The study of the limbs is of great importance, because, although it is the special province of the bust to contain the organs of vegetative life, it is the limbs which render it useful. In fact, it is the lower limbs which control our locomotion and the upper limbs which execute the labour of mankind.

One characteristic of man, equally with that of standing in an erect position, supported only on the lower limbs, is the independence of the upper limbs, which are raised from the ground and relieved of the function of locomotion—a function that still continues in all other mammals, excepting the anthropoid apes, whose upper limbs are extremely long and barely escape the earth, and serve the animal merely as an aid and a support in walking. The birds, although supported on their hind limbs alone, nevertheless have their fore limbs assigned to the sole office of wings for the transportation of their bodies.

Consequently, the free and disposable upper limb, peculiar to mankind, would seem to mark a new function in the biologic scale—human labour.

Anatomy of the Skeleton of the Limbs.—In contrast to the bust, the limbs have an internal skeleton, adapted solely to the function of support (not of protection). The bones are covered with masses of striped muscles, which have as their special function voluntary movement, that is to say, obedience to the brain.

The upper and lower limbs correspond numerically, and the arrangement of the bones is analogous; and this holds true for all the higher vertebrates. The nearest bones, those that are attached to the trunk, are single in all four limbs. Then, just as though branching out, they next double in number, and then multiply successively as we approach the extremities of the limbs. Thus the forearm and the lower leg have two bones, and the hands and feet have many.

In the upper arm we have the humerus, in the thigh the femur, in the forearm the ulna and radius (the ulna is situated on the same side as the little finger and the radius on that of the thumb), in the lower leg the tibia and fibula. Then come the many short bones (eight in the carpus and seven in the tarsus) which in the hand form the wrist or carpus, and in the foot the ankle or instep, the tarsus. These are followed by other long bones (five in the hand and five in the foot), which constitute the metacarpus and metatarsus, and these in turn by the long bones of the phalanges (fingers and toes), which grow successively smaller toward the extremities and are successively named proximal, middle and distal phalanges (phalangettes). These last are missing in the thumb and the big toe. In conjunction with the last phalanges, the fingers and toes are protected by nails.

The Growth of the Limbs.—Recent studies, conducted principally by Godin in France, author of the classic work upon growth, have demonstrated that the long bones of the limbs obey certain special laws of biologic growth.

While a long bone is growing in length it does not grow in width or thickness, and while it is increasing in thickness it does not gain in length; hence the lengthening of the bones takes place in alternate periods; during the period of repose relative to growth in length, the bone gains in thickness.

I have already explained, in connection with the stature, that we owe the growth of the long bones to a variety of formative elements, the cartilages of the epiphyses, which control the growth in length of the long bones, and the enveloping membrane of the body of the bone, the periosteum, which presides over the growth in thickness.

The above mentioned alternation in the growth of the bones must therefore be attributed to an alternation in the action of these various formative elements of the bones.

In the case of two successive long bones (for example, the humerus and radius, the femur and tibia, the metacarpus and phalanges, etc.), they alternate in their growth; while one of them is lengthening, the other is thickening; consequently the growth of a limb in length is not simultaneous in all the bones, but takes place alternately in the successive bones. During the time when the growth devolves upon the longest bone, the limbs show the greatest rate of increase in length, and when, on the contrary, it devolves upon the shortest bone, the growth is less; but in either case it continues to grow.

The growth of the long bones of the limbs proceeds by alternate periods of activity and repose, which succeed each other regularly.

These periods of activity and repose occur inversely in each two successive bones.

The periods of repose from growth in length are utilised for gain in thickness, and reciprocally. The long bones lengthen and thicken alternately, and not simultaneously.

It is only at the age of puberty (fifteenth year) that a complete simultaneity of growth takes place, after which epoch the growth in stature and length of limb diminishes, yielding precedence to that of the vertebral column.

When the complete development of the bodily proportions is attained (eighteenth year), the length of the lower limbs is equal to one-half the stature.

