It deals with "the past and present condition of organic nature;" with the method by which the causes of these conditions of nature are to be discovered; the origin and perpetuation of living beings, and the phenomena that accompany these. It further enters into a critical examination of Mr. Darwin's book on the origin of species, suggesting to its readers how far they should be guided by the theories and hypotheses which it contains; and lastly, what is to us by far its most important feature, it is itself a verbatim report of a course of lectures delivered by the author (we believe in his public and official capacity) to the working classes of the great metropolis.

Our readers will therefore perceive that we are not called upon to deal with a mere scientific inquiry or criticism, of whose value every one may form a more or less accurate estimate, but that the doctrines and conclusions of the author will be taken for granted by, and serve as a guide to many who were previously unacquainted with the subject except by hearsay; whilst others more enlightened, perhaps, but still to a great extent strangers and new-comers in the world of science, will carefully scan its contents as the popular exposition of the great scientific movement of the day; and such persons will naturally form from its contents what appears to them to be the most accurate estimate of the efforts of modern science as applied to the laws of nature, as well as of the opinions held by scientific men.

The avowed purpose of the present work is, as already stated, to communicate to the partially educated masses what appears to the author to be a faithful account of Mr. Darwin's views concerning the origin of species, and to convey his (the author's) unbiassed opinion as to how far these views are entitled to their acceptance.

With this object, it may readily be supposed, that the author would find it necessary to impart to his readers some knowledge regarding the past and present condition of organic nature; and, considering the disparity which exists between him and his readers in extent of knowledge and modes of thought, it would have been impossible for him to have performed this portion of his task more efficiently than he has done. Indeed, there is no need for any qualification in our approval; and we are only doing him justice when we say that the combination of popular phraseology with accurate scientific information has never been surpassed, perhaps not equalled in any similar course of scientific lectures of a popular character that has come under our notice.

The mode in which the reader (or hearer) is enabled to carry away with him a simple, yet accurate ideal of the animal frame; and the familiar similes whereby the functions of the living creature are impressed upon the mind are above all praise. In fact, whenever the author attempts to convey to his imperfectly educated hearers (we speak, of course, of their scientific education only) a knowledge of those phenomena in nature which are recognized as facts, he does so with admirable tact, and in nearly every case with undeniable accuracy.

Had he confined his labours within these limits, and simply proposed to himself to make his readers and hearers acquainted with the phenomena of nature as they are, our criticism would have ended here;

but unfortunately he has not done so; and as his fame and position preclude our passing over the inaccuracies in his work with a brief comment or laying it aside altogether, we have no other alternative than to deal with its defects as with its merits. This we will endeavour to do as fairly as we are able, not confining ourselves to a mere expression of opinion as to what appears to us inaccurate or inconsistent, but endeavouring to point out where the error lies, and where the argument yields under investigation.

It would be almost impossible, in this criticism, to sever the author's views concerning the laws of nature from those of Mr. Darwin. Not that we consider them identical, but the author seems to believe that they are, and would have us think the same; so he has written his book accordingly.

To some extent, no doubt, their views are identical, and in one important particular they may be considered completely to coincide. Both believe that the formation of a new species in nature is the result of the gradual modification of some other species (that each is not a special creation); and that the operating cause is the conjoint action of what the author calls "atavism* and variability," and the various conditions of existence in which the animals are placed; in fact, they believe that the production of varieties and the perpetuation of races are due to inherent tendencies or properties possessed by the animals themselves, and by the external conditions by which they are surrounded; and then extending this principle further, they believe in the formation, by this mode, of species, genera, &c. This is the doctrine of Mr. Darwin. But our author is not content to be a teacher, a mere repeater of the theory of another: he takes upon himself the duty of a guide and critic, and tells us that, before we accept any new theory of this kind, we ought to subject it to the most searching scrutiny; thus constituting himself our guide, he proceeds to lead us accordingly.

