Notes should be made of any observations which cannot be represented in the drawings; for example, on the behavior of the living animals. All notes referring to matters of life-history should be dated.
Field-observations and notes.—Scattered through this book will be found numerous suggestions for student field-work, for the observation of the life-history and habits and conditions of animals in nature. As explained in the Preface, the initiation and direction of such work must be left to the teacher. But its importance both because of its instructiveness and its interest is great. Pupils should not only be incited to make individual observations whenever and wherever they can, but the teacher should make little field-excursions with the class or with parts of it at various times, to ponds or streams or woods, and "show things" to all. The life-history and feeding-habits of insects, the web-making of spiders, the flight, songs, nesting, and care of young of birds, the haunts of fishes, the development of frogs, toads, and salamanders, the home-building and feeding-habits of squirrels, mice, and other familiar mammals are all (as has been called attention to at proper places in the book) specially fit subjects for field-observation.
Each pupil should keep a field note-book, recording from day to day, under exact date, any observations he may make. Let the most trivial things be noted; when referred to later in connection with other notes they may not seem so trivial. The field note-book should be smaller than the laboratory note- and drawing-book, small enough to be carried in the pocket. Notes should be made on the spot of observation; do not wait to get home. Sketches, even rough ones, may be advantageously put into the book. Students with photographic cameras can do some very interesting and valuable field-work in making photographs of animals, their nests and favorite haunts. Such photographic work is very effectively used now in the illustration of books about animals and plants (see the reproductions of photographs in this book). If the class is making a collection the collecting notes or data made in the field-books of the different pupil collectors should all be transferred to a common "Notes on Collections" book kept by the whole class.
[APPENDIX II]
LABORATORY EQUIPMENT AND METHODS
Equipment of laboratory.—The equipment of the laboratory or classroom will, of necessity, depend upon the opportunities afforded the teacher by the school officers to provide such facilities as instruments, books, and charts. If dissections are to be seriously and properly made, however, some equipment is indispensable. Flat-topped tables, not over 30 inches high, a few compound microscopes (one is much better than none), as many simple lenses, or, far better, simple dissecting-microscopes, as there are students, dissecting-dishes, a pair of bone-clippers, one injecting-syringe, a bunch of bristles, water, a few simple reagents and some inexpensive glassware, as slides, cover-glasses, watch-crystals, and fruit- or battery-jars for live cages and aquaria, make up a sufficient equipment for good work. Much can be done with less, and perhaps a little more with some additional facilities.
The dissecting-pans should be of galvanized iron or tin, oblong, about 6 × 8 inches by 2 inches deep, with slightly flaring sides. If an iron wire be run around the margin, and the margin bent back over it, it will strengthen the dish, and make a broader and smoother edge for the hands to rest on. Diagonally across the dish, about one-fourth inch from the bottom, should run a thick wire. A layer of paraffin one-half inch thick should cover the bottom. It should be poured in melted, when the diagonal wire will be imbedded in it and will hold it in place. Acids must not be put into the pan.
The reagents necessary are alcohol of 95 per cent and 85 per cent, and formalin of 4 per cent (the formaldehyde sold by druggists is 40 per cent and should be diluted ten times with water), these for preserving material for dissection; chloroform for killing specimens; glycerin for making temporary microscopic mounts, and 20 per cent nitric acid for preparing specimens for study of the nervous system. In addition there will be needed the few other materials mentioned in the following paragraphs as necessary in the preparation of injecting-fluids, the staining of fresh tissue and preserving by special methods.