When the upper limbs are extended vertically along the sides of the body, the tip of the middle finger reaches the middle point of the thigh, while the wrist coincides with the ischium (hip-bone). The total spread of the arms is, on an average, equal in length to the stature.

The proportions between the lower limbs and the bust, resulting from the attainment of complete individual development, determine the types of stature: macroscelia and brachyscelia. Since the order of growth as between the two essential portions of stature is now determined, we are able to interpret macroscelia as a phenomenon of infantilism (arrested development of the bust).

Malformations. Excessive Development of the Nearer and Remoter Segments.—But there are other proportions that are of interest to us, within the limbs themselves. Even between the nearer and remoter portions of the limbs there ought to be certain constant relations (indices) that constitute differential characteristics between the various human races and between man and the ape. If the humerus or upper arm is taken as equal to 100, the radius or forearm is equal to 73 in the European, while in the negro it is equal to about 80. Furthermore, it is a well-known fact that excessive length of the forearm is an ape-like characteristic.

Consequently, the measurement of the segments of the limbs is important, and it is made with a special form of calipers; when the index of the segments deviates from the accepted normal figure, this constitutes a serious anomaly, frequently found in degenerates, and it often happens that an excessive development of the remoter segments, the bones of the extremities, explains the excess of the total spread of the arms over the stature, unassociated with the macroscelous type.

Absence of Calf.—In addition to this fundamental deviation from normality, there are other malformations worthy of note that may occur in the limbs. Such, for example, is a deficiency or absence of the calf of the leg. The well-turned leg, which we admire as an element of beauty is a distinctive human trait most conspicuous among the races that we regard as superior. Among the more debased negro races the leg is spindling and without any calf; furthermore, it is well known that monkeys have no calves, and still less do they exist among the lower orders of mammals.

Flat Feet.—Another important malformation relates to the morphology of the feet. Everyone knows the distinctive curve or arch of the foot, and the characteristic imprint which it consequently leaves on the ground. Sometimes, however, this arch is missing, and the sole of the foot is all on the same plane (flat foot). The dark-skinned natives of Australia have flat feet as one of their racial characteristics; in our own race it constitutes an anomaly that is frequent among degenerates. Flat feet may also be acquired as the result of certain employments (butler, door-keeper, etc.), which compel certain individuals to remain much of the time on foot. But in such cases the deformity is accompanied by a pathological condition (neuralgic symptoms and local myalgia). Like all malformations, this may have special importance in connection with infantile hygiene (the position of the pupil, the work done by the children, etc.).

Opposable Big Toe.—Another malformation combined with a functional anomaly, that is never met with as a deformity resulting from adaptation, is the opposable big toe. Sometimes the big toe is greatly developed and slightly curved toward the other toes, and capable of such movement as to give it a slight degree of opposability; hence the foot is prehensile. This characteristic, regularly present in monkeys, is so far developed in certain degenerates as to make it possible for them to perform work with their feet (knitting stockings, picking up objects, etc.); so that this class of degenerates, who are essentially parasites, solve the problem of supporting themselves by trading on the curiosity of the public, so that, by straining a point, we might bestow upon them the title of foot labourers.

Loose and Stiff Joints.—Anomalies may also occur in connection with the articulation of the joints. It sometimes happens that they are extremely loose and weak, and allow the bones an excessive play of movement; and, if the lower limbs are thus affected, it increases the difficulty of maintaining equilibrium when standing erect or walking. On the other hand, it may happen that the articulations are too stiff, and consequently render many movements difficult, especially if through an anomalous development of the outer coating of the bone, it results in congenital ankylosis.

Curvature of the Legs.—A special importance attaches to certain alterations undergone by the heads of the bones which contribute to the formation of the knee, because of the curvature of the leg which results from them (rachitis, paralysis). The leg may become bowed outward or inward; when it is bowed inward (knock-knees, genu valgum), the knees strike together in walking; when, on the contrary, it is bowed outward, the result is bow-legs (genu varum), known popularly in Italy as "legs of Hercules," a deformity which in a mild degree may also result from the practice of horse-back riding.