We should not, he says, reject this or any other hypothesis merely because we are told that it is not in accordance with the Baconian philosophy, but we should deal with it as we would treat any question in common life. To enable us to do this, he gives, in one portion of his work, numerous illustrations of the kind of treatment of which subjects of this kind are susceptible, selecting one example in particular that appears to him to be peculiarly applicable to the solution of the problem connected with the production of a new species; and in a later discourse, he lays down with more precision the rules by which, according to his views, the accuracy of Mr. Darwin's hypothesis should be tested.

"The method of scientific investigation," he tells us, "is nothing but the expression of the necessary mode of working of the human mind;" and, as an incident taken from common life, illustrative of the method by which phenomena may be attributed to their true causes, he mentions the case of a man who, having left some plate in his parlour over night, comes down the next morning and misses it. Seeing

*Hereditary similitude, from atavus (ancestor).

that the window is open, he inspects it, and finds the mark of a dirty hand on the window-frame, and subsequently the impress of a hob-nailed boot outside on the gravel. Of course, he suspects that his plate has been stolen, and the hypothesis is that the owner of the dirty hand and hobnailed boot is the thief. Undeterred by the counter-hypothesis of some kind friend, who suggests the possibility of the laws of nature having been "suspended during the night," and that there might have been “ some supernatural interference in the case," he calls in the aid of the police, who track the burglar with the property on his person, and find that the marks correspond with his hands and boots. Under such circumstances, he thinks a jury would verify the hypothesis by convicting the prisoner.

After showing that it was by such hypotheses that Newton and Laplace made their discoveries, and telling his readers that the value of the result of the hypothesis depends upon the pains taken in its verification, he proceeds to say that it is on this inductive method of inquiry he means to consider the state of "our present knowledge of the nature of the processes which have resulted in the present condition of organic nature."

The precise bearing of this anecdote to the point at issue is not given with the story itself, and we shall inquire how far it is applicable to the natural problem before us; supplying what appear to us to be deficiencies, which might not occur to the "working classes.”*

The Story :

1. A gentleman misses his plate, and asks himself what has become of it.

2. He finds evidence of a man having escaped from the window. 3. From this evidence he concludes, or rather forms the hypothesis, that a burglar had stolen his plate, and has escaped from the window; and determined to be guided by this hypothesis, he directs his investigations accordingly.

4. On proceeding in his investigations, he finds the burglar with the property on his person, and has him convicted.

The Moral: :

1. A naturalist observes that certain groups called species are related together by structural and functional peculiarities; and he asks himself how these species have originated.

2. He finds that by artificial breeding or selection, man is able to form varieties and races; and that similar influences to that exercised by man are all at work in nature.

3. He conceives the idea of natural selection; and assumes that "species" have thus originated.

4. To be complete, the moral should conclude thus :-He investigates the operations of nature; finds species formed by natural selection ; and thus realizing his hypothesis, he arrives at a satisfactory solution of his problem.

At p. 137, the author specially refers to this anecdote as constituting a case analogous to the one at issue, namely, the causes of origin of new species.

This we presume should be the rationale of the story; but is it so?

It is very easy to frame a suppositional argument, carry it to a satisfactory conclusion, and leave the reader to infer that it is precisely analogous to another that is hypothetical; but the author cannot be surprised if his readers, finding that his analogy does not hold good, should throw away his whole theory as worthless; and we fear that with many it will be so in the present instance. We have no objection to handle the inquiry after the author's own approved fashion; but we trust he will not object to the introduction of a little fresh evidence and one or two additional witnesses. As it is a serious case, too, and affects the liberty of the subject (for he sentences his man), we hope he will allow us to employ counsel, on our granting him the same privilege. We, too, shall put an hypothesis.

His "objector," who happens to visit him in his trouble, endeavours to dissuade him from calling in the assistance of the police, and does so on the ground that as the spoons were taken away at night, the possibility is that the laws of nature might have been suspended at this season and that there may have been some supernatural interference in the case, into which it would be presumptuous in the owner of the spoons to inquire.

