The question nevertheless confronts society,--and in such shape, too, that society cannot escape, even if it would, the responsibility of a decision. Either by action or inaction the State must decide whether the practice of vivisection shall be wholly abolished, as desired by some; whether it shall be restricted by law within certain limits and for certain definite objects, as in Great Britain; or whether we are to continue in this country to follow the example of France and Germany, in permitting the practice of physiological experimentation to any extent devised or desired by the experimentalist himself. Any information tending to indicate which of these courses is best cannot be inopportune. Having witnessed experiments by some of the most distinguished European physiologists, such as Claude Bernard (the successor of Magendie), Milne-Edwards and Brown-Sequard; and, still better (or worse, as the reader may think), having performed some experiments in this direction for purposes of investigation and for the instruction of others, the present writer believes himself justified in holding and stating a pronounced opinion on this subject, even if it be to some extent, opposed to the one prevailing in the profession. Suppose, therefore, we review briefly the arguments to be adduced both in favor of the practice and against it. Two principal arguments may be advanced in its favor. I. It is undeniable that to the practice of vivisection we are indebted for very much of our present knowledge of physiology. This is the fortress of the advocates of vivisection, and a certain refuge when other arguments are of no avail. II. As a means of teaching physiological facts, vivisection is unsurpassed. No teacher of science needs to be told the vast superiority of demonstration over affirmation. Take for instance, the circulation of the blood. The student who displays but a languid interest in statements of fact, or even in the best delineations and charts obtainable, will be thoroughly aroused by seeing the process actually before his eyes. A week's study upon the book will less certainly be retained in his memory than a single view of the opened thorax of a frog or dog. There before him is the throbbing heart; he sees its relations to adjoining structures, and marks, with a wonder he never before knew, that mystery of life by which the heart, even though excised from the body, does not cease for a time its rhythmic beat. To imagine, then, that teachers of physiology find mere amusement in these operations is the greatest of ignorant mistakes. They deem it desirable that certain facts be accurately fixed in memory, and they know that no system of mnemonics equals for such purpose the demonstration of the function itself.