Club-foot (Talipes).—Other deviations from the normal position occur in connection with the foot. Certain paralytic children (Little's disease) walk on the fore part of the foot (talipes equinus, "horse's foot"); in some cases the foot is also turned inward, and consequently such children cross their legs as they walk (talipes equino-varus).

The Hand

Chiromancy and Physiognomy. The Hand in Figurative Speech. The High and Low Type of Hand.—The hand is in the highest degree a human characteristic. It is man's organ of grasp and of the sense of touch, while in animals these two functions are relegated to the mouth. The hand has always claimed the attention not only of scientists but of all mankind without distinction. Attempts have been made to discover the secrets of human personality from the hand, and a whole art has been built up, called chiromancy, which endeavours to read from the hand man's destiny and psychic personality, just as physiognomy was the art of interpreting the character from the face.

Chiromancy was an accredited art as far back as the days of ancient Greece, and it also had a great vogue in the middle ages; while to-day it is out of date and superseded, or perhaps is destined to rise again in some new form, just as physiognomy has risen again in the study of "expressions" of the face and the imprints which they leave behind them. Scientists also have made the hand the object of their careful consideration; and the result of their researches shows that the hand really does contain individual characteristics that are not only interesting but, up to a certain point, are revelations of personality. A written word, a clasp of the hand, may furnish documents for the study of the individual. Graphology, for instance, is naturally related to the functional action and to the characteristics of the hand itself. Gina Lombroso has recently made a study of the hand-clasp in its relation to character; when a haughty person offers his hand, he has the appearance of wishing to thrust you from him; the miser barely offers the tips of his fingers; the timid man yields a moist and chilly hand to your touch; the loyal friend makes you feel the whole vigor of his hand in its cordial pressure.

In the gesture we have an individual form of linguistic expression. Consequently, man reveals himself, not alone through his creative part, the head, but also through its obedient servant, the hand. "The hand is gesture, gesture is visible speech, speech is the soul, the soul is man, the soul of man is in the hand."

Furthermore, we can judge from the hand whether a man is fitted for work or not; and it is to work that the hand owes its human importance. The first traces of mankind upon earth are not remains of skeletons, but remains of work—the splintered stone. The whole history of social evolution might be called the history of the hand. To say that the hand is the servant of the intelligence is to express the truth in too restricted a way, because the intelligence is nourished and developed through the products of the hand, as by degrees the work of the latter transformed the environment. Hence, the history of our intellectual development, like that of our civilization, is based upon the creative work evolved by the collaboration of hand and head. And so, in the orphan asylums, we have the children sing the hymn to the hand, which is a hymn to labour and to progress:

All the solemn acts of life require the cooperation and sanction of the hand. We take oath with the hand; marriage is performed by uniting the hands of the bridal pair; in proof of friendship or to seal a compact, we clasp hands. The word hand has come to be often used in a symbolic sense in many expressive phrases possessing a social and moral significance: "Take heed that the hand of the Lord does not fall upon you;" "Pilate washed his hands;" "to put oneself into another's hands;" "to have a lavish hand;" "to sit with idle hands" or "with the hands in the pockets;" "one hand washes the other;" "to have a hand in the pie;" "to turn one's hand to something;" "to lend a final hand;" "to speak with the hand on the heart;" "to believe the evidence of one's hands," etc.

And this high and symbolic significance given to the hand dates back even to bible times:

Solomon says: "The length of days is in her right hand; and in her left hand riches and honour" (Prov. 3, 16).

And Moses: "Therefore shall ye lay up these my words in your soul and bind them for a sign upon your hand" (Deut. 11, 18).

Attempts have recently been made to describe the "psychological types" of the human hand. Zimmermann, for instance, studies two types of hand: the high type, delicate, small, slender, with rounded, tapering fingers, and convex nails; a hand which would indicate a fine sensibility, delicate and refined sentiments, a well balanced mind, a high degree of intelligence, a strong and noble character. And there is the low type, coarse, short and stocky, with thick fingers and flat nails; an index of sluggish sensibilities, vulgar sentiments and a low order of intelligence, a weak will and apathetic character.

