diseases during certain times of year. Nore to TEacuers. — The exercises which follow are intended to be suggestive and may be extended indefinitely as time may permit. To make this work of most value, as much collateral reading as can well be made available should be used in addition to the definitely planned home and laboratory work outlined in the following chapter. Field work is of especial importance in this connection as it shows the pupils what the city departments are doing toward the inspection of factories, care of food supplies, inspection of milk, both in production and in the sale, provision for a safe and ample water supply, disposal of wastes and care of the public health. An effort should be made to have each pupil procure a copy of the 262 PROBLEM 235 263 Sanitary Code of the city in which he lives and then by careful study to see which sections are commonly broken and honored in the breach by the police or health officials. Concerted action on the part of the younger members of a community may bring about decided results for the betterment of a given neighborhood. Thus our biology courses may become, in truth, courses in civic biology. Problem 234: How to ventilate my bedroom. ‘(Home Problem.) NOTE. — This problem varies, depending on the number and position of the windows in the room. Remember that air without direct draft is what is desired. Method. — Recall the experiment of the candle and the box with the holes in it. (See problem 214.) What happened when the corks were removed from the two upper holes on one side only? The two lower holes on one side only? The upper and lower holes on one side only? Now apply this principle to the room in which you sleep. Make a diagram to show the air currents in the room when you open the window for ventilation. Is this the best way to have the air currents move? Why? Where should you place the bed and why? Should you use a screen in your room? If so, where should you place it? Conclusion. — Make a diagram showing the best way to ventilate your bedroom and give your reasons for thinking this is the best way. Problem 235: To compare the duster and the dry cloth with the moist cloth in cleaning the schoolroom. Materials. — Sterile Petri dish with culture medium, broom, oiled rags, oiled sawdust. Method. — Expose a sterile Petri dish culture in the schoolroom for two minutes while members of the class dust with dry cloths and broom. The same day have members of the class clean a neighboring room, having the same conditions of dust and dirt, by means of damp cloths and brooms with damp cloths tied or pinned over the part that touches the surface of the floor. Use damp sawdust on the floor. Expose Petri dish as in above test. Try the experiment in a third room, using oiled rags and oiled sawdust. Expose Petri dish as in test number one. 264 MAN’S IMPROVEMENT OF HIS ENVIRONMENT Place the three Petri dishes in a moderately warm and dark place for three days. Then examine. Observations. —In which of the three dishes are the most colonies of bacteria and molds? Continue your observations for about one week’s time. Conclusion. — Which of the above methods of dusting a room is the most hygienic and why? (Read Hodge, Nature Study and Infe, page 476.) Problem 236: What should I eat for luncheon? Materials. — Food tables on pages 204 to 209. Method and Observations. — Eight boys in a class eat the following lunches: A brings from home two ham sandwiches, a sponge cake, and an orange. B brings from home two cheese sandwiches and buys a glass of milk and five cents’ worth of candy. C buys a hot roast beef sandwich, a cup of cocoa, and an apple. D buys a dish of ice cream, one piece of sponge cake, and five cents’ worth of candy. E brings two slices of bread and a square of chocolate and buys a glass of milk. F buys a Frankfurter, a roll, a small helping of sauerkraut, and a glass of lemonade. G buys a plate of vegetable soup, a slice of bread and butter, a cup of tea with milk and sugar, and a piece of apple pie. H buys a helping of beans and a dish of ice cream. Using the tables on pages 204-209, work out the proportion of carbohydrate, fat, and protein contained in each. Add up the total number of Calories in each. Use any standard you wish, Atwater, Chittenden, or Voit. In like manner add your own luncheon to the list. Conclusion. — Which do you think the best balanced? Which the most poorly balanced? Which the cheapest (most nutri- ment for the least money)? Which the best for a spring or a fall luncheon? PROBLEM. 237 265 Problem 237: To make a sanitary map of my own environ- ment. Method and Observations. —— 1. Make a large map of your immediate neighborhood by drawing to scale on cardboard, or heavy paper, a map of your home block (if you live in the city) or the neighborhood surrounding your house (if you live in a small town). Locate on the map all the houses by oblong shaded areas and use cross lines to indicate stores. Make an index at the bottom of the map to explain the uses of the different stores or buildings shown. Using board of health signs, indicate any homes in which your local board of health has placarded contagious diseases. 2. Locate on the map any standing water, especially water in old tin cans, gutters, or depressed roofs, sewer openings, catch basins, open barrels, or small ponds in vacant lots. Why should you locate standing water? 3. Find the position of any stables and determine if the heaps of manure are allowed to collect and stand for long periods of time. Why would such manure heaps be a menace to the public health of your neighborhood ? 