A comparison of the casts (Figs. 1 and 2), and of the numbers given above as indicating the relative breadth of the cerebellum to the cerebrum, will probably strike the physiologist at first sight, as affording some corroboration of the usually received theory of the function of the cerebellum, viz. "that of regulating and combining muscular movements." The Gibbons, as is well known, are the most agile of the apes; the accounts we have received from good observers of the graceful ease and precision with which they take great leaps from bough to bough, sometimes catching with their hands such objects as a flying bird as they pass, are truly surprising; while, on the other hand, the heavy-bodied baboons generally confine their locomotive powers to walking upon the ground, or climbing among

rocks.

But physiological conclusions of any value, especially upon the most obscure and difficult of subjects-the functions of the different portions of the nervous centres, must be based upon much wider, as well as more rigidly exact observations. After comparing, as far as I have hitherto had an opportunity of doing, the relative size of the cerebellum with the motor powers of the various forms of quadrumana, the conclusions arrived at are only negative. The active Gibbons have large cerebella, but the organ is equally well developed in the other anthropoid apes. The slower Baboons have a small cerebellum, but so also have the vivacious Cercopitheci and Macaques, zoologically allied to them. An individual of the species whose cerebellum is perhaps the most reduced of all, the Squirrel Monkey (Chrysothrix sciureus), (Fig. 3) now living in the Gardens of the Zoological Society, is, the keeper informs me, a lively little animal, capable of taking considerable leaps with great precision, and Humboldt's testimony of its habits in its native state is to the same effect,* while the inert lemur-like Douroucouli (Nyctipithecus) has its cerebellum tolerably well developed. In the greater number of the inferior Vertebrata, possessing more or less activity and power of combining and regulating their movements in running, leaping, flying or swimming, that portion of the cerebellum, the great development of which is characteristic of Man and the higher Quadrumana, viz. the body of the lateral lobes, is in a rudimentary condition, or entirely absent. When we consider the complex structure of this organ, and the extremely varying condition of its several component parts in the Mammalia alone, it is evident that it cannot be regarded as a whole in respect to its function, and further difficulties will remain behind, until physiologists have determined what kind of muscular actions in the living animal (whether, as Dr. Rolleston suggests,†

"Ses mouvements sont pleins de grâces. On le trouve occupé sans cesse à jouer, à sauter et à prendre des insectes."-Cours d'histoire naturelle des Mammiféres, par Geoff. St. Hilaire, 1829, 10e Leçon, p. 15.

+ Med. Times and Gazette, 1859, Vol. XL p. 77; and 1860, Vol. I. p. 161.

the power of maintaining the erect position, exhibited in the slow moving Bears, or, as others suppose, the rapid combination of motor energy, manifested in the Tiger's unerring spring, or the Monkey's airy gambols) are to be regarded as the external indications of the power either of "co-ordination of movements," or of the appreciation of "muscular sensibility indispensably necessary for the performance of complicated muscular efforts."

XXVII.-ON THE ANATOMY OF THE OLFACTORY LOBES IN CERTAIN OF THE MAMMALIA. By James Rorie, M.D. Dundee.

To the Anatomist and Physiologist, the Olfactory Lobes present an interest greater than any other individual portion of the nervous system, the spinal cord perhaps alone excepted. From their comparatively isolated condition in many Mammalia, the examination is easily conducted, and in consequence of their immediate relation with an organ of special sense on the one hand, and with the brain proper on the other, a correct knowledge of their anatomical details may be considered as affording, in a great measure, a key to the complex arrangement of nerve fibres which constitute the greater portion of the encephalon, and which has as yet almost completely baffled enquiry.

The most recent information on the anatomy of the olfactory lobes, so far as I am aware, is that afforded by the researches of Ph. Owsjannikow.* The results at which he has arrived, and which may be regarded as representing the present state of our knowledge on the subject, may be summed up as follows:

1. That in each olfactory lobe a cavity exists, lined by cylindrical epithelium.

2. That the grey matter of these organs is composed of multipolar nerve-cells, from which nerve-fibres pass, some to be distributed on the mucous membrane of the nasal cavities, and others inwards towards the brain proper, terminating in the nerve-cells in the grey matter of the cerebrum.

3. That no commissural fibres could be detected passing between the two olfactory lobes.

The following details, embracing the results at which I have arrived, may not be altogether devoid of interest, for while, to a certain extent, they confirm Owsjannikow's observations, in other respects they differ from them very essentially. The cavities to which the above distinguished observer refers, I have only found to exist in animals which have not reached maturity. In the young

* Medico-Chirug. Review, No. 54.

Pig (Sus scrofa), for example, they are well marked and easily distinguished; while in the full grown Rat (Mus decumanus), I could detect no trace of their existence. I am, therefore, inclined to regard them merely as the result of the development of these organs, and not of any essential physiological import. It is to the anatomy of the commissure of the olfactory lobes, however, that I would chiefly direct attention.

On examining the under surface of the brain of most mammalia, a band of white fibres will be seen running backwards and outwards from each lobe, and becoming lost in the grey substance of the brain. This, usually termed the "root" of the olfactory lobe, is simply the band of communication between the olfactory lobes and the cerebrum proper, and its function is evidently that of conveying the impressions made on the olfactory lobe to the grey matter of the brain.

