between the different delineations of the same hand, for every observer has his own way of seeing and interpreting as well as of delineating what lies before him; but ultimately a more extended collation would be requisite. To Mr. Birt, as editor of the "English Lunar Map," now in progress, our own observers would naturally refer for the safe preservation and general comparison of their united labours; but it is obviously important that what is thus communicated should be the result, not of rough and hasty attempts, but of careful and attentive delineation. It is also very desirable that such a representation should be accompanied by a list, as well as by some description, of the objects delineated; this being the most effective method of ensuring certainty to the evidence, and making it fully dependable for future comparison and inference.

It may have been noticed that no allusion has been made to the representation of those well-known streaks and specks and clouds of white and grey which give so peculiar and unintelligible a character to the aspect of the Full Moon. The delineation of these would be found in one respect more difficult, as requiring wider gradation of tone; in another easier, from the greater permanency of the object. It has been hitherto little attempted in detail, but is well worthy of separate study. We have not space to enter now upon its characteristics, which indeed have been but very imperfectly investigated. Here also, however, indications of d cided change have not been wanting; and the diligent and persevering explorer would probably be rewarded in the end.

243

MAN AND APES.

BY ST. GEORGE MIVART, F.R.S.

HA

PART II.

AVING completed our survey of certain characters presented by the skeleton in different species of the order PRIMATES, other systems of organs may now be adverted to.

That system of parts which clothes and is attached to the various parts of the skeleton may be taken naturally after the skeleton itself.

This system consists of the flesh which, being divided into a number of segments and layers by intervening membrane, constitutes the muscles or active organs of motion.

The muscles, however, present few characters of any great value for our purpose, and this might be anticipated, since being the special organs of motion, they would naturally be expected to be peculiarly modifiable and to present every variety of adaptive modification.

Speaking generally, the Apes resemble man myologically more than do the Half-Apes, and the latter may present us with special aberrant modifications; such e.g. as the presence of an extra muscle, called rotator fibula, placed between the shinbone (tibia) and the adjacent small bone (fibula) of the leg.

It is the Latisternal Apes (Simiina) which approach man most closely in muscular structure, as we have seen they do in the bony framework which supports the muscles.

Amongst these higher Apes the Orang shows again a certain inferiority as to its muscles, reminding us of the aberrations we have already seen to exist in its skeleton.

Thus in its foot, the great toe, in spite of its small relative size, is furnished with a special, short muscle (called opponens hallucis) not found in other Latisternal Apes, any more than in man. This, indeed, is a special development, and is no approximation to an inferior type of structure.

On the contrary, both the great toe and the thumb have no distinct tendon sent to them from the deep long flexor muscles

of the arm and leg respectively. In this respect we find an inverse difference to that precedingly noticed.

Again, the long muscle called flexor longus hallucis does not take origin, as in the other higher Apes, from the leg, but from the bone of the thigh.

But neither the skeleton, nor yet the flesh which clothes it, can be considered as the most important system of organs, nor that best calculated to manifest degrees of affinity or supremacy. It is not the pillars, shields, and levers of the body (bones), nor the cords and fastenings which brace together (ligaments), or by tension act upon (muscles) those pillars and levers which can rationally be regarded as supreme. Such supremacy must rather be conceded to the regulating and co-ordinating apparatus, by means of which the tensions are so varied and directed as to produce harmonious and consentient results. But this supremacy is still further manifest when we consider that the very integrity of these structures is maintained, and their repair effected, by the agency of that very same co-ordinating apparatus which is the controller of animal life, the lord of all within its own boundaries, and which says to every other system of parts, "Starve thou before me."

This supreme and dominant apparatus is the nervous system. The Ape which has this system-and especially the dominant part of this dominant system, namely, the brain-most in conformity with the same system in man, must surely be held to be the most materially man-like in structure.

Now it is not the Chimpanzee, certainly not the Gorilla, nor yet the Gibbons which most resemble man as regards his brain. In this respect the Orang stands highest in rank.

In the first place, the height of the Orang's cerebrum in front is greater in proportion than in either the Chimpanzee or the Gorilla; while the brain of the last-named animal falls below that of the Chimpanzee, in that it is relatively longer and more depressed, as compared with man's brain.

Each half of the cerebrum is divisible into four parts or lobes. The first of these (marked 1, 2, and 3) is the "frontal." The second (marked 4, 5, and 6) is the "parietal. The third (marked 10, 11, and 12) is the "occipital;" and the fourth (marked 7, 8, and 9) is the "temporal."

On comparing the brain of man with the brains of the Orang, Chimpanzee, and Baboon, we find a successive decrease in the frontal lobe, and a successive and very great increase in the relative size of the occipital lobe. Concomitantly with this increase and decrease, certain folds of brain substance, called "bridging convolutions" (marked a and B), which in man are conspicuously interposed between the parietal and occipital lobes, seem as utterly to disappear in the Chim

panzee as they do in the Baboon. In the Orang, however, though much reduced, they are still to be distinguished. Besides these matters, the temporal lobe becomes less horizontal and more depressed, as we proceed from Man to the Baboon.

*

These distinctions, with some others, have been pointed out in France by the late lamented M. Gratiolet, and in England by Professor Rolleston.† Mr. Marshall, F.R.S., has also given his verdict on the interesting question of the relative superiority of the Chimpanzee's and Orang's brain" "in favour of the latter."

Messrs. Schroeder, Van der Kolk and W. Vrolik, the distinguished naturalists of Amsterdam, fully recognise the resemblance of the brain of the Orang to that of man to be closer than that presented by the brain of any other Ape.

The actual and absolute mass of the brain is, however, slightly greater in the Chimpanzee than in the Orang, as is the relative vertical extent of the middle part of the cerebrum, although, as before said, the frontal portion is higher in the Orang. When we turn to the Gorilla we find, from M. Gratiolet,§ that this much vaunted and belauded Ape is not only inferior to the Orang in cerebral development, but even to his smaller African congener-the Chimpanzee.

In the first place its brain scarcely equals (at least in some cases) that of the Chimpanzee in actual mass. It is also flatter, and its frontal lobe is less projecting in front of its temporal

*

"Mémoire sur les plis cérébraux de l'homme et des primates."

"Nat. Hist. Review," vol. i. p. 201, and in a Lecture at the Royal Institution, reported in the "Medical Times," for February and March, 1862.

"Nat. Hist. Review," vol. i. p. 310.

§ See "Comptes rendus," April 30th, 1860, p. 801.