Principles and practice of poultry culture

Front matter

Historic, archived document

Do not assume content reflects current scientific knowledge, policies, or practices.

j

Preface

The method of treatment adopted in this book is the simple, scientific metliod, — that of presenting essential facts in logical order. The following of this method has led to some departures from the conventional way of presenting poultry topics. The unity of the poultry group is here conceived as essential and arising from the nature of the birds, rather than as artificial and relating to the purposes for which they are used ; and I have tried to give practical effect to my very strong conviction that permanent poultry culture must be a feature in permanent agriculture, and that each of the 7i common kinds of poultry has its peculiar place in agriculture. J) Hence the methods of managing the different kinds of poultry are _ not stated separately, as has been usual, but topics are discussed in their own appropriate order with reference to all the kinds. This ^ arrangement emphasizes the things which apply a4ike to all kinds ^ of poultry, and makes it easy to show that good practice is simple and that the same treatment will usually answer, in whole or in part, for several different kinds, thus lightening the work of the poultry keeper. It is believed also that by this arrangement of matter the student or reader is given, with instruction in the details of methods, a more coinprehensive view of the subject as a whole than by the usual mode of presenting it.

To the best of ni)- ability the book gives the consensus of authoritative opinion of a many-sided subject. In apjiraising this consensus I have had regard alike to practical authority, expressed in the views and practice of good poultrymen, and to scientific authority, found in the bulletins and other papers of those instructors and investigators who have been foremost in reducing to order the confused mass of common knowledge of poultry culture. To the practical poultrymen and fanciers I am most indebted for facts ; to the instructors and investigators, for interpretations of facts and for

vii

Vlll ideas and suggestions as to the presentation of the subject in such a way as to meet the requirements of formal instruction.

To give credit, in the proper connection, to each of the many whose experiences and opinions have contributed something to a work which represents a Ufe interest in poultry and more than a score of years of intimate business and professional acquaintance with poultry culture would be impossible. So it has seemed best to make few direct references in the text, but to give in the appendix a classified list of the literature of the subject.

The illustrations not credited to others are by the author. Although many of the photographs and drawings were made for this book, the elaborate scheme of illustration adopted was practi-. cable only because I already had a large private collection of photographs from which to select, and because I had access to the files of photographs which had been used in Farm-Poultry. Those from the latter source the publishers have kindly allowed me to use, with this general acknowledgment.

JOHN H. ROBINSON

Reading, Massachusetts

Introduction

Need of instruction — Scope of instruction, i — Limits of instruction, 2 — Conditions of student practice, 3 — Collateral reading — Technical terms and definitions, 4

Part I The Poultry Industry

CHAPTER

I. Nature and Uses of Poultry

Classes of domestic birds — Kinds of poultry — Common characters of poultry, 5 — The elementary poultry character, 7 — Values of poultry, 8 — Properties of eggs, 10 — Services of poultry in agriculture — Recreation in poultry culture, 11

n. Evolution of the Poultry Industry

Antiquity of poultry culture — Pre-modern poultry culture, 12 — Persistence of primitive conditions explained — Quality of common poultry, 13 — Improved native stocks — Interest in distinctive types, 14 — First effects of acquaintance with improved breeds, 15 — Development of the American type, 16 — Artificial incubation, 17 — Exhibitions — Poultry literature of the early period, 18 — Modern poultry literature — Journalism, 19 — Books, 20 — Instruction and investigation, 2 1 — Individual influence, 22 — Trade spirit, 23

III. Economic Aspects of Poultry Culture

First statistics of poultry, 24 — Present value of poultry products in the United States, 25 — The poultry industry, 26 — Trend of development — Natural division of the poultry industry — Limitations on development, 27 — Permanent poultry culture a branch of agriculture, 28 — Poultry culture a necessary feature in agriculture, 29 — Poultry culture a diversified industry — -Branches of poultry culture, 30 — Egg farming, 32 — Factory methods in poultry culture, 33 — Farm methods, 35 — The Petaluma district, 40 — Broiler farming, 43 — Roaster growing, 45 — Duck growing, 48 — Goose growing, 54 — Turkey growing, 58 — Other kinds of poultry — P'ancy poultry, 59 — Profitable combinations in poultry culture, 61 — Combinations with poultry — Supply and demand, 62 ix

X

Part II Production

CHAPTER

PAGE

IV.

