ditional tendons from the third and fourth digits and is now restricted to the little finger. The extensor primi internodii pollicis is separated from the extensor ossis metacarpi pollicis, etc. On the other hand, the muscles of man's foot, which in his simian ancestors were concerned in making his foot prehensile as well as locomotor, are, through disuse, undergoing atrophy and disappearance (e. g., adductor and abductor hallucis; the flaxor brevis minimi digiti) where they are not generalizing by fusing (e. g., the flexor longus hallucis with the flexor longus digitorum).

The opponens hallucis is a muscle that is found normally only in the orang. It occasionally occurs in man as a reversion.* Therefore, in view of these facts, the following question is an interesting one: Do the different races in respect to these structures present different percentages of reversion to the simian characteristics?

It is interesting to note in this connection that percentages of reversion in osseous structures differ in different races and epochs. For instance, it has been observed that the intercondylar foramen is present in a little over 3 per cent of the skeletons of the present time; in a little over 5 per cent of those that belong to the time from the fourth to the tenth centuries; in 24 per cent of those belonging to the Dolmen period; and, finally, in 30 per cent of those of the Reindeer period.

Again, the third trochanter of the femur has been found in 1 per cent of our race; in 37 per cent among the Swedes; in 50 per cent of the Sioux, and in 64 per cent among the Laplanders.

In the light of these facts it would appear to me that a wider study of muscular variations in different peoples will present an interesting and instructive field for the investigation of racial anatomical peculiarities.

In conclusion, it may not be amiss to briefly mention some of the anatomical peculiarities which, taken together, stamp a race as high or low, viz, cranial sutures that are simple in arrangement and unite early; a wide nasal aperture, with the nasal bones ankylosed; undue projection of the jaws and receding chin; well developed wisdom teeth appearing early and permanent; a humerus of undue length and perforated; an elongated calcaneum; a small calf of the leg; a flattened tibia; a narrow pelvis, etc.

These characters are simioid, and the races possessing them in largest number and development are the lowest in the scale.

Measured by these criteria the Caucasian stands at the head of the racial scale and the Negro at its bottom.

Dr FRANK BAKER remarked that the reason why anthropometry has contributed no more to the establishment of racial distinctions seems to arise from the fact that its methods have been too scholastic and do not reach the true morphological characters. The mere measurement of the length and width of an organ gives but little idea of its characteristic forms. In other biological sciences the general facies of a species is used for classification rather than meager data depending on measurements alone. It seems, however, pretty clear that whatever may be the racial distinctions of man they are not such as would entitle us to establish distinct species of mankind. The differences are varietal rather than specific. The conditions under which man has developed would necessarily produce this result. The character which first differentiated him from other animals was an increased intelligence, by which he was enabled to secure a wide range for his food and activities. Consequently he became from the first a continental animal, spreading over vast areas and adapting himself by his intelligence to a vast variety of conditions. Under these circumstances there was no opportunity for him to get set in any small environment which would produce specific characters markedly differentiating him from his fellows.

The use of the term atavism has been considerably abused by biologists. It would seem that it has not always been considered what vast periods of time intervene between the formation of widely different stocks in the animal kingdom. When Sutton suggests that the round ligament of the hip joint is a survival of an insertion of a muscle found only in the lizards, and Waldeyer considers that certain fibers of the ciliary muscle are vestiges of the Cramptonian muscle of birds, it seems to me that those eminent authorities forget the extreme improbability of genetic continuation of structures between such widely different stocks and through such innumerable generations, they having, nevertheless, totally disappeared in intervening forms. Such speculations can only be considered sound when a fairly continuous series of forms is found along the probable line of descent.

For that reason we should be very careful not to attribute to atavism every aberrant form of muscle which may be found, even if it resembles more or less remotely some forms that are stable in lower animals. An exact scientific morphology of the muscular system is yet wanting, and it will be impossible to give proper value to muscular variations until we have more knowledge of the laws which regulate the general formation and distribution of muscles.

Dr Shute has alluded to the racial peculiarities of the negro. These have probably been misunderstood. The ape-like character of the negro is often commented upon in popular prints and in the speech of those not versed in anatomical studies, but as a matter of fact there does not seem to be adequate ground for the conclusion that his racial peculiarities are remarkably simian. In the remote past, when the human stock budded off from the primitive, possibly lemuriform, common stem from which both men and apes have come, it would appear that the African race went on living in tropical climates, suffering, perhaps, some retardation from the peculiarities of its environment, but on the whole becoming markedly modified from its primitive form. The Caucasian race lived mainly in temperate climates and developed in another direction. Neither are remarkably simian, for it must be remembered that the apes, too, have been modified in their own way. Each has proceeded in development according to the condition of its existence.