We presume that this means, that as species originated before man appeared on earth, or before the beginning of the historic record, therefore, it is possible that the laws of nature were different then to what they now are; that species were supernaturally created; and it would be presumptuous in us to inquire into their origin.

We will now introduce another witness and a fresh element into the inquiry, the nature of which will be fully comprehended from what follows.

Another friend who happens to enter the room just as the owner of the stolen spoons has pushed his first friend aside, and is about to depart in search of the police, and hears what has happened, stops his exit, and says, "Softly, my friend; I don't put so much faith in the reversal of the order of nature as does your friend there; but don't be hasty: you are very much agitated in consequence of your loss; and, perhaps whilst you are running off in search of the police, the thief may be down stairs cleaning your boots, and he or she may take the opportunity to secrete the plate. Just let me see the marks on the window." And it is possible that when he comes to the window, his friend might say, "My good fellow, I always knew you to be an excellent leaper; but you seem to think there are better than yourself in the world; for this window is at least thirty feet from the ground, and if the thief did not fall into the area and break his neck, he would certainly be impaled upon the spiked railings beyond. Have you ever tried the experiment yourself?" Now we can imagine our friend of the stolen plate a little puzzled at first, but replying with great confidence: "Well, not exactly; but it occurs to me that a friend of mine, a much more active man than I am, once tried to get down into the garden, and he succeeded after endless labour and risk in reaching that ledge which projects from the wall about half way down. He came up again and expressed his conviction that the remainder of the descent was feasible also,- and so with your permission I shall go for the police." Well, we may tell our readers frankly that we think this

person was very hasty, and would have done better if he had looked about in his own house, and had sent the most trusty of his servants to seek the police at the same time. We apprehend that if he found a burglar, or a man of notoriously bad character, with the plate upon him, there could be no doubt as to who was the thief, without either the evidence of the dirty hands or footmarks in the garden; but thieves do not generally carry stolen property about with them, especially when it is as heavy as silver plate is usually supposed to be; and we must beg our author to let us presume that the plate was discovered at a pawnbroker's, and that a man with dirty hands and hob-nailed boots was found, whom the pawnbroker believed to be the person that pawned the plate. Now we anticipate that the jury would like to be satisfied

1st. As to whether this was the man who left his marks on the window.

2nd. Whether the pawnbroker was correct as to the identity of the thief. For it is just possible that the actual thief may still have been in the house, and may have employed him of the dirty hands and hob-nailed boots to pawn the property for him.

Let us follow the owner of the property. We suppose that although he might think the evidence perfectly clear, he would entrust his case to counsel, and the professional gentleman, not being the victim of the theft, would naturally inquire into all the circumstances, and, amongst others, would hear of the height of the window from the ground; so, too, would the counsel for the defence. But, as our readers know, it is the duty of a barrister to make out his case, and upon his ability to do so under difficulties depends the success of his client. Well, we can imagine the prosecuting counsel being very much puzzled to connect the marks left by the man with the man himself, and endeavouring to get over the difficulty by some such pleading as this:

"Every portion of the evidence, gentlemen, is quite clear, excepting one link; and this there is good reason to believe is much more tenable than it appears, for a friend of my client once succeeded, though with some difficulty, in getting upon the ledge half-way down, and he has been consulted, and repeats what he said at the time of his experiment, viz., that he is satisfied the thing could be accomplished. My client, who is a clever gymnast himself, thinks the same. And I defy my learned friend, the counsel for the prisoner, to show that it was impossible for the prisoner to have effected his escape to the ledge, and from the ledge to the ground. We don't pretend to explain how it can be done, but we see every reason to believe that it is possible, and unless my learned friend can prove the contrary, I argue that the jury has no other alternative than to commit the prisoner!"

Now it appears to us that the best course for the defending counsel to adopt would be to leave the evidence precisely where it stands; and not even to avail himself of the arguments used by the objector on the ground of "supernatural interference," in the hope that some of the jury might be "orthodox;" for we have little doubt that the prisoner would be