The Poultry Keeper's Problems

Common tasks — Hard problems, 64 — Relation of natural conditions to poultry problems — Differences between practical and theoretical problems, 66 — The beginner's most difficult problem, 67

V. Poultry Types and their Relations to Objects,

Conditions, and Methods of Poultry Keeping . 69

Type defined — Type and breed, 6g — Breed type — Breed divisions— Breed relations — Economic classification of fowls, 70 — Class properties, 71 — Necessary differences in conditions and methods, 72

VL Problems of Location 74

Phases of the question of location — Climate, 74 — Special features — Soils and drainage, 76 — Sunlight — Ventilation — Markets, 77 — Transportation, 78

VIL Systems of Poultry Keeping 79

Definitions — General methods — Essence of system, 79 — Ordinary farm methods — Extensive systems, 80 — The Rhode Island colony system, 8i — Ordinary town methods, 84 — Intensive systems, 85 — Comparison of extensive and intensive systems, 87 — Combining advantages of the two systems. 91 — Temporary range — Weakest point in intensive systems, 94

Vin. Yards and Fences 95

Prime considerations in shelters, 103 — Principal requirements for comfort — Earliest form of poultry shelter — Simplest shelter made for poultry, 104 — Poultry in owner's dwelling — Tight houses, 108 — Ventilation in tight houses — Beginning of the fresh-air movement, 112 — Houses with open fronts — No best house, 114 — Floor dimensions, 116 — Height of structures —

Yards a necessary evil. 95 — Height of fence, 96 — Area of yard, 97 — Alternating yards — Fence material, 98 — Openings in fences, 100

IX.

CONTENTS xi

Depth of structures. iiS — Standard-size poultry-house unit — Length of pouhry houses, 119 — Styles of roof, 121 — Walls — Floors, 125 — Eccentric features to be avoided — Materials for poultry structures, 126 — Quality of construction, 127 — Preser\'ation of structures — Structures for different kinds of poultry, 129 — Ancient and modern coops, 131 — Coops for indoor brooders and growing chicks, 132 — Small houses, stationary and portable, 134 — Colony poultry houses, 136 — Cloth-front houses, 137 — Late styles of poultry houses, 141 — Long poultry houses, 145 — Stages in construction of a long poultry house, 148 — Fattening and killing houses — Brooder houses, 149 — Cockerel house, 153 — Poultry houses on hillsides, 154

X. Poultry-House Fittings 155

Roosts, 156 — Droppings boards, 158 — Roosting closets, 159 — Nests, 160 — Feed troughs, 163 — Feed hoppers, 165 — Drinking vessels — Drinking fountains, 166 — Dusting boxes — Common tools, 167 — Cooking apparatus — Food mixers, 168 — lione cutters — Hay cutters — Root cutters, 1 69 — Carts for poultry work, 170 — Egg testers — Nest eggs — Transportation on the poultry plant, 171

XI. Nutrition of Poultry 172

Nutritive requirements — Nutritive organs, 172 — Differences in beaks and crops — Natural foods and feeding habits of poultry, 175 — Common poultry foods — Composition of foods, 178 — Nutrient ratio, 180 — Expression of nutritive values, 181

XII. Poultry Foods 183

Wheat, 183 — Wheat screenings — Low-grade flour — Middlings, 184 — Bran — Stale Bread — Corn, 185 — Corn meal, 186 — Corn bran and corn middlings — Corn and cob meal — Hominy meal

— Gluten meal and gluten feed — Whole oats, 187 — Oatmeal

— Oat bran and oat feed — Oat middlings — Sprouted oats — Barley, iSS — Barley screenings — Barley meal — Malt sprouts. Dried brewer's grains — Rye, 189 — Mixed mill feeds, 190 — Buckwheat — Buckwheat by-products — Rice, 191 — Sorghum seed — Broom-corn seed — Flaxseed and cotton seed, 192 — Ground linseed — Linseed meal — Cottonseed by-products, 193 Peas and beans — Miscellaneous seeds, 194 — Green foods, 195