In accordance with the theories of mechanics, the type of hand has been considered in relation to its organic use and morphological adaptation. In general, the hand used in the coarser forms of work is of the low type; the high type of hand is that required for nimble and fine movements, in which there is need of the successive concurrence of all those delicate little groups of muscles which are able to act independently and thus give to this organ the marvelous and subtle variety of movements which distinguish it. In regard to dimensions, the large, heavy hand would betoken use, and the little hand disuse. Therefore, the small hand may be considered as a stigma of parasitism, a distinction which at the present day has lost its nobility. Excepting in so far as the "brain workers," who make themselves useful without employing their hands, may still show a distinctive smallness of these members.

We should not, however, adhere solely either to the psychological theory of the hand, or to the theory of adaptation; it is necessary to consider the characteristics of the hand from several different points of view.

Dimensions.—The dimensions of the hand bear a constant relation to the stature and to certain partial dimensions of the body, while the various parts of the hand preserve constant reciprocal proportions.

As far back as in the time of Vitruvius it was known that the human hand is related to the stature in the proportion of 10 to 100. This is a very important fact to know, because the proportion varies in the inferior races and in the anthropoid apes, the descent in the scale showing a corresponding increase of length of hand relatively to the stature. Thus, for example, in the Mongolian races the proportional length of the hand is 12.50, and in the higher apes it equals 18. Consequently too long a hand is in itself an anomaly that indicates a low type of man; it is to be classed with those anomalies that were formerly regarded as atavistic reversions, phenomena of absolute retrogression in the biological scale.

Relations between the Hand and the other Dimensions of the Body.—The closed fist, taking the extreme outside measurement between the metacarpophalangeal articulations, corresponds to the breadth of the heart.

The length of the hand corresponds to the height of the visage, and also to the distance intervening between the sternal incisura and the auricular foramen; it is also equal to the distance between the two nipples, and therefore also corresponds to the depth of the chest.

There may be hands which are either excessively large or much too small, and that are really marks of degeneration. An excessive volume of these members is called megalomelia, and an excessive smallness oligomelia.

We may encounter an extremely small hand quite as often in the son of an alcoholic labourer as in the son of a degenerate aristocrat; frequently men whose parents were mentally deficient have small, delicate, almost effeminate hands.

The Proportions between the Various Segments of the Hands.—The length of the middle finger, measured from the digito-palmar plica or fold, ought to equal the length of the palm.

Hence the index of the palm should be the proportion between the length of the palm itself and the length of the middle finger. This proportion is of importance because it has certain human characteristics; as a matter of fact, in the anthropoid apes the metacarpus is much longer than the fingers and the palm has a far lower index than that of man. In degenerates (thieves) the hand is frequently narrow and long.

The Proportions of the Fingers.—If the first and second articulations of the fingers are flexed, leaving the third extended, we find that the extremity of the middle finger reaches to the point where the thenar and hypothenar eminences (fleshy prominences at base of palm) are nearest to each other.

This basic point is only approximate and serves to tell us whether the middle finger is normal. The middle finger serves as a measure for the others, as follows:

• The index-finger reaches to the base of the nail of the middle finger.
• The thumb, to the middle of the first phalanx of the middle finger.
• The ring finger, to the middle of the nail of the middle finger.[47]
• The little finger, to the third articulation of the ring finger.

It often happens that the development of the ulnar side of the hand—the little finger, or both little and ring finger together—is defective. Sometimes the little finger is not only extremely small, but a special malformation renders it shorter still when the hand is open; the second phalanx remains flexed, and cannot be extended. Combined with the shortness of such fingers there is also an extreme slenderness—cubital oligodactylia. It is a far rarer thing to find similar anomalies in the case of the index-finger. The thumb, on the contrary, is sometimes extremely short, in consequence of which it has slight opposability.

