further extended and may be made applicable to the whole of the scattered small groups and isolated species which are defended by the possession of such unpleasant attributes, the convergence being often independent of relative affinity. If such insects are looked at as a whole, it is seen that the same colours are repeated again and again, and are those which are known to produce the greatest effect upon the vertebrate eye. So, also, there are a few eminently conspicuous and simple patterns which are met with again and again in totally distinct groups of insects. The advantage of this convergence in colour and in pattern is certainly found in the fact that it facilitates the education of the vertebrate enemies of insects. Such convergence also passes into and always contains an element of true " mimicry"; and Dr. Walker will find an example of the undoubted protective effects of "mimicry among our own lepidopterous fauna, which I proved by experiment during the past summer (P. auriflua and L. salicis. Abstract of British Association at Manchester, Section D). Further references and details upon the subject will be found in my paper in the Zool. Soc. Proc,, and I have only here attempted to bring forward mere notes of the course of our knowledge on this most interesting subject.

Dr. Walker, in the note on his last page, alludes to instances of protective resemblance, and I understand him to imply that such instances as he cites are relatively rare: I think the difficulty is, not to see such modes of protection in five out of six of the species one meets with. A considerable number will be found described in my paper, but only such as have been subjected to experiment and found to be edible or otherwise.

I trust that I may be pardoned for the references to my own paper, but I do not know any other which deals with the historical aspects of the subject, for I paid especial attention to this side of the question in its preparation.

Rev. Dr. WALKER.-There are one or two points raised in this discussion to which I should like to refer. The new definition in place of “natural mimicry" has been said to consist of eight words,though I think it will be found to consist of seven,-while the definition I have given is in two words only,-" natural mimicry." I may have omitted one or two cases of what I have termed "natural mimicry" in our own temperate region; but what I say is that, for one of these instances in England, we can find hundreds in the

tropics. The last speaker referred to the similarity between Acronycta Psi and Tridens, and Mr. Kirby alluded to the similarity between Ophecia Apiformis and the hornet. For some unknown purpose in nature, we find that one species of one genus of insect almost exactly mimics another species belonging to another genus, and that one tribe almost always mimics another tribe. Mr. Kirby mentions Sericinus Montela as a tribe allied to the Papilio. Mr. Kirby is better informed than I am as to the affinity he speaks of; but the marking of Sericinus Montela is more like Apollo than any species of the Papilio, or swallow-tail.

W. N. WEST, Esq. (HON. TREASURER), IN THE CHAIR..

The Minutes of the last meeting were read and confirmed, and the following Elections were announced :—

LIFE MEMBER.-G. W. James, Esq., F.R.A.S., F.R.H.S., United States. ASSOCIATE.-Rev. G. J. Perram, M.A., London.

The following paper was then read by Mr. H. Cadman Jones, the author being unavoidably absent in Ireland :

A PHYSICAL THEORY OF MORAL FREEDOM.

Jo

By JOSEPH JOHN MURPHY, Esq.

OHN STUART MILL has quoted from some unnamed writer that "on all great subjects much remains to be said." Perhaps, however, he would have made an exception of those subjects which are contemptuously called metaphysical by that Positivist school whereof he was the ablest English exponent; perhaps he would have said that they are partly solved and partly proved to be insoluble, and that on this question of Freedom and Necessity the last word which has been or can be spoken is, not that freedom is proved impossible,-Mill was too cautious a reasoner to commit himself to such an assertion,-but that no valid reason can be given for admitting any exception or limitation to the absolute uniformity of the order of Nature, including not only unconscious Nature, but conscious Mind. And this appears to be the general belief of that philosophical, or scientific, school, which is dominant among us, and has Mr. Herbert Spencer as its chief living exponent. Some, indeed, speak as if they thought this absolute uniformity of the course of things was of the nature of a logical truth, which cannot

be denied without affirming a contradiction. But the more general and plausible opinion is that this uniformity follows by mathematical necessity from the laws of physical nature.

We think, on the contrary, that this question of Freedom versus Necessity is not, and perhaps may never be, a closed question. We think it one of those "great questions on which much remains to be said"; and we propose to give an account of some views on the subject, which have been published by French writers during the last few years.

We must begin by stating the question in dispute; for we believe there are many who really affirm this doctrine of absolute uniformity in the order of things-philosophical necessity as it was formerly called, or determinism as it is called now—and yet say that in some transcendental sense they are believers in moral freedom. If we do not misunderstand them, this is the position of Dr. Chalmers and the Duke of Argyll. We cannot state the question in more suitable words than those of Professor Delboeuf, of Liège,* which we translate:

"The fundamental proposition of determinism is the following:-The present state of the Universe, and consequently the movement of the least of its atoms, is the necessary and the only possible consequence of its immediately preceding state, and the sufficient cause of its immediately following state, so that a sufficiently powerful intelligence would be able from a single glance (at the present state of the Universe) to infer its entire past and its entire future.

"The partial denial of this proposition will evidently give the definition (of freedom) which we seek :-Freedom is a faculty or power, which produces movements which are not implied (renfermés) in the immediately preceding movements, and consequently cannot be predicted" (by any intelligence, however powerful, which acts under the same conditions as ours).

We have added the concluding words to Delbouf's, because we believe that the Divine Intelligence does not exist under the same conditions as that of Man, but transcends time, and comprehends all things, past, present, and future.

We do not purpose to go back on the metaphysical aspect of the controversy, but to treat it only in its relations to physical science.

The physical or mechanical, as distinguished from the

* Bulletin de l'Académie Royale de Belgique. 3me série, tome 1, No. 4, 1881.-3me série, No. 2, 1882. The quotation in the text is from the latter of these two memoirs.

metaphysical, difficulty in recognising Will as an agency capable of acting on matter was, we believe, first seen by Descartes. He taught that matter and spirit, though in union, are absolutely distinct; that matter acts and is acted on according to rigidly mechanical laws; and that the total quantity of motion in the universe is invariable. From these premises it is an obvious consequence that Will cannot be a source of motive power in the universe of matter; but Descartes solved the difficulty by adding that Will, though unable to produce motion, is able to direct it. We believe this to be in substance the true solution; and it is substantially that of at least two of the three writers of whose views we have undertaken to give an account; but it needs to be translated into not only the language, but the ideas of modern science. "Quantity of motion" is an ambiguous expression; but the truth after which Descartes was groping is what is now known as the doctrine of the Conservation of Energy; that the energy of the universe, though perpetually undergoing transformation, is a constant quantity; that a given quantity of energy, when it undergoes transformation, does an exactly equivalent quantity of work, which work re-appears in some other form of energy. Muscular action, as such, is no exception to this law of Conservation; for it is disputed by none that the energy put forth in muscular action is not created by an effort of the will, but has previously existed in the animal organism, stored up in some form which can be drawn on when needed for use.

Expressed in modern language, the mechanical argument against the possibility of Freedom is that Freedom would be inconsistent with the law of the Conservation of Energy. Freedom, as Delboeuf has defined it in the passage quoted above, implies that it would have been possible for certain events to have befallen differently from what actually has befallen; and it is asserted that, if this had been the case, the sum total of energy in the universe would have been changed either by increase or by decrease;-which is impossible. A possible reply to this is that energy may be transformed, without either gain or loss of quantity, under the influence of a force which remains unchanged, and does not itself pass into energy. Thus, in a "dynamo," or generator of electricity for illuminating or other purposes, the energy due to the motion of the machinery is transformed into electricity, under the influence of magnets which themselves undergo neither increase nor diminution of magnetic power; and it may be argued that the function of the will, in determining the transformation of nervous and mus