— Ensilage — Clovers and alfalfa, 196 — Clover meal and alfalfa meal — Potatoes, 197 — Beets — Turnips — Onions, 198 — Apples

— Green bones — Meat by-products, 199 — Fresh fish, 200 — Fish scrap — Shellfish — Milk, 201 — Cheese — Milk albumin — Eggs, 202 — Mineral foods, 203 — Dry bone — Oyster shells, 204

— Charcoal, 205

Xll

CHAPTER

PAGE

XIII. Rations and Methods of Feeding

A ration defined — A balanced ration, 206 — A balanced ration an average ration, 207 — Common practice in feeding — How methods of feeding are determined, 208 — Rations for special purposes, 210 — Different rations for different kinds of poultry, 211 — Same ration for young and old poultry of the same kind

— Forcing rations, 212 — Special preparation of food — Mashes, 214 — • Standard mashes, 217 — Popular standard mashes approximately balanced rations — Errors in use of wet mashes — Dry mashes, 218 — Dangers in use of dry mashes, 220 — Rations for fowls, 221 — Maine Experiment Station rations, 224 — Ontario Experiment Station rations, 228 — West Virginia Experiment Station ration — Kansas Experiment Station rations, 229 — Cornell Experiment Station rations, 230 — Rations for turkeys, peafowls, guineas, and pheasants, 233 — Rations for ducks, 235

— Rations for geese, 237

Relation of incubation to other operations — The egg, 238 — A fertile egg, 239 — Function of heat in incubation, 240 — Antiquity of artificial methods — The problem in artificial incubation, 241

— Value of both methods of incubation — Hatching by natural methods — Broodiness, 242 — System in natural incubation, 243

— Nests for sitting hens, 244 — Nest material — Selection of eggs, 245 — Number of eggs in setting — Keeping hens confined to nests, 246 — Food of the sitting hen — Cleanliness — Testing eggs, 248 — Period of incubation — Effects of chilling on eggs, 250 — Treatment of eggs at hatching time, 251 — Helping birds out of the shell — Conditions of good hatching, 252 — Hatching by artificial methods — Responsibility of the operator, 253 — Selection of an incubator, 254 — Manufacturers' directions for operating incubators, 255 — Selection of eggs for artificial incubation, 257 — Preliminary regulation of heat — Routine work of operation, 258 — Factors in artificial incubation, 259 — Source of moisture in incubation — Use of ventilation, 260 — Measuring ventilation, 262 — Management of incubator at hatching — Accounting for results, 263 — Causes of poor hatches, 264 — Common errors in operating incubators, 265

XV. Growing Poultry 266

Growth a natural process — Constitution inherited — Initial selection, 266 — Preservation of vitality in young poultry, 267 — Overcrowding the great cause of trouble in growing poultry, 268 — What constitutes overcrowding, 269 — Overcrowding mostly unnecessary, 274 — Warmth the first requirement — Brooding temperatures, 275 — Regulation of heat in artificial brooding, 276 — Methods of artificial brooding, 277 — Lampheated brooders — Pipe brooder systems, 278 — Temperature

XIV. Incubation

COxNTENTS xiii

CHAI'TER PAGE

in artificial brooding — Regulation of temperature in brooders, 280 — Period of artificial brooding — Protection from enemies, 282 — Protection from parasites, 283 — Growth the test of the work of the grower — Rate of growth, 284 — Separation of sexes while growing — Separation according to age and size, 2S7 — Disturbances to be avoided, 288

XVI. EtiG Production 289

Egg production distinguished from reproduction — Reproductive organs of the female, 289 — Laying normally follows completion of growth, 290 — Causes of retarded laying, 291 — Conditions of egg production, 293 — Duration of laying periods, 297 — Molting and egg production — Variability of egg yields, 298 — Selection of stock for laying, 299 — Effect of age on production, 300