Functional Characteristics.—What characterises the functional action of the human hand is the opposability of the thumb. There ought to be a perfect movement of opposability of the thumb in respect to all the other fingers; but many imbecile children accomplish this movement imperfectly. The mobility of the thumb is associated with a group of muscles situated at its base which forms the great tenar eminence of the palm, opposite which, in corresponding relation to the little finger is the small hypothenar eminence. An insufficient development of these palmar eminences represents a serious malformation, which entails functional disturbances. The hand of the monkey is flat.

The Nails.—We have already seen that in the high type of hand the nails should be convex and long, and that in the low type, on the contrary, they are short and flat.

The normal nail should extend to an even level with the fingertip. Manual labour should normally serve the purpose of keeping the nails worn down; but we, who are not hand-labourers, must use the scissors, in order to maintain the normal state.

For, if they were not worn down, the nails would attain an enormous length, like the nails of certain kings of savage tribes, who as a badge of authority have such long nails that their hands are necessarily kept motionless; these kings must in consequence be waited on, even for the smallest need, and actually become the slaves of their own nails, which might be shattered by any sudden movement on the part of their royal possessor. Long nails, therefore, are a sign of idleness, while at the same time they demand a great deal of attention. Accordingly, let us repudiate the fashion of long nails.

As a form of anomaly, we sometimes meet with nails of such exaggerated length that they have the aspect of claws—onychogryposis; or, again, an almost total absence of nails, which are reduced to a narrow transverse strip—this characteristic is often found in idiots, and is aggravated by the fact that from childhood such persons have had the habit of "biting their nails."

Sometimes the nails are exceedingly dense, or actually consist of several superimposed layers, so rich in pigment that they lose their characteristic transparency.

This condition is due to trophic disorders of the nails.

Teratology and Various Anomalies.—There are certain monstrosities that sometimes occur in connection with the hand, such as hexadactylism and polydactylism, or hands with six or more fingers; or else hands with less than five fingers—syndactylism. There may even be a congenital absence of a phalanx, with a consequent notable shortness of the finger—brachydactylism.

Another sort of anomaly frequently found in deficients consists of an excessive development of the interdigital membrane, to the extent of giving the hand the appearance of being web-fingered. An anomaly of minor importance consists in a distortion of the fingers; the little finger has one of its phalanges turned backward. All the fingers ought to be in contact throughout their whole length, and not leave open spaces between them.

Lines of the Palms.—The lines of the palms, which used to be of so much importance in chiromancy, are now taken into consideration even in anthropology, being studied in normal and abnormal man, and also in the hands of monkeys. The lines of the palms are three in number. The one which follows the curve of the tenar eminence is known in chiromancy as the line of life, and, if long, deep and unbroken, was supposed to denote good health and the prospect of a long life; in anthropology it is called the biological line. The second crease, which ought to meet the former between the thumb and the index-finger, is the line of the head, or cephalic line, and in chiromancy its union with the line of life was supposed to denote a well-balanced character.

The line highest up, which begins between the index- and middle finger and extends to the extreme margin of the palm, is the line of the heart or the cardiac line, which in chiromancy is supposed to indicate the emotional development of the individual. These lines taken together form a semblance of the letter M, and are characteristically and gracefully curved. It is considered as an anomaly, to be met with among degenerates and even in mongoloid idiots, to lack any of these lines (numerical reduction) or to have their arrangement distinctly horizontal, and reminiscent of the hand of the monkey.

If we trace backward in the zoological scale, we find as a matter of fact that to begin with, there were no lines in the palms, and then there appeared a single crease high up, such as we still find in the Cebus. In the human hand Carrara has recently made a study of these anomalies, distinguishing several types. In the first type there is a single transverse furrow. In the second type there are two furrows which, however, follow a definitely straight and horizontal direction and consequently are parallel. In a third type a single transverse furrow is associated with a very deep longitudinal furrow running from the carpus to the base of the index- and middle finger—a form that Carrara has found only in criminals. Nevertheless, many idiots exhibit a similar longitudinal furrow, due to a peculiar development of the palmar aponeurosis.

Fig. 129.—Imprint of human hand, showing papillary lines on palm and fingers.