In the Rat these bands are very distinct, and terminate in the outer anterior portion of the cerebrum. Other fibres in connection with these lobes, however, will readily be found, and as they are most easily demonstrated in the above mentioned mammal, I will first describe them as they exist in that animal. On turning aside the white bands already described, and removing gently the grey matter from the inferior surface of the anterior third of the cerebrum, another series of white bands will be perceived as shown in Fig. 1. In order to obtain a clear view of all their relations, it will be necessary to remove the under surface of the olfactory lobes, and to clear away the greater part of the grey matter from the base of the brain, and to turn aside the optic tracts. The following will now be found to be the relation of the fibres referred to:-From the outer and anterior part of each olfactory lobe will be found a small, well-defined, and round band of fibres passing backwards and inwards and uniting immediately posterior to the fissure between the olfactory lobes; or perhaps it may be more correctly described as a band passing in a semicircular direction, the terminations of which are situated in the outer anterior portion of each olfactory lobe. In the Rat this horseshoe shaped band is about the size of fine sewing thread. It evidently constitutes the true commissure of the olfactory lobes. In favourable dissections a few fibres may be seen passing directly outwards from the convexity of the arch and terminating in that part of the cerebrum in which we find the superficial band of fibres connecting the olfactory lobes with the cerebrum to have their termination.

From the inner and anterior portion of each olfactory lobe, a band of fibres arises and passes backwards through the structures at the base of the brain, the two bands slightly diverging from each other in their course. By a careful dissection these bands may be traced till they are lost in the anterior columns of the spinal cord. In the Pig the fibres above described present nearly the same relations as in the Rat, the only differences I could detect being the following:-1st. I could find no fibres passing outwards from the convexity of the olfactory commissure. 2nd. The bands of fibres passing between the

olfactory lobes and the spinal cord arose from the outer anterior part of lobe, instead of from the inner as in the Rat, and became lost in the crura cerebri. 3rd. The olfactory commissure terminated in the inner anterior part of the lobes, the outer anterior part being occupied by the long bands just described.

I may here add that an olfactory commissure is not confined to the mammalia. It undoubtedly exists in some fishes. At least I have found it well marked in the Mackerel (Scomber Scomber), and occupying a position similar to that already described (Fig. 2). As to the functions which these fibres may be considered to perform, we have already stated that the superficial fibres of communication between the olfactory lobes and the cerebrum may be regarded as conveying to the brain proper the impressions made on the olfactory lobes. The commissural fibres, no doubt, have the same function here as elsewhere, and serve to co-ordinate such impressions.

The functions of the other fibres, however, are not so easily explained. Those arising from the convexity of the commissure may, I think, be regarded as fibres passing from each olfactory lobe respectively to the opposite side of the cerebrum, thus crossing each other in their course. Constituting as they do only about one-fifth of the whole fibres of the commissure, and existing, so far as I could ascertain, in only one of the species examined, their function may be merely of a secondary nature, that of assisting in the co-ordinating action of the commissure. With regard to the fibres passing from the olfactory lobes towards the spinal cord, two views may be entertained; either that they terminate in the spinal centres of locomotion or of respiration. In either case they would appear to constitute a reflex apparatus, whereby locomotion or respiration might be excited independently of cerebral action, an arrangement which must be regarded as highly necessary, when we take into consideration the habits of these animals.

FIG. 1.-Section showing the arrangement of the deep bundles of nerve fibres in the olfactory lobes of the common Rat (Mus decumanus.)

FIG. 2.-Section showing the olfactory commissure in the lobes of the Mackerel (Scomber Scomber).

XXVIII.-SCOTCH KJÖKKENMÖDDINGS.

THE Rev. G. Gordon has published a very interesting account of some Kjökkenmöddings on the Elginshire coast, which appear to agree very closely with those found in Denmark. "By far the most striking," he says, "if not the most ancient example of the Kjok"kenmöddings we have in our vicinity, is that one which lies within "a small wood on the old margin of the Loch of Spynie, and on a "sort of promontory formed of those raised shingle beaches, so "well developed in that quarter. This mound, or rather these "two mounds (for there is an intervening portion of the ground that has no shells), must have been of considerable "extent. A rough measurement gives eighty by thirty yards "for the larger, and twenty-six by thirty for the smaller por"tion. The most abundant shell is the periwinkle. . . . . Next in "order as to frequency, is the oyster. ... which . . as well as "those who had it as a large item in their bill of fare, has passed away from our coasts. Save in some of the nooks of our Firth, as "at Cromarty, Altirlie, and Avoch, we know not where a small dish "of them could be procured. . . . . As third in order, in this mound, "is the mussel, and then the cockle. Each of these species, how"ever, bears but a small proportion to either of the former two.”

Mr. Gordon informs us, by letter, that similar refuse-heaps are being found all around the shores of the Moray Firth; but it appears that the farmers are gradually carting them away, to serve as manure or topdressings. It is, therefore, much to be hoped that the Scotch antiquaries will lose no time in examining those that still remain.

J. L.