XVII. Finishing Poultry for the Table 301

Fattening a finishing process — Common practice, 301 — Simple methods of fattening, 302 — Causes of failure in finishing by ordinary methods, 305 — Special fattening plants using ordinary methods, 306 — Special finishing methods — Crate feeding, 307 — Cramming, 308 — Caponizing, 309

XVIII. Preparation of Poultry Products for Market . 311

Dressed poultry — Fasting — Killing, 311 — Wringing the neck — Cutting off the head, 312 — Sticking, 313 — Scalding, 314 — Dry picking, 316 — Scalding and dry picking compared — Market requirements as to picking, 31S — Importance of proper cooling, 319 — Shaping — Grading, 320 — Packing, 321 — Standard sizes of boxes, 322 — Feathers — Shipping live poultry — Sorting and grading, 324 — Eggs — Cleaning eggs, 325 — Sorting eggs for color — Grading eggs for size, 326 — Egg cases and boxes, 327

XIX. Marketing Poultry Products 329

Poultry keepers and middlemen, 329 — Collection and distribution of poultry products — Eggs, 330 — Live poultry — Dressed poultry — Relative advantages of selling poultry alive and dressed, 333 — Feathers, 334 — Manure — Cooperative selling of poultry products, 335

XX. Prevention and Treatment of Disease and Vice . 337

Hygiene and sanitation, 337 — Causes of disease — Constitutional causes of disease — Dietetic causes of disease, 338 — Environmental causes of disease — Contagious diseases — .Symptoms of disease, 339 — Special symptoms plain to ordinary observation — General treatment of disease, 340 — Injuries — Internal parasites, 341 — External parasites — Vices, 342

XIV

Part III Reproduction

CHAPTER PAGE

XXI. Types, Breeds, and Varieties of Fowls . . . . 344

Original type of the domestic fowl, 344 — Types of domestic fowls, 346 — Game types, 347 — Aseel, 348 — English Game, 349

— Cornish Indian, 350 — Malay, 351 — Laying types, 352 — Laying breeds, 353 — Mediterranean laying types, 3 54 — Italian stocks, 355 — Spanish section of Mediterranean class, 362 — Other races of the Mediterranean type, 367 — Mid-European laying types, 36S

— Primitive crested types, 375 — European meat types, 376 — English meat types, 377 — French and Belgian meat types, 380

— The Asiatic meat type, 384 — Divisions of the Asiatic meat type, 387 — General-purpose types, 394 — Earliest American types, 397 — Origin of the Barred Plymouth Rock, 398 — The Wyandottes, 406 — Rhode Island Reds, 413 — The Orpingtons, 416 — Continental European general-purpose types, 423 — Deformed types, 424 — Bantams, 425

XXIL Turkeys, Peafowls, Guineas, and Pheasants . . 429 Turkeys, 429 — Peafowls, 436 — Guineas — Pheasants, 437

XXIIL Types and Breeds of Ducks 438

The common wild duck, 438 — Common domestic ducks — Improved races of ducks — Meat types, 439 — Laying-type ducks, 447 — Common ornamental ducks, 44S

XXIV. Geese and Swans

Economic races of geese — Common geese, 449 — Improved breeds of geese, 451 — Asiatic types of geese, 453 — The American Wild Goose, 457 — Ornamental geese — Swans, 458

XXV. Phenomena and Principles of Breedino .... 459

Kinds of reproduction — Likeness in asexual reproduction — Relations of body and germ, 459 — Beginning of variation — The function of sex, 461 — Likeness in sexual reproduction, 462 — Relation of sex to inheritance, 463 — Prepotency, 464 — Prepotency and selection — Transmission of prepotency, 466 — Present and latent characters — Alternate inheritance, reversion, and atavism, 467 — Laws of heredity — Galton's law, 468 — Mendel's law, 469 — Correlation of characters, 471

CONTENTS

XV

XX\T. Ari'LiCATioN OF Principles of Poultry Breeding 475

Adaptability of poultry breeding — Length of life and breeding value, 476 — Relative value of male and female, 477 — Selection, 478 — Poultry standards, 479 — Relative value of characters in selection, 480 — Systems of selection, 481 — Essential characters — Substantial characters, 482 — Superficial characters, 483 — Collective selection and compensation in breeding, 484 — Inbreeding and line breeding — Close breeding, 4S5 — The rule of good practice, 486 — I )anger of new blood — Age and breeding'quality, 487 — Ratio of females to males, 488 — Period of fertility, 4S9 — Regulation of sex, 490 — Mating systems — Details of matings, 491 — Mating for egg production, 492 — Mating for table poultry, 495 — Selection for shape in mating Standard poultry, 504 — Color matings of poultry, 507

PART lY

THK I'OLILTKV FANCY

XXVir. Poultry ExniiuTiONS 535

Primary poultry exhibitions, 535 — Modern poultry exhibitions, 536 — Educational aspects of exhibitions, 537 — Nature of competition, 538 — Financing a show, 539 — Management of a show, 540 — Quality of exhibits — Judges, 541 — Methods of judging — Classification, 542 — Sweepstakes prizes — Special exhibits, 548 — Balancing exhibits — Practical exhibits, 549 — Suggestions for improving shows, 550 — Institutes at poultry shows, 552 — College poultry exhibitions, 553

XXVIII. Fitting and exhibiting Poultry

Selecting for exhibition, 554- — Conditioning, 555 — Grooming and faking, 557 — Ethics of conditioning — Details of artificial fitting, 560 — Shipment to shows, 563 — Care of birds at shows — Returning birds from shows, 564

XXIX. Judging 566

Judging defined — Objects of judging, 566 — Methods of judging, 567 — Factors in score-card judging, 568 — Limitations of the score card, 569 — L'se of score cards, 57 1 — Uniformity in judging

— Recognition of utility values in judging exhibition poultry

— Judging poultry products, 574 xvi

CHAPTER

XXX. The Trade in Pure-Bred Poultry and Eggs

Composite character of the trade, 576 — Values in pure-bred poultry and eggs, 577 — Profits from fancy poultry — Peculiarities of the trade, 578 — Confidence the basis of trade, 579 — Advertising, 580 — Correspondence — Terms and obligation, 581 — Scales of prices, 583 — Packing and shipping, 585

INTRODUCTION

Need of instruction. The practice of poultry culture is an art or a craft or a combination of art and craft according to the purpose for which it is pursued and the taste and skill of those engaged in it. A workman may attain great proficiency in many operations mcrel)- through skill in imitation. Such a workman, however, must work always after a model or under the direction of one familiar with all phases of his art or craft and thoroughly understanding its principles. In any enterprise engaging large numbers of people, only a small proportion of these need be qualified to oversee and direct the work ; but as the number of person."} engaged diminishes, the proportion understanding the proces.ses involved and their relations must increase, until, in such occupations as farming and housekeeping, each husbandman and housewife must be able to do and to direct the doing of a variety of operations, adapting and adjusting all to the general result sought.

The relation of this fact to agricultural and technical education has not been sufficiently emphasized. Considering it here only in its application to poultry culture, it is plain that a general knowledge of the subject is as necessary and as useful to one whose plans contemplate perhaps the maintenance of a flock of a few hundred fowls on the farm as to one who intends to undertake operations on a large scale. Both require the same preparation, as far as prejxiration can be given by book and class instruction.

Scope of instruction. The subject includes a great variety of topics. An accurate general knowledge of the subject requires such familiarity with all these topics that the relations of the various phenomena of poultry culture will be promptly recognized and effects estimated with approximate correctness whenever there

XIV

PART III

REPRODUCTION

CHAPTER PAGE

XXL Types, Breeds, and Varieties of Fowls .... 344

Original type of the domestic fowl, 344 — Types of domestic fowls, 346 — Game types, 347 — Aseel, 348 — English Game, 349

— Cornish Indian, 350 — Malay, 351 — Laying types, 352 — Laying breeds, 353 — Mediterranean laying types, 3 54 — Italian stocks, 355 — Spanish section of Mediterranean class, 362 — Other races of the Mediterranean type, 367 — Mid-European laying types, 36S

— Primitive crested types, 375 — European meat types, 376 — English meat types, 377 — French and Belgian meat types, 380 — -The Asiatic meat type, 384 — Divisions of the Asiatic meat type, 387 — General-purpose types, 394 — Earliest American types, 397 — Origin of the Barred Plymouth Rock, 398 — The Wyandottes, 406 — Rhode Island Reds, 413 — The Orpingtons, 416 — Continental European general-purpose types, 423 — Deformed types, 424 — Bantams, 425

XXIL Turkeys, Peafowls, Guineas, and Pheasants . . 429 Turkeys, 429 — Peafowls, 436 — Guineas — Pheasants, 437

XXIII. Types and Breeds of Ducks 438

The common wild duck, 438 — Common domestic ducks — Improved races of ducks — Meat types, 439 — Laying-t3'pe ducks. 447 — Common ornamental ducks, 448

XXIV. Geese and Swans 449

Economic races of geese — Common geese, 449- — Improved breeds of geese, 451 — Asiatic types of geese, 453 — The American Wild Goose, 457 — Ornamental geese — Swans, 458

XXV. Phenomena and Principles of Breeding .... 459

Kinds of reproduction — Likeness in asexual reproduction — Relations of body and germ, 459 — Beginning of variation — The function of sex, 461 — Likeness in sexual reproduction, 462 — Relation of sex to inheritance, 463 — Prepotency, 464 — Prepotency and selection — Transmission of prepotency, 466 — Present and latent characters — Alternate inheritance, reversion, and atavism, 467 — Laws of heredity — Galton's law, 468 — Mendel's law, 469 — Correlation of characters, 471

CONTENTS

XV

XX\'I. AlM'LICATION OK PRINCIPLES OF POULTRY BREEDING 475

Adaptability of poultry breeding — -Length of life and breeding value, 476 — Relative value of male and female, 477 — Selection, 47S — Poultry standards, 479 — Relative value of characters in selection, 4S0 — Systems of selection, 481 — Essential characters — Substantial characters, 482 — Superficial characters, 483 — Collective selection and compensation in breeding, 484 — Inbreeding and line breeding — Close breeding, 4S5 — The rule of good practice, 486 — Danger of new blood — Age and breeding'quality, 487 — Ratio of females to males, 488 — Period of fertility, 489 — Regulation of sex, 490 — Mating systems — Details of matings, 491 — Mating for egg production, 492 — Mating for table poultry, 495 — Selection for shape in mating Standard poultry, 504 — Color matings of poultry, 507

Part IV The Poultry Fancy

XXVIL Poultry • ExHiiiiTiONS 535

Primary poultry exhibitions, 535 — Modern poultry exhibitions, 536 — Educational aspects of exhibitions, 537 — Nature of competition, 538 — Financing a show, 539 — Management of a show, 540 — Quality of exhibits — Judges, 541 — Methods of judging — Classification, 542' — Sweepstakes prizes — Special exhibits, 548 — Balancing exhibits — Practical exhibits, 549 — Suggestions for improving shows, 550 — Institutes at poultry shows, 552 — College poultry exhibitions, 553

XXVI IL Ftttinc; and exhikiting Poultry

Selecting for exhibition, 554 — Conditioning, 555 — Grooming and faking, 557 — Ethics of conditioning — Details of artificial fitting, 560 — Shipment to shows, 563 — Care of birds at shows — Returning birds from shows, 564

XXIX. Judging 566

Judging defined — Objects of judging, 566 — Methods of judging, 567 — Factors in score-card judging, 568 — Limitations of the score card, 569 — I'se of score cards, 57 1 — Uniformity in judging

— Recognition of utility values in judging exhibition poultry

— Judging poultry products, 574

XVI

XXX. The Trade in Pure- Bred Poultry and Eggs . . 576

Composite character of the trade, 576 — Values in pure-bred poultry and eggs, 577 — Profits from fancy poultry — Peculiarities of the trade, 578 — Confidence the basis of trade, 579 — Advertising, 580 — Correspondence — Terms and obligation, 581 — Scales of prices, 583 — Packing and shipping, 585

INTRODUCTION

Need of instruction. The practice of poultry culture is an art or a craft or a combination of art and craft according to the purpose for which it is ])ursucd and the taste and skill of those engaged in it. A workman may attain great proficiency in many operations merely through skill in imitiition. Such a workman, however, must work always after a model or under the direction of one familiar with all phases of his art or craft and thoroughly understanding its principles. In any enterprise engaging large numbers of people, only a small proportion of these need be qualified to oversee and direct the work ; but as the number of person!; engaged diminishes, the proportion understanding the processes involved and their relations must increase, until, in such occupations as farming and housekeeping, each husbandman and housewife must be able to do and to direct the doing of a variety of operations, adapting and adjusting all to the general result sought.

The relation of this fact to agricultural and technical education has not been sufficiently emphasized. Considering it here only in its application to poultry culture, it is plain that a general knowledge of the subject is as necessary and as useful to one whose plans contemplate perhaps the maintenance of a flock of a few hundred fowls on the farm as to one who intends to undertake operations on a large scale. Both require the same preparation, as far as preparation can be given by book and class instruction.

Scope of instruction. The subject includes a great variety of topics. An accurate general knowledge of the subject requires such familiarity with all these topics that the relations of the various phenomena of poultry culture will be prompdy recognized and effects estimated with approximate correctness whenever there is occasion to consider tliem. It is from inability to do this that poultry keepers who have become proficient in a special line carried on under particular conditions so often make serious mistakes when conditions change or when they make departures from methods with which they are familiar. As it is not possible for a student during the period of a course of instruction, or even in some years of practice, to acquire such acquaintance with all phases of the subject empirically, a textbook must so present the subject that historical fact and description and discussion of materials and methods will, as far as possible, compensate for lack of experience. Thus a textbook must especially emphasize many things that do not strongly appeal to the novice most interested in what he can immediately put into practice.

The limits of instruction. The quantity of theory of this subject which one may assimilate and the rate at which principles may be mastered vary with the nature of the matter as well as with the preparation and capacity of the student.

Thus a thorough knowledge of the principles of poultry-house construction may be acquired from books alone in a comparatively short time, and with knowledge so acquired a person with a little skill in carpentry may design and build a house in ever)' respect as good as any experienced poultryman would make, provided always that the principles are understood and correctly applied. But in feeding, a working knowledge of principles is rarely, if ever, acquired without practice. Practice in feeding sufficient to assist to a good understanding of principles can be had in a few months or even in a few weeks. In such matters as breeding, real practice cannot be given in connection with courses of instruction. Longcourse students who are familiar with the general principles of breeding and their application to domestic animals should have no difficulty in understanding their applications to poultry. The shortcourse student who lacks this preparation, and who has had no experience in breeding, gets at best but a limited appreciation of principles from the condensed statement of them appropriate in a general treatise on poultry. The student at home is even more heavily handicapped. As a rule such an understanding of the principles of breeding as every breeder should have is only acquired after thorough study and long practice.

INTRODUCTION

The three cases mentioned are representative of classes of topics in which book instruction alone, even when insufficient, may be of considerable value without practice. The practice of poultry culture includes also many operations (as killing and dressing poultry, caponizing, etc.) difficult to describe in words even when descriptions are supplemented with illustrations. Actual skill in these is not, however, essential to a general knowledge of the subject.

Conditions of student practice. In an agricultural college or school, students are given practice under the supervision of an instructor. As a rule the amount of actual practice by each student is no more (often less) than he would have at home with a small flock ; but each student may observe the practice of other students and benefit by the instructor's suggestions to all. Students at these institutions have the further advantage of observation of the work at the permanent plant of the department, conducted usually by a skillful manager assisted by advanced students. As it is not generally feasible to make practice correspond chronologically with the work in the classroom, much of it is at first done by direction, just as it would be on a poultry plant where formal instruction was not given.