A certain broadening of scope of the practical customary among us for students in animal physiology has become desirable, and has seemed so for some time past in the opinion of not a few. A number of facts fundamentals to physiology cab be seen by the student very readily and appropriately in the frog. But other facts there are, of great value and interest especially to the future practitioner of medicine, which can be better displayed and more easily obtained in the mammalian preparation. Although that preparation as available for a class-student is merely a carcase, the circulatory activity which it retains for the time being, and the temporary survival of many of its glandular and muscular tissues and of its simpler nervous structures, render obtainable from it under suitable precautions a number of reactions which can be studied with extreme advantage by the student for himself. The exercises detailed in the following pages consist of experiments of that kind. Several of them are repetitions, simplified in accordance with the limits of the preparation and of the student's experience, of famous observations which in the hands of the masters who first made them marked distinct advances in natural knowledge. The particular experiments chosen are of course not the only ones which might have been selected. In such a choice each teacher will to some extent have his own predilections. The mammalian preparation decapitate or decerebrate is capable of serving many uses for practical class-instruction. The particular experiments included here are, however, all such as experience actually proves the student to be well able, with ordinary care on his part and some supervision on the part of his teacher, to accomplish successfully for himself.