After examination of many bodies of Africans found in the dissecting rooms, it seems evident that ape-like characters are no more common among them than among whites. There is sometimes a slighter degree of differentiation found in the muscles of the hand. It is, for example, not infrequent to find the long flexor of the thumb blended with the deep flexor of the fingers. The peculiarities of the lumbar curve in the negro, mentioned by Cunningham, and the longer heel are both adaptations to the semi-erect posture necessary when running through the bush in hunting or in predatory excursions. Together with the long heel we find small calf muscles, Marey having shown that in all running animals there is a correlation between the size of these muscles and the length of the calcaneal lever. When the heel is long, the leverage is such that small muscles are sufficient for the activities of the animal, and vice versa.

With regard to the intercondyloid foramen, some doubts may well be raised as to its value as a racial characteristic. In a large percentage of modern Caucasian skeletons the bone is here quite thin. How natural it is that after long exposure to the elements the slight wear that occurs at the surface should cause an originally completely closed humerus to show a perforation here. Besides, as has been ably shown by Dr Washington Matthews, it appears highly probable that food habits have a great effect upon this as upon other osseous characters. Those races that have plenty of meat and are well nourished will show ceteris paribus the most firm and resistant bones. If they feed mainly upon grains and have periods of scarcity, the bones will show a corresponding tendency to deteriorate. It is highly probable, therefore, that in dealing with the intercondyloid foramen in ancient peoples we are likely to be misled both by the wear of the bones and by accidental variations.

The statement made as to the occurrence of the third trochanter of the femur seems exaggerated. An inspection of the skeletons of the Sioux in the Army Medical Museum will convince Dr Shute that he has overestimated its frequency in that tribe.

The subject of racial peculiarities is a vast one and requires an extensive knowledge of comparative anatomy for its proper discussion. It is to be hoped that in a future paper Dr Shute will give some definite statements of the results which he has obtained from actual inspection of anomalies in the African and Caucasian.

Dr THEODORE GILL expressed his gratification at the able treatment of the subject under consideration by Dr Shute and Dr Baker, but did not entirely agree with all their conclusions, and ventured to express his own ideas. Whether the differences between any of the varieties of man are of specific value was a moot question; but almost all investigators would agree with the previous speakers that they were not. If we only had typical forms to determine, such as a Congo negro, a Tartar Mongol, or a high-caste European, the differences would be equal to those between some very closely related species of other mammals; but the gaps between such typical forms are bridged by intermediate stages to such an extent that it becomes impossible to accord more than subspecific rank to any variations. (Species,

be it remarked, in the language of the zoologist, are forms between which no true gradation occurs, while subspecies are those which are almost always geographically limited, and would be called species if gradation was not known to occur.)

The speaker was inclined to consider the existing condition as the final result of what has been called "eugenesis" and the earlier result of confinement of the ancestral stock within a comparatively restricted (not continental) area, until the evolution of man from the simioid stock had been completed. That evolution was doubtless rapid, geologically speaking, and the ancestral stock not far to seek.

The speaker presumed that when Dr Baker referred to the primitive, arboreal, lemuriform ancestors of man he did so simply in a spirit of euphemism and with a desire to save the feelings of the extremely sensitive; but he (the speaker) felt at liberty at least to acknowledge his own ancestors, and he claimed descent from forms so much like the chimpanzee and the gorilla of the present day that the ordinary man would have recognized at once the resemblance if he could have observed them.

The very numerous characteristics which man shares with the higher simioid apes-and even with the chimpanzee and gorilla as compared with the orang-outan-warrant the assumption that their not very remote ancestors were probably the same as ours, and that while we have so widely diverged from the common primitive stock they have diverged but little.

Dr Shute struck the keynote when he affirmed that use and disuse account for many of the differences. This the speaker had long maintained and would now illustrate by a few examples.

Disuse is at the bottom of a series of changes which has affected the face of man. Our simian ancestors, like all the other simioids, had strong canines and used them for offensive and defensive purposes. At last some almost ceased to use them as such, resorting rather to clubs and hands. With disuse or decreased use the teeth became reduced in size; with such reduction the diastemata for their reception became obliterated, and then the continuous rows characteristic of man supervened. Consequent on the smaller teeth the jaws became less prognathous. Next the masseter and temporal muscles which moved the lower jaw lost their vigor. There being then no demand for the lambdoidal and sagittal crests, those at last disappeared.