Somewhere in the course of preparation the teacher must have obtained a thorough knowledge of laboratory apparatus and supplies. The selection of types of apparatus best fitted to the course, and the knowledge of where to buy are both necessary. Also judgement must be exercised in purchase for few are the places where funds are adequate for the ideal equipment of a laboratory. The money value of every piece of apparatus must be balanced against its relative usefulness in the successful culmination of the course. Besides this there must be a knowledge of the various uses to which the available apparatus may be put. A great deal depends on the ingenuity of the teacher in the adaptation of even comparatively simple apparatus. In connection with the laboratory part (and this should be the major part) of the course, there arises the question of field work and excursions. Laboratory is at best merely a substitute for the great out-of-doors, so the more work that can be done in the field the better. Aside from exploration to discover what parts of the particular locality will yield the largest fund of valuable biological information, the problem here is mainly one of method. The teacher to be at his best must be somewhat of a naturalist. Upon his fund of interesting stories about the animals and plants that the children all know, will depend very largely the appeal of the work to the pupil. Something of the spirit that distinguished John Muir as the great naturalist is an inestimable asset to the teacher. If it is not among his natal blessings, he need not be completely discouraged for it can be acquired to some degree at least. Besides the advantage just mentioned, the fauna and flora must be sufficiently well known so that _choice_ is possible for laboratory experiment and illustrative purposes.