4. Notice the condition of the garbage pails in your neighbor- hood. Is garbage collected regularly? Are all the pails provided with covers? If not, locate coverless pails. Does garbage ever stand for more than two or three days without collection? Are the garbage pails, after the collection of garbage, washed clean, or is garbage allowed to remain sticking to the sides of the pails from one week to another? What dangers might arise from such pails as the latter? 5. Investigate the condition of all butcher shops, restaurants, or stores where perishable food is exposed for sale. Do you find the shops screened, and the exposed food protected from flies? Are there excessive numbers of flies in the butcher shops? If so, then try to locate their breeding places. Look for bits of stale meat or other refuse that may have been allowed to stand un- touched in a given place for over two weeks. 6. Locate any sewer openings or catch basins from which come bad odors. Also locate any outdoor privies, especially if not 266 MAN’S IMPROVEMENT OF HIS ENVIRONMENT connected with the sewer system of the city. If such toilets are not screened from flies, report the matter at once to your board of health. Why are the latter toilets a particular menace to public health? (See Civic Biology, page 224.) 7. Locate on your map any pushcarts, stands, or stores in which vegetables or fruit are exposed for sale. Indicate if they are obeying the laws of your sanitary code with reference to the ex- posure of goods for sale. Why isit a wise law that requires goods exposed for sale to be covered? Is there any spitting in the streets in this locality? Are there any other ways in which germs might get in the dust of the street? How might bacteria be carried from the street surface to the food exposed? 8. Find any public fountains having drinking cups; bubble fountains. Which is more hygienic? Why? 9. Locate any hotels or other places having common roller towels. Why are common towels a danger to public health? What can you do to prevent the use of the public towel in your neighborhood? 10. Locate any other factors that might in your opinion affect public health in your neighborhood. Factories belching forth smoke or acid fumes, tall buildings shutting out light, old tenement houses, and filthy conditions of street are among such factors. Conclusion. — 1. Is my neighborhood a good one in which to live? Give reasons. 2. How may I help to better the conditions that affect public health in my locality? Problem 238 : To determine the bacterial content of different Srades of milk. Materials. — Different grades of milk, sterile bulb pipette, sterile test tubes, absorbent cotton, sterile Petri dishes containing -agar culture media. Method. — Procure milk from different sources and of different grades if in a large city. Be sure to include milk dipped from a can in some store. Have samples of milk collected kept under identical conditions and be sure that the milk has been collected from the milk companies at the same time. Then treat each PROBLEM 239 267 sample according to the following directions: With a sterile bulb pipette draw off 1 c.c. of milk from a well-shaken sample bottle. Add to this 19 c.c. of distilled water, taking care to have the water in a sterile test tube, protected from any dust by an absorbent cotton plug. After mixing the contents of the tube thoroughly, quickly flood the surface of a sterile Petri dish con- taining agar culture media with the mixture of milk and water. Drain the dish, keeping it covered during the operation; label; fasten down the cover with strips of paper; and place to one side. Treat each of the other samples of milk in the same manner as just described, taking care to label each as to the source of the milk, etc. Place the dishes side by side in a mod- erately warm place. Observations. — After two days, and on each successive day for a week, examine the different Petri dishes. Count the number of colonies in each dish. Also note the different [Milk|| 3D 4D SD__| Benge kinds of colonies of LL“ bacteria present in = each of the Petri = dishes. Tabulate the [¢ results. F Conclusion. — 1. Which of the grades of milk examined seems to be most free from bacteria? 2. Should milk be entirely free from bacteria? What do the bacteria present in greatest quantities probably do to the milk? 3. If several kinds of bacteria are present in milk, what can you say of its purity? What ought to be done with such milk before it is used? Problem 239: To determine the bacterial content of some kinds of water. Materials. —See Problem 238. Omit milk and ‘substitute samples of water. Method. — By means of a sterile bulb pipette place, in sterile Petri dishes containing agar culture media, equal amounts of 268 MAN’S IMPROVEMENT OF HIS ENVIRONMENT different waters to be tested. Suggested samples are as follows: distilled water, rain water, bottled spring waters of various kinds, city tap water, standing water from lakes or pools near your home, river water thought to contain sewage, dilute sewage. After inoculating the Petri dishes with the water to be tested, place all Number of Colonies in each of the dishes contain- Water] 3D 4D 5D. | inass=] ing the samples in a moderately warm place. Examine after two or three days, and on suc- cessive days for one week. Tabulate the results. Observations. — In which Petri dishes does the most bacterial growth take place? Conclusion. — 1. Which of the examined samples of water are free from bacteria? 