The teacher not only has a responsibility for teaching but for the most efficient teaching at a minimum cost in time and energy to the pupil. The immediate and ultimate uses of collected materials should be the most important criteria as to kind and amount. When the pupils have an opportunity to choose illustrations which show good application of art they are not only developing their powers of discrimination but are revealing the degree to which these powers have been developed. Some practices in judgment are valuable and probably sufficient in themselves. For instance, when a pupil selects two or three good examples of rhythmic movement in design she will have developed a finer feeling for rhythm and will have demonstrated her recognition of it. Of what value would it be for her to make a permanent record of these illustrations? There are other selections that may be of more permanent value, such as pictures chosen to illustrate some art application. When these are mounted or framed attractively they make desirable additions to the girl's room and home. Illustrations suggestive of new and interesting ways of applying trimming, or of arrangements for dressing table covers, window draperies, and similar materials are also of more permanent value. They may serve the immediate purpose of illustration in the art class and then be made available for later use if they are filed in some way. One of the most satisfactory means of keeping such materials is in large envelopes or portfolios. These may be provided at small expenditure of time and money by using heavy wrapping or construction paper. The latter may be made very simply by cutting and folding the paper to form a double-pocket envelope. Rather than encourage the notebook type of collection of magazine illustrations and samples of materials, the teacher may interest the girls and women in selecting simple articles that may be used in their own homes and will give lasting enjoyment. If a notebook or portfolio is to be used for keeping certain records for later reference, the requirements for it should be limited to those which are easily attainable by all members of the class. However, this does not suggest a restriction of the efforts of the especially-talented pupil. Each page of the simplest notebook offers opportunity for the application of art principles in the planning of good margins, as well as in making attractive groupings of illustrations on mounted and written pages. It would seem desirable to discourage the elaborately decorated type of notebook covers because they consume considerable time for making and have such a temporary use. Portfolios well constructed and of lasting quality may be used later for keeping choice, unmounted pictures, or photographs. THE PLACE OF LABORATORY PROBLEMS The "laboratory problem" is a term quite generally used to designate a problem which is carried on within the classroom and involves some pupil activity.