But regulation is quite a different thing from prohibition. Now, I showed that certain practices should be condemned. Should they, however, be condemned by law? Why should the law be substituted for the exigencies of science? Here is a physiologist, fully conscious of the magnitude of his task, to whom the government or a university has confided the direction of a laboratory, who finds himself face to face with a problem needing to be solved. It is impossible to limit his efforts and to lay down principles from which he could not turn aside. Just as he is referred to for the purchase of his instruments and the nomination of his staff, so must he be left full latitude in the arrangement of his experiments. Nothing is so pernicious in matters of science as official regulation; it takes away all initiative, and does not allow the genius of the inventor to have full play. As a matter of fact, even in England, the only country where up to the present the conditions of vivisection have been regulated by law, no one has ventured to confine the initiative of the experimenter within narrow regulations. And it is fortunate that no one has ventured to define the limits of experimental investigation, for most excellent work is due to contemporary English Physiologists--Schäfer, Horsley, Sherrington, Langley, Bayliss, Starling, Stirling, etc. They have been able to pursue their researches freely, to the very great advantage of our science. One should not, then, think of prohibiting such or such a proceeding in vivisection. It may even be dangerous to absolutely prohibit vivisections without anæsthesia. I make no mystery of my opinion on this point, since I have distinctly declared further back that no sensitive animal should ever be operated upon. I regard as a moral error all vivisection made on an animal capable of suffering. But I would leave the physiologist to be the judge in the matter. I do not believe the law should take his place; for perhaps cases will occur where anæsthesia is impossible, and he cannot be placed under the hard alternative of not making an experiment which his conscience as a _savant_ judges to be useful, or of disobeying the law. Moreover, how are the many possible conditions of an experiment to be precisely laid down? Is the law to indicate the kind of anæsthetic to be used, and the degree of anæsthesia to be attained? Is it to prohibit all experiments on toxic actions? Many insoluble difficulties would be encountered, the sole result of which would be to paralyse the _savant_ in his researches or to cause him to break the laws of his country. And yet I recognise that regulation is indispensable, but it ought not to bear on the nature of the experiment; it should deal solely with the person experimenting.