2. Which of the samples are best for drinking purposes? Give reasons for your answer. lili ale |> Problem 240: To determine some of the problems of water supply and sewage disposal for a city. Method. — Visit the sanitation exhibit in a city museum. Observations. — From information gained from maps in the museum, or in some other way, trace the growth of the water supply of your city since its beginning. Where did the city first get its water? What is now the source of the water supply? What impurities are commonly found in water? What do reservoirs do to a water supply? State several ways in which a water supply becomes contaminated. How might contaminated waters bounding a city affect the health of the citizens of that city? How does the sewage of your city affect the waters surrounding it? How is this contamination brought about? What methods are there for sewage disposal? Which would you choose for use in your city? Why? How is sewage now disposed of? How do conditions of water supply and sewage disposal on a PROBLEM 242 269 farm compare with those in a city? How can the unsanitary environment of the farm be made sanitary? Conclusion. — 1. What steps should a large city take to obtain and protect its water supply? 2. What should be done with the sewage in the city in which you live? Why? 3. What other hygienic steps should a city take to protect its citizens? Problem 241: Is typhoid a city or a country disease? Observation. — Make a graph from the following table! to show the relative death rate from typhoid in states having a large urban population, and in states having a large rural population. AVERAGE TYPHOID Gent or Ronan | Fever Deava PoPpuLaTION 100,000 Five states in which the city population was more than 60 % of the total. 30 25 Six states in which the city population was between 40 % and 60% . 5 49 42 Seven states in which the city population was between 30% and 40% . . 67 38 Eight states in which the city population was between 20% and30% .. . 75 46 Twelve states in which the city population was between 10% and 20% ... . 87 62 Twelve states or territories in which the city population was less than10% . . 95 67 Conclusion. — Is typhoid a city or a country disease? Why isitso? Look up diagram in your textbook. Problem 242: What is the annual cost to New York city of some preventable diseases ? Materials. — Report of board of health. Method. — Using the board of health tables for the year 1910, find the number of persons who die from each of the given prevent- able diseases. Which are particularly children’s diseases? Fol- lowing these directions, compute the annual cost in lives. 1 Modified from Allen’s Civics and Health. 270 MAN’S IMPROVEMENT OF HIS ENVIRONMENT City of City of City of City of City of City of New York | New York | New York | New York | New York | New York Jan. |Jan. |Feb. |Feb. |Mar.| Mar.|Apr. |Apr. | May| May] June] June ! 1911} 1910] 1911) 1910} 1911) 1910] 1911] 1910) 1911] 1910; 1911] 1910 Total deaths, all causes |6,961|7,090)6,470|6,270|7,445|7.300|7,185 6,916]|6,677/6,323|5,368/5,946 —| — —= SSS | ! Typhoid Fever . .| 27] 37} 21) 27] 24] 32] 20) 24] 24] 23) 32] 37 ! Malarial Fever . . 1 vd ie ae 3 6 1 1 3 9 ee 1 ! Smallpox .. Be I aes 1] hdd [Poet II GaGa IN Gobtee iT atance a Seta De.) aes Lit ose 2 : Measles = .| 384) 77) 57) 77) 72) 129) 77 | 135} 116 | 107/113] 85 4 Searlet Fever... 65 | 150 85 | 150 | 126 | 159 | 143 | 148 | 131 | 116 73 83 i Whooping Cough .| 29] 17) 31] 13] 31 17| 37] 29| 40] 28] 35] 25 Diphtheria and Creue 135 | 202 | 128 | 183 | 149 | 212 | 151 | 221 | 161 | 186 90 | 152 : Influenza . : 152 | 47]101/ 49] 82| 75| 50] 52] 35; 24 6| 13 | Asiatic Cholera Be Ns Glee ees css sche Seay t| ah apse lle cetece I PASsrap lt aeuecsiey| “sautgan | Mbgaiphed| ye doue | Cholera Nostras . . 2 Other Epidemic Dis- i eases. . 47 42 52 53 53 61 68 35 71 41 5L 38 Tuberculosis, Pulm . | 814 | 767 | 782 | 707 | 824 | 859 | 835 | 809 | 812 | 755 | 678 | 657 Tub., Meningitis. .| 67] 76] 71| 69) 84} 67) 81] 64]103| 88] 95] 79 ' Other Forms of Tuber- f culosis . 46 48 54 42 53 56 51 64 61 53 51 43 i Cancer, Malignant | Tumor . . | 309 | 298 | 275 | 301 | 319 | 330 | 302 | 301 | 323 | 311 | 292 | 304 i Simple Meningitis .| 53] 51] 49] 52] 75] 62] 44] 52] 51 58 | 48) 51 which Cerebro-Spinal Men- : ingitis . 22] 26] 27] 23] 25] 26] 18] 30] 19] 30] 15} 27 Apoplexy, and Soften- ing of Brain. . 134 | 102] 94) 83]| 80] 94] 105] 66] 63] 98| 62] 74 Organic Heart Dis- eases... 831 | 679 | 719 | 629 | 738 | 603 | 721 | 576 | 684 | 573 | 528 | 557 Acute Bronchitis’ || 98|125| 95| 92| 94] 96] 97) 95| 77) 57| 44| 65 [ Chronic Bronchitis .| 41] 48] 44] 39] 29] 37] 28] 58] 26] 387; 25) 17 ‘| Pneumonia (exc. Bron- i cho Pneumonia) . | 753 | 708 | 632 | 527 | 736 | 736 | 725 | 646 | 456 | 470 | 253 | 307 Broncho Pneumonia |} 486 | 624 | 486 | 515 | 640 | 597 | 590 | 538 | 484 | 408 | 298 | 334 Other Respiratory Diseases . .| 77} 84] 65} 59} 87] 87] 80] 96] 86) 74] 48] 63 Diseases of the Stomach (Cancer excepted) . . .| 45) 40; 43|] 45) 39] 54/] 35) 41] 87] 46] 39) 32 Diarrheal Diseases (under 5 years) . | 154 | 150 | 186 | 129 | 274 | 162 | 243 | 210 | 264 | 248 | 272 | 463 Appendicitis and Typhlitis . 48) 54] 48| 48] 44] 57] 61 56} 53] 43] 54] 56 Hernia, Intestinal Ob- struction . . 54 | 46] 56] 48] 46] 56| 37] 44] 48] 39} 40] 50 Cirrhosis of Liver +. | 102] 128], 91] 99/127) 89] 96] 91]101| 86} 93] 93 Bright's Disease and Nephritis . . 551 | 529 | 485 | 498 | 558 | 549 | 585 | 498 | 454 | 483 | 342 | 460 Diseases of Women (not Cancer) . .| 26/ 25] 21] 29] 37] 23) 36/ 36] 36/ 41] 42] 33 Puerperal Septicemia | 28 | 29 25 | 31 27 |} 36] 26| 33 31 20) 24 | 24 Other Puerperal Dis- eases . - . .]| 40] 43/ 38| 46] 45] 52] 38] 46] 47] 47] 43] 48 Congenital Debility and Malformations | 354 | 392 | 342 | 329 | 357 | 432 | 323 | 366 | 282 | 402 | 271 | 348 Old Age. 71} 68/ 44] 60] 64] 65] 54} 48] 48) 74} 24) 60 Violent Deaths . | 274 | 326 | 261 | 222 | 417 | 281 | 302 | 299 | 361 | 313 | 324 | 323 a. Sunstroke . doptar Nh siacs Wh Beale. [adsl oh, ataede Il teaalgn lt deauan saave ll seo eulh aes 6} 25 b. Other Accidents| 249 | 296 | 248 | 203 | 395 | 262 | 284 | 276 | 337 | 393 | 298 | 273 ce. Homicide zi 25 30 13 19 22 19 18 23 24 20 20 25 Suicide . c 62 69 50 59 64 66 75 65 74 79 69 92 All Other Causes . . | 924 | 973 | 913 | 916 | 1015) 1022} 1089; 1030) 1005) 848 | 879 | 815 Ill-defined Causes .| 29) 35) 26! 41] 29] 46] 29] 39! 23] 45, 30) 67 PROBLEM 242 271 City of City of City of City of City of City of New York | New York/New York | New York | New York | New York July |July |Aug. |Aug. |Sept.|Sept.| Oct. | Oct. | Nov.|Nov. | Dec.| Dee. 1911 |1910 |1911 ]1910 |1911 |1910 |1911 1910 |1911 |1910 |1911 |1910 Total deaths, all causes |6,648|7,060|6,039|6,052|5,361|5,674|5,495/5,597|5,620|5,566/6,154/6,948 Typhoid Fever . .| 56/ 53] 88] 58] 81/ 71] 63] 78| 57] 66|/ 52] 52 Malarial Fever . . 2 3 2 5 5 3 7 3 3 2 2 1 Smallpox . eel] ssatassen I eae, | sus, (ll etn! eie. |) aoe 1h ese en peered Rees 2. | cece Measles - + + «| 76] 60} 41] 388] 18] 28] 11 9} 10} 19] 33] 21 Scarlet Fever . -| 40] 39) 11) 11 11 | 16 7) 12) 15| 24) 384) 45 Whooping Cough .| 46/ 46] 49] 41 35 | 21] 30] 17 8] 18] 15] 22 Diphtheria and Croup 80 | 116 76 92 49 55 | 78 76 84 | 112 | 100 | 108 Influenza . % 2 5 1 3 5 1 10 7/ 16) 14] 21 76 ‘Asiatic Cholera Se.) Sse] waked seca. | aanae |! seach ane 5. apsyen Ith geese ve aed] haces eas Cholera Nostras . .| ...]... |... ] 0... 46 | 36} 32] 25] 24] 27 Other Epidemic Dis- eases. -| 35 | 39] 43] 44 | 658 | 674 | 658 | 666 | 673 | 662 | 24] 26 Tuberculosis, Pulm | | 650 | 728 | 693 G65) | osc | ogee] eee | wae | eas | eax | 711 | 248 Tub., Meningitis. .| 82/ 77]! 67] 54 58} 61 60} 58] 49] 55| 46 53 Other Forms of Tuber- culosis . . . .| 50] 57] 55] 48] 88] 48] 32] 43] 42] 37] 54] 42 Cancer, Malignant Tumor .. . | 315 | 291 | 345 | 316 | 328 | 319 | 376 | 323 | 337 | 308 | 337 | 308 ehuple Meningitis »| 85] 52] 53] 41 36 | 45] 39] 48] 31] 36] 28] 60 f whic Cerebro-Spinal Men- ingitis . 18| 23] 22} 19] 19] 21] 14] 25] 138] 15 9} 29 Apoplexy, and Soften- ing of Brain . 105 | 66] 54] 44] 62| 74] 63] 89] 75] 87] 108 | 102 Organic Heart Dis- eases . . 596 | 460 | 525 | 391 | 529 | 463 | 629 | 503 | 706 | 608 | 768 | 828 Acute Bronchitis -| 40) 45] 32] 48] 36] 60; 59|] 52] 87] 84] 115 | 109 Chronic Bronchitis . 8} 27) 15] 11] 14] 14] 15] 18] 22) 85] 27] 66 Pneumonia (exc. Bron- cho Pneumonia) . | 215 | 199 | 152 | 176 | 165 | 197 | 280 | 309 | 365 | 430 | 543 | 835 Broncho Pneumonia | 251 | 286 | 245 | 241 | 238 | 288 | 288 | 287 | 348 | 332 | 429 | 529 Other Respiratory Diseases » . «| 60) 55} 42] 47] 30] 64] 48] 41/ 55] 65} 58] 85 Diseases of the Stomach (Cancer excepted) . . .| 41] 25] 35] 41] 38] 40] 45] 51] 38] 35] 87} 51 Diarrheal Diseases (under 5 years) . | 807 |1632 |1034 |1175 | 701 | 791 | 408 | 572 | 174 | 231 | 168 | 155 Appendicitis and Typhlitis. . 77) 80} 69] 58] 55} 39] 31] 59] 41] 36] 50] 53 Hernia, Intestinal O struction .. 47; 53] 46; 58] 41] 46| 31) 43] 52] 44/ 45] 60 Cirrhosis of Liver .| 73] 74} 93/102] 95] 100] 102] 76] 114] 80 | 100; 122 Bright's Disease and Nephritis . 379 | 414 | 335 | 412 | 326 | 380 | 363 | 388 | 410 | 469 | 449 | 558 Diseases of Women (not Cancer) . .| 32] 35] 24] 24 11] 22} 32/ 28] 29| 28 11] 27 Puerperal Septicemia | 17 11 25 | 20] 20 13 10 9 17 13 20 16 Other Puerperal Dis- eases - . .{ 86] 49] 43] 86] 382] 37] 34] 34] 36) 32] 35) 41 Congenital Debility and Malformations | 314 | 319 | 332 | 360 | 313 | 351 | 318 | 370 | 316 | 292 | 362 | 390 Old Age. . .{ 51} 46] 24] 50} 28} 39] 40] 52] 29] 63] 48] 58 Wicleat Deaths . | 939 | 534 | 361 | 331 | 323 | 284 | 293 | 308 | 300 | 310 | 321 | 282 a. Sunstroke . 5385] 115)} 17] 12 1 Os eres lh as Means (ppeeee: cs faves easel eae b. Other Accidents| 379 | 389 | 322 | 286 | 301 | 253 | 268 | 290 | 270 | 282 | 284 | 263 c. Homicide .| 25} 80] 22] 33] 21] 22] 25) 18| 380] 19) 37] 19 Suicide .. -| 57] 85) 50] 59] 43] 67] 63] 64] 58] 59] 72] 57 All Other Causes. | | 941 | 886 | 883 | 836 | 804 | 838 | 844 | 807 | 964 | 971 | 921 | 943 Ill-defined Causes .| 93} 113] 96]116|] 89] 89] 95) 72| 37| 24 8| 24 272 MAN’S IMPROVEMENT OF HIS ENVIRONMENT Conclusion. — What is the annual cost of typhoid, tuberculosis, and diarrheal diseases of children to the city of New York? Problem 243: What are the chief causes of death in a city? Method and Observations. — From the foregoing table deter- mine: (1) The relation of the number of deaths from infectious dis- eases to the total death rate. (2) The diseases which kill the most children. (3) The per cent who actually die of old age. Conclusion. — 1. What percentage of all people of the city die from old age? 2. What diseases kill most babies and children under five years of age? 3. What diseases in the list might be influenced by alcohol? Problem 244: To study the relation of the death rate to the season. Method. — Study tables carefully in the following manner: Note a given disease, as typhoid, and make a graph, using figures given, to determine the number of cases reported and number of deaths monthly in New York city. Conclusion. — Is typhoid equally prevalent all the year round? How do you account for its great prevalence in the fall? (The instructor should divide up the work so that each member of the class will be responsible for a separate graph. A general discussion may then be held on the relation of various diseases to the city death rate. For example: What disease is responsible for the greatest death rate ?) Problem 245: To find a relation between flies and mortality. Method. —Refer to mortality tables published on pages 270, 271, and fill in the table on the opposite page. Observations. — With the aid of the given data, construct a graph showing the prevalence of flies and number of deaths per month for the dates given. (In making curves on cross section paper let 1 em. = 50 deaths, and 1 cm. = 200 flies.) Conclusion. —1. Is there any relation between the prevalence of flies and the number of deaths from diarrhea? PROBLEM 246 273 Date Jan.|FeB.| Marca|Aprit|May|Jung|JULY|Ava.|Sepr.|Ocr.|Nov.|Drc. Diarrheals under five : Average. Prevalence of files 0,0 0) 0 | 0 |250 |1900/2200|200 |400} 0 | 0 2. What factors increase the death of babies during the summer months? 3. How would you fight these unfavorable factors? Problem 246: To determine the number of school children who needed treatment for different diseases in New York city, 1914-1918. Method. — Examine the following table carefully. Estimate the percentage of pupils needing attention; the number having defective teeth, vision, hearing, and enlarged tonsils. Conclusion. — 1. Would any of the difficulties stated in the table interfere with studies? Name and give reason. 2. How would you improve scholarship conditions in the New York city schools? PuysicaL EXAMINATION oF ScHooL CHILDREN, 1914-1915, In New Yorx Ciry ToTaL PERCENTAGE Number of children examined . : 305,665 100 Defects found: Malnutrition . . .. : ew 16,340 Heart troubles . . . hoe 4,121 Pulmonary disease . eM Lip Leo) Dd Zz 502 Defective vision . . . ..... 25,531 Defective hearing . bi Gs ae OMS 1,870 Obstructed nasal Hreathine es bal Vind bs 29,067 Defective teeth . . . : 195,595 Enlarged tonsils . . . . : 34,378 Orthopedic defects or eare : 1,729 Nervous diseases eee ae ae 1,887 General defects . . . ee 86,667 HUNTER LAB. PROB. — 18 274, MAN’S IMPROVEMENT OF HIS ENVIRONMENT Problem 247: How to discover the presence of adenoids. Method. — A good medical authority has given the following symptoms as indicating the presence of adenoids, growths in the nose and throat which prevent a sufficient air supply from reaching the tissues of the body : 1. Inability to breathe through the nose. 2. A chronically running nose, accompanied by frequent nose- bleeds and a cough to clear the throat. 3. Stuffy speech and delayed learning to talk. ‘Common’ is pronounced ‘ cobbéd’; ‘ nose,’ ‘ doze’; and ‘ song,’ ‘ sogg.’ 4. A narrow upper jaw and irregular crowding of the teeth. 5. Deafness. 6. Nervousness. 7. Inflamed eyes. Observations. — Observe members of your own family. Conclusion. — 1. Do any of the family appear to have adenoids? What makes you believe this? 2. What ought people suffering with adenoids to do? Problem 248 : To find some ways of preventing the spread of disease. NOTE. — Remembering that disease germs must come from the bodies of those who are sick and that such germs are spread usually by means of material from the mouth, food tube, or other openings where germs could escape, our problem be- comes threefold. The three parts of the main problem are: first, the destruction of such germs as escape from the bodies of the sick; second, the prevention of such germs as escape from entering the body of well people; and third, the problem of how to make the body safe or immune from the attacks of such germs as do get into the body of a well person. a. How to kill Germs that escape from the Bodies of those who are Sick Method and Observations. — Using your Civic Biology and such other books of reference as you have access to, answer the follow- ing questions: Take some specific disease, as typhoid fever, tuberculosis, or diphtheria. From what part of the body do the disease-causing germs escape ? PROBLEM 248 275 Having determined this point, next apply what you have learned about disinfectants to the particular disease you are trying to prevent the spread of from one person to another. Remember contact with the germ is necessary in order for the well person to take the disease. In the case of tuberculosis what methods would you advocate for receiving and destroying the material from the mouth (sputum) containing the disease germs? Conclusion. — How would you destroy the disease germs in a given disease such as tuberculosis, typhoid, or diphtheria? b. How to prevent the Germs of those Sick from Reaching those in Neighboring Families who are Well. Quarantine Method and Observations. — Notice the manner in which your local board of health treats families in which infectious disease has come. NOTE. — This isolation of the patient is called quarantine. Quarantine may be done in the home or by removing the sick person to a hospital where only that particular disease is treated. Why should persons ill with a germ disease be isolated until they are well? What methods have the board of health for warn- ing strangers of the presence of the disease in a home? Why is this necessary? What should be done with heavy rugs, curtains, etc. in the room where one is ill with a germ disease? Why? How could the germs that might lodge in such hangings be killed? Suggest methods. What do we mean by disinfection? Look up your local board of health rules on disinfection and note what is used and how used. (See page 390, Civic Biology.) What should be done to the body, clothing, and hair of a person who has been ill with a germ disease before he is allowed to go among well persons again? Why is this necessary? Would a person be selfish who neglected such precautions? Give reasons. Conclusion. — 1. What is the reason for quarantine and by what should it be followed to be effective? - 2. Why is there a quarantine station at the entrance of New York harbor? Why is it of particular value there? 276 MAN’S IMPROVEMENT OF HIS ENVIRONMENT c. How to keep Germs from Entering the Body of a Well Person Method and Observations. — Notice conditions existing in crowded cities with reference to the number of flies and the relative number of screens over food exposed for sale, etc. Note the con- dition of the streets and sidewalks, locate saloons or other places where spittoons are found. Find any other places where you think germs might exist and from which they might be carried by flies or other insects. What household insects might be disease carriers? (See Civic Biology, pages 225-227.) Do you find any public drinking fountains? Any common towels? Common combs and brushes? Also inquire into the condition of your local water supply. Is it pure at the source? Does the supply come from a river? If so, are there any towns or hamlets that empty their sewage into it? What danger might come from this? Is your city doing anything to eliminate this danger? What might your city do to prevent it? What can you do to prevent disease from this source? What is the condition of your milk supply? Does your board of health do anything to protect the milk supply? If so, then what does it do? Are several grades of milk sold? Is dipped milk sold? If so, for what purposes? How can you protect yourself? What is the condition of the disposal of sewage in your city? Does the sewage reach a river near by untreated, or is the sewage treated before it escapes? Look up some book of reference in this chapter on sewage disposal, and make a report to the class on some of the methods of sewage disposal. Visit a municipal museum, if possible, and report on various methods of sewage disposal as shown in the sanitation exhibit there. Conclusion. — Write up a short composition for your notebook, showing all the public and private means that should be taken to prevent germs from entering the body of a well person. d. How to develop Immunity in the Body of a Well Person Method and Observations. — Read in your Civic Biology and other reference books as to what immunity is and how it is brought about. PROBLEM 249 277 NOTE. — Immunity is usually meant when the body develops certain substances in the blood.known as antibodies. These substances seem to give to the body the. power to resist the work of germs that enter it. Natural immunity is only possible when the bodily condition is good. Of what use to the body in this respect would be good food, rest, sleep, and moderate exercise? Take each factor separately in your discussion. What might the colorless corpuscles do to help in this gaining of immunity ?. NOTE. — Artificial immunity to certain diseases is brought about in the body by the introduction of antitoxins into the body. These substances fight the effects of the toxins formed in the body by the bacteria of certain diseases. Diphtheria is one disease so fought. See your local board of health reports for a statement of the preparation and distribution of this antitoxin. Do you know of any diseases that are fought successfully by antitoxins? (Read Civic Biology, pages 390-393.) What great names are connected with the antitoxin treatment of disease? (See Civic Biology, pages 391, 402, etc.) How are antitoxins ad- ministered? Why in this manner? Look up the subject of vaccination in Civic Biology, pages 157 and 391. Who discovered this method of treatment of disease? To what diseases is it applied? Are there any other artificial means of developing immunity in the human body? Conclusion. — Write a short composition discussing all the ways of developing immunity in the human body. General Conclusion.—1. What are the functions of the board of health in any city? 2. How may I codperate with them in their work for the com- mon welfare? 3. How may I develop immunity? Problem 249: First aid in the home. A summary of what to do and how to do it. Tue First-aip EMerGceNcy MEpIcINE CHEST Every family should have the following materials in the medicine cabinet out of reach of young children : Alcohol, small bottle. 278 MAN’S IMPROVEMENT OF HIS ENVIRONMENT Aromatic spirits of ammonia, rubber stoppered, small bottle. Carbolated vaseline, small bottle. Castor oil, large bottle. Boracic acid, one ounce. Collodion, in bottle with small brush (use for small cuts). Chlorate of potash tablets. Mustard, powdered, two ounces. Oil of cloves, small bottle (label poison). Seidlitz powders, small box. Soda mint tablets, small bottle. Spirits of camphor, small bottle. Sirup of ginger, small bottle. Sirup of ipecac, small bottle. ; Subnitrate of bismuth, five-grain tablets, small bottle. Tincture of iodine, small bottle. The following articles should also be kept, either in the case or in an emergency kit: Adhesive tape, small roll. Absorbent cotton, small package. Antiseptic gauze, small package. Clinical thermometer. Bottle of peroxide or 4 per cent carbolic solution. Knife, sharp and used for this purpose only. Scissors. Paper of pins, safety and common. Tooth plasters, small package. The above-mentioned articles ought to be sufficient to make unnecessary the presence of a doctor except in serious cases of illness. How to use the Materials in the Medicine Chest Method. — Use any good pamphlets or books on first aid. The small pamphlet known as First Aid in the Home, printed and dis- tributed free of charge by the Metropolitan Life Insurance Com- pany, may be used asa text. The uses of most, if not all, of the household remedies are there described. PROBLEM QUESTIONS 279 Try to answer the following practical questions on first aid: _ 1. What would you do to prevent bleeding from a cut from which blood issued in jets or spurts? 2. What would you do in case of convulsions? 3. How would you treat poisoning in its first stages? 4. If you knew what the substance was that a person had absorbed or taken as a poison, what would you then do? Give three or four different instances, taking common poisons in each case. 5. What would you do in a case of fainting? Drowning? 6. How would you treat a case of sunstroke? Heat exhaustion? 7. What would you do in the case of a burn? 8. How would you treat a bad sprain? 9. How would you go to work to treat a person who has fallen and fractured his arm or leg? 10. How would you treat a cut from a rusty or dirty metal instrument ? 11. How would you treat a cold? A case of indigestion? Sick headache? Summer complaint? Conclusion. — Are you prepared to meet an emergency re- quiring first aid? PROBLEM QUESTIONS 1. What home conditions do you personally have control over? How would you go about to improve them? 2. What school conditions might you control? What would you do to improve them? 3. What methods of ventilation are best for a schoolroom and why? Imlustrate with diagrams. 4. How would you ventilate your bedroom so as to insure fresh air but no draft on the bed? Use a diagram to explain your answer. 5. Why is sunlight important for every bedroom? 6. “We spend one third of our life in our bedroom. Why not have it cozy and well filled with furniture, hangings, and rugs?” Criticize this statement from the hygienic standpoint. 7. Why is a damp cloth the best means of dusting a bedroom ? 280 MAN’S IMPROVEMENT OF HIS ENVIRONMENT 8. Why, in moving into a new apartment, should the tenant insist on complete renovation? 9. What method of heating is best and why? Explain fully. 10. Give'three rules which will help prevent insect pests in an apartment. 11. Why is illuminating gas a dangerous friend at times? 12. Give three good school luncheon menus and tell why they are good. 13. In what respects is factory inspection biological ? 14. Why should foods be regularly inspected in a city? 15. How is our city milk supply safeguarded? (See your Sanitary Code.) 16. Show three ways in which a city may protect its water supply. 17. To what extent might a filter attached to a faucet be useful? Why would it not be likely to be effective against germs? 18. Why is typhoid fever considered a country rather than a city disease? 19. What is the work of the department of street cleaning? How can you help in this work? 20. What is immunity? 21. What is the theory underlying the practice of vaccination? How does this treatment differ from the antitoxin treatment for diphtheria? 22. What is the method of vaccination for typhoid? Has this method proved of value? 23. How may you codperate with the department of health in your city? REFERENCE Booxs Hunter, Civic Biology, Chap. XXIV. American Book Company. Hunter, Elements of Biology, pp. 317-428. American Book Company. Hunter, Essentials of Biology, Chap. XXIX. American Book Company. Allen, Civics and Health. Ginn and Company. Allen, The Man of Perfect Health. World’s Work, July, 1909. Andrews, The White Peril. White Peril Company, Danbury, Conn. Annual Report of Department of Health, City of New York (and other cities). A War on Consumption. Metropolitan Life Insurance Company. Banks, The Problems of Youth. Funk and Wagnalls Company. Barry, Hygiene of the Schoolroom. Silver, Burdett and Company. REFERENCE BOOKS 281 Bashore, Outlines of Practical Sanitation. John Wiley and Sons. Bell, Our Teeth, How to Take Care of Them. Young American Publishing Company. Bjorkman, What Health is Worth to Us. World’s Work, March, 1909. Bosworth, Taking Cold. C.S8. Davis, Detroit. Brown, Health in Home and Town. D.C. Heath and Company. Bryce, Laws of Life and Health. J.B. Lippincott Company. Bulletins and Publications of Committee of One Hundred on National Health. Burbank, Training of the Human Plant. Century Company. Burton-Fanning, Open Air Treatment of Pulmonary Tuberculosis. Paul B. Holber. Carrington, Directions for Living and Sleeping in the Open Air. Metropolitan Life Insurance Company. Cavanagh, Care of the Body. E. P. Dutton and Company. Chapin, Municipal Sanitation in the United States. Snow and Farnham. Chapin, Sources and Modes of Infection. John Wiley and Sons. Chappell, The House Fly — Man Killer. Pearson's Magazine, June, 1910. Clarke, Vital Economy, or How to Conserve your Strength. Wessels and Bissell Company. Coleman, The People’s Health. The Macmillan Company. Conklin, Heredity and Environment. Princeton University Press. Conn, Practical Dairy Bacteriology. Orange Judd Company. Creelman, Is Typhoid to be conquered at Last? Pearson’s Magazine, December, 1909. Curtis, Nature and Health. Henry Holt and Company. Ditmar, Home Hygiene and Prevention of Disease. Duffield and Company. Doane, Insects and Disease. Henry Holt and Company. Dock, Hygiene and Morality. G. P. Putnam’s Sons. Dorr, A Fighting Chance for the City Child. Hampton’s Magazine, July, 1910. Dorset, Some Common Disinfectants. Farmers’ Bulletin 345, U. 8S. Department of Agriculture, 1908. Dressler, School Hygiene. The Macmillan Company. Du Puy and Brewster, Our Duel with the Rat. McClure’s Magazine, May, 1910. Egbert, A Manual of Hygiene and Sanitation. The Macmillan Company. Fisher, A Department of Dollars vs. A Department of Health. McClure’s Magazine, July, 1910. Fisher, National Vitality. Senate Document No. 676, Vol. III, 60th Congress. Frankland, Bacteria in Daily Life. Longmans, Green and Company. Godfrey, The Health of the City. Houghton Mifflin Company. Goler, Teeth, Tonsils, Adenoids. Metropolitan Life Insurance Company. Grinnell, Our Army versus a Bacillus. National Geographic Magazine. Gulick, The Efficient Life. Doubleday, Page and Company. Health News. Monthly Bulletin of New York State Department of Health. Herms, Malaria — Cause and Control. The Macmillan Company. Home Care of the Sick. Library of Home Economics, Chicago. Horsley and Sturge, Alcohol and the Human Body. The Macmillan Company. Hough and Sedgwick, The Human Mechanism. Part II. Ginn and Company. Howard, The House Fly the Disease Carrier. F. A. Stokes Company. Huber, Consumption and Civilization. J. B. Lippincott Company. Hutchinson, Common Diseases. Handbook of Health. Preventable Diseases. Houghton Mifflin Company. Hutchinson, Sound Bodies for Sound Minds. Good Housekeeping, September, 1914. 282 MAN’S IMPROVEMENT OF HIS ENVIRONMENT Hutchinson, The Child’s Day. Houghton Mifflin Company. Jacobs, Fake Consumption Cures. Metropolitan Life Insurance Company. Jewett, Body and its Defenses. Ginn and Company. Lee, Scientific Features of Modern Medicine. Columbia University Press. Lewis, The Warfare against Tuberculosis. Review of Reviews, September, 1908. Lippert, F. E. & H. A., When to send for the Doctor and What to do before the Doctor Comes. J.B. Lippincott Company. Lorand, Old Age Deferred. F. A. Davis Company. Lynch, First Aid in the Home. Metropolitan Life Insurance Company. Macfie, Air and Health. Methuen and Company, London. Mason, A Plea for Wider Sanitary Science Knowledge. Science, February, 1910. Metchnikov, E., Prolongation of Life. G.P. Putnam’s Sons. Metropolitan Magazine. Metropolitan Life Insurance Company. Millard, Building and Care of the Body. The Macmillan Company. Morrison and Hilditch, Does Money Carry Disease? Literary Digest, March, 1910. Morrison, The Transmission of Disease by Money. Popular Science Monthly, January, 1910. Morrow, The Immediate Care of the Engine. W.B. Saunders. Morse, The Collection and Disposal of Municipal Waste. Municipal Journal and Engineer. Otis, The Great White Plague. T. Y. Crowell Company. Overlock, The Working People, Their Health and How to Protect It. Massachusetts Health Book Publishing Company. Overton, General Hygiene. American Book Company. Pamphlets, Nos. 4, 6, 14, 15, 21, 26, 34. Russell Sage Foundation Department of Child Hygiene. Personal Hygiene. Library of Home Economics, Chicago. Price, Handbook of Sanitation. John Wiley and Sons. Pure Milk and Human Life. Success, March, 1909. Pyle, A Manual of Personal Hygiene. W.B. Saunders. Ramaley and Giffin, Prevention and Control of Disease. F. Ramaley, Col. Rats as Pests. Farmers’ Bulletin 369, U.S. Department of Agriculture. Richards, Euthenics, the Science of Controllable Environment. Whitcomb and Bar- rows. Richards, Sanitation in Daily Live. Whitcomb and/Barrows. Richman and Wallach, Good Citizenship. American Book Company. Ritchie, Primer of Sanitation. World Book Company. Roe, The Physical Nature of the Child. (Advanced.) The Macmillan Company. Rogers, Life and Health. J. B. Lippincott Company. Rosenau, Preventive Medicine and Hygiene. D. Appleton and Company. Ross, The Reduction of Domestic Flies. John Murray, London. Sadler, The Cause and Cure of Colds. A.C. McClurg and Company. Sadler, The Science of Living, or the Art of Keeping Well. A.C. McClurg and Com- pany. Sanitary Drinking Cups. Bulletin, Kansas Board of Health, No. 3, 1909. School Hygiene. American School Hygiene Association. Seymore, Better Stock Miracle. Country Life, January, 1914. Sharpe, Laboratory Manual in Biology, pp. 320-334. American Book Company. Shaw, School Hygiene. The Macmillan Company. REFERENCE BOOKS 283 Smallpox and its Prevention. Metropolitan Life Insurance Company. Terman, The Teacher's Health. Houghton Miffin Company. The Child. Metropolitan Life Insurance Company. Thomas, Ventilation, Heating, and Management of Churches and Public Buildings. Longmans, Green and Company. Tolman, Hygiene for the Worker. American Book Company. Typhoid Fever and How to Prevent it. Metropolitan Life Insurance Company. Veiller, Housing Reform: a Handbook for Practical Use in American Cities. Chari- ties Publishing Company. White, The Occupation and Exercise Cure. Outlook, March, 1910. Winslow, The Health of the Worker. Metropolitan Life Insurance Company. Woodworth, The Care of the Body. The Macmillan Company. Zinsser, Infection